Philosophiae Doctor - PhD / The reproductive health of individuals is severely compromised by HIV infection, with candidiasis being the most prevalent oral complication in patients. Although not usually associated with severe morbidity, oropharyngeal candidiasis can be clinically significant, as it can interfere with the administration of medications and adequate nutritional intake, and may spread to the esophagus. Azole antifungal agents are commonly prescribed for the treatment and prophylaxis of candidal infections. However, the emergence of drug resistant strains and dose limiting toxic effects have complicated the treatment of candidiasis. Consequently, safe and effective and affordable medicine is required to combat this fungus. Commercial garlic (Allium sativum) has been used time since immemorial as a natural antibiotic, however very little is known about the antifungal properties of two indigenous South African species of garlic, namely Tulbaghia alliacea and Tulbaghia violacea, that are used as folk medicines for a variety of infections. This study compares the in vitro anti-candidal activity of Tulbaghia alliacea, Tulbaghia violacea and Allium sativum extracts. It was found that the greatest concentrations of inhibitory components were extracted by chloroform or water. The IC50 concentrations of Tulbaghia alliacea were between 0.007 - 0.038% (w/v). Assays using S. cerevisiae revealed that the T. alliacea extract was fungicidal, with a killing half-life of approximately 2 hours. This inhibitory effect of the T. alliacea extracts was observed via TLC, and may be due to an active compound called Marasmicin, that was identified using NMR. This investigation confirms that extracts of T.alliacea exhibit anti-infective activity against candida species in vitro. / South Africa

Philosophiae Doctor - PhD / Natural products have been a source of many pharmaceutical drugs and a number of drugs that are currently used in the treatment of cancer are derivatives of compounds originally isolated from natural products. There is evidence that extracts of Tulbaghia violacea can be used to treat cancer. The activation of apoptosis in cancer cells is a target for the development of novel anti-cancer drugs since one of the characteristics of cancer cells is resistance to apoptosis due to the deregulation of biochemical pathways leading to apoptosis. In fact, many current anti-cancer drugs exert their effects through the activation of apoptosis. Previous studies showed that extracts of T.violacea induce apoptosis in cancer cells and one study reported on the isolation of a compound (methyl-ԃ-D-glucopyranoside), which is responsible for the pro-apoptotic activity of the T.violacea extract. Therefore the aim of this study was to investigate the anti-cancer activity of methyl-ԃ-Dglucopyranoside and extracts prepared from T.violacea. In this study the pro-apoptotic activity of methyl-ԃ-D-glucopyranoside and extracts prepared from T.violacea were investigated on a panel of human cancer cell lines, which included HepG2, MCF7, H157, HT29 and the non-cancerous cell line, KMST6. The induction of apoptosis was evaluated by flow cytometry using several bioassays which measures biochemical events (caspase activation, phosphatidylserine externalisation and reactive oxygen species (ROS) production that is associated with the induction of apoptosis. The results demonstrated that the effects of methyl--D-glucopyranoside on cultured cells are transient and that the cells recover from the effects of methyl--D-glucopyranoside. This suggested thatmethyl-ԃ-D-glucopyranoside is not the compound responsible for the pro-apoptotic bioactivity in the T.violacea extract. This study also showed that cytotoxic and pro-apoptotic bioactivity of the leaf-extract was significantly higher in comparison to the tuber-extract. The bioactivity of the organic solvent extracts (dichloromethane, hexane, methanol and 50% methanol/water) of T.violacea leaves was also significantly higher than water extracts of T.violacea leaves. A comparison of the different organic extracts prepared from the T.violacea leaves showed that the highest activity was observed for the dichloromethane and hexane extracts. In an effort to identify the bioactive compound(s) the dichloromethane extract was subjected to Versaflash® column chromatography. However, due to problems experienced with the solubility of the dichloromethane sub-fractions, these compounds could not be tested for their bioactivity. Palmitone (16-hentriacontanone) was identified as one of the major compounds present in the dichloromethane sub-fractions. This compound was previously shown to have anticonvulsant bioactivity but there is no evidence in the literature that it has anti-cancer or pro-apoptotic activities. Fingerprinting of the methanol extract showed the presence of long chain fatty acid derivatives, flavonoids and allicin derivatives in the methanol extract. Although, this study failed to isolate the pro-apoptotic bioactive compound(s) present in the extracts of T.violacea, it confirmed that extracts of this plant induce apoptosis in cultured human cancer cell lines.

Magister Scientiae (Medical Bioscience) - MSc(MBS) / Endocrine disrupting compounds (EDCs) are exogenous compounds/chemicals which interfere with, or have adverse effects on the production, distribution and function of natural hormones, thereby affecting normal endocrine activity, health and quality of life of both humans and wildlife. The reproductive system is highly susceptible to EDCs due to it being controlled by an array of hormonal signals. The effects of EDCs on the male reproductive system include infertility, decreased sperm count, function and morphology, abnormal development of secondary sex characteristics, reproductive function and sexual behaviour as well as decreased libido. There are various sources by which EDCs enter the environment which include effluents from several industries (mining, agriculture, smelting, hazardous waste sites, manufacturing industries, etc.), sewage treatment effluents, urban and agricultural runoff and effluents which include natural and pharmaceutical chemicals excreted in the urine of humans and domestic livestock, pesticides, polychlorinated biphenyls, dioxins, plasticizers, surfactants, etc. Humans and animals can also be affected by EDCs by consuming food containing endocrine active substances. The growing concern regarding adverse effects due to EDC exposure of humans and wildlife, as well as the increased incidence of EDC contamination has prompted extensive research into the development and validation of screening tests to detect and monitor known EDCs and new substances with endocrine-disrupting capability. These screening tests involve assessing the effect of known and potential EDCs on reproductive function and development as well as hormone production. To assess the effect of EDCs on the reproductive system different methods are employed which include in vitro, in vivo and ex vivo methods. In vitro methods have been suggested as a suitable screening tool for EDC monitoring due to low costs, reduced animal usage, the use of standard and basic equipment as well as the ability to screen a large number of samples with multiple endpoints. Of the available in vitro methods, the minced testes method has been suggested as the most suitable method for screening EDCs and for this reason has been employed in this study. The aim of this study was thus to employ a minced testes method to screen samples for male reproductive toxicity using cell viability and hormone production (testosterone and estradiol) as endpoints.The first objective of this study was to optimize an in vitro testicular cell culture assay by determining both optimal luteinizing hormone (LH)  concentration and incubation time needed for testosterone production. Testicular cell cultures were prepared and cells were treated with varying concentrations of LH (10, 1, 0.1, 0.01 and 0 mu/ml) and incubated for 4 hours and 20 hours. Testosterone production was evaluated for each incubation period. Testosterone production was significantly increased for both incubation periods at all LH concentrations tested as compared to the control. For both incubation periods, there was no significant difference in testosterone production between the different LH concentrations tested. From the data obtained, the 4 hour incubation period as well as the LH concentration of 10 mu/ml were selected as optimal for the testicular cell culture assay. The second objective of this study was to determine the effect of Tulbaghia violacea Harv. on the male reproductive system. T. violacea is a plant species indigenous to southern Africa and is used locally as a herbal remedy/medicine to treat several ailments. Cells were treated with varying concentrations of the T. violacea ethanol extract (with/without LH-treatment) and incubated for 4 hours. Hormone production and cell viability were evaluated. The results obtained from this pilot in vitro study demonstrated that the ethanol extract of T.violacea has androgenic properties by significantly increasing LH-induced testosterone production in mouse testes with no significant change in cell viability. The third objective of this study was to assess the effect of Sutherlandia frutescens(L.) R.Br and Artemisia afra Jacq. Ex Willd. on the male reproductive system. S. frutescens and A. afra are also plant species indigenous to southern Africa and used locally as a herbal remedy/medicine to treat several ailments. Ethanol extracts of each plant was prepared and cells were treated with varying concentrations of each extract (0, 156.25, 312.5, 625, 1250,2500 and 5000 μg/ml) with or without LH-treatment and incubated for 4 hours. Cytotoxicity by LDH measurement and hormone production (testosterone and estradiol) were endpoints that were evaluated. The results obtained showed that the ethanol extracts of both plants are not cytotoxic to testicular cells and that A. afra decreases testosterone production at high concentrations. The fourth and final objective of this study was to assess the acute effect of four heavy metals, namely manganese, copper, cadmium and magnesium on the male reproductive system. These heavy metals are used extensively in manufacturing and mining industries. Cells were treated with varying concentrations of each metal salt (200, 100, 50, 25, 12.5, and 6.25 & mu;M) with or without LH-treatment and incubated for 4 hours. Endpoints evaluated included cell viability, testosterone and estradiol production. The results obtained showed that manganese, cadmium and copper are highly toxic to testicular cells in vitro and therefore may potentially cause reproductive toxicity. / South Africa

Philosophiae Doctor - PhD / Fusarium verticil/ioides (Sacc) Nirenberg a common phytopathogen of maize and maize-based products produces fumonisin B (FB) mycotoxins that have been related to several diseases such as equine leukoencephalomalacia (ELEM), porcine pulmonary edema (PPE), liver toxicity in several animals and esophageal and liver cancer in humans. In one of our studies we hypothesize that aqueous extracts of indigenous South African wild garlic species (Tulbaghia violacea, T. alliacea and T. simmleri) may enhance the efficacy of the fungicides, SporekilPu, Thiram, Itraconazole and Fluconazole against F. verticil/ioides (MRC 826). Data analysis from in vitro results indicates that for the 16 different mixtures of each plant extract and fungicide combination, several significantly (P<O.05) higher growth inhibition responses were produced. More synergistic interactions were observed for the combinations of sporekill with T. violacea (62%) and T. alliacea (75%) than for T. simmleri (25%) .. Mixtures between the azole fungicides and T. simmleri produced 94 % synergistic interactions. Combination of fungicides and plant compounds offers the opportunity to find synergistic mixtures and may validate disease control strategies with increased biological activity and low dose rate application. Modulation studies of hepatic drug metabolizing enzymes and oxidative properties of AI/ium sativum, Tulbaghia violacea and T. alliacea in male Fischer rats were also evaluated. Due to its complex phytochemical composition a battery of assays were used to evaluate antioxidant potential. The extracts exhibited no adverse effects in the liver and kidneys of the rats. Total plasma iron was not affected showing no evidence for iron catalyzed lipid peroxidation. An increase was noted in hepatic ORAC values for rats consuming T. violacea and T. al/iacea. However, no correlation was observed between the phenolic intake by the rats and the increased hepatic ORAC levels. In this study, pre-treatment with aqueous extracts of T. violacea, T. al/iacea and A. sativum resulted in a significant elevation in GSH levels, induction of GST -IJ and UDP-GT and modulation of CAT and SOD. This modulated oxidative status and phase II drug metabolizing enzymes in the liver may protect the liver against the adverse effects related to oxidative damage and mutagenesis. The chemoprotective properties of crude aqueous extracts of A. sativum, T. violacea and T. alliacea were investigated on preneoplastic foci formation promoted by culture material of F. verticil/ioides MRC 826 utilizing diethylnitrosamine (DEN) as cancer initiator. Clinical chemical parameters related to liver and kidney function and decreased body weight gain suggesting that severe, acute liver injury had been induced in the positive control (DEN-eMF) rats, while the levels were mostly reduced by the garlic treatments. This study further indicates that T. alliaceae (2 % w/v) and A. sativum (1% w/v) treatment suppressed GST-P+ foci formation with the modulation of GST-0 phase II detoxification enzymes, as well as the antioxidant enzyme, SOD (T. alliaceae) and decreased GSH levels as being possible mechanisms of protection. These results provide new evidence showing the modulation of phase II drug metabolizing enzymes and the oxidative status in the liver of rats by the wild garlic species as well as A. sativum.

<p>Endocrine&ndash / disrupting compounds (EDCs) are exogenous compounds/chemicals which interfere with, or have adverse effects on the production, distribution and function of natural hormones, thereby affecting normal endocrine activity, health and quality of life of both humans and wildlife. The reproductive system is highly susceptible to EDCs due to it being controlled by an array of hormonal signals. The effects of EDCs on the male reproductive system include infertility, decreased sperm count, function and morphology, abnormal development of secondary sex characteristics, reproductive function and sexual behaviour as well as decreased libido. There are various sources by which EDCs enter the environment which include effluents from several industries (mining, agriculture, smelting, hazardous waste sites, manufacturing industries, etc.), sewage treatment effluents, urban and agricultural runoff and effluents which include natural and pharmaceutical chemicals excreted in the urine of humans and domestic livestock, pesticides, polychlorinated biphenyls, dioxins, plasticizers, surfactants, etc. Humans and animals can also be affected by EDCs by consuming food containing endocrine active substances. The growing concern regarding adverse effects due to EDC exposure of humans and wildlife, as well as the increased incidence of EDC contamination has prompted extensive research into the development and validation of screening tests to detect and monitor known EDCs and new substances with endocrine-disrupting capability. These screening tests involve assessing the effect of known and potential EDCs on reproductive function and development as well as&nbsp / hormone production. To assess the effect of EDCs on the reproductive system different methods are employed which include in vitro, in vivo and ex vivo methods. In vitro methods have been suggested as a suitable screening tool for EDC monitoring due to low costs, reduced animal usage, the use of standard and basic equipment as well as the ability to screen a large number of samples with multiple endpoints. Of the available in vitro methods, the minced testes method has been suggested as the most suitable method for screening EDCs and for this reason has been employed in this study. The aim of this study was thus to employ a minced testes method to screen samples for male reproductive toxicity using cell viability and hormone production (testosterone and estradiol) as endpoints.The first objective of this study was to optimize an in vitro testicular cell culture assay by determining both optimal luteinizing hormone (LH)&nbsp / concentration and incubation time needed for testosterone production. Testicular cell cultures were prepared and cells were treated with varying concentrations of LH (10, 1, 0.1, 0.01 and 0 mu/ml) and incubated for 4 hours and 20 hours. Testosterone production was evaluated for each incubation period. Testosterone production was significantly increased for both incubation periods at all LH concentrations tested as compared to the control. For both incubation periods, there was no significant difference in testosterone production between the different LH concentrations tested. From the data obtained, the 4 hour incubation period as well as the LH concentration of 10 mu/ml were selected as optimal for the testicular cell culture assay. The second objective of this study was to determine the effect of Tulbaghia violacea Harv. on the male reproductive system. T. violacea is a plant species indigenous to southern Africa and is used locally as a herbal remedy/medicine to treat several ailments. Cells were treated with varying concentrations of the T. violacea ethanol extract (with/without LH-treatment) and incubated for 4 hours. Hormone production and cell viability were evaluated. The results obtained from this pilot in vitro study demonstrated that the ethanol extract of T.violacea has androgenic properties by significantly increasing LH-induced testosterone production in mouse testes with no significant change in cell viability. The third objective of this study was to assess the effect of Sutherlandia frutescens(L.) R.Br and Artemisia afra Jacq. Ex Willd. on the male reproductive system. S. frutescens and A. afra are also plant species indigenous to southern Africa and used locally as a herbal remedy/medicine to treat several ailments. Ethanol extracts of each plant was prepared and cells were treated with varying concentrations of each extract (0, 156.25, 312.5, 625, 1250,2500 and 5000 &mu / g/ml) with or without LH-treatment and incubated for 4 hours. Cytotoxicity by LDH measurement and hormone production (testosterone and estradiol) were endpoints that were evaluated. The results obtained showed that the ethanol extracts of both plants are not cytotoxic to testicular cells and that A. afra decreases testosterone production at high concentrations. The fourth and final objective of this study was to assess the acute effect of four heavy metals, namely manganese, copper, cadmium and magnesium on the male reproductive system. These heavy metals are used extensively in manufacturing and mining industries. Cells were treated with varying concentrations of each metal salt (200, 100, 50, 25, 12.5, and 6.25&nbsp / &mu / M) with or without LH-treatment and incubated for 4 hours. Endpoints evaluated included cell viability, testosterone and estradiol production. The results obtained showed that manganese, cadmium and copper are highly toxic to testicular cells in vitro and therefore may potentially cause reproductive toxicity.</p>

<p>Endocrine&ndash / disrupting compounds (EDCs) are exogenous compounds/chemicals which interfere with, or have adverse effects on the production, distribution and function of natural hormones, thereby affecting normal endocrine activity, health and quality of life of both humans and wildlife. The reproductive system is highly susceptible to EDCs due to it being controlled by an array of hormonal signals. The effects of EDCs on the male reproductive system include infertility, decreased sperm count, function and morphology, abnormal development of secondary sex characteristics, reproductive function and sexual behaviour as well as decreased libido. There are various sources by which EDCs enter the environment which include effluents from several industries (mining, agriculture, smelting, hazardous waste sites, manufacturing industries, etc.), sewage treatment effluents, urban and agricultural runoff and effluents which include natural and pharmaceutical chemicals excreted in the urine of humans and domestic livestock, pesticides, polychlorinated biphenyls, dioxins, plasticizers, surfactants, etc. Humans and animals can also be affected by EDCs by consuming food containing endocrine active substances. The growing concern regarding adverse effects due to EDC exposure of humans and wildlife, as well as the increased incidence of EDC contamination has prompted extensive research into the development and validation of screening tests to detect and monitor known EDCs and new substances with endocrine-disrupting capability. These screening tests involve assessing the effect of known and potential EDCs on reproductive function and development as well as&nbsp / hormone production. To assess the effect of EDCs on the reproductive system different methods are employed which include in vitro, in vivo and ex vivo methods. In vitro methods have been suggested as a suitable screening tool for EDC monitoring due to low costs, reduced animal usage, the use of standard and basic equipment as well as the ability to screen a large number of samples with multiple endpoints. Of the available in vitro methods, the minced testes method has been suggested as the most suitable method for screening EDCs and for this reason has been employed in this study. The aim of this study was thus to employ a minced testes method to screen samples for male reproductive toxicity using cell viability and hormone production (testosterone and estradiol) as endpoints.The first objective of this study was to optimize an in vitro testicular cell culture assay by determining both optimal luteinizing hormone (LH)&nbsp / concentration and incubation time needed for testosterone production. Testicular cell cultures were prepared and cells were treated with varying concentrations of LH (10, 1, 0.1, 0.01 and 0 mu/ml) and incubated for 4 hours and 20 hours. Testosterone production was evaluated for each incubation period. Testosterone production was significantly increased for both incubation periods at all LH concentrations tested as compared to the control. For both incubation periods, there was no significant difference in testosterone production between the different LH concentrations tested. From the data obtained, the 4 hour incubation period as well as the LH concentration of 10 mu/ml were selected as optimal for the testicular cell culture assay. The second objective of this study was to determine the effect of Tulbaghia violacea Harv. on the male reproductive system. T. violacea is a plant species indigenous to southern Africa and is used locally as a herbal remedy/medicine to treat several ailments. Cells were treated with varying concentrations of the T. violacea ethanol extract (with/without LH-treatment) and incubated for 4 hours. Hormone production and cell viability were evaluated. The results obtained from this pilot in vitro study demonstrated that the ethanol extract of T.violacea has androgenic properties by significantly increasing LH-induced testosterone production in mouse testes with no significant change in cell viability. The third objective of this study was to assess the effect of Sutherlandia frutescens(L.) R.Br and Artemisia afra Jacq. Ex Willd. on the male reproductive system. S. frutescens and A. afra are also plant species indigenous to southern Africa and used locally as a herbal remedy/medicine to treat several ailments. Ethanol extracts of each plant was prepared and cells were treated with varying concentrations of each extract (0, 156.25, 312.5, 625, 1250,2500 and 5000 &mu / g/ml) with or without LH-treatment and incubated for 4 hours. Cytotoxicity by LDH measurement and hormone production (testosterone and estradiol) were endpoints that were evaluated. The results obtained showed that the ethanol extracts of both plants are not cytotoxic to testicular cells and that A. afra decreases testosterone production at high concentrations. The fourth and final objective of this study was to assess the acute effect of four heavy metals, namely manganese, copper, cadmium and magnesium on the male reproductive system. These heavy metals are used extensively in manufacturing and mining industries. Cells were treated with varying concentrations of each metal salt (200, 100, 50, 25, 12.5, and 6.25&nbsp / &mu / M) with or without LH-treatment and incubated for 4 hours. Endpoints evaluated included cell viability, testosterone and estradiol production. The results obtained showed that manganese, cadmium and copper are highly toxic to testicular cells in vitro and therefore may potentially cause reproductive toxicity.</p>

<p>Tulbaghia violacea Harv. (Alliaceae) is a small bulbous herb which belongs to the family, Alliaceae, most commonly associated with onions and garlic. In South Africa (SA), this&nbsp / herb has been traditionally used in the treatment of various ailments, including fever, colds, asthma, paralysis, hypertension (HTN) and stomach problems. The aim of this study&nbsp / was to evaluate the effect of methanol leaf extracts (MLE) of T. violacea on the blood pressure (BP) and heart rate (HR) in anaesthetized male spontaneously hypertensive rats / &nbsp / and to find out the mechanism(s) by which it acts. The MLE of T. violacea (5 - 150 mg/kg), angiotensin I (ang I, 3.1 - 100 &mu / g/kg), captopril (10 mg/kg), angiotensin II (ang II, 3.1 - 50&nbsp / g/kg), losartan (30 mg/kg), phenylephrine (0.01 &ndash / 0.16 mg/kg), prazosin (1 mg/kg), dobutamine (0.2 &ndash / 10.0 &mu / g/kg), propranolol (0.1 - 12.8 mg/kg), muscarine (0.16 -10 &mu / g/kg),&nbsp / and atropine (0.02 - 20.48 mg/kg) were administered intravenously into male spontaneously hypertensive rats (SHR) weighing between 300 g and 350 g and aged less than 5&nbsp / months. The MLE of T. violacea and/or the standard drugs were infused alone, simultaneously, or separately into each animal. The BP and HR were measured via a pressure&nbsp / transducer connecting the femoral artery and the Powerlab. The vehicle (0.2 mls of a mixture of dimethylsulfoxide and normal saline), T. violacea (60 mg/kg) and captopril (10&nbsp / mg/kg) were injected intraperitoneally into some SHR for 21 days to investigate the chronic effect of these agents on plasma levels of aldosterone. The mean change, the mean&nbsp / of the individual percentage changes and the percentage difference (in mean) observed with each intervention was calculated and statistically analyzed using the Student&rsquo / s t test&nbsp / for significant difference (p &lt / 0.05). The Microsoft Excel software was used for statistical analysis. T. violacea significantly (p &lt / 0.05) reduced the systolic, diastolic, and mean&nbsp / arterial BP / and HR dose-dependently. In a dose-dependent manner, ang I, ang II, phenylephrine significantly (p &lt / 0.05) increased the BP, while propranolol, muscarine and&nbsp / atropine reduced the BP. The increases in BP due to dobutamine were not dose-dependent. In a dose dependent manner, phenylephrine and propranolol reduced the HR, while dobutamine increased the HR. The effect of ang I, ang II, muscarine and atropine on HR were not dose-dependent / with both increases as well as decreases observed with ang&nbsp / I, and II and atropine, while decreases were seen with muscarine. Captopril produced&nbsp / significant (p &lt / 0.05) reduction in BP which were not associated with any change in HR. The co-infusion of ang I with the MLE produced significant (p &lt / 0.05) reduction in BP, which were not associated with significant changes in HR. The co-infusion of ang II with the&nbsp / MLE did not produce any significant changes in BP or HR when compared to the infusion of the standard drug alone. The co-infusion of phenylephrine with the MLE did not&nbsp / produce any significant change in BP or HR when compared to the values obtained with the infusion of the standard drug alone, in both the absence and presence of prazosin.&nbsp / The co-infusion of dobutamine with T. violacea produced siginificant (p &lt / 0.05) increases in DBP which were associated with significant (p &lt / 0.05) reductions in HR, when&nbsp / compared to the values obtained with the infusion of the standard drug alone. Theco-infusion of atropine with the MLE did not produce any significant change in BP or HR when&nbsp / compared to the values obtained with the infusion of atropine alone. However, the infusion of T. violacea, 20 minutes after pre-treating animals with atropine (5.12 mg/kg) lead to&nbsp / dose dependent significant (p &lt / 0.05) increases in BP, which were associated with dose-dependent increases in HR. The chronic treatment of animals with T. violacea or&nbsp / captropril produced (a) signicant (p &lt / 0.05) reductions in the plasma levels of aldosterone when compared to the values obtained in the vehicle-treated group, (b) produced&nbsp / signifiant (p &lt / 0.05) reduction in BP in the captopril treated group when compared to the vehicle-treated, (c) did not produce any signficant change in BP in the T. violacea-treated&nbsp / group when compared to the vehicle-treated group and (d) did not produce any signifiant change in HR or body weight in any of the groups. The result obtained in this study&nbsp / suggests that T. violacea reduced BP and HR in the SHR. Secondly, the BP and HR reducing effect of the MLE may involve a) the inhibition of the ACE, b) the inhibition of the &beta / 1&nbsp / adrenoceptors, c) the stimulation of the muscarinic receptors and d) the reduction of the levels of aldosternone in plasma. The results also&nbsp / suggest that the MLE may not act&nbsp / through the angiotensin II receptors or the &alpha / 1 adrenergic receptors.&nbsp / </p>

<p>Tulbaghia violacea Harv. (Alliaceae) is a small bulbous herb which belongs to the family, Alliaceae, most commonly associated with onions and garlic. In South Africa (SA), this&nbsp / herb has been traditionally used in the treatment of various ailments, including fever, colds, asthma, paralysis, hypertension (HTN) and stomach problems. The aim of this study&nbsp / was to evaluate the effect of methanol leaf extracts (MLE) of T. violacea on the blood pressure (BP) and heart rate (HR) in anaesthetized male spontaneously hypertensive rats / &nbsp / and to find out the mechanism(s) by which it acts. The MLE of T. violacea (5 - 150 mg/kg), angiotensin I (ang I, 3.1 - 100 &mu / g/kg), captopril (10 mg/kg), angiotensin II (ang II, 3.1 - 50&nbsp / g/kg), losartan (30 mg/kg), phenylephrine (0.01 &ndash / 0.16 mg/kg), prazosin (1 mg/kg), dobutamine (0.2 &ndash / 10.0 &mu / g/kg), propranolol (0.1 - 12.8 mg/kg), muscarine (0.16 -10 &mu / g/kg),&nbsp / and atropine (0.02 - 20.48 mg/kg) were administered intravenously into male spontaneously hypertensive rats (SHR) weighing between 300 g and 350 g and aged less than 5&nbsp / months. The MLE of T. violacea and/or the standard drugs were infused alone, simultaneously, or separately into each animal. The BP and HR were measured via a pressure&nbsp / transducer connecting the femoral artery and the Powerlab. The vehicle (0.2 mls of a mixture of dimethylsulfoxide and normal saline), T. violacea (60 mg/kg) and captopril (10&nbsp / mg/kg) were injected intraperitoneally into some SHR for 21 days to investigate the chronic effect of these agents on plasma levels of aldosterone. The mean change, the mean&nbsp / of the individual percentage changes and the percentage difference (in mean) observed with each intervention was calculated and statistically analyzed using the Student&rsquo / s t test&nbsp / for significant difference (p &lt / 0.05). The Microsoft Excel software was used for statistical analysis. T. violacea significantly (p &lt / 0.05) reduced the systolic, diastolic, and mean&nbsp / arterial BP / and HR dose-dependently. In a dose-dependent manner, ang I, ang II, phenylephrine significantly (p &lt / 0.05) increased the BP, while propranolol, muscarine and&nbsp / atropine reduced the BP. The increases in BP due to dobutamine were not dose-dependent. In a dose dependent manner, phenylephrine and propranolol reduced the HR, while dobutamine increased the HR. The effect of ang I, ang II, muscarine and atropine on HR were not dose-dependent / with both increases as well as decreases observed with ang&nbsp / I, and II and atropine, while decreases were seen with muscarine. Captopril produced&nbsp / significant (p &lt / 0.05) reduction in BP which were not associated with any change in HR. The co-infusion of ang I with the MLE produced significant (p &lt / 0.05) reduction in BP, which were not associated with significant changes in HR. The co-infusion of ang II with the&nbsp / MLE did not produce any significant changes in BP or HR when compared to the infusion of the standard drug alone. The co-infusion of phenylephrine with the MLE did not&nbsp / produce any significant change in BP or HR when compared to the values obtained with the infusion of the standard drug alone, in both the absence and presence of prazosin.&nbsp / The co-infusion of dobutamine with T. violacea produced siginificant (p &lt / 0.05) increases in DBP which were associated with significant (p &lt / 0.05) reductions in HR, when&nbsp / compared to the values obtained with the infusion of the standard drug alone. Theco-infusion of atropine with the MLE did not produce any significant change in BP or HR when&nbsp / compared to the values obtained with the infusion of atropine alone. However, the infusion of T. violacea, 20 minutes after pre-treating animals with atropine (5.12 mg/kg) lead to&nbsp / dose dependent significant (p &lt / 0.05) increases in BP, which were associated with dose-dependent increases in HR. The chronic treatment of animals with T. violacea or&nbsp / captropril produced (a) signicant (p &lt / 0.05) reductions in the plasma levels of aldosterone when compared to the values obtained in the vehicle-treated group, (b) produced&nbsp / signifiant (p &lt / 0.05) reduction in BP in the captopril treated group when compared to the vehicle-treated, (c) did not produce any signficant change in BP in the T. violacea-treated&nbsp / group when compared to the vehicle-treated group and (d) did not produce any signifiant change in HR or body weight in any of the groups. The result obtained in this study&nbsp / suggests that T. violacea reduced BP and HR in the SHR. Secondly, the BP and HR reducing effect of the MLE may involve a) the inhibition of the ACE, b) the inhibition of the &beta / 1&nbsp / adrenoceptors, c) the stimulation of the muscarinic receptors and d) the reduction of the levels of aldosternone in plasma. The results also&nbsp / suggest that the MLE may not act&nbsp / through the angiotensin II receptors or the &alpha / 1 adrenergic receptors.&nbsp / </p>

M. Tech. (Biotechnology, Faculty of Applied and Computer Science), Vaal University of Technology / Tulbaghia violacea Harv. (wild garlic) has been used in traditional medicine in Southern Africa for the treatment of various ailments. Despite the widespread use and popularity of this medicinal plant as a herbal medicine, there is contradictory evidence regarding the safety and toxicity of the plant. The phytochemical profiling of the plant has also been neglected in research. The determination of chemical constituents present in plant material as well as the potential toxicity found in plants are preliminary steps necessary for the discovery and development of novel therapeutic agents with improved efficacy. The aim of this study was to evaluate the cytotoxic and genotoxic potential of crude extracts from the leaves, stems and roots of T. violacea. This was performed in vitro using aqueous and ethanol extracts of the leaves, stems and roots. The aim of the study was achieved by three major objectives; (1) to identify the active phytocompounds present in the leaves, stems and roots, (2) to assess the cytotoxicity using the MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) cell proliferation assay, and (3) to evaluate the genotoxic potential of the leaf, stem and root water extracts using the Allium cepa assay. A total of 14 phytochemicals were each extracted separately with distilled water and 70% ethanol by maceration from the leaves, stem and roots of T. violacea. The results of the qualitative phytochemical analysis showed that pharmacologically active compounds such as tannins, terpenoids, flavonoids, saponins, proteins, steroids, cardiac glycosides, phenols and coumarins were present in some organs of T. violacea. However, phlobatannins, leucoanthocyanins, alkaloids, carbohydrates and anthocyanins were absent in all plant parts. Overall, the leaves of the plant contained more active compounds than those present in the stems and roots when both water and 70% ethanol were used as the extractants. The quantitative phytochemical analysis for the Total Flavonoids Content (TFC) and Total Phenolic Contents (TPC) was also assessed. The water (0.027 mg/g) and 70% ethanol (0.053 mg/g) were most effective in extracting flavonoids from the leaves while the least amounts were obtained from the stems and roots. This observation was similar to the TFC were the water extracts of the leaves were the most effective in extracting phenols followed by the stems and roots. The MTT assay was conducted using two cell lines RAW 264.7 and C2C12. The experiment was conducted in triplicates for the leaf, stem and root extracts (water and ethanol) of T. violacea. The experimental design employed a 23 factorial design where three independent variables (concentration, incubation time and type of extracts) were selected using two levels for each variable (high (+) and low (-)). The results illustrated that both the water and ethanol vi extracts only showed a significant reduction in the number of viable cells at the concentration higher than 250 μg/ml treatment for both RAW 264.7 and C2C12 cells. The ethanol extracts from the leaves, stems and roots were found to be toxic towards the RAW 264.7 cells even at lower concentrations at both 24 and 48 h incubation periods (% cell viability < 50%). The water extracts were non-toxic to RAW 264.7 cells except for the water stem extract which showed toxicity after 48 h incubation (IC50 = 9.475 (4.061 to 23.39)). For the C2C12 cells, the lowest potent toxic concentration was 250 μg/ml for the ethanol extract of the stem after 48 h incubation. Overall, the T. violacea plant extracts were non-toxic as percentage cell viability greater than 50% was noted for both extraction solvents in all the plant parts of T. violacea. No cytotoxic activity was observed in all T. violacea plant parts with the C2C12 cell line (IC50 > 30 μg/ml). For the Allium cepa assay, only the water crude extracts of the leaves, stems and roots of T. violacea were used. A similar trend of potent genotoxic activity in the water stem extracts compared to the leaf and root extracts at the concentration ranges studied. Similar to the MTT assay, it is clear from the study that at higher concentrations, the water crude extracts from the leaves, stems and roots of T. violacea is toxic. From this study, it can be concluded that the extraction of compounds using water is more efficient than using ethanol. Overall, the T. violacea leaf extracts extracted the most phytocompounds and showed the highest percentage of viable cells as well as desirable IC50 values. However, preparation of herbal remedies using T. violacea plant extracts should be done with caution due to their possible genotoxic and cytotoxic potential at higher concentrations. This study raises a need to further conduct in vivo cytogenetic studies to ascertain the possible toxic effects of T. violacea crude extracts.

Doctor Pharmaceuticae - DPharm / Tulbaghia violacea Harv. (Alliaceae) is a small bulbous herb which belongs to the family, Alliaceae, most commonly associated with onions and garlic. In South Africa (SA), this herb has been traditionally used in the treatment of various ailments, including fever, colds, asthma, paralysis, hypertension (HTN) and stomach problems. The aim of this study was to evaluate the effect of methanol leaf extracts (MLE) of T. violacea on the blood pressure (BP) and heart rate (HR) in anaesthetized male spontaneously hypertensive rats and to find out the mechanism(s) by which it acts. The MLE of T. violacea (5 - 150 mg/kg), angiotensin I (ang I, 3.1 - 100 mg/kg), captopril (10 mg/kg), angiotensin II (ang II, 3.1 - 50 g/kg), losartan (30 mg/kg), phenylephrine (0.01 ; 0.16 mg/kg), prazosin (1 mg/kg), dobutamine (0.2 ; 10.0mg/kg), propranolol (0.1 - 12.8 mg/kg), muscarine (0.16 -10 mg/kg), and atropine (0.02 - 20.48 mg/kg) were administered intravenously into male spontaneously hypertensive rats (SHR) weighing between 300 g and 350 g and aged less than 5; months. The MLE of T. violacea and/or the standard drugs were infused alone, simultaneously, or separately into each animal. The BP and HR were measured via a pressure transducer connecting the femoral artery and the Powerlab. The vehicle (0.2 mls of a mixture of dimethylsulfoxide and normal saline), T. violacea (60 mg/kg) and captopril (10 mg/kg) were injected intraperitoneally into some SHR for 21 days to investigate the chronic effect of these agents on plasma levels of aldosterone. The mean change, the mean of the individual percentage changes and the percentage difference (in mean) observed with each intervention was calculated and statistically analyzed using the Student t test for significant difference (p < 0.05). The Microsoft Excel software was used for statistical analysis. T. violacea significantly (p < 0.05) reduced the systolic, diastolic, and mean arterial BP; and HR dose-dependently. In a dose-dependent manner, ang I, ang II, phenylephrine significantly (p < 0.05) increased the BP, while propranolol, muscarine and atropine reduced the BP. The increases in BP due to dobutamine were not dose-dependent. In a dose dependent manner, phenylephrine and propranolol reduced the HR, while dobutamine increased the HR. The effect of ang I, ang II, muscarine and atropine on HR were not dose-dependent; with both increases as well as decreases observed with ang I, and II and atropine, while decreases were seen with muscarine. Captopril produced significant (p < 0.05) reduction in BP which were not associated with any change in HR. The co-infusion of ang I with the MLE produced significant (p < 0.05) reduction in BP, which were not associated with significant changes in HR. The co-infusion of ang II with the MLE did not produce any significant changes in BP or HR when compared to the infusion of the standard drug alone. The co-infusion of phenylephrine with the MLE did not produce any significant change in BP or HR when compared to the values obtained with the infusion of the standard drug alone, in both the absence and presence of prazosin. The co-infusion of dobutamine with T. violacea produced siginificant (p < 0.05) increases in DBP which were associated with significant (p < 0.05) reductions in HR, when compared to the values obtained with the infusion of the standard drug alone. Theco-infusion of atropine with the MLE did not produce any significant change in BP or HR when compared to the values obtained with the infusion of atropine alone. However, the infusion of T. violacea, 20 minutes after pre-treating animals with atropine (5.12 mg/kg) lead to dose dependent significant (p< 0.05) increases in BP, which were associated with dose-dependent increases in HR. The chronic treatment of animals with T. violacea or captropril produced (a) signicant (p < 0.05) reductions in the plasma levels of aldosterone when compared to the values obtained in the vehicle-treated group, (b) produced signifiant (p< 0.05) reduction in BP in the captopril treated group when compared to the vehicle-treated, (c) did not produce any signficant change in BP in the T. violacea-treated group when compared to the vehicle-treated group and (d) did not produce any signifiant change in HR or body weight in any of the groups. The result obtained in this study suggests that T. violacea reduced BP and HR in the SHR. Secondly, the BP and HR reducing effect of the MLE may involve a) the inhibition of the ACE, b) the inhibition of the beta; adrenoceptors, c) the stimulation of the muscarinic receptors and d) the reduction of the levels of aldosternone in plasma. The results also suggest that the MLE may not act through the angiotensin II receptors or the alpha adrenergic receptors. / South Africa