• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 1
  • Tagged with
  • 6
  • 6
  • 5
  • 5
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Étude de la toxicité des agropesticides utilisés à Djutitsa (Ouest Cameroun) sur la fonction de reproduction mâle et effet protecteur d’extraits de plantes médicinales / Study of the toxicity of agropesticides used in Djutitsa (West Cameroon) on male reproductive function and protective effect of medicinal plant extracts

Manfo Tsague, Faustin Pascal 25 February 2011 (has links)
L’impact de l’utilisation des agropesticides sur la fonction de reproduction mâle est évalué chez des agriculteurs de Djutitsa (Ouest Cameroun). Le pesticide le plus utilisé par ces agriculteurs est testé in vivo sur la fonction de reproduction du rat mâle, ex vivo et/ou in vitro sur la stéroïdogenèse Leydigienne afin d’évaluer son implication dans les déséquilibres observés chez les agriculteurs. Ensuite, l’effet protecteur des extraits de Carpolobia alba et Basella alba contre les effets délétères dudit pesticide est évalué in vivo chez des rats mâles, ainsi que leur influence sur la production de la protéine de transport des stéroïdes (SHBG) par les cellules HepG2. Les résultats montrent que les agriculteurs utilisent 25 agropesticides et présentent des symptômes liés à une protection inadéquate. De plus, ils présentent une diminution de la testostérone avec une élévation de l’androstènedione sériques comparé au groupe témoin non exposé (P < 0,05) et ces déséquilibres androgéniques sont accompagnés de difficultés de reproduction. Le manèbe est l’agropesticide le plus utilisé et perturbe chez le rat mâle la stéroïdogenèse Leydigienne (à travers l’inhibition de la CYP11A1) et la fertilité. Cette fertilité est améliorée/rétablie lorsque le pesticide est concomitamment administré avec l’un des extraits, suggérant ainsi l’effet protecteur desdits extraits qui est imputable à leur activité androgénique également démontré chez les rats. Toutefois, ces extraits et le manèbe n’affectent pas la production de la SHBG in vitro. Ces résultats soulignent l’altération de la fonction de reproduction mâle par les agropesticides et l’effet bénéfique des plantes médicinales / The effect of agropesticides use on male reproductive function was evaluated in male farmers in Djutitsa (West Cameroon). The most frequently used agropesticide by farmers was selected and tested in vivo on the reproductive function of male rats, ex vivo and/or in vitro on Leydig cells steroidogenesis, in order to evaluate its implication in disorders observed in farmers. The ability of 2 Cameroonian medicinal plants (Carpolobia alba and Basella alba) to prevent pesticide-induced toxicity was also investigated in vivo in male rats. Furthermore, both extracts and selected pesticide were tested on the release of a steroid transporter protein (SHBG) by HepG2 cells. The results showed that farmers used 25 agropesticides and presented symptoms related to inadequate protection. Moreover, they had lower serum testosterone and higher androstenedione levels compared to a control group with no history of agropesticide exposure (P < 0.05), and these androgenic imbalances were accompanied by difficulties of reproduction. Maneb was the most common ingredient, and its administration to male rats resulted in decrease/alteration of Leydig cells steroidogenesis (through inhibition of CYP11A1) as well as fertility. The latter fertility was improved/restored when maneb was coadministrated to rats with any of the plant extracts, suggesting their protective effect that may be attributed to their proven androgenic activity. However maneb and the plant extracts did not affect SHBG release by HepG2 cells. These results highlight agropesticides deleterious effect on male reproductive function, which may be prevented by the investigated plant extracts
2

Antidiabetic and profertility mechanisms of aqueous extract of Basella alba in male Wistar rats

Arokoyo, Dennis Seyi January 2017 (has links)
Thesis (PhD (Biomedical Sciences))--Cape Peninsula University of Technology, 2017. / The use of medicinal plants in the management of various health problems date back to the ancient times. However, only in recent years, researchers are starting to focus on the use of natural plant products as alternative treatment in disease control. Basella alba (Ba), commonly called Ceylon or Indian spinach is one of such medicinal plants, wildly cultivated and consumed mostly as vegetable. Studies have established many beneficial effects of Ba, including androgenic effects as well as antidiabetic effects which have been described in rats following oral administration of the leave extract. However, the actual mechanisms underlying the antihyperglyceamic effect of Ba have not been reported in any study and little or no research details are yet available on the potential beneficial effects of Ba in reproductive dysfunction resulting from diabetes mellitus. This study was aimed at investigating the mechanisms underlying the antidiabetic effect of Ba and the possibility of a role for the plant in correcting diabetic-induced reproductive dysfunctions in male Wistar rats. The first part of the study involved comparing of three different solvent extracts of Ba leaves namely ethyl acetate, methanolic and aqueous extracts for their antioxidant potentials, after which the aqueous extract was selected for further use in the experiments. Animal experimentation involved male rats (n=40) aged 8-10 weeks, randomly divided into four equal groups as follows: Healthy Control, Diabetic Control, Healthy Treatment and Diabetic Treatment. Diabetes was induced via a single intraperitoneal injection of streptozotocin (55mg/kg) and all animals subsequently received treatment via gavage (Rats in Control groups received 0.5ml/100g normal saline daily and treatment groups received 200mg/kg plant extract daily) for a period of four weeks. Fasting blood sugar and body weights were recorded weekly throughout the study. Animals were sacrificed upon completion of the treatment and blood samples and tissues collected for further analysis which included computer aided sperm analysis, Luminex® technology and enzyme-linked immunosorbent hormonal assays, inflammatory cytokine assays, analysis of oxidative stress markers and Histopathological analysis. The single intraperitoneal injection of a high streptozotocin dose resulted in hyperglycaemia, weight loss, subnormal sperm parameters, negative balance of inflammatory cytokines and endogenous antioxidants and degenerative changes in the pancreas, testes and epididymis as observed in the diabetic control rats. Oral administration with the aqueous extract of Ba for four weeks in diabetic treatment rats led to a significant reduction in blood sugar and improvement of sperm parameters by modulating the production of gonadal hormones, in vivo antioxidants and inflammatory cytokines. There was also significant recovery of normal islet histology and reduction in testicular and epididymal degeneration in the diabetic treatment rats when compared to their diabetic control counterparts. It was concluded from the findings of this study that the antidiabetic and profertility effects of Ba are largely dependent on the modulation of in vivo production of antioxidants, gonadal hormones and inflammatory cytokines, probably stimulated by one or more phytochemical component(s) that can be isolated in the aqueous extract of the plant.
3

Antidiabetic and profertility mechanisms of aqueous extract of Basella alba in male Wistar rats

Arokoyo, Dennis Seyi January 2017 (has links)
Thesis (PhD (Biomedical Sciences))--Cape Peninsula University of Technology, 2017. / The use of medicinal plants in the management of various health problems date back to the ancient times. However, only in recent years, researchers are starting to focus on the use of natural plant products as alternative treatment in disease control. Basella alba (Ba), commonly called Ceylon or Indian spinach is one of such medicinal plants, wildly cultivated and consumed mostly as vegetable. Studies have established many beneficial effects of Ba, including androgenic effects as well as antidiabetic effects which have been described in rats following oral administration of the leave extract. However, the actual mechanisms underlying the antihyperglyceamic effect of Ba have not been reported in any study and little or no research details are yet available on the potential beneficial effects of Ba in reproductive dysfunction resulting from diabetes mellitus. This study was aimed at investigating the mechanisms underlying the antidiabetic effect of Ba and the possibility of a role for the plant in correcting diabetic-induced reproductive dysfunctions in male Wistar rats. The first part of the study involved comparing of three different solvent extracts of Ba leaves namely ethyl acetate, methanolic and aqueous extracts for their antioxidant potentials, after which the aqueous extract was selected for further use in the experiments. Animal experimentation involved male rats (n=40) aged 8-10 weeks, randomly divided into four equal groups as follows: Healthy Control, Diabetic Control, Healthy Treatment and Diabetic Treatment. Diabetes was induced via a single intraperitoneal injection of streptozotocin (55mg/kg) and all animals subsequently received treatment via gavage (Rats in Control groups received 0.5ml/100g normal saline daily and treatment groups received 200mg/kg plant extract daily) for a period of four weeks. Fasting blood sugar and body weights were recorded weekly throughout the study. Animals were sacrificed upon completion of the treatment and blood samples and tissues collected for further analysis which included computer aided sperm analysis, Luminex® technology and enzyme-linked immunosorbent hormonal assays, inflammatory cytokine assays, analysis of oxidative stress markers and Histopathological analysis. The single intraperitoneal injection of a high streptozotocin dose resulted in hyperglycaemia, weight loss, subnormal sperm parameters, negative balance of inflammatory cytokines and endogenous antioxidants and degenerative changes in the pancreas, testes and epididymis as observed in the diabetic control rats. Oral administration with the aqueous extract of Ba for four weeks in diabetic treatment rats led to a significant reduction in blood sugar and improvement of sperm parameters by modulating the production of gonadal hormones, in vivo antioxidants and inflammatory cytokines. There was also significant recovery of normal islet histology and reduction in testicular and epididymal degeneration in the diabetic treatment rats when compared to their diabetic control counterparts. It was concluded from the findings of this study that the antidiabetic and profertility effects of Ba are largely dependent on the modulation of in vivo production of antioxidants, gonadal hormones and inflammatory cytokines, probably stimulated by one or more phytochemical component(s) that can be isolated in the aqueous extract of the plant
4

Effect of basella alba and hibiscus macranthus on tm4 sertoli cell functions

Opuwari, Chinyerum January 2009 (has links)
<p>Basella alba (BA) and Hibiscus macranthus (HM) are used by traditional healers in Cameroon to treat male sexual fertility problems. Previous studies showed that in vivo administration of the leaf extracts of both plants caused a significant increase in rat seminal vesicle weight and spermatozoa numbers was accompanied by a significant increase in serum testosterone. The aim of this study was to establish the effects of BA and HM extracts on Sertoli cell functions. TM4 cell line was used in this study as it exhibited properties similar to the Sertoli cells (Mather, 1982). Sertoli cell play a key role in spermatogenesis by regulating and supporting germ cell development. Therefore, any alterations in Sertoli cell physiology or structure may lead to impaired spermatogenesis, germ cell loss and male infertility. Developing germ cells in the seminiferous tubule require a constant supply of lactate and pyruvate (Jutte et al, 1981 / 1982) and toxicant induced alterations in these nutrients have been shown to induce germ cell necrosis (Monsees et al., 2000). TM4 Sertoli cells were cultured in DMEM/Ham F-12 (M) for one day and exposed to<br /> 0.01, 0.1, 1, 10, 100 &mu / g/ml of BA and HM extracts, respectively, for four further days. The extracts were dissolved in 0.5 % DMSO in M, while 0.5 % and 2% DMSO in M were used as negative or positive controls, respectively, and 100mM ethanol as positive control where indicated. Results obtained from the Sertoli cells exposed to BA extracts, showed that the plant extract had no significant effect on the cell viability but induced a significant concentration-dependent increase in lactate (19-67%) and pyruvate levels (39-102%) and a concentration-dependent decrease in the protein content (9-42%). The H&amp / E histological study confirmed that the BA extract had no cytotoxic effect, as there were no changes in the morphology of the cell. Likewise, apoptotic study using DAPI showed no alteration in the nucleus when compared to the negative control. The HM plant extract significantly enhanced mitochondrial dehydrogenase activity (7fold) in the Sertoli cells but caused only slight alterations in the lactate and pyruvate levels. There was no effect seen in the protein content of the Sertoli cells. H&amp / E and DAPI staining revealed that there were neither changes in the morphology of the cells nor any alteration regarding the mitotic and apoptotic indices. Thus, the HM extract did not have a cytotoxic effect on the cells. This study demonstrated that the Basella alba methanol extract may enhance spermatogenesis as it stimulated the source of energy required for the development of germ cells without exerting a cytotoxic effect. The Hibiscus macranthus extract stimulated mitochondrial dehydrogenase activities and may thus trigger changes in Sertoli cell physiology. In summary, both plant extracts enhanced certain Sertoli cell<br /> functions and thus might explain the positive in vivo effects of the combined plant extracts on rat spermatogenesis observed by Moundipa et al. (1999).</p>
5

Effect of basella alba and hibiscus macranthus on tm4 sertoli cell functions

Opuwari, Chinyerum January 2009 (has links)
<p>Basella alba (BA) and Hibiscus macranthus (HM) are used by traditional healers in Cameroon to treat male sexual fertility problems. Previous studies showed that in vivo administration of the leaf extracts of both plants caused a significant increase in rat seminal vesicle weight and spermatozoa numbers was accompanied by a significant increase in serum testosterone. The aim of this study was to establish the effects of BA and HM extracts on Sertoli cell functions. TM4 cell line was used in this study as it exhibited properties similar to the Sertoli cells (Mather, 1982). Sertoli cell play a key role in spermatogenesis by regulating and supporting germ cell development. Therefore, any alterations in Sertoli cell physiology or structure may lead to impaired spermatogenesis, germ cell loss and male infertility. Developing germ cells in the seminiferous tubule require a constant supply of lactate and pyruvate (Jutte et al, 1981 / 1982) and toxicant induced alterations in these nutrients have been shown to induce germ cell necrosis (Monsees et al., 2000). TM4 Sertoli cells were cultured in DMEM/Ham F-12 (M) for one day and exposed to<br /> 0.01, 0.1, 1, 10, 100 &mu / g/ml of BA and HM extracts, respectively, for four further days. The extracts were dissolved in 0.5 % DMSO in M, while 0.5 % and 2% DMSO in M were used as negative or positive controls, respectively, and 100mM ethanol as positive control where indicated. Results obtained from the Sertoli cells exposed to BA extracts, showed that the plant extract had no significant effect on the cell viability but induced a significant concentration-dependent increase in lactate (19-67%) and pyruvate levels (39-102%) and a concentration-dependent decrease in the protein content (9-42%). The H&amp / E histological study confirmed that the BA extract had no cytotoxic effect, as there were no changes in the morphology of the cell. Likewise, apoptotic study using DAPI showed no alteration in the nucleus when compared to the negative control. The HM plant extract significantly enhanced mitochondrial dehydrogenase activity (7fold) in the Sertoli cells but caused only slight alterations in the lactate and pyruvate levels. There was no effect seen in the protein content of the Sertoli cells. H&amp / E and DAPI staining revealed that there were neither changes in the morphology of the cells nor any alteration regarding the mitotic and apoptotic indices. Thus, the HM extract did not have a cytotoxic effect on the cells. This study demonstrated that the Basella alba methanol extract may enhance spermatogenesis as it stimulated the source of energy required for the development of germ cells without exerting a cytotoxic effect. The Hibiscus macranthus extract stimulated mitochondrial dehydrogenase activities and may thus trigger changes in Sertoli cell physiology. In summary, both plant extracts enhanced certain Sertoli cell<br /> functions and thus might explain the positive in vivo effects of the combined plant extracts on rat spermatogenesis observed by Moundipa et al. (1999).</p>
6

Effect of basella alba and hibiscus macranthus on tm4 sertoli cell functions

Opuwari, Chinyerum January 2009 (has links)
Magister Scientiae - MSc / Basella alba (BA) and Hibiscus macranthus (HM) are used by traditional healers in Cameroon to treat male sexual fertility problems. Previous studies showed that in vivo administration of the leaf extracts of both plants caused a significant increase in rat seminal vesicle weight and spermatozoa numbers was accompanied by a significant increase in serum testosterone. The aim of this study was to establish the effects of BA and HM extracts on Sertoli cell functions. TM4 cell line was used in this study as it exhibited properties similar to the Sertoli cells (Mather, 1982). Sertoli cell play a key role in spermatogenesis by regulating and supporting germ cell development. Therefore, any alterations in Sertoli cell physiology or structure may lead to impaired spermatogenesis, germ cell loss and male infertility. Developing germ cells in the seminiferous tubule require a constant supply of lactate and pyruvate (Jutte et al, 1981; 1982) and toxicant induced alterations in these nutrients have been shown to induce germ cell necrosis (Monsees et al., 2000). TM4 Sertoli cells were cultured in DMEM/Ham F-12 (M) for one day and exposed to 0.01, 0.1, 1, 10, 100 μg/ml of BA and HM extracts, respectively, for four further days. The extracts were dissolved in 0.5 % DMSO in M, while 0.5 % and 2% DMSO in M were used as negative or positive controls, respectively, and 100mM ethanol as positive control where indicated. Results obtained from the Sertoli cells exposed to BA extracts, showed that the plant extract had no significant effect on the cell viability but induced a significant concentration-dependent increase in lactate (19-67%) and pyruvate levels (39-102%) and a concentration-dependent decrease in the protein content (9-42%). The H&E histological study confirmed that the BA extract had no cytotoxic effect, as there were no changes in the morphology of the cell. Likewise, apoptotic study using DAPI showed no alteration in the nucleus when compared to the negative control. The HM plant extract significantly enhanced mitochondrial dehydrogenase activity (7fold) in the Sertoli cells but caused only slight alterations in the lactate and pyruvate levels. There was no effect seen in the protein content of the Sertoli cells. H&E and DAPI staining revealed that there were neither changes in the morphology of the cells nor any alteration regarding the mitotic and apoptotic indices. Thus, the HM extract did not have a cytotoxic effect on the cells. This study demonstrated that the Basella alba methanol extract may enhance spermatogenesis as it stimulated the source of energy required for the development of germ cells without exerting a cytotoxic effect. The Hibiscus macranthus extract stimulated mitochondrial dehydrogenase activities and may thus trigger changes in Sertoli cell physiology. In summary, both plant extracts enhanced certain Sertoli cell functions and thus might explain the positive in vivo effects of the combined plant extracts on rat spermatogenesis observed by Moundipa et al. (1999). / South Africa

Page generated in 0.0535 seconds