During the past fifteen years, non-timber or special forest products have become an important economic resource in the Pacific Northwest. These products are primarily derived from understory species and contribute approximately $200 million to the regional economy. Medicinal plants are a little researched component of the non-timber forest product industry that relies on cultivated and wildcrafted (or wild-collected) medicinal plant species. This study examines the commercial extraction of wildcrafted medicinal plants from Mount Hood National Forest. Specifically, this study documents the medicinal plant species extracted from Mount Hood National Forest, their annual yield amounts, harvesting methods, and the changes in cover of target species after harvest. This research uses survey data obtained from employees of two herbal companies and representatives of the U.S. Forest Service to describe medicinal plant extraction and administration as it pertains to the commercial extraction of plant species from Mount Hood National Forest. Field data were also used to examine changes in plant cover for four medicinal plant species (kinnikinnick, yarrow, Oregon grape and valerian) following harvest. Field results indicate that medicinal plant cover decreased significantly in all but one harvested sampling unit. Permanent unit markers were established at all the study sites to provide opportunities for long-term monitoring of target species responses to harvest. Eleven medicinal plant species are commonly collected for commercial purposes from Mount Hood National Forest. The general lack of regulation and enforcement of commercial medicinal plant extraction coupled with an increasing demand for wildcrafted medicinal plants warrant a need for increased collaboration between regulatory agencies, herbal companies, and the general public. Additional management and research recommendations regarding the ecological impacts of medicinal plant removal are also presented.

Thesis (M. Sc. (Microbiology)) -- University of Limpopo, 2022 / Sexually transmitted infections represent one of the main health problems related to reproductive and sexual function, constituting one of the main causes of infertility. Plants have been employed traditionally in treating diseases for centuries. Elephantorrhiza burkei, Securidaca longepedunculata and Wrightia natalensis medicinal plants were selected for this study based on their use in traditional medicine to treat sexual health problems in Limpopo Province. The aim of the study was to determine antimicrobial and antioxidant properties of the selected plants. Different extraction procedures coupled with solvents of varying polarities were used in the extraction of the plant materials. Possible microbial contaminants were identified using the VITEK 2 instrument. Qualitative phytochemical analysis was determined using standard chemical tests and Thin-Layer Chromatography. Total polyphenol content was quantified calorimetrically. Antioxidant activity was quantified using 2, 2-diphenyl- 1-picrylhydrazyl (DPPH) and ferric reducing power assays. In vitro antimicrobial activities were determined using a broth micro-dilution assay and bioautography. Combinational effects of the addition of multiple plant species on antimicrobial activity were investigated for additive, synergistic and antagonistic interactions. The plant species phytochemical profile contained polyphenols that are known to have antimicrobial effects against two Gram-positive bacteria, Staphylococcus aureus (ATCC 29213) and Enterococcus faecalis (ATCC 29212), a Gram-negative bacterium, as well as the fungus, Candida albicans (ATCC 10231). Elephantorrhiza burkei exhibited high antioxidant activity and antimicrobial activity against the test pathogens, although most of the interactions were antagonistic and indifferent. Toxicity was found in the herbal treatment and acute toxicity was found in the selected plants. Based on the good correlations which were found in E. burkei, it was selected for bioactivity guided by an isolation of antibacterial compounds. Elephantorrhiza burkei was not successfully isolated, but the fraction collected showed exceptional biological activity that validates its usage against disease-causing pathogens related to sexually transmitted infections, which compromises male sexual health. This study suggests that the evaluated plants are potential sources of novel anti-infective agents. Further in vivo and in vitro studies are recommended for all the plants, respectively. / University of Limpopo and CSIR

Thesis (M. Sc. (Biochemistry)) --University of Limpopo, 2017 / Diabetes mellitus is a chronic metabolic disorder characterised by perpetual hyperglycaemia. Various oral pharmacological theraputic management strategies currently exist but are too expensive and having a host of undesirable side effects. Therefore people resort to the use of traditional medicinal plants as they offer a cost effective and readily available health care avenue. Despite the wide-spread use of traditional medicinal plants, several worrisome concerns about their effectiveness, clinical modes of action and safety have been raised. Leaves of five selected plants (Toona celliata, Seriphium plumosum, Schkuhria pinnata, Olea africana, Opuntia ficus-indica) were collected from Mankweng area, Capricon Local Municipality, Limpopo province, South Africa. Ground plant materials were exhaustively extracted by maceration in methanol, acetone or hexane. The presence of different plant secondary metabolites in the crude extracts was determined using various standard chemical tests and thin layer chromatography (TLC). A myriad of compounds which represented various secondary plant metabolites groups were observed on the TLC plates and were best resolved in the non-polar (BEA) and intermediate (CEF) mobile phases. The total phenolic content and total flavonoids of the different extracts were determined spectrophotometrically using the Folin-Ciocalteu`s phenol reagent method and Aluminium chloride colorimetric assay respectively. The plants contained comparatively higher amounts of total phenolic compounds as compared to the flavonoids. The antiglycation activity of the plant extracts were determined using the bovine serum albumin assay. The acetone extract of Seriphium plumosum (SPlA) exhibited the most glycation inhibitory activity among all the examined extracts, as it resulted in 2,22% glycation. The antioxidant potential of each of the different extracts was quantitatively determined spectrophotometrically using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and the ferric ion reducing power assay. The methanol extract of Seriphium plumosum showed the best antioxidant activity among all the extracts in this study. It exhibited the lowest EC50 values of 0.72 mg/ml and 2.31 mg/ml for the DPPH scavenging activity and the ferric reducing power assay respectively. The cytotoxicity profiles of the different plant extracts on C2C12 cell line were determined using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium xiii bromide (MTT) assay. It was concluded that since the all the extracts investigated had CC50 values greater than 50 μg/ml they were generally non-toxic. The amount of glucose taken up by differentiated C2C12 cells was quantified using the glucose uptake assay. Treatment of the C2C12 cells with the hexane extract of Seriphium plumosum resulted in the best glucose utilisation effect of 35,77% which was higher than that of insulin which was 26,06% after 6 hours. The translocation assay was used to determine the effect of the plant extract on GLUT4 translocation while the expression of various mitogen activated protein kinases in the cells was determined using the human MAPK profiler assay. It was established that treatment with Seriphium plumosum hexane extract resulted in increased GLUT4 translocation from the intracellular vesicular stores to the cell surface membrane. The increase in GLUT4 translocation may have resulted from the upregulation of expression of phosphorylated Akt-1, Akt-2, GSK3β, ERK1, ERK2 p70S kinase and MKK3 under the influence of Seriphium plumosum hexane extract. The study documents a probable insulin-mimetic activity of the hexane extract of Seriphium plumosum. This activity may be responsible for its hypoglycaemic capability and may occur via the augmentation of proximal mitogen activated protein kinases involved in the GLUT4 translocation pathway. Further investigations need to be conducted to ascertain this novel finding which may help provide a cost-effective and readily available antidiabetic therapeutic agent. / National Research Foundation (NRF)

Thesis (Ph.D. (Botany)) -- University of Limpopo, 2023 / The use of medicinal plants as a source of treatment for various ailments including fungal infections is still practised in South Africa and across the globe. Fungal infections especially of Cryptococcus, Candida and Aspergillus species are the main cause of morbidity and mortality worldwide, particularly in developing countries. Traditional medicine is used as a source of remedies worldwide and has contributed extensively towards the development of modern medicine. Twelve selected medicinal plants (Kleinia longiflora DC. Berchemia discolor (Klotzsch) Hemsl., Persea americana Mill., Sansevieria hyacinthoides (L.) Druce, Dichrostachys cinerea (L.) Wright &Arn, Withania somnifera Dunal (Ashgandh), Momordica balsamina L., Lonchocarpus capassa, Pappea capensis, Rhus lancea L. fil, Peltophorum africanum, Maytenus heterophylla (Eckl. & Zeyh.) Robson) were analysed qualitatively for antifungal activities against Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans. The plant materials were extracted with solvents of various polarities such as acetone, dichloromethane, methanol, hexane, and water. Methanol extracted the highest amount of crude extracts from all the plant species as compared to other organic solvents. Chemical components of the extracts were analysed using aluminum backed Thin Layer Chromatography (TLC) plates and developed using three different eluent systems: Ethyl acetate: methanol: water [EMW], Chloroform: ethyl acetate: formic acid [CEF] and Benzene: ethanol: ammonia hydroxide [BEA]. CEF was the best eluent solvent system since it separated more compounds from plant extracts. This indicates that the active compounds were relatively non-polar. More chemical compounds were observed in TLC chromatograms separated with CEF, followed by BEA and EMW. All plant extracts had shown different chemical components when separated from the three solvent systems. The bioautography and serial dilution assays were used to determine the biological activity of plant extracts against the tested microorganisms, respectively. All the tested plant extracts revealed some varying degrees of fungal inhibition, with minimum inhibitory concentrations (MIC) values ranging between 0.02 mg/ml and 2.5 mg/ml. The aqueous extracts had shown some activity against the tested microorganisms. Noteworthy, antifungal activity was observed in acetone, DCM, hexane, and methanol root extracts of D. cinerea against the three tested microorganisms with MIC values ranging between 0.02 mg/ml and 0.04 mg/ml. Furthermore, acetone extracts of D. cinerea and P. africanum had excellent activity against three fungal pathogens with MIC values of 0.02 mg/ml and 0.08 mg/ml. Active compounds were observed in dichloromethane extracts of W. somnifera with Rf values of 0.40 and 0.64. In TLC chromatograms separated with BEA, active compounds were observed in acetone, hexane, and methanol leaf extract of P. americana, this indicates that the fungal compounds were relatively non-polar. No active compounds were observed in plant extracts of K. longiflora. Active compounds were visible in all extracts of P. capensis in TLC chromatograms developed in CEF and EMW. The antioxidant present in plants prevents the free radicals from causing various diseases in humans by inhibiting the oxidation of free radicals at the cellular level. The qualitative and quantitative 1,1-diphenyl-2-picrylhydrazyl (DPPH) methods were used to determine the antioxidant activities of plant extracts. The presence of antioxidant compounds was indicated by yellow bands against the purple background on the TLC plates. More antioxidant compounds were observed in acetone and dichloromethane extracts of S. hyacinthoides developed in BEA compared to other plant species tested. Methanol, hexane, and water extracts of L. capassa revealed good antioxidant activity against DPPH by having a high percentage of inhibition compared to other solvents. Noticeably, extracts of P. africanum possess strong antioxidant activity as compared to other plant species. Solvent-solvent fractionation using column chromatography of the acetone extract led to the isolation of six compounds. The biological activity of the isolated compounds of L. capassa was investigated against the tested pathogenic fungi. The isolated compounds revealed some varying degrees of inhibition to the fungal pathogens. The largest quantity was isolated from compound 1 (80 mg), compound 4 (39 mg), compound 3 (27 mg), compounds 2 and 5 (14 mg) and the least was compound 6 (4.8 mg). However only three compounds were successfully identified as Lupeol (compound 1), Friedelin (compound 3) and 6-(γ,γ-Dimethylallyl)-3’,4’-dimethoxy-6”,6”- dimethylpyrano-[2”,3”:7,8]-flavanone (compound 4). Compounds 2, 5 and were not identified due to some impurities. More importantly, the isolated compounds exhibited good antioxidant activity in qualitative and quantitative scavenging assays, which indicates that isolated compounds of L. capassa can scavenge the free radicals causing fungal infections in humans. The results support the traditional use of the selected plants to combat fungal infections and related ailments by the local people and traditional health practitioners in Vhembe District, Limpopo Province. The (3-(4,5-dimethylthiazol) -2,5-diphenyltetrazoliumbromide) (MTT) assay was used to determine the toxic effects of the plant crude extract and isolated compounds. Lupeol and 6-(γ,γ-Dimethylallyl)-3’,4’-dimethoxy-6”,6”-dimethylpyrano-[2”,3”:7,8]- flavanone revealed the same degree of cytotoxicity against the Vero monkey kidney cells. All the compounds were not toxic with an LC50 value of ˃ 0.2 mg/ml. / University of Limpopo and National Research Foundation

M. Tech. (Department of Health Sciences, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Tuberculosis (TB) remains one of the most difficult infectious diseases to control in the world today. The disease spreads easily in overcrowded, badly ventilated places and among people who are undernourished. Trends in the incidence of TB together with the development of multi-drug (MDR-TB) and extensively drug resistant (XDR-TB) strains of TB raises the need to intensify the search for more efficient drugs to combat this disease. Herbal remedies used in traditional medicine provide an interesting and largely unexplored source for the discovery of potentially new drugs for infections such as TB. The aim of the study was to evaluate the in vitro antimycobacterial activity of synthesized compounds from medicinal plants against Mycobacterium tuberculosis (M. tuberculosis). About 40 synthesized compounds isolated from South African medicinal plants were screened against H37RV using microplate alamar blue assay (MABA). Identified active compounds were screened against resistant strains of M. tuberculosis (MDR, XDR and pre-XDR) and sensitive clinical isolates of TB. Cytotoxicity and synergistic drug combination studies were done on active compounds to validate their toxicity and synergy levels. Cytotoxicity was done by sulforhodamine assay (SRB) against the C2C12 cell line. Only six compounds showed activity against M. tuberculosis with minimum inhibitory concentration (MIC) below 10μg/ml. The results obtained indicated that the cytotoxicity effects of the three compounds on C2C12 cells demonstrated marginal toxicity except for MVB 282/61215 which showed a high toxicity at the lowest concentration of 0.156μg/ml with over 100% viable cells at the highest concentration (5μg/ml). MVB 282/61271 had the highest percentage cell viability (65%) at the lowest concentration. Only two compounds had a higher potency evoking a bigger response at low concentrations with treated cells still viable after 3 days of incubation with the compound which was comparable with the treatment of isoniazid (INH). Synergistic activity of the six compounds was less in INH combination as compared to the rifampicin’s (RIF) combination. The results demonstrated that the synergistic interaction between the compounds and RIF could the antituberculosis acitivity. In conclusion the synergistic effects with RIF translate to lower dosing requirements of the compounds and the potential to combat multidrug resistant TB. In deed there is no doubt that natural products, with their range of interesting chemical structures and powerful antimycobacterial effects are certain to remain important participants in the development of new generations of antimycobacterial drugs.

Infectious diarrhoea is the second largest single cause of mortality in children under the age of five globally. Bacteria are responsible for most diarrhoeal episodes especially in developing countries, and progressive increase in antimicrobial resistance has given rise to the need to investigate other sources of therapy such as medicinal plants. Ten plant extracts were analysed for their antimicrobial activities using the agar well diffusion and broth microdilution method. Their phytochemical contents were screened, and their effect on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) was used to assess their antioxidant activities. Their toxicity profiles were evaluated using the XTT Cytotoxicity Assay. Water and methanol extracts of Adansonia digitata v ABSTRACT Infectious diarrhoea is the second largest single cause of mortality in children under the age of five globally. Bacteria are responsible for most diarrhoeal episodes especially in developing countries, and progressive increase in antimicrobial resistance has given rise to the need to investigate other sources of therapy such as medicinal plants. Ten plant extracts were analysed for their antimicrobial activities using the agar well diffusion and broth microdilution method. Their phytochemical contents were screened, and their effect on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) was used to assess their antioxidant activities. Their toxicity profiles were evaluated using the XTT Cytotoxicity Assay. Water and methanol extracts of Adansonia digitata seeds and pulp showed no inhibition against all the test organisms, while water and methanol extracts of A. digitata leaves showed inhibition, with minimum inhibitory concentration (MIC) ranging from 0.39 to 6.25mg/ml. Water and methanol extracts of Garcinia livingstonei and Sclerocarya birrea barks showed good activity against all the test organisms, with MICs between 0.39 and 1.56 mg/ml. Alkaloids, phenols, flavonoids, saponins, tannins, and terpenoids were found in one or more of the plant extracts, and all the plant extracts demonstrated scavenging power against DPPH.The cytotoxicity of extracts of Garcinia livingstonei, and Sclerocarya birrea barks ranged between 105.9 μg/ml and 769.9 μg/ml. The results obtained in this study validate the traditional use of A. digitata leaves, G. livingstonei and S. birrea bark in treating bacteria causing diarrhoea. / Life Sciences / M. Sc. (Life Sciences)

Submitted in fulfillment of the requirements for the Degree of Master of Technology: Biotechnology, Durban University of Technology, 2009. / Dichrostachys cinerea, Carpobrotus dimidiatus, Capparis tomentosa and Leonotis leonurus are all plants that are indigenous to South Africa. These plants are used in traditional medicine to treat various ailments. However, there is little or no scientific data to justify these traditional uses. Furthermore, it is difficult to reconcile traditional knowledge with scientific evidence because of the overwhelming targeting of signal-responsive systems by plant defensive compounds, multiple sites of action and the connectedness of the signaling pathways, which provide many cures and have pleiotropic effects. In order to evaluate the action spectrum of these plants, and validate its widespread use, this research evaluated the antibacterial, antioxidant, anti-inflammatory, anti-mosquito and immunomodulatory properties of these plants. Antimicrobial activity of the extract was determined by evaluating the bactericidal and fungicidal action using the agar disc diffusion assay. Anti-oxidative properties of the extracts were tested using the DPPH photometric assay. Anti-inflammatory properties were carried out using the 5-lipoxygenase assay. The larvicidal, repellency and insecticidal assay was determined against A.arabiensis. The safe use of these plant extracts was determined by evaluating toxicity, a brine shrimp lethality assay and an in vitro cell culture system using human myelogenous leukemia cell line. Potential carcinogenic activity was evaluated using the Ames Salmonella Mutagenecity assay. The immunomodulatory activity of the extracts on human peripheral blood mononuclear cells 6 was evaluated on freshly harvested lymphocytes using the MTT assay. Cytokine response was evaluated by measuring the secretion of interferon-gamma and interleukin-10. Elucidation of the B cells, T cells, activated T cells, CD 4+, CD 8+ and NK cells was performed by flow cytometry. The extracts showed anti-microbial activity against Escherichia coli, Pseudomonas aeruginosa, Klebsiella oxytoca, Salmonella typhimurium, Serratia marcescens, Bacillus cereus and Tricoderm sp. The highest activity was shown by methanolic and aqueous extracts of L. leonurus leaves followed by methanolic and aqueous extracts of D. cinerea. Extracts of C. tomentosa and D.cinerea demonstrated a higher degree of free radical scavenging than rutin, which was used as a standard indicating that these plants have strong antioxidant properties. None of the plants showed significant anti-inflammatory activity when compared to NDGA. In the anti-mosquito assays, the extracts showed strong repellency and insecticidal activity. L. leonurus extracts demonstrated the highest insecticidal and repellency activity against the mosquito, and was also found to cause ‗knockdown‘ and mortality. The extracts display no toxicity, cytotoxicity and mutagenicity. The immunological studies for immune modulation showed that the methanol extracts of these plants induce a Th1- predominant immune response because they significantly suppressed the secretion of IL-10 and augment IFN-γ production, which are hallmarks used to indicate a stimulation of the innate immune response. This study also provides new information, with respect to the potential use of these plants in producing a mosquito repellent and an immunostimulant. / National Research Foundation

Submitted in fulfillment for the Degree of Doctor of Technology: Biotechnology, Durban University of Technology, 2010. / Ceratatheca triloba (Bernh.) E. Mey. Ex Hook. f. is one of four species that is common to the summer rainfall areas in South Africa, especially the grasslands. It is used in traditional medicine to treat stomach cramps, nausea, fever and diarrhea. Like many other plants used in the traditional medicine system, these uses are not justified through scientific investigations. This study was undertaken to characterize the functionality of the main bioactive compounds from Ceratatheca triloba. This was achieved by isolating and identifying predominant chemicals from the non polar extracts using conventional chromatography techniques. Once identified the crude extracts and identified compounds were tested for their antimicrobial, anti-oxidant activity, anti-inflammatory activity and anticancer activity. This was followed by investigating the safety of the crude extracts and the purified compounds by the Brine shrimp lethality assay, and its toxicity to HepG2 cells and the Salmonella mutagenecity test. For large scale production, we set up a protocol to produce 9, 10 anthracenedione in a cell suspension culture system. Following the complete chemical profile of the roots, stems, flowers and leaves the predominant compounds were isolated, characterized and identified by UV-Vis, IR, EI-LCMS and NMR (COSY, HMQC, HMBC and DEPT). Three anthraquinone derivatives and one steroid, 9, 10 anthracenedione, 1-hydroxy-4-methylanthraquinone, 5, 8-dimethoxy-2, 3, 10, 10a-tetrahydro-1H-phenanthrene-4, 9-dione and androst-5-ene-3, 17, 19-triol were determine by analysis of spectral data (UV, 1H NMR, 13C NMR and EI-LC-MS) 9, 10 anthracenedione and 1 hydroxy-4-methylanthraquinone showed antibacterial activity against S.aureus, M. luteus, B cureus and E. coli. Due to the synergistic effect of the individual compounds, the crude extract exhibited good potency (>500) against S.aureus and M. luteus, medium potency against E. coli. and S. typhimurium (<100) and very low potency against B cureus (<10). Although a similar trend was observed for 9, 10 anthracenedione and 1 hydroxy-4-methylanthraquinone unlike the crude extract. A very low potency against S.aureus for 9, 10 anthracenedione and a high potency for 1 hydroxy-4-methylanthraquinone. Thus 9, 10 anthracenedione is an effective drug against E. coli and S. typhimurium and 1 hydroxy-4-methylanthraquinone is effective against S.aureus and M. luteus. The crude root extracts and 9, 10 anthracenedione, 1 hydroxy-4-methylanthraquinone, 8-dimethoxy-2, 3, 10, 10a-tetrahydro-1H-phenanthrene-4 showed a ± 50% reduction of the free radicals. No anti-inflammatory activity was observed. The purified extracts showed moderate toxicity against HepG2 cells at high concentrations and no toxicity was observed against brine shimp larvae. No mutagenecity was observed with the crude extracts using the Ames test. All purified and crude extracts showed potent inhibition of the human topoisomerase II enzyme. In conclusion, although this study does not indicate any relationship to its traditional usage it provides valuable information that paves a way for commercial exploitation of C. triloba. 9, 10 anthracenedione and 1 hydroxy-4-methylanthraquinone can be used as antibacterial agents. Their antioxidative potential can be exploited for anti-cancer as in many cancers reactive oxygen species are implicated in the aetiology of these cancers. Furthermore, in this study 9, 10 anthracenedione was produced from both callus cultures and cell suspension cultures. This compound demonstrates potent anti-topoisomerase II activity which is vital to cancer treatment. Thus, the synergistic effect of 9, 10 anthracenedione and 1 hydroxy-4-methylanthraquinone as antibacterial, anti-oxidative and anti-cancer compounds demonstrate the importance of C. triloba. / Centre for Research Capacity Development ; National Research Foundation

Thesis (M.Tech.: Homoeopathy)-Dept. of Homoeopathy, Durban University of Technology, 2007. xi, 238 leaves / The first objective of this study was to determine the symptomatology that the plant remedy Peucedanum galbanum 30CH, produced in healthy individuals, so that it could be prescribed according to the Law of Similars, as required by homoeopathy. The second objective was to analyse this symptomatology in relation to the doctrine of signatures. It was hypothesised that Peucedanum galbanum 30CH would produce symptomatology in healthy individuals which would correlate to the doctrine of signatures of the plant.

Thesis (M.Tech.: Homoeopathy)-Dept. of Homoeopathy Durban University of Technology, 2007. 250 leaves / This research study was conducted to elucidate the total symptomatology that the plant Peucedanum galbanum in the thirtieth centesimal potency would produce on healthy individuals so that it may be prescribed according to the Law of Similiars. A further aim of the investigation was to compare this remedy to other remedies yielding the highest numerical values and total number of rubrics on repertorisation of the proving symptoms. Wagner (2007), in a concurrent study, analysed the proving results of Peucedanum galbanum in relation to the doctrine of signatures. It was hypothesised that Peucedanum galbanum 30CH would produce recognizable signs and symptoms in healthy provers, and that the comparative study of this remedy would highlight the differences and similarities between remedy symptoms and thus confusion as to indication is eliminated, plus a fuller understanding of the remedy and its relationship to other remedies is gained.