Theses and Dissertations (Botany)
http://hdl.handle.net/10386/71
2024-03-28T20:44:21ZA floristic assessment of the Turfloop Nature Reserve
http://hdl.handle.net/10386/4473
A floristic assessment of the Turfloop Nature Reserve
Mashatole, Masilo Makome
The aim of the study was to generate new ecological data for the Turfloop Nature
Reserve (TNR), which would lead to practical management recommendations that
should reduce or minimise the current negative anthropogenic and ecological
impacts on the TNR. A limited ethnobotanical survey was conducted at the two villages, Badimong and Ga-kama, surrounding the TNR. Questionnaires were used to ascertain these communities’ attitude towards the reserve and their use of the reserve. Results
show that the surrounding communities have great interest in the reserve for
various socio-economic reasons. These include collecting wood for building,
firewood and grass for thatching, resulting in serious damage to the reserve.
Utilisation of the reserve is motivated by high levels of poverty, and a general
absence of environmental knowledge. A phytosociological study of the vegetation was undertaken using the Braun Blanquet method. A total of 33 plots were sampled and classified by means of TURBOVEG, TWINSPAN and MEGATAB. The study revealed that the vegetation of the TNR could be divided into five main communities, some with a number of sub-communities and variants. The TNR is composed of two different vegetation types, namely the Mamabolo Mountain Bushveld and Polokwane Plateau
Bushveld. Recommendations on viable ecological vegetation management, to minimize
current anthropogenic influences on the reserve, are provided.
Thesis (M.Sc. (Botany)) -- University of Limpopo, 2009
2009-01-01T00:00:00ZAntimicrobial properties and phytochemical analysis of medical plants used for the treatment of ear infections
http://hdl.handle.net/10386/4359
Antimicrobial properties and phytochemical analysis of medical plants used for the treatment of ear infections
Chauke, Sinorita
Ear infections are a major health concern that negatively affects the health and welfare of individuals across the globe. The infection is caused by a wide spectrum of bacterial, fungal, and viral pathogens. Treatments of ear infections involve the use of antimicrobials such as antibiotics, antifungals, and antivirals. However, most microbial pathogens have developed resistance to the available antimicrobial drugs. Hence, the study aimed to identify plant species used in traditional medicine as a remedy for ear infections and investigate their antifungal activities against the selected fungal pathogens (Aspergillus fumigatus and Candida albicans). These fungal pathogens cause ear infections in humans. Eight plant species including Carpobrotus edulis L., Cotyledon orbiculata L., Dichrostachys cinerea (L.) Wight & Arn., Erythrina lysistemon Hutch., Flacourtia indica (Burm. f.) Merr., Psidium guajava L., Ricinus communis L., and Sansevieria hyacinthoides (L.) Druce were selected from the ethnomedicinal plant's database of over 300 medicinal plants used for therapeutic purposes in humans.
Fresh and dried leaves of selected plants were extracted with solvents of various polarities such as acetone, hexane, methanol, and water. In the current study, methanol extracted a larger quantity (30.75%) of plant materials followed by acetone (6.5%) from dried leaf extract of C. edulis and P. guajava. Acetone extracted more plant material (8.05%) from fresh leaf extract of C. orbiculata. Acetone was the second-best solvent for extracting a larger quantity of dried leaf materials as compared to other solvents.
Thin layer chromatography (TLC) was used to analyse the phyto-constituents of different plant extracts. The TLC plates were developed using different eluent solvent systems such as Benzene: ethanol: ammonia hydroxide (BEA), Chloroform: ethyl acetate: formic acid (CEF) and Ethyl acetate: methanol: water (EMW). The TLC chromatograms were visualized under UV radiation at 360 nm. In TLC chromatograms separated with BEA, chemical components with a similar Rf value of 0.88 were observed in acetone, hexane, and methanol-dried leaf extracts of R. communis and S. hyacinthoides. Surprisingly, TLC chromatograms separated in BEA, dried leaf extracts contained the highest number of phyto-constituents with a total of 73 followed by 30 in CEF and EMW (29). However, in chromatograms of fresh leaf extracts a total
of 12 compounds were visible in BEA, followed by 5 compounds in EMW, and 1 in CEF. Therefore, the BEA solvent system was the best eluent for separating compounds. In addition, different bands were observed after spraying the TLC plates with vanillin reagent.
Antifungal activities of plant extracts were determined using serial microdilution assay against the selected fungal pathogens (Aspergillus fumigatus and Candida albicans). Noteworthy activities (0.02 mg/ml) against C. albicans were observed from P. guajava acetone extract and S. hyacinthoides acetone fresh leaf extracts. The methanol-dried leaf extract of C. edulis was active against A. fumigatus with MIC of 0.02 mg/ml while fresh leaf extract was active with MIC of 0.31–2.5 mg/ml. The dried leaf water extracts of C. edulis and D. cinerea had an excellent activity of 0.02 mg/ml against A. fumigatus.
The bioautography assay was used to determine the number of active components in different plant extracts. Antifungal compounds were visible in dried leaf extracts of P. guajava, R. communis, and S. hyacinthoides. A total of 19 antifungal compounds were observed against A. fumigatus. Dried leaf extracts of P. guajava, R. communis, and S. hyacinthoides had an active component with an Rf value of 0.88 against A. fumigatus. In TLC bioautograms developed in BEA, two active compounds with similar Rf values of 0.20 were visible in acetone and methanol extract of P. guajava against C. albicans.
The results of this study support the traditional use of the selected plant species to combat ear infections and related ailments in humans. The crude extracts have the potential to serve as an ototopic. The antifungal compounds also have the potential to be isolated and used in the formulation of ototopical drugs that may help lift the health burden caused by ear infections across the globe.
Thesis (M.Sc. (Botany)) -- University of Limpopo, 2023
2023-01-01T00:00:00ZIsolation, characterisation and cytotoxicity of antifungal compounds present in medicinal plants used against crytococcus neoformans in Vhembe District, Limpopo Province
http://hdl.handle.net/10386/4291
Isolation, characterisation and cytotoxicity of antifungal compounds present in medicinal plants used against crytococcus neoformans in Vhembe District, Limpopo Province
Machaba, Tambudzani Caroline
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.
Thesis (Ph.D. (Botany)) -- University of Limpopo, 2023
2023-01-01T00:00:00ZEthnobotanical survey of medicinal plants with antifungal activities in Makhado Local Municipality, Limpopo Province, South Africa
http://hdl.handle.net/10386/4262
Ethnobotanical survey of medicinal plants with antifungal activities in Makhado Local Municipality, Limpopo Province, South Africa
Machaba, Tambudzani Caroline
The aim of the study was to investigate medicinal plants used for the treatment of various ailments by the traditional healers and local people and to determine antifungal activities against animal fungal pathogens. Ethnobotanical survey was conducted to identify medicinal plants used by local people and traditional healers to treat various ailments in Makhado Local Municipality, Vhembe District, Limpopo, South Africa. A questionnaire was designed to gather information on the local name of plants, plant parts used and the methods of preparation and administration by the traditional healers. In our findings, sixty-three medicinal plants belonging to thirty-three families were identified to be used for treatment of various diseases such as chest complaint, sexual transmitted infections, headache, swollen legs, hypertension, blood purification, asthma, and infertility. Specific parts of the plant used for medicinal purposes vary from species to species and from one traditional healer to another. The dominant families were Fabaceae, Celastraceae and Euphorbiaceae. Of the sixty-three plants species identified, trees were the most predominant plant form (53%), followed by shrubs (23%), herbs (14%), and climbers (10%). Root, fruit, bark, leaves, seeds and in some instances the whole plant are used for the preparation of medicine while decoction and infusion were the general methods of preparation. The mode of administration of medicine was mainly oral. The most frequently used plant species were Warbugia salutaris (Bertol.f.) Chiov, Sclerocarya birrea (A.Rich) Hochst and Eleondron transvaalense (Burtt Davy) R.H. Archer.
Eight plant species (Asparagus buchananii Bak., Albuca seineri (Engl. & K.Krause) J.C Manning & Goldblatt, Elephantorrhiza elephantina (Burch.) Skeels, Indigofera circinnata Benth, Maerua juncea Pax, Pentarrhinum insipidum E. Mey., Senna italica Mill. and Schinus molle L.) were selected based on the information given by the local people and the traditional healers for further phytochemical analysis and microbiological assays. Antifungal activities of the selected plant species were determined against three fungal pathogens namely, Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus. Of the tested plant species, hexane leaf extracts of M. juncea, ethyl acetate leaf extracts of S. italica, A. buchananii and E. elephantina were the most active against Candida albicans, Cryptococcus
v
neoformans and Aspergillus fumigatus with Minimum inhibitory concentration (MIC) values ranging between 0.02 mg/ml and 0.08 mg/ml.
Bioautography assay was used to determine the number of active compounds in the plant extracts. No active compounds were observed in some plant extracts against the tested animal fungal pathogens indicating possible synergism. The most promising plant species were: A. buchananii, A. seineri and M. juncea, all had shown good activity with 4 compounds against A. fumigatus. Acetone and methanol extracts had the same active compounds visible on bioautograms. Most of the active compounds were observed in TLC chromatograms developed Benzene: ethanol: ammonia hydroxide (BEA) eluent solvent system.
Based on excellent antifungal activity against the tested microorganisms, leaf extracts of A. buchananii, A. seineri M. juncea, P. insipidum and root extracts of I. circinnata were also tested for cytotoxicity against the Vero kidney cells. All plant extracts investigated were relatively not toxic against the cells with LC50 ranging between 0.131 mg/ml and 1 mg/ml. Water extracts of A. buchananii, A. seineri and M. juncea had LC50 1 mg/ml. The leaf aqueous extracts of P. insipidum were less toxic than root aqueous extracts of I. circinnata with LC50 of 0.65 mg/ml and 0.49 mg/ml against the Vero kidney cells respectively.
The results indicate that the local people and traditional healers in Makhado Local Municipality use medicinal plants and their indigenous knowledge on the treatment of fungal infections and related ailments.
Thesis (M. Sc. (Botany)) -- University of Limpopo, 2018
2018-01-01T00:00:00Z