Pharmacological, toxicological and phytochemical evaluation of helichrysum petiolare hilliard & b.l. burtt - an indigenous plant traditionally used in the treatment of diabetes in the eastern cape province of South Africa
- Authors: Aladejana, Adebowale Emmanuel https://orcid.org/0000-0003-1871-926X
- Date: 2022-04
- Subjects: Diabetes -- Alternative treatment , Traditional medicine , Medicinal plants
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22787 , vital:52755
- Description: Diabetes mellitus is one of the leading causes of death in South Africa, and it has already placed significant stress on the country’s health sector and economy. The orthodox hypoglycaemic drugs are not only ineffective in the management of the disease and its complications, but they also possess unwanted side effects. The need for alternative non-toxic drugs is therefore imperative. Various studies have listed several medicinal plants that can be successfully used in the herbal treatment of diabetes and have investigated them for their anti-diabetic potentials in vivo and/or in vitro. Out of the different potential herbal species, plants belonging to the Asteraceae family possess highly potent hypoglycaemic properties with negligible toxicities. Five Asteraceae plants widely used in different parts of South Africa for the treatment of diabetes were reviewed. The review provided an update of scientific evidence on the hypoglycaemic properties of the plants. However, Helichrysum petiolare was studied extensively in this study for its antidiabetic activity H. petiolare has been listed in many ethnobotanical surveys as a plant with potent hypoglycaemic potential, this, however, has not been properly verified in scientific literature and there has hardly been any study on the essential oil and nutritional composition, and antioxidant, antidiabetic, and cytotoxicity potentials of the plant. The effects of hydro-distillation (HD) and solvent-free microwave extraction (SFME) methods on the chemical constituents of H. petiolare-derived essential oils were evaluated. The SFME method had a higher yield of essential oil than the HD. There were substantial amounts of monoterpenes, monoterpene alcohols, sesquiterpenes, and sesquiterpene alcohols in both essential oils obtained, but these compounds were more profound in the SFME derived essential oil which has 62 compounds compared to the 52 derived through HD. The SFME derived essential oil can therefore be said to be of better quality than the HD method. The compounds obtained in the essential oils have high pharmaceutical and cosmetic value, and as observed in this study, their quantity is dependent on the method of extraction (Ibáñez and Blázquez, 2021; Kaur et al., 2021). The proximate analysis of the whole plant of H. petiolare showed high levels of Acid Detergent Fibre (ADF), vitamins (A, C and E), Neutral Detergent Fibre (NDF), and minerals. The high ADF level is believed to be responsible for the low energy, fat and carbohydrate levels observed in the study. The result showed a high level of oxalate and therefore suggests cooking of the plant before human consumption. Overall nutrition and mineral compositions of the plant showed that H. petiolare is immensely rich in vital nutrients that are of great importance to health and metabolism; these nutrients are suggested to be partly responsible for the plant’s useful medicinal properties. The phytochemical contents of the acetone (ACQ), ethanol (ETQ), and boiled (BAQ) and cold (CAQ) aqueous whole-plant extracts of Helichrysum petiolare were determined using standard phytochemical reaction methods. ABTS, DPPH, NO and TAC assays were used to evaluate their antioxidant properties. The highest total phenolic content (212,963 mg/g) was reported in the BAQ extract, while the ETQ had the highest flavonoid (172.393 mg/g) and proanthocyanidin contents (65.855 mg/g). Alkaloids, flavonols, and saponin were highest in the ACQ extract, while the CAQ had the lowest phytochemical content. Among the extracts, the BAQ had the highest DPPH•+ (IC50 0.02 mg/mL) and ABTS•+ (IC50 0.07) inhibition capacities, while the ETQ exhibited the highest NO• Inhibition (IC50 0.41 mg/mL) and TAC (IC50 0.19 mg/mL). These findings justify the use of H. petiolare in traditional medicine and further recommend the ETQ and BAQ extracts of the plant as more effective extracts for medicinal treatment. The hepatotoxicity (cytotoxicity, mitotoxicity and lipotoxicity) potential of the BAQ, CAQ and ETQ extracts of Helichrysum petiolare was evaluated using standard procedures. The results showed negligible BAQ and CAQ cytotoxicities, which were further, corroborated by stability in the mitochondrial membrane potentials and were congruent with the CAQ and BAQ results for steatosis and phospholipidosis. The data suggested favourable CAQ and BAQ toxicity profiles with limited risks for hepatotoxicity. The ETQ extract, however, showed significantly high levels of cytotoxicity and lipotoxicity, and a low level of mitotoxicity. Our result suggested a potential risk of the ETQ extract for hepatotoxicity but appears partly independent of direct mitochondrial involvement. Glucose uptake assay showed significantly increased glucose uptake in the BAQ and CAQ treated L6 and C3A cell lines. The CAQ extract enhanced glucose uptake more in the L6 myocytes than in the C3A cell-lines hepatocytes. The BAQ extract showed higher levels of inhibition on α–amylase and α-glucosidase activities as compared to CAQ. The BAQ and CAQ extracts of H. petiolare may, therefore, contain pharmacologically active and relatively non-toxic hypoglycaemic chemicals, which may be effective substitutes in the treatment of diabetes mellitus. This study provides up to date scientific information on the use of H. petiolare in the treatment of diabetes mellitus in the Eastern Cape of South Africa. It justifies the use of this plant in herbal medicine and sheds more light on its previously vaguely understood nutritional and medicinal potentials. More studies, however, need to be done to isolate, identify and purify the constituent bioactive compound(s). Their dosage of application and mode of action also needs to be understood. , Thesis (PhD) -- Faculty of Science and Agriculture, 2022
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Compartmentalization of mineral elements, nutritional factors, biological potentials and phytochemical profiles in the fruits of Musa sinensis L.(Banana) and Musa paradisiaca L.(Plantain): A comparison among soft flesh, peel and boiled peel extract
- Authors: Oyeyinka, Barnabas Oluwatomide https://orcid.org/0000-0003-1191-9365
- Date: 2021-09
- Subjects: Bananas , Plantain banana
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23655 , vital:58274
- Description: Fruits are key contributors to human nutrition and health. However, banana and plantain are typical examples of fruits that have nutritionally under-utilized peel by-products. This study was thus carried out to investigate the compartmental distribution (soft flesh, peel, and boiled peel extract) of mineral elements, nutritional factors, biological potentials, and phytochemical profiles in M. sinensis and M. paradisiaca fruits (ripening stage 4-5), with focus on the peels. Proximal and and antinutritive analyses were done with standard methods of the Association of Official Analytical Chemists (AOAC), while mineral element composition in the fruit components was analyzed with the inductively coupled plasma optical emission spectroscopy (ICP-OES). The pharmacological potential of M. sinensis and M. paradisiaca fruit components was investigated spectrophotometrically by evaluating the polyphenolic constituents (total phenol, proanthocyanidin, flavonoid) and in vitro radical scavenging activities of the aqueous, acetone and ethanol extracts, using DPPH, ABTS, and FRAP assay models. The correlational evaluation of the polyphenolics and antioxidant activity in the components of both fruits using Pearson’s correlational coefficient (r). The proximal assays revealed that moisture content, fiber content, and carbohydratecontent were substantially present in the flesh and peel of M. sinensis and M. paradisiaca, while lipid content was low. The antinutritive results revealed safe levels of alkaloid, oxalate, phytate, and saponin factors in the flesh and peel by-products. Mineral analysis results indicated substantial levels of the macroelements K, Mg, Ca, and P in the peels. Other results revealed that acetone extracts had the highest phenolic, proanthocyanidin and flavonoid constituents respectively, across the soft flesh components ofM. sinensis (119.05 ± 5.80 mgGAE/g; 337.48 ± 13.16 mgCE/g; 602.64 ± 3.65 mgQE/g), M. paradisiaca (114.80 ± 1.49 mgGAE/g; 436.09 ± 36.44 mgCE/g; 777.35 ± 150.95mgQE/g) and the peel component of M. paradisiaca (136.87 ± 5.69 mgGAE/g; 530.06 ± 53.51 mgCE/g; 750.87 ± 55.61 mgQE/g), with an exception of the phenolic content of M. sinensis peel, where it was highest in the ethanol extract (157.19 ± 4.76 mgGAE/g). The ABTS (0.03 mg/mL) and DPPH (0.03 mg/mL) activities were at their highest in the boiled peel extracts of M. sinensis and M. paradisiaca, while ferric reducing power was highest in ethanol extracts across M. sinensis soft flesh, peel, and M. paradisiaca flesh. Acetone extract of M. paradisiaca peel had the highest ferric reducing capacity at peak concentration (0.1 mg/mL). Correlational analysis revealed a negative correlation between respective phenolic, proanthocyanidin, and flavonoid content and the IC50DPPH antioxidant capacity in M. sinensis flesh, M. sinensis peel and M. paradisiaca flesh. Conversely, there was positive correlation between IC50 DPPH with proanthocyanidin and flavonoid in M. paradisiaca peel. Negative correlation was detected between the phenolic, proanthocyanidin and flavonoid contents and IC50ABTS in M. sinensis flesh. Positive correlation was observed between respective phenolic, proanthocyanidin and flavonoid contentwith IC50 ABTS in M. sinensis peel, M. paradisiaca flesh and M. paradisiaca peel. There was negative correlation between the respective phenolic, proanthocyanidin and flavonoid contents and IC50 FRAP in the flesh of M. sinensis, while positive correlation was observed in M. sinensis peel. M. paradisiaca flesh on the other hand, showed positive correlation between the IC50 FRAP and the respective phytochemical contents. However, the peel, there was negative correlation. The correlational evaluation in this study revealed general positive and negative correlational patterns, which implies that no polyphenolic constituent contributed exclusively to antioxidant activity, but rather in combination. Ultrastructure and elemental spectra of M. sinensis and M. paradisiaca exocarps were analysed with electron microscopy (SEM)and energy dispersive x-ray (EDX). Microstructures such as interlocked, polyhedral epidermal cells, ellipsoid-shaped stomata, guard cells, intercellular space, anticlinal-patterned walls, and subsidiary cells were observed. The elemental spectra revealed the presence of elements such as potassium, iron, carbon, oxygen, silicon, and gold, with consistently high to relatively high carbon and oxygen peaks in M. sinensis and M. paradisiaca exocarps. The relative similarity observed in the constituents of a number of the elemental spectra in M. sinensis and M. paradisiaca peels, reflects some degree of relatedness. These outcomes indicate that banana and plantain peel and boiled peel extracts are nutritive, medicinal and potential nutraceuticals, with food preservative, shelf-life and quality enhancement potentials. The instrumentation in this study also have potential relevance in industrial food product analysis. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
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Pharmacological investigation of Citrus limon leaf extract and its efficacy as biofungicide against potato rot disease
- Authors: Ehiobu, John Meomikem
- Date: 2021
- Subjects: Potatoes -- Diseases and pests , Potato ring rot , Bacterial wilt of potato
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23666 , vital:58278
- Description: Potato, the fourth major staple and economic food crop is readily attacked by fungal pathogens. This is of public and economic importance. Interests have shifted from the age-old rot management by synthetic fungicide to botanicals due to the attended negative effects of the former. The bioactive molecules domicile in plants have been found to possess pharmacological properties against diverse pathogens of plants and animals. This study investigated the pharmacological properties of the Citrus limon leaf extracts of using different leaf solvent extracts and the potential utilization of these extracts in managing potato rot diseases. The tubers were purchased from selected supermarkets within Raymond Mhlaba Local Municipality of the Eastern Cape province of South Africa. A survey study was carried out by using a well-structured designed questionnaire administered to selected supermarkets in three major towns namely; Alice, King Williams Town and Fort Beaufort. The questionnaires were randomly administered to 62 supermarket owners in each of the selected super markets. Rotten potato tubers were randomly collected from these supermarkets. On each occasion, the tubers were packaged in a sterile polythene bag and taken to the laboratory for isolation and identification of the pathogens associated with the disease (rot) using standard mycological techniques. Fresh leaves of Citrus limon were collected from a residential area within the study location, processed and extracted using water, ethanol and acetone solvents before analysing their phytochemical contents, antioxidant properties and antifungal activites against the rotten potato tuber pathogens at graded concentrations of 25g/l, 50g/l and 100g/l. Effects of different temperatures (10-40oC) on the tuber weight loss and mycelia growth were also evaluated. Analysis of the results revealed that the supermarket owners incurred economic loss of 43percentwith annual potato loss incurement of R1501- 2000. The losses occurred more in the warmer summer seasons. About 91percent of the respondents agreed to use any novel botanicals, as alternatives to the increasing artificial fungicides due to their high costs, toxic nature and the environmental hazard effects. Phytochemical results showed that the ethanol extracts yielded the highest total flavonoid quantification of 1052.58±39.44mg GAE/g, followed by phenols (209.72 ± 6.38 GAE/g), alkaloid (12.23percent) and saponin (5.53percent). There was no significant difference in phenol content between the acetone and ethanol; but a significant difference (P < 0.05) was observed for the aqueous extracts of C. limon leaf. The aqueous, acetone and ethanol leaf extracts also showed significantly high antioxidant capacity with the ABTS (67.85percent - 90.85percent), FRAP (128.26 - 182.12 mgRE/g) and DPPH (28.72percent - 33.64percent). The fungal pathogens isolated from rotten potato tubers were identified as Curvularia mebaldsii, Fusarium oxysporum and Penicillium species. The effect of C. limon leaf extracts on the isolates was concentration and extracting solvent dependent. For the aqueous solvent, the mycelial growth of Penicillium species were most inhibited with 95.82 ± 0.11percent, 89.1 ± 0.19percent and 74.81 ± 0.82 percent, followed by F. oxysporum with 76 ± 2.83, 76percent ± 5.95percent and 29.05 ± 3.17percent and Curvularia mebaldsii (68.46 ± 3.0percent, 63.76 ± 2.87 percent and 53.47± 3.64percent) respectively. However, the ethanol and acetone extracts at 100g/l concentrations displayed a 100percent growth inhibition against the three rot fungi. The effects 50g/l ethanol concentration also showed 100percent against both F. oxysporum and C. mebaldsii, but 90.97percent against Penicillium sp. The growth inhibition at 25g/l extract against F. oxysporum were 99percent and 96.52percent for acetone and ethanol extracts respectively, but 96.52percent and 85.57percent against C. mebaldsii and Penicillium sp. respectively. The effects of temperature on the average radial mycelial growth of fungal isolates at 10oC, 20oC, 30oC, and 40oC were 17.53 mm, 28.33 mm, 42.33 mm, and 34.50 mm respectively. The highest percentage weight loss of infected potato was 19.53percent at 30oC, while the lowest was 5.12percent at 10oC. The optimal temperature of maximum activities of the isolates was 30oC and this indicates that healthy potato tubers stored at 30oC will undergo faster fungal deterioration and spoilage than those stored at 10oC. The findings indicated that the ethanol and acetone extracts displayed significantly higher phytochemicals, antioxidant properties and in vitro antifungal activity against the potato rot disease fungal pathogens. Hence, the plant leaf could be considered as a potent bio-fungicides against potato rot disease. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
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Cultivation, nutritional and pharmacological evaluation of Celosia argentea (L) Kuntze: an endangered wild vegetable in the Eastern Cape Province of South Africa
- Authors: Adegbaju, Oluwafunmilayo Dorcas
- Date: 2019-09
- Subjects: Celosia , Edible greens
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19806 , vital:43250
- Description: Green leafy vegetables are important in human nutrition, but their cultivation is limited to a few staple ones. These vegetables possess high nutritious and therapeutic properties that could help in achieving nutritional security and alleviating the burden of some diseases. A typical example is Celosia argentea, which in South Africa, is little known and grossly under-utilized despite its numerous nutritional and pharmacological values. The present study investigated the cultivation, nutritional and pharmacological potentials of C. argentea at three stages of maturity of two trials. Evaluation of cultivation in the greenhouse towards possible domestication of C. argentea included seed viability test, seed germination under varying temperatures (5, 10, 15, 20 25 30, 35, 40°C), light conditions (continuous light, continuous darkness, alternating light and dark (12h light/12 dark photoperiod) and sowing depths (0, 1, 2, 3, 4 and 5cm). The nutritional evaluation assessed the proximal, mineral, vitamins and antinutrient content of the plant; while pharmacological potentials of C. argentea were evaluated by investigating the ultramorphology, phytochemical content, anti-oxidant, antimicrobial, toxicity and cell-based anti-inflammatory properties of the plant at different stages of growth. Germination experiment revealed that optimum seed germination requirements for C. argentea were 25°C, alternating light and dark regime and a sowing depth of 1cm. Microrphological assessment of C. argentea revealed that the leaves were amphistomatic; with the abaxial surface having higher stomata density. Characteristic, distinguishing protuberances were observed at the polar ends of the stomata on the adaxial surface of the plant epidermis, and the major elements on the foliar epidermis were beryllium, carbon, oxygen and potassium; while pigmentation and colouration, showing localization of bioactive compounds were mostly at the site where trichomes were abundant. Growth parameters and yield potential (plant height, stem girth, leaf area, number of leaves, number of branches, number of days to flowering, number of flowers as well as dry and fresh weight) of C. argentea showed that for agricultural practices on the field, increase in growth parameters should be expected around 4-5 weeks after transplanting while higher yield should be expected around 7-9 weeks after transplanting. The results encouraged cultivation during summer or late spring for best farm management. Proximal, mineral, vitamins and anti-nutrients content of C. argentea at three different maturity stages of two trials were performed using AOAC, ALASA and inductively coupled plasma-optical emission spectrometer techniques. Results revealed that the pre-flowering stage of growth had the highest ash (28.15± 0.10 percent) and crude protein (25.80 ± 0.20 percent) contents. While post-flowering stage had the highest carbohydrate (28.51± 0.20 percent and 36.16± 0.22 percent), crude fibre (33.41± 0.87 percent) and energy (435.28± 27.6 percent) with low fat and moisture (8.43± 0.15 percent and 6.35±0.09 percent) contents respectively; while no marked demarcation in most mineral contents in all the growth stages was observed. Zinc was highest at the flowering stage of growth, while vitamin contents decreased as the plant approached maturation. Antinutrients content of the plant was not dependent on growth stage. Total phenols, flavonoids and proanthocyanidin content of C. argentea were evaluated colourimetrically, while the antioxidant potency of the aqueous, acetone and methanolic extracts was measured using 2,2 diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), Ferric reducing antioxidant power (FRAP) and total antioxidant capacity (TAC) models. All the solvent extracts of the flowering stage had the highest total phenolic (80.75±4.21GAE/g), flavonoids (946.19±7.87QE/mg) and proanthocyanidin contents (100.90±1.29 CE/g); with the acetone extracts showing significantly higher phytochemical content. The flowering stage exhibited the best radical inhibitory activity, with the methanol extract having the highest scavenging power for ABTS and DPPH radicals, while acetone extract showed the highest inhibition against FRAP and highest total antioxidant capacity. The antimicrobial potential of the aqueous acetone and methanolic extracts of C. argentea evaluated using agar dilution method against six bacteria (Klebsiella pneumonia, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Bacillus cereus) and four fungal strains (Candida glabarata, Candida albicans and Penicillium aurantiogriseum and Penicillium chrysogenum) showed that Streptococcus pyrogenes and P. aeruginosa were susceptible to the methanol extracts of all the growing phases of both trials at 10 mg/mL; while Klebsiella pneumoniae was susceptible at 10 mg/mL to only the methanol post-flowering extracts of both trials. C. albicans and P. aurantiogriseum were highly susceptible to all the extracts. Possible toxicity evaluated using brine shrimp lethality assay and calculation of LC50 against brine shrimp nauplii revealed that C. argentea was not toxic at any stage of maturity at all concentrations evaluated. Anti-inflammatory activities and cytotoxicity of C. argentea extracts evaluated using RAW 264.7 macrophages and 3T3-L1 cell lines revealed that the acetone extract of the flowering stage had moderate anti-inflammatory activity with no significant toxicity against activated macrophages. Findings from this study indicate that C. argentea is a safe functional leafy vegetable of high nutritional and pharmacological importance which can easily be cultivated and domesticated in South Africa. This could significantly alleviate the burden of micronutrient deficiencies among pre-school children in rural communities. , Thesis (PhD) (Botany) -- University of Fort Hare, 2019
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