Magister Pharmaceuticae - MPharm

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An assessment of three Carpobrotus species extracts as potential antimicrobial agents.
(University of the Western Cape, 2001) Springfield, Evan; Amabeoku, George J.
For centuries, indigenous people in South Africa have used a variety of medicinal herbs to treat chronic infections. This investigation focused on three Carpobrotus species, in an attempt to assess their potential antimicrobial activity. Extracts of varying polarities of the plants were prepared and tested against Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and Mycobacterium smegmatis. For the disc diffusion method Ciprofloxacin (4Opg/disc) served as positive control for ^S. aureus, P. aeruginosa and M. smegmatis, whereas amphotericin B (25 pg/disc) was the control for C. albicans. A sample concentration of 10mg/ml was used. Minimum inhibitory concentrations (MIC) were determined by two-fold serial dilution. Phytochemical analysis was completed to test for the presence of flavanoids, hydrolysable tannins, phytosterols and aromatic acids. The ethyl acetate extracts {2lpl of 95mg/ml) were used for bio-autography, together with TLC analyses and HPLC fingerprinting. Carpobrotus mellei, Carpobrotus muirrii and Carpobrotus quidrifidus showed antimicrobial activity against S. aureus and M. smegmatis in the disc diffusion method and inhibition against S. aureus and M.smegmatis was observed by clear zones on the TLC plate. HPLC fingerprinting of the three species showed similarities with common peaks detected at 366 nmi, and providing a phytochemical map of potentially important natural bioactives. This investigation confirms that extracts of the three Carpobrotus species that are used as indigenous medicines, exhibits anti-bacterial activity. This scientific information can serye as an important platform, for the development of inexpensive, safe and effective natural anti-infective therapeutics.
Evaluation of the anticonvulsant activity of Elytropappus rhinocerotis (L.f) Less
(University of the Western Cape, 2016) Iyamu, Osaro; Amabeoku, George J.
M.Pharm thesis, Discipline of Pharmacology, School of Pharmacy, University of the Western Cape. Epilepsy is a worldwide neurological disorder which is also prevalent in South Africa. Herbal medicines, besides orthodox medicines, have been used from time immemorial for the treatment of epilepsy even though, generally, there is want of scientific evidence to substantiate their effectiveness. People with epilepsy have used different types of plants and herbs now known as herbal therapies over thousands of years although no clinical benefit is implied by this term. Moreover, the use of traditional medicine to treat CNS disorders such as epilepsy in South Africa still lacks a lot of scientific data although a study that was conducted in the Western Cape Province of South Africa revealed that the people in the Bredasdorp community use Elytropappus rhinocerotis to treat convulsions.
Evaluation of the antinociceptive, anti-inflammatory and antipyretic activities of Ruta Graveolens L. in mice and rats
(University of the Western Cape, 2012) Loonat, Firdows; Amabeoku, George J.
Evaluation of the antinociceptive, anti-inflammatory and antipyretic activities of Ruta graveolens L. in mice and rats FIRDOWS LOONAT M. Pharm. Pharmaceutical Sciences thesis: School of Pharmacy, University of the Western Cape Ruta graveolens (Rutaceae) L. is a medicinal plant that is commonly used to manage and treat essential events such as pain, inflammation and fever. Despite its popularity, particularly as a medicinal plant in the Calvinia district and Bredasdorp region of South Africa, scientific data to substantiate its widespread traditional use and the possible mechanisms of action for this plant species is lacking. Therefore, the objectives of this study were: to scientifically evaluate and validate the antinociceptive, anti-inflammatory and antipyretic activities of Ruta graveolens using the acetic-acid writhing test and hot-plate test, the carrageenan rat paw oedema test, and the E. coli-induced pyrexia test, respectively; to investigate the possible mechanisms of the antinociceptive, anti-inflammatory and antipyretic activities of the plant using interaction studies; to determine some secondary metabolites present in the plant species using standard phytochemical analytical procedures; to characterise the plant species using HPLC techniques; and to determine the safety profile of the plant species using an acute toxicity study.Three percent (3 %) acetic acid (0.25 ml, i.p.) produced a substantial number of writhes in mice. The leaf methanol extract of Ruta graveolens (100 mg/kg, i.p.) significantly reduced the number of writhes induced by 3 % acetic acid (0.25 ml, i.p.). R. graveolens (100 mg/kg,i.p.) produced 54 % inhibition of 3 % acetic acid-induced writhes. Indomethacin (20 mg/kg,i.p.) and paracetamol (500 mg/kg, i.p.) significantly reduced the number of 3 % acetic acidinduced writhes. Indomethacin (20 mg/kg, i.p.) and paracetamol (500 mg/kg, i.p.) produced 57 % and 80 % inhibition of 3 % acetic acid-induced writhes, respectively. R. graveolens (25– 50 mg/kg, i.p. and 200 – 400 mg/kg, i.p.) and indomethacin (10 mg/kg, i.p.) did not significantly reduce the number of writhes induced by 3 % acetic acid. However, combined therapy of the leaf methanol extract of R. graveolens (25 mg/kg, i.p.) and indomethacin (10 mg/kg, i.p.) significantly reduced the number of 3 % acetic acid-induced writhes. The combined therapy of the lowest and sub-effective doses of the leaf methanol extract of R. graveolens (25 mg/kg, i.p.) and indomethacin (10 mg/kg, i.p.) produced 59 % inhibition of the writhes elicited by 3 % acetic acid. The leaf methanol extract of R. graveolens (50 – 400 mg/kg, i.p.) greatly delayed the reaction time in mice to thermal stimulation produced with hot-plate. 50 – 400 mg/kg (i.p.) of the leaf methanol extract of R. graveolens significantly antagonised rat paw oedema induced by 1 % carrageenan (0.1 ml, subplantar) over the 4 h period of testing. In addition, indomethacin (10 mg/kg, i.p.) significantly antagonised 1 % carrageenan-induced rat paw oedema. R. graveolens (25 mg/kg, i.p.) and indomethacin (2mg/kg, i.p.) given separately did not significantly alter rat paw oedema induced by 1 % carrageenan. However, combined therapy of the leaf methanol extract of R. graveolens (25 mg/kg, i.p.) and indomethacin (2 mg/kg, i.p.) significantly reduced 1 % carrageenan-induced rat paw oedema. The leaf methanol extract of R. graveolens (400 mg/kg, i.p.) significantly reduced the mean rectal temperature of normothermic rats. Ruta graveolens (100 – 400 mg/kg, i.p.) significantly reduced pyrexia induced by E. coli (50 μg/kg, i.m.) over the 5 h period of testing. In addition, pentoxifylline (50 mg/kg, i.p.) significantly reduced E. coliinduced pyrexia. Ruta graveolens (25 – 50 mg/kg, i.p.), paracetamol (500 mg/kg, i.p.) and pentoxifylline (10 mg/kg, i.p.) did not significantly reduce pyrexia induced by E. coli.However, combined therapy of the leaf methanol extract of R. graveolens (25 mg/kg, i.p.)and pentoxifylline (10 mg/kg, i.p.) significantly reduced E. coli (50 μg/kg, i.m.)-induced pyrexia.The phytochemical studies of the powdered leaves of Ruta graveolens indicated the presence of alkaloids, cardiac glycosides, flavonoids, saponins, tannins and triterpene steroids. The HPLC fingerprint indicated characteristic peaks at the following retention times; 1.654 min,2.271 min, 2.403 min, 4.705 min and 7.691 min. The LD50 obtained for Ruta graveolens after oral administration was probably greater than 4000 mg/kg which shows that the plant extract is non-toxic to mice.In conclusion, the data obtained indicate that Ruta graveolens possesses antinociceptive, antiinflammatory and antipyretic activities. Since prostaglandins have been shown to mediate acetic acid-induced writhes, prostaglandins, histamine, serotonin, capsaicin and bradykinin implicated in carrageenan-induced rat paw oedema, and tumor necrosis factor-α (TNF-α) implicated in E.coli-induced pyrexia, it is possible that R. graveolens may be producing its antinociceptive, anti-inflammatory and antipyretic activities by affecting these chemical mediators. The data obtained also justify the use of the plant species by traditional medicine practitioners for the treatment of painful and inflammatory conditions, and pyrexia.
Investigation of the antidiabetic activity of Cnicusbenedictus L. in rats
(University of the Western Cape, 2016) Bekale, Raymonde Bamboukou; Amabeoku, George J.
Diabetes Mellitus, one of the major diseases affecting human population all over the world has caused significant morbidity and mortality. The management of this condition has raised the demand of safe and cost effective remedial measures due to several side effects associated with the present use of modern medicines. Thus, it is crucial to explore other options for diabetes management such as the use of medical plants. Cnicus benedictus L. is one of the known plant species used by traditional medicine practitioners in South Africa for the treatment of various ailments including inflammatory conditions, pain and diabetes. Even though the plant species has been extensively studied, scientifically, no evidence exists in literature to corroborate the claim made by traditional medicine practitioners of its therapeutic success in the treatment of diabetes and pain. Therefore, the objectives of this present study were: to investigate the antidiabetic activity of C. benedictus using leaf methanol extract of the plant species on animal model involving male and female Albino rats; to investigate the antinociceptive activity of the plant species on mice; to determine the safety profile of the plant by investigating the acute toxicity and to carry out HPLC study in order to characterize the plant species. Animals were divided into groups of six each and fasted overnight prior to the induction of diabetes in rats using Streptozocin (STZ). The plasma glucose was measured at intervals of 30 min for 4 hours by means of a glucometer. Cnicus benedictus (100 – 400 mg/kg, i.p.) significantly reduced the blood glucose concentrations of fasted normal rats with percentage maximum reduction ranging from 46 to 79% and chlorpropramide (250 mg/kg, i.p.) significantly reduced the blood glucose concentrations of fasted normal rats by 84%. Cnicus benedictus (100 – 400 mg/kg, i.p.) significantly reduced the blood glucose concentrations of STZinduced diabetic rats with percentage maximum reduction ranging from 44.82 to 66.04% and chlorpropramide (250 mg/kg, i.p.) significantly reduced the blood glucose concentration of STZ-induced diabetic rats by 71.71%. In the oral glucose tolerance test, administration of leaf methanol extract of Cnicus benedictus (100 – 400 mg/kg, i.p.) following oral glucose load on fasted normoglycaemic rats significantly reduced the increased blood glucose concentrations with percentage maximum reduction ranging from 42.45 to 70.75%. Chlorpropramide (250 mg/kg, i.p.) following oral glucose load on fasted normoglycaemic rats significantly reduce the increased blood glucose concentration with a percentage maximum reduction of 79.04%. In acetic acid writhing test, animals were divided into groups of eight per dose. Cnicus benedictus (25-400 mg/kg, i.p.) significantly reduced the number of writhes in mice with percentage inhibition of the writhes ranging from 67.95 to 73.71%. Indomethacin (20 mg/kg, i.p.) and paracetamol (500 mg/kg, i.p.) significantly reduced the number of writhes in mice with percentage inhibition of 75.44 and 69.18% respectively. Combined treatment of lowest and sub-effective doses of C.benedictus (12.5 mg/kg, i.p.) and indomethacin (10 mg/kg, i.p.) significantly reduced the writhes with a percentage inhibition of 58.32%. In hot plat test, animals were divided into groups of eight per dose. Cnicus benedictus (25-400 mg/kg, i.p.) significantly delayed the reaction times of the mice to hot-plate thermal stimulation. Morphine (10 mg/kg, i.p.) significantly delayed the reaction time of the mice to the hot-plate stimulation. The no-adverse-effect-level (NOAEL) of leaf methanol extract of Cnicus benedictus was obtained at 3200 mg/kg (p.o.) and the LD50 value of the plant species was found to be 4000 mg/kg (p.o.). The HPLC fingerprint of the leaf methanol extract of Cnicusbenedictus showed distinct peaks at the following retention times of 6.387, 14.628, 18.431, 23.228 and 29.829 min. In conclusion, the data obtained showed that leaf methanol extract of Cnicus benedictus possesses both antidiabetic and antinocipetive activities.
Pharmacological evaluation of antidiarrhoeal and antidiabetic activities of Syzygium Cordatum Hochst. ex C. Krauss
(University of the Western Cape, 2011) Deliwe, Mzonke; Amabeoku, George J.; School of Pharmacy; Faculty of Science
Syzygium cordatum is a medicinal plant indigenous to South Africa and Mozambique, commonly used to treat stomach aches, diabetes, respiratory problems and tuberculosis. In spite of the folklore use, adequate scientific data to credit its widespread traditional use is lacking. The objectives of this study were: to evaluate and validate scientifically the successful therapeutic claims by traditional medicine practitioners that Syzygium cordatum is effective in treating diarrhoea and diabetes; to determine the effects of the plant extract on gastrointestinal transit of a charcoal meal in mice; to determine the effects on castor oilinduced intestinal fluid accumulation; to determine the safety profile of the plant by carrying out acute toxicology study and to carry out preliminary screening of the active compounds present in the plant using standard phytochemical analytical procedures. The aqueous leaf extract of Syzygium cordatum (3.125 -50mg/kg, p.o) significantly reduced the faecal output caused by castor oil (0.7ml). All the doses used, reduced faecal output from 100% produced by castor oil to between 40 and 61%. S.cordatum (6.25 – 50mg/kg, p.o) significantly and in a dose dependent manner, delayed the onset of castor oil-induced diarrhoea.
Pharmacological evaluation of some central nervous system effects of Cotyledon Orbiculata
(University of the Western Cape, 2005) Kabatende, Joseph; Amabeoku, George J.; Green, Ivan R.; School of Pharmacy; Faculty of Science
The use of traditional medicine through the use of medicinal plants in Africa and especially in South Africa has long been considered an important characteristic of people's daily lives and socio-cultural heritage. Cotyledon Orbiculata is among the medicinal plants that are used by South African traditional practitioners for the treatment of epilepsy and painful conditions such as corns, warts, toothache, earache, boils and various other ailments. However, the claim of therapeutic successes of medicinal plants by traditional medicine practitioners are hardly subjected to scientific scrutiny. This study therefore, investigated the anti-epileptic property of Cotyledon Orbiculata by studying the effects of the methanol extract of the plant against chemically induced seizures by pentylenetetrazole, picrotoxin, bicuculline and N-methyl-DL-aspartic acid in mice. The study also investigated the analgestic effects of Cotyledon Orbiculata by studying the effect of the plant extract on pain induced by acetic acid and hot plate thermal stimulation.

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