Medicine
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This repository contains the published and unpublished research of the Faculty of Medicine by the staff members of the faculty
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Item An Evaluation of the potency of Osbeckia octandra and Melothria maderaspantana as antihepatotoxic agents.(George Thieme, 1989) Jayathilake, K.A.; Thabrew, M.I.; Pathirana, C.; de Silva, D.G.H.; Perera, D.J.Aqueous extracts of the aerial parts of Melothria maderasptana and the leaves of Osbeckia octandra have been compared with (+)-3-cyanidanol with regard to their abilities to alleviate carbon tetrachloride (CCl4)-induced liver dysfunction in albino rats by comparing the abilities of these drugs to protect the liver against CCl4-mediated alterations in the liver histopathology and serum levels of aspartate aminotransferase (GOT), alkaline amino-transferase (GPT), and alkaline phosphatase. In both pretreatment and post-treatment (administration of drugs before or after CCl4 treatment) experiments, the most marked rate of recovery of the liver was exhibited by the group of rats treated with Melothria maderaspatana extract. Although the protection offered by (+)-3-cyanidanol and Osbeckia octandra appears to be comparable in post-treatment, Osbeckia was significantly more effective in pre-treatment. From the overall results obtained it appears that the aqueous extracts of Melothria maderaspatana and Osbeckia octandra are both as potent or in some instances (in pretreatment experiments) more potent than (+)-3-cyanidanol. Of the two plants tested under the present experimental conditions used, Melothria maderaspatana appears to be marginally more effective than Osbeckia octandra in protecting the liver against CCl4-induced alterations.Item A Preliminary investigation of the possible hypoglycaemic activity of Asteracanthus longifolia(Elsevier, 1989) Fernando, M.R.; Wickramasinghe, N.; Thabrew, M.I.; Karunanayaka, E.H.Investigations were carried out to confirm or otherwise disprove the view held by many Ayurvedic and other traditional medical practitioners in Sri Lanka, that Asteracanthus longifolia possesses hypoglycaemic properties. The effects of an aqueous extract of the whole plant on fasting blood glucose level and glucose tolerance were investigated using Sprague-Dawley rats. The results indicate that aqueous extracts of A. longifolia can significantly lower the fasting blood glucose level and markedly improve the glucose tolerance of the rats. The hypoglycaemic effect produced by a therapeutic dose (equivalent to 5 g/kg of starting material) was comparable to that produced by a therapeutic dose (15 mg/kg of tolbutamide. The magnitude of the hypoglycaemic effect was found to vary with the dosage administered and the storage time of the prepared extract.Item Evaluation of the efficacy of Melothria maderaspatana in the alleviation of carbon tetrachloride-induced liver dysfunction(Elsevier, 1988) Thabrew, M.I.; Jayathilake, K.A.; Perera, D.J.An investigation was carried out to evaluate the ability of Melothria maderaspatana to protect the livers of albino rats from carbon tetrachloride-mediated alterations in liver histopathology and serum levels of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase. Treatment with an aqueous extract of Melothria aerial parts (either before or after CCl4 administration) markedly decreased CCl4-mediated alterations in liver histopathology as well as serum enzyme levels. Results provide supportive evidence for the folklore view that this plant is a good hepatotonicItem A Comparative study of the efficacy of Pavetta indica and Osbeckia octandra in the treatment of liver dysfunction(George Thieme, 1987) Thabrew, M.I.; Joice, P.D.; Rajatissa, W.No Abstract AvailableItem Drug induced alterations in some rat hepatic microsomal components:a comparative study of four structurally different antimalarials(Pergamon Press, 1985) Thabrew, M.I.; Nashiru, T.O.; Emerole, G.O.Alterations in microsomal drug metabolizing enzymes, microsomal lipids and some serum enzymes following pre-treatment of rats with therapeutic doses of four structurally different antimalarial compounds, chloroquine (CQ), quinine (Q), quinacrine (QK) and primaquine (PQ) have been investigated. CQ and Q significantly decreased the activities of aminopyrene N-demethylase, aniline hydroxylase and both microsomal and cytosolic glutathione S-transferases. Only aniline hydroxylase was markedly decreased by QK, while PQ did not have much effect on any of these enzymes. CQ, Q and QK significantly increased the cholesterol:phospholipid ratio while all four compounds decreased the phosphatidyl choline:sphingomyelin (PC/S) ratio. All the drugs increased the activities of the serum enzymes glutamate-oxaloacetate transaminase, glutamate-pyruvate transaminase and alkaline phosphatase. The possible relationships of these results to structural variations in the four drugs being investigated has been discussedItem Covalent binding and glutathione depletion in the rat following niridazole (ambilhar) pretreatment(Springer-Verlag, 1985) Oduah, I.N.; Thabrew, M.I.; Emerole, G.O.In vivo and in vitro studies with rats have shown that (14C) niridazole (Ambilhar) binds covalently to tissue proteins, but not to nucleic acids. In the in vitro experiments, binding required the presence of NADPH in the incubation medium, suggesting the production of an active metabolite via a cytochrome P-450-mediated reaction. Niridazole also caused significant dose-dependent decreases in liver and kidney glutathione levels, even though it had no apparent effect on blood glutathione. Alteration of tissue glutathione availability by pretreatment with chloracetamide or cysteine respectively either increased or decreased the NADPH-dependent covalent binding. Pretreatment with phenobarbital, 3-methylcholanthrene or cobaltous chloride, which change the rate of metabolism of (14C) niridazole, similarly altered the extent of protein binding. It is shown that the decrease in tissue glutathione concentration is not due to an effect of the drug on the activities of either glucose-6-phosphate dehydrogenase or glutathione-S-transferases. However, there is a significant reduction in glutathione reductase activity in all the tissues studied. The possible relationships between the results obtained and the cytotoxic effects of niridazole have been discussed.