Browsing by Author "Wickremasinghe, S.M.D.N."

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An Aqueous extract of the green leafy vegetables Ipomoea aquatica is as effective as the oral hypoglacaemic drug Tolbutamide in reducing the blood sugar levels of Wistar rats
(Wiley, 2001) Malalavidhane, T.S.; Wickremasinghe, S.M.D.N.; Jansz, E.R.
This study was undertaken to compare the oral hypoglycaemic activity of an aqueous extract of the green leafy vegetable Ipomoea aquatica (dose equivalent to 3.3 g starting material /kg body weight) with that of the known oral hypoglycaemic drug tolbutamide (15 mg/kg body weight) in glucosechallenged Wistar rats (3 g/kg body weight, administered 30 min after the administration of Ipomoea aquatica or tolbutamide). One and half hours after administration of glucose (equivalent to 2 h after administration of plant extract or tolbutamide), the mean blood glucose level of the Ipomoeaaquatica treated group was 47.5% lower than that of the control group treated with distilled water. The tolbutamide treated group showed a meanblood glucose level which was only 33.8% lower than that of the control group. However, statistical analysis indicated that the blood glucose levels of the Ipomoea aquatica treated group were not significantly different from that of the tolbutamide treated group. Our results show that the aqueousextract of Ipomoea aquatica is as effectve as tolbutamide in reducing the blood glucose levels of glucose-challenged Wistar rats.
Extra pancreatic effects of Hygrophila longifolia
(Informa Healthcare, 1998) Fernando, M.R.; Wickremasinghe, S.M.D.N.; Thabrew, M.I.
The extra-pancreatic effects of the oral hypoglycemic plant Hygrophila longifolia have been investigated in rats. Administration of an aqueous extract of the plant prior to glucose loading resulted in a significant increase in the glycogen content of liver and muscle (by 108.5 + or - 9.5 and 57.8 + or - 4.2 percent, respectively), and a significant increase in triacylglycerol content of adipose tissue (by 10.2 + or - 1.8 percent) in comparison with control rats. However, the plant extract had no effect on the gluconeogenic capacity of the kidney or intestinal glucose absorption. The results obtained in the present study suggest Hygrophila longifolia may exert hypoglycemic action by mechanisms similar to those of the sulphonylureas.
An Investigation of the toxic effects of a herbal formulation with anti-carcinogenic properties
(University of Colombo, 2005) Iddamaldeniya, S.; Wickremasinghe, S.M.D.N.; Thabrew, M.I.; Ratnatunga, N.; Tammitiyagodage, M.G.
A decoction prepared from a mixture of Nigelld sativa seeds, Hemidesmus indicus root, and Smilax glabra rhizome used by some traditional medical practitioners in Sri Lanka is considered to be useful for the treatment of cancer patients. However, there is a lack of information about any adverse effects of this decoction. Experiments were carried out using Wistar rats and ICR mice as the experimental model, to evaluate any adverse effects mediated by the above decoction. Results of the investigations showed that administration of the decoction (at doses of 4g/kg body weight/day and 6g/kg body weight/day) to rats for three months had no adverse effects on the liver functions (as assessed by its effects on serum levels of alanine and aspartate aminotrans ferase and alkaline phosphatase) or haematological parameters (red blood cell count, white blood cell count, haemoglobin concentration, packed cell volume, mean corpuscular haemoglobin, mean corpuscular volume and mean corpuscular haemoglobin concentration). No significant pathological changes were observed in sections of the major body organs (liver, heart, lungs, stomach, duodenum and kidney) of animals treated with the decoction for three months. The investigations also demonstrated that the decoction did not have anti-ovulatory, an ti-implantation, spermicidal activity. An attempt to determine the LD50 concentration was unsuccessful. Even at a dose equivalent to 40 times (240g/kg/day) the normal therapeutic dose (6g/kg/day), no mortality or other toxic symptoms (loss of consciousness, salivation, muscle tremor, incoordination, hyperaesthesia, polyuria, anuria, polydipsea, defecation, piloerection, changes in locomotor activity, changes in posture, ataxia and loss of reflexes) were observed. Three month treatment with the decoction also did not produce any changes in average feed consumption, average body weight: liver weight ratios, or the general behaviour of the animals.
The Oral hypoglacaemic activity of Ipomea aquatica
(Elsevier, 2000) Malalavidhane, T.S.; Wickremasinghe, S.M.D.N.; Jansz, E.R.
Ipomoea aquatica is a commonly consumed green leafy vegetable in Sri Lanka which is supposed to possess an insulin-like activity [Jayaweera, D.M.A., 1982. Medicinal Plants (Indigenous and Exotic) Used in Ceylon. Part 11. National Science Council, Colombo, Sri Lanka, pp. 99]. Only a little attention has been paid to the therapeutic use of this plant. We studied the oral hypoglycaemic activity of single and multiple doses of I. aquatica in healthy, male Wistar rats after a glucose challenge. There was a significant reduction in the serum glucose concentrations with both single (33%, P<0.0027) and multiple (25%, P<0.02) doses. The optimum dose was 3.4 g/kg while the optimum activity was given 2 h after the administration of the extract. The present study indicates that a boiled, whole extract of I. aquatica exerts an oral hypoglycaemic effect in healthy, male, Wistar rats after a glucose challenge.
Oral hypoglygaemic activity of Ipomea aquatica in streptozotocin induced diabetic wistar rats and type II diabetics
(Wiley, 2003) Malalavidhane, T.S.; Wickremasinghe, S.M.D.N.; Perera, M.S.A.; Jansz, E.R.
Ipomoea aquatica Forsk is a common green leafy vegetable consumed in many parts of the world. The present study was designed to investigate theoral hypoglycaemic activity of Ipomea aquatica in streptozotocin induced diabetic Wistar rats, and Type II diabetic patients. Experimental diabetes was induced with streptozotocin in Wistar rats. The rats were then divided into test and control groups. In addition to the standard feed given to both groups the test was fed with the shredded leaves of Ipomoea aquatica (3.4 g/kg) for one week. Type II diabetic patients were subjected to a glucose challenge before and after a single dose of blended I. aquatica. Patients acted as their own controls. The results revealed that consumption of the shredded, fresh, edible portion of I. aquatica for one week, effectively reduced the fasting blood sugar level of streptozotocin-induced diabetic rats (p = 0.01). When subjected to a glucose challenge, the Type II diabetic subjects showed a significant reduction (p = 0.001) in the serum glucose concentration 2 h after the glucose load. However, it was not significantly reduced at 1 h (p < 0.09) post glucose load. There was a 29.4% decrease in the serum glucose concentration of the diabetic patients when treated with the plant extract.
Possible toxicity of a medicinal plant, "Asteracantha longifolia"
(University of Colombo, 2000) Fernando, R.M.; Wickremasinghe, S.M.D.N.; Thabrew, M.I.;
Asteracantha longifolia is a medicinal plant that is extensively used for the treatment of diabetes mellitus in Sri Lanka. Experiments were carried out to evaluate any possible toxicological effects mediated by the long-term administration of an aqueous extract of this plant. Investigations with Asteracantha longifolia showed that the aqueous extracts of this plant had no adverse effects on the histology of liver, heart, lung, kidney, intestine and pancreas, on liver function, haematological parameters (haemoglobin concentration, red blood cell count, white blood cell count and packed cell volume) or on the reproductive ability of rats.
Protection against diethylnitrosamine induced hepatocarcinogenecity by an indigenous herbal remedy comprised of Nigella sativa, Hemidesmus indicus and Simlax glabra: a preliminary study
(Medknow Publications, 2003) Iddamaldeniya, S.S.; Wickremasinghe, S.M.D.N.; Thabrew, M.I.; Ranatunge, N.; Tammitiyagodage, M.G.
BBACKGROUND: A decoction comprised of Nigella sativa seeds, Hemidesmus indicus root and Smilax glabra rhizome is used to treat cancer patients in Sri Lanka. However, the anti-carcinogenic properties of this decoction have not been experimentally confirmed. The purpose of this study was to determine whether the above decoction could protect against chemically induce hepatocarcinogenesis. METHODS: The effects of this decoction on diethylnitrosamine (DEN) induced hepatocarcinogenesis were examined in male Wistar rats using the medium term bioassay system of Ito, based on a 2-step model of hepatocarcinogenesis. Rats were randomly divided into 6 groups of 10 each. Groups 1 to 4 were injected with DEN (200 mg/kg) to initiate carcinogenesis. Twenty-four hours later groups 1 and 2 were administered the decoction at 4 g/kg body weight/day (dose 1) and 6 g/kg body weight/day (dose 2), respectively. Group 3 and group 4 were given distilled water instead of the decoction and a suspension of garlic powder (20 g/kg body weight/day) in distilled water (positive control), respectively. Group 5 and 6 were injected with normal saline and twenty-four hours later group 5 was given distilled water (normal control) while group 6 was given decoction dose 2 (decoction control). Oral feeding continued for two weeks after which all rats were subjected to 2/3 partial hepatectomy to promote carcinogenesis. Oral feeding continued for eight more weeks. At the end of the 10th week, rats were sacrificed and samples of livers taken for immunohistochemical studies. Carcinogenic potential was scored by comparing the number, area and staining intensity of glutathione S-transferase placental form (GST-P) positive foci and the number of cells/cm2 of the positive foci in the livers of the six groups of rats. RESULTS: The number and area of DEN-mediated GST-P positive foci, number of cells/cm2 of foci and staining intensity of the foci were significantly (P > 0.001) reduced by the decoction and garlic in the order dose 2 = garlic >dose 1. CONCLUSION: Overall results indicate that the decoction comprised of N. sativa, S. glabra and H. indicus has the potential to protect rat liver against DEN induced hepatocarcinogenesiss