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This study was conducted to investigate the protective effect of Asteracantha longifolia Linn (Acanthaceae) plant extract on carbon tetrachloride (CCl4)- and paracetamol-induced acute hepatotoxicity in mice. Hepatotoxicity was induced by the administration of a single intraperitoneal dose of CCl4 (0.5 mL kg(-1) CCl4 in olive oil) in one model and in the other by administration of paracetamol (300 mg kg(-1) in saline) orally, after a 16-h fast. An aqueous extract of the whole plant (0.9 g kg(-1)) was used on a pre- and post-treatment basis. Asteracantha reduced the alanine aminotransferase (ALT) level by 69.32% (P < 0.001) and increased the liver reduced glutathione level by 64.65% (P < 0.001) in the pre-treated group, 4 days after the administration of CCl4. A similar pattern was observed in the pre-treated group 4 h after the administration of paracetamol with a reduction in serum levels of ALT, aspartate aminotransferase and alkaline phosphatase enzymes by 65.04, 55.79 and 45.75% respectively (P < 0.001). Plant extract also increased the glutathione concentration of the liver significantly (P < 0.001). Histopathological studies also provided supportive evidence for results from the biochemical analysis with marked improvement in liver architecture being observed in the Asteracantha-treated groups. Pre-treatment showed better results than post-treatment in both hepatotoxic models. Overall results indicate that the aqueous extract of Asteracantha longifolia possesses hepatoprotective effects on CCl4- and paracetamol-induced hepatotoxicity in mice.

Background:Diabetes mellitus, for a long time, has been treated with plant derived medicines in Sri Lanka.Aim:The aim of this study is to determine the efficacy and dose response of oral antihyperglycaemic activity of eight Sri Lankan medicinal plant extracts, which are used to treat diabetes in traditional medicine in diabetic rats.Materials and Methods:Medicinal plants selected for the study on the basis of documented effectiveness and wide use among traditional Ayurveda physicians in the Southern region of Sri Lanka for the treatment of diabetes mellitus. The effect of different doses of aqueous stem bark extracts of Spondias pinnata (Anacardiaceae), Kokoona zeylanica (Celastraceae), Syzygium caryophyllatum (Myrtaceae), Gmelina arborea (Verbenaceae), aerial part extracts of Scoparia dulcis (Scrophulariaceae), Sida alnifolia (Malvaceae), leaf extract of Coccinia grandis (Cucurbitaceae) and root extract of Languas galanga (Zingiberaceae) on oral glucose tolerance test was evaluated. A single dose of 0.25, 0.50, 0.75, 1.00, 1.25, 2.00 g/kg of plant extract was administered orally to alloxan induced (150 mg/kg, ip) diabetic Wistar rats (n = 6). Glibenclamide (0.50 mg/kg) was used as the standard drug. The acute effect was evaluated over a 4 h period using area under the oral glucose tolerance curve.Statistical Analysis:The results were evaluated by analysis of variance followed by Dunnett's test.Results:The eight plant extracts showed statistically significant dose dependent improvement on glucose tolerance (P < 0.05). The optimum effective dose on glucose tolerance for six extracts was found to be 1.00 g/kg in diabetic rats with the exception of C. grandis: 0.75 g/kg and L. galanga: 1.25 g/kg.Conclusion:The aqueous extract of G. arborea, S. pinnata, K. zeylanica, S. caryophyllatum, S. dulcis, S. alnifolia, L. galanga and C. grandis possess potent acute antihyperglycaemic activity in alloxan induced diabetic rats.

Dose-dependent cardiotoxicity of doxorubicin may lead to irreversible congestive heart failure. Although multiple mechanisms are involved, generation of free radicals is the most commonly postulated mechanism. erefore, free radical scavengers are considered as potential therapeutic agents. As Murraya koenigii leaves are a rich source of flavonoids and phenols, they have the ability to scavenge free radicals effectively. erefore, the objective of this study was to investigate the cardioprotective potential of Murraya leaf extract against doxorubicin-induced cardiotoxicity in rats. Rats were randomly divided into five groups with 10 animals in each group. Doxorubicin was administered intraperitonially at 18 mg/kg while lyophilized plant extract was administered orally at 2 g/kg. Dexrazoxane, at 180 mg/kg, was used as the positive control. Cardiac damage of doxorubicin control was evident with a significant increase (p < 0.05) in cardiac troponin I, NT-pro BNP, AST, and LDH compared to the normal control. Plant-treated group showed cardioprotective effect by significantly reducing (p < 0.05) all of the above parameters compared to doxorubicin control (p < 0.05). Increased oxidative stress in doxorubicin control was evident with a significant reduction in reduced glutathione, glutathione reductase, glutathione peroxidase, total antioxidant capacity, superoxide dismutase, and catalase activity and a significant increase in lipid peroxidation compared to the control. Interestingly, treatment with Murraya leaf extract showed a significant increase in all of the above antioxidant parameters and a significant reduction in lipid peroxidation by showing an antioxidant effect. A significant increase in myeloperoxidase activity confirmed the increased inflammatory activity in doxorubicin control group whereas plant-treated group showed a significant reduction (p < 0.05) which expressed the anti-inflammatory effect of Murraya leaf extract. Doxorubicin-treated group showed histological evidence of extensive damage to the myocardium while plant-treated group showed a preserved myocardium with lesser degree of damage. Pretreatment with Murraya leaf extract may replenish cardiomyocytes with antioxidants and promote the defense against doxorubicin-induced cardiotoxicity.

Gmelina arborea Roxb. (common name: Et-demata, Family: Verbenaceae) has been used traditionally in Sri Lanka as a remedy against diabetes mellitus. The objective of the present study was to evaluate antidiabetic mechanisms of the aqueous bark extract of G. arborea in streptozotocin induced (STZ) diabetic male Wistar rats. Aqueous bark extract of G. arborea (1.00 g/kg) and glibenclamide as the standard drug (0.50 mg/kg) were administered orally using a gavage to STZ diabetic rats (65 mg/kg, ip) for 30 days. The antidiabetic mechanisms of aqueous extract of G. arborea (1.00 g/kg) were determined at the end of the experiment. The fasting blood glucose concentration was significantly lowered and the serum insulin and C-peptide concentrations were increased by 57% and 39% in plant extract treated rats on day 30, respectively (p < 0.05). The histopathology and immunohistochemistry results of the plant extract treated group showed a regenerative effect on β-cells of the pancreas in diabetic rats. In addition, serum lipid parameters were improved in G. arborea extract treated diabetic rats. The results revealed that the aqueous stem bark extract of G. arborea (1.00 g/kg) showed beneficial effects against diabetes mellitus through upregulating the β-cell regeneration and biosynthesis of insulin in diabetic rats.