In vivo toxicity study of Erythroxylum cuneatum leaves extract and its effects on working memory of rats

Erythroxylum cuneatum has been traditionally proven to possess beneficial properties in treating drug addiction and other illness. Due to less information on this plant, this elusive plant was investigated further to evaluate the in vivo toxicity profile of the plant and to investigate the effect of E. cuneatum on cognitive performance in rats. Two different extracts were produced from the leaves of E. cuneatum which were aqueous and alkaloid extracts. Acute in vivo toxicity test was evaluated in ICR mice to determine their medium lethal dose 50 value. In the in-vivo toxicity study, aqueous extract showed the almost similar toxic effect as alkaloid extract which was 416.86 mg/kg for alkaloid extract and 316.23 mg/kg for aqueous extract. These findings suggesting that aqueous and alkaloid extracts showed toxic effects at the high dose, thus safe at a low dose. Working memory task using novel object discrimination test (NOD) was performed for the determination of neurobehavioral profiles. In the NOD test, alkaloid-treated rats did not show any significant discrimination between the familiar and novel object (P > 0.05); thus it can be interpreted as not induce a memory defi cit. It can also be postulated that the extract has no effect on memory and learning neither improvises nor impairs the cognitive function. In conclusion, since E. cuneatum does not show any impairment on cognitive, its pharmacological properties could be further investigated without significant changes in cognitive performance

Methanol extract of Melastoma malabathricum leaves exerted antioxidant and liver protective activity in rats

Background Melastoma malabathricum L. (Melastomaceae) is a small shrub with various medicinal uses. The present study was carried out to determine the hepatoprotective activity of methanol extract of M. malabathricum leaves (MEMM) against the paracetamol-induced liver toxicity in rats model. Methods The respective chemicals and herbal solutions (10% DMSO, 200 mg/kg silymarin or MEMM (50, 250 and 500 mg/kg)) were administered orally to rats once everyday for 7 days followed by the hepatotoxicity assay. The blood samples and livers were collected and subjected to biochemical and microscopical analysis. Prior to the hepatoprotective study, MEMM was subjected to determination of the total phenolic content (TPC) and the antioxidant properties using several standard assays (e.g. 2, 2-diphenyl-1-picrylhydrazyl- and superoxide anion- radical scavenging assay, and oxygen radical absorbance capacity assay). Results MEMM exerted significant (p < 0.05) and high antioxidant activity in which high TPC was recorded; while in the hepatotoxicity study, the extract exhibited significant hepatoprotective effects against the paracetamol-induced hepatotoxic model. The results observed for serum liver enzymes (ALT, ALP and AST) as well as the microscopic observations and microscopic scoring supported the hepatoprotective potential of MEMM. The phytochemical and HPLC analysis of MEMM demonstrated the presence of flavonoids as its major constituents. Conclusions The MEMM-induced hepatoprotective activity could be allied partly to its antioxidant activity and the presence of flavonoids