Immunomodulatory activity of methanolic extract of Morus alba Linn. (mulberry) leaves.

The leaves of Morus alba Linn. (Family: Moraceae) commonly known as mulberry are mainly used as food for the silkworms and they are sometimes eaten as vegetable or used as cattle fodder in different parts of the world. The effect of Morus alba on the immune system was evaluated by using different experimental models such as carbon clearance test, cyclophosphamide induced neutropenia, neutrophil adhesion test, effect on serum immunoglobulins, mice lethality test and indirect haemagglutination test. Methanolic extract of Morus alba was administered orally at low dose and high dose of 100 mg/kg and 1 g/kg respectively and Ocimum sanctum (100 mg/kg, po) was used as standard drug. Morus alba extract in both doses increased the levels of serum immunoglobulins and prevented the mortality induced by bovine Pasteurella multocida in mice. It also increased the circulating antibody titre in indirect haemagglutination test. On the other hand, it showed significant increase in the phagocytic index in carbon clearance assay, a significant protection against cyclophosphamide induced neutropenia and increased the adhesion of neutrophils in the neutrophil adhesion test. Hence, it was concluded that Morus alba increases both humoral immunity and cell mediated immunity.

Effect of central administration of ondansetron, a 5-hydroxytryptamine-3 receptor antagonist on gastric and duodenal ulcers.

The effect of central administration of ondansetron, a 5-hydroxytryptamine-3 (5-HT3) receptor antagonist on gastric secretion and gastric cytoprotection was evaluated using four different models of gastric ulcers and cysteamine induced duodenal ulcer. Ondansetron was administered at two different doses of 20 microg/kg, intracerebroventricular (i.c.v.) and 40 microg/kg, i.c.v. Both doses of ondansetron showed significant increase in healing of acetic acid induced gastric ulcers and reduced the formation of ethanol-induced and pylorus ligation-induced gastric ulcers and cysteamine-induced duodenal ulcer. High dose of ondansetron (40 microg/kg, i.c.v.) was more effective compared with the low dose (20 microg/kg, i.c.v.). However, both doses of ondansetron did not influence the development of cold restraint stress induced gastric ulcers. It was concluded that blocking of 5-HT3 receptors in brain decreases gastric acid secretion and increases gastric mucus secretion.