Some newer marker phytoconstituents in methanolic extract of Moringa oleifera leaves and evaluation of its immunomodulatory and splenocytes proliferation potential in rats

Objectives: The present study was undertaken to unravel the newer marker phytoconstituents in methanolic extract of Moringa oleifera leaves (MOLE) and evaluation of its immunomodulatory and splenocytes proliferation potential in rats. Materials and Methods: Hot methanolic extract of MOLE was subjected to gas chromatography-mass spectrometry (GC-MS) analysis. Immunomodulatory potential was studied in four groups of rats following administration of MOLE at 62.5 and 125 mg/kg for 21 days, followed by immunization with Salmonella typhimurium O antigen and antibody titer determined using indirect enzyme-linked immunosorbent assay kit. Total lymphocytes and T-and B-lymphocytes count were determined in control and after MOLE administration (62.5 and 125 mg/kg) to rats for 42 days. Splenocytes (2 x 10(6) spleen cells/ml) from MOLE treated rats were harvested and stimulated using concanavalin A and optical density (OD) and stimulation index were determined. Splenocytes from healthy control rats were also collected and treated in vitro with different concentrations of MOLE (5, 10, 25, 50, and 100 g/ml) and concanavalin A to determine effect of MOLE on OD and stimulation index. Results: GC-MS analysis revealed presence of 9,12,15-octadecatrienoic acid ethyl ester, 6-octadecenoic acid, cis-vaccenic acid and 2-octyl-cyclopropaneoctanal in MOLE. MOLE at 125 mg/kg increased the antibody titer by 50%. Although there was slight decline in lymphocytes count (total, B-and T-lymphocytes) in MOLE treated rats, percentage of T-lymphocytes was increased nonsignificantly. Ex vivo and in vitro studies revealed marked increase in OD and stimulation index indicating MOLE-induced splenocytes proliferation. Conclusion: GC-MS study revealed four new compounds in MOLE apart from promising its immunomodulatory potential based on humoral immune response, percentage increase in T-lymphocytes count, and induction of splenocytes proliferation.