Effect of Bacopa monniera Linn. extract on murine immune response in vitro

The study was to investigate and compare the effects of the Bacopa monniera Linn. extract and bacoside A on the ICR mice immune system in vitro. Splenocyte proliferation without or with mitogen (lipopolysaccharide, pokeweed mitogen, phytohaemagglutinin and concanavalin A) and phagocytic activity were assayed. The results showed that B. monniera extract at 0.001-1 mg/mL slightly suppressed splenocyte proliferation (SI 0.7) and decreased T-lymphocyte proliferation (SI 0.4) at 0.001 and 0.1 mg/mL with concanavalin A. Bacoside A at 0.001 mg/mL gave the highest splenocyte proliferation (SI 1.5) and strongly increased T-lymphocyte proliferation (SI 2.0) at 0.1 mg/mL with concanavalin A. Thus, it is possible to attribute the effect of B. monniera extract on splenocyte proliferation to the presence of bacoside A with other combined components. However, only B. monniera extract at 10 mg/mL produced a slight increase in lysosomal enzyme activity (PI 1.2), indicating a weak effect on phagocytic activation. It might be concluded that B. monniera manifests various effects on the murine immune system depending on the immune cell types, in accordance with its folklore uses. New assays are being carried out to study its mechanisms and to further investigate its applications in the treatment of human immune mediated diseases.