Effects of the extract of Spirostachys venenifera Pax on the immune response in mice.
The effect of the methanol extract of bark of S. venenifera on the immune response was investigated in mice. Keyhole limpet haemocyanin was used as the antigen. ELISA was used to monitor serum antibody levels in mice exposed to S. venenifera (0-100 µg/ml). In vivo, S. venenifera suppressed the immune response compared with control mice. A haemolytic plaque assay was used to monitor the effect of S. venenifera on antibody producing B lymphocytes from the peritoneum and from the spleen in vitro. In peritoneal B cells, S. venenifera (0.1 µg/ml) reduced the number of plaque forming cells. In spleen B cells, the number of plaque forming cells was reduced at higher doses of S. venenifera (1-100 µg/ml).