Isolation and characterisation of the potential immunomodulatory principles from Astragalus membranaceus

This thesis describes an in-vivo evaluation of ethanolic extracts of Astragalus membranaceus and fractions derived from this extract administered either orally by gavage or by intraperitoneal injection to Balb/c mice. Total antibody titre was used as an indicator of humoral immune response. Cell mediated immune response was determined using Interferon-γ and Interleukin-12 as indicators. Additionally, mice were vaccinated with a killed Salmonella typhimurium vaccine, previously demonstrated to induce humoral response but not cell mediated immunity, to determine whether the acquired immune response was enhanced or suppressed. Serum was analysed for total antibody titre using an enzyme-linked immunosorbent assay. Serum and splenocyte culture supernatants were analysed for levels of interferon-γ and interleukin-12. No statistically significant differences were observed between groups either orally gavaged or intraperitoneally injected with extracts of Astragalus membranaceus, or orally gavaged with fractions derived from this extract when compared with the control groups.