Immunostimulant activity of standardised extracts of Mangifera indica leaf and Curcuma domestica rhizome in mice

Purpose: To investigate the immunomodulating activity of Mangifera indica. (MI) and Curcuma domestica (CD) extracts in mice. Methods: Mice were randomly divided into 4 groups, namely, vehicle, untreated, MI and CD groups (n = 6). They were treated with MI (160 mg/kg) or CD (200 mg/kg) extracts, and vehicle for control group, for 14 days and sacrificed on day 15. In innate immunity test, the mice were challenged with sheep red blood cells (SRBCs) antigen on day 8, while in adaptive immunity test, mice were immunized and challenged on days 7 and 14, respectively, with SRBC. White blood cells count (WBC), spleen index (SI), and haemagglutination (HA) titer, and delayed type hypersensitivity (DTH) responses were determined. Results: For both plant extracts, adaptive immunity groups showed the highest response compared to innate groups. In adaptive immunity, the WBC count of MI and CD treated animals was significantly higher than in the untreated and vehicle treated groups (p < 0.001). Moreover, the SI of mice from MI and CD treated groups differed significantly that of the untreated group (p < 0.01 and p < 0.05, respectively). HA titer in CD (both non-challenged and challenged) groups was significantly higher than in the non-challenged vehicle group (p < 0.001). HA titer in MI group (non-challenged) was significantly lower than in non-challenged CD and challenged groups (p < 0.01 and p < 0.001, respectively). Conclusion: MI and CD extracts, in appropriate doses, exerted immunostimulant effects in mice by enhancing both innate and adaptive immune systems via increase in WBC, SI, HA titer and DTH responses.