ABSTRACT
To study the immunomodulatory activity of saline extracts of leaves of Aloe vera Linn. (Family: Liliaceae) on the albino mice. The saline extract of leaves of Aloe vera was administered orally according to their body weight in mice. The assessment of immunomodulatory activity on specific and nonspecific immunity was studied by administration of test extract. The method of pyrogallol induced immunosupression was employed with slight modification to study the immunomodulatory potential of the extract. Humoral antibody response to SRBC measurement of antibody titer by haemagglutination reaction was done and cellular immune response (Foot pad reaction test) the edema was induced in the right paw of mice by injecting SRBC (0.025x109 cells) in the sub planar region. Pyrogallol-induced suppression of humoral as well as cell mediated immune response was significantly attenuated by daily oral treatment with saline extract of Aloe vera. Vitamin E treated group exhibited similar attenuation of the suppression in immune responses. Aloe vera extract at the dose of 100 mg/kg was found to suppress delayed type hypersensitivity reaction induced by SRBCs in mice. As evidenced by marked increase in haemagglutination titers in mice was also observed. The study demonstrates that A. vera triggers both specific and non-specific responses to a greater extent. The study comprised the acute toxicity and preliminary phytochemical screening of A. vera. From the results obtained and phytochemical studies the immunostimulant effect of Aloe vera could be attributed to the alkaloids content.