MVSc

The immunomodulatory activity of acetone soluble and acetone insoluble fractions of ethanolic extract of Emblica officinalis was investigated in the present study. The extracts were also qualitatively tested for the presence of various active principles. One hundred and forty four male swiss albino mice were used to assess humoral and cellular immunity by feeding the extracts at dose level of 200 mg per kg body weight for 19 days. Few animals were also administered with dexamethasone at the dose rate of 0.75 mg per kg body weight intra peritoneally for seven days before the start of the experiment to suppress the immune system and thereby to study the effect of extracts on immunosuppressed animals also. The control group received vehicle alone (five percent gum acacia).

Various physiological, haematological, biochemical, enzymatic and immunological parameters like body weight, relative organ weight, total leukocyte count, differential leukocyte count, total serum, protein, serum globulin, albumin-globulin ratio, quantification of superoxide dismutase and catalase, haemagglutination test, Jerene’s plaque forming assay to assess the humoral immune response and tests like delayed type of hypersensitivity, macrophage migration index, nitroblue tetrazolium reduction test to assess the cellular immune response were performed.

Both the fractions increased the body weight, spleen weight and liver weight in normal as well as in immunosuppressed animals. A significantly increased total WBC counts on days 5, 12 and 19 and the distribution of lymphocytes on days 12 and 19 were seen in normal animals. In immunosuppressed animals, non-significant increase in both total leukocyte counts and distribution of lymphocytes from day zero to nineteen was seen.

Total serum protein as well as serum globulin concentration was significantly increased and albumin globulin ratio was significantly decreased in immunocompetent animals treated with both the fractions on 12th and 19th day. However, both the fractions showed only a non-significant increase in total serum protein and serum globulin in normal as well as in immunosuppressed animals, from zero day to 19th day. Significant increase was noticed in superoxide dismutase and catalase level in immunocompetent animals treated with both the fractions on 19th day.
A significant stimulation of humoral immune response as indicated by an increase in antibody titre and number of antibody producing cells on both 12th and 19th day of acetone soluble and acetone insoluble fraction treated immunocompetent animals was noted. Immunosuppressed animals also showed a non-significant increase in both antibody titre and number of antibody producing cells through out the experiment.
The bone marrow cellularity and foot pad swelling reaction showed a significant stimulation in immunocompetent animals on 12th and 19th day. In immunosuppressed animals also, foot pad swelling response showed a significant increase on 19th day but bone marrow cellularity was not significant.
In immunocompetent animals the acetone soluble and acetone insoluble fractions showed a significant increase in macrophage migration index (MMI) and Nitro blue Tetrazolium (NBT) dye reduction test value on 12th and 19th day. However, in immunosuppressed animals both the fractions showed only a non-significant increase.
The phytochemical study on both the fractions of ethanolic extract of dried Emblica officinalis fruit pulp revealed that diterpenes and triterpenes were present in acetone soluble fraction and tannins, phenolic compounds, flavonoids, glycosides, and saponins were present in acetone insoluble fraction. Thus the present study showed the higher immunostimulant activity for acetone soluble fractions in immunocompetent as well as immunosuppressed animals.