Effects of Hypericum perforatum extract on IgG titer, leukocytes subset and spleen index in rats

Objectives: Hypericum perforatum L. is a medicinal plant containing many polyphenolic compounds, ‎including flavonoids and phenolic acids with antidepressant and anti-inflammatory properties. ‎This study was investigated the effects of Hypericum perforatum extract (HPE) on immunity, ‎body weight (BW), and spleen index (SI) in rats.‎ Materials and Methods: A total of 24 Wistar male rats were randomly received 4 different doses (6 rats each) of HPE ‎‎(0, 100, 200 and 400 mg/kg BW) intraperitoneally for 14 days using a completely ‎randomized design. On days 1 and 7, rats were received 0.5 ml SRBC (10%) injection. Blood ‎samples were collected on day 14 to evaluate IgG titer and leukocyte count. On days 1, 7 and ‎‎14, the BW and on day 14 spleen were weighted for SI. ‎ Results: The IgG titer increased with higher doses of HPE. The HPE increased number of ‎lymphocytes at 200 mg but decreased at 400 mg, number of neutrophils decreased at 200 mg ‎but increased at 400 mg, and number of monocytes increased at 100 mg and 200 mg but ‎decreased at 400 mg (p<0.01). Increasing doses of HPE lowered BW (p<0.01). ‎The HPE increased SI at 100 mg and 200 mg but decreased at 400 mg (p>0.072). ‎ Conclusions: The results showed that HPE slightly improved IgG titer but significantly increased ‎the number of leukocytes and monocytes at 200 mg, and neutrophils at 400 mg. The HPE ‎decreased BW at 100 mg and 200 mg with no damage on spleen. ‎