Stimulation of humoral and cell-mediated immunities in healthy and cyclophosphamide-induced immunosuppressed rats by the lyophilized Houttuynia cordata fermented drink

Houttuynia cordata fermented drinks (HCFDs) are dietary liquid supplements widely marketed and consumed for immune enhancement. In this study, the acute oral toxicity and immunostimulatory activity of the selected lyophilized HCFD in healthy and cyclophosphamide-induced immunosuppressed rats were evaluated. The lyophilized selected commercialized HCFD was safe in animal model as there was no acute oral toxic death at up to 2000 mg/kg in male Wistar rats. After 14 days of treatment, in immunosuppressed rats, lyophilized HCFD enhanced rat body weight gain and significantly increased spleen index at a dose of 100 mg/kg. Moreover, B-cell proliferation and anti-sheep red blood cell antibody production were significantly increased at doses of 100 and 200 mg/kg, respectively. The delayed-type hypersensitivity response was significantly stimulated at a dose of 200 mg/kg. These findings exhibited the immunostimulatory activity of the lyophilized HCFD by enhancing the immune responses in both humoral and cell-mediated immunities in immunosuppressed rats.