Anti-Rotaviral Effects of Calliandra haematocephala Leaf Extracts In-vitro and In-vivo

Abstract

Objectives This study was designed to determine the antiviral activity of different extracts from Calliandra haematocephala leaves against rotavirus (RV) infection in-vitro. Then, based on the in-vitro results, selection of the most effective extract to be evaluated for its in-vivo anti-RV activities. Materials and Methods Methanol, chloroform, ethyl acetate, n-butanol, and aqueous extracts from the leaves of Calliandra haematocephala were screened for their cytotoxic effect on MA-104 cell lines by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazoliumbromide (MTT) colorimetric assay. The in-vitro antirotavirus activities were determined by MTT and TCID50/0.1 ml assays in three different ways (virucidal, pre-treatment, and post-treatment) in order to understand the mode of antiviral action. In-vivo, different concentrations (100, 200, 300, and 400 mg/kg body weight) of the selected extract were used to determine the cytotoxicity of the extract in mice then by using two safe doses the anti-RV activities was performed by assessing the mortality, severity and duration of diarrhea, virus titers, and lesions scores of the small intestine in BALB/c mice infected with RV. Results: Our in-vitro results demonstrated that all extracts of C. haematocephala at non cytotoxic concentrations exhibited anti-RV activities at different magnitude of potency with therapeutic index ranged from 1.3 to 32 and reduction in virus titer ranged from 0.25 log10 TCID50 to 5.75 log10 TCID50 where the methanol extract was the strongest against RV infection than the other extracts. In-vivo, oral administration of the methanol extract at 50 mg and 100 mg/kg/day significantly reduced mortality, virus titers, duration and severity of diarrhea, as well as the lesion of the small intestine was alleviated in RVinfected mice treated with methanol extract, compared with those infected mice without the treatment. Conclusions: Collectively, our findings suggest that the methanol, chloroform, ethyl acetate, butanol, and aqueous extracts of C. haematocephala leaves have antiviral activity against RV infection in-vitro. Furthermore, the methanol extract cured the rotavirus enteritis in the treated mice by coordinating.