The phytochemical composition and in vitro antiviral activity of decoctions from galls of Guiera senegalensis J.F. Gmel. (Combretaceae) and their relative non-toxicity for chickens

Abstract

Aqueous decoctions obtained from the galls of Guiera senegalensis were screened to determine their phytochemical composition and in vitro antiviral activity against fowlpox virus. In addition, we wanted to investigate the toxic effects, if any, of crude extracts in chickens. Steroids as well as cardiac glycosides not previously reported, an alkaloid, polyphenols and saponins were detected in the various fractions of organic solvents used for extracting the decoctions. Antiviral activity was determined by cytopathic effect inhibition assay in primary chicken embryo skin cells. The 50 % inhibitory concentration (EC₅₀) was shown to be 15.6 µg/ml. Toxicity for cells was established by determining the 50 % cytotoxic concentration (CCy₅₀). A value of 90 µg/ml and a selectivity index (CCy₅₀/EC₅₀) of 5.8 were obtained. In vivo studies of toxicity were performed in chickens that were dosed orally with decoctions of several concentrations for 2 weeks and then monitored for 3 months. No significant changes in several blood chemical parameters were obtained, except for a significant decline in SGOT levels in birds dosed with 100 mg/kg. These levels were nevertheless within the accepted normal range. The findings suggest that aqueous decoctions of galls from G. senegalensis are non-toxic for chickens when administered orally, even at a daily dose of 100 mg/kg for 14 days.