In vitro cytotoxicity and biological activities of Genipa americana (Rubiaceae) ethanolic extracts

This study aimed to determine the in vitro toxicity of Genipa americana and its antiviral and anti-microbial activities. Due to lack of knowledge on G. americana validation as medicinal plant, biological studies were performed. For the cytotoxicity experiments, decreasing concentrations of ethanolic extracts of G. americana branches, fruits, and leaves were added to a confluent monolayer of Vero cells. After 72 h, it was determined, the first concentration of each extract in which any cellular change was observed (maximum non-cytotoxic concentration- MNCC). The MNCC of fruit and branches extracts was of 0.5 and 0.25 mg/mL, respectively. The leaves extract did not show cytotoxicity in the tested dilutions. The antiviral activities of G. americana extracts were tested on the suid (SuHV-1) and equine (EHV-1) alpha herpes viruses through reduction of their viral titers. The fruit extract presented a viral inhibition on EHV-1 of 86%, but it was not effective for SuHV-1. Instead, the leaves and branch extracts showed antiviral activity against SuHV-1, with a viral inhibition of 73 and 79%, respectively, but no inhibition on EHV-1. The antimicrobial action on Escherichia coli and Staphylococcus aureus was performed by the agar diffusion and the microdilution methods; and by agar diffusion method against Candida albicans, Candida parapsilosis, Candida glabrata and Candida krusey. The fruits extract showed inhibition of bacterial growth for E. coli and S. aureus with a bacteriostatic effect on E. coli and a bactericidal effect on S. aureus. There was no effect on any Candida species. Ethanolic extract of G. americana fruits seemed to be a promising source of phytotherapic drugs with a spectrum of action on diverse microorganisms in non-toxic concentrations. Key words: Alphaherpes virus, medicinal plant, antimicrobial, antiviral, cell line, broad spectrum.