In vitro antiviral activity against rotavirus and astrovirus infection exerted by substances obtained from Achyrocline bogotensis (Kunth) DC. (Compositae).

BACKGROUND: Achyrocline bogotensis has been traditionally used to treat infections of skin, respiratory, tract urinary and other infections, but not to treat viral gastrointestinal disease. In this study, this Colombian native medicinal plant was investigated by its in vitro anti-rotavirus and anti-astrovirus activity. METHODS: Several extracts and fractions phytochemically obtained from A. bogotensis were evaluated initially for their cell toxicity on MA104 and Caco2 cells and then for their anti-rotavirus (RRV) and anti-astrovirus (Yuc8) activity following three strategies: pre-treatment of cells (blocking effect), direct viral activity (virucidal effect) and post-treatment of infected cells (reduction of viral yield post-infection). In addition qualitative chemical studies were developed for the active compounds. RESULTS: Non-toxic concentrations of a fraction obtained exhibited antiviral activity against both viruses characterized by a virucidal effect and by the reduction of the infectious particles produced post-infection. Steroids, sterols, terpenes, phenols, flavonoids and sesquiterpenlactones were identified qualitatively in the active fraction. CONCLUSIONS: A. bogotensis contains substances with in vitro antiviral activity against rotavirus and astrovirus. This study confirms their anti-microbial properties and describes by the first time its antiviral activity in vitro.

Toxicological studies of the aqueous extract from Achyrocline satureioides (Lam.) DC (Marcela).

Achyrocline satureioides (Lam.) DC (Marcela) is known to possess a broad spectrum of pharmacological, medicinal and therapeutic properties. Previous studies have demonstrated various protective abilities of the marcela extracts against various pathological conditions. However, no extensive safety studies have been conducted on these extracts to date. In this paper, we evaluated the acute toxicity (dose levels of 30-300 mg/kg) of an aqueous extract of marcela, administered intraperitoneally and orally in mice and rats. The acute oral maximun tolerable dose in repeated administration during 4 h (1, 3 until 5 g/kg) was also studied in rats. The extract had low acute toxicity when administered intraperitoneally and no toxicity upon oral administration. The LD(50) of aqueous extracts of marcela was found to be greater than 5 g/kg when administered once via gastric intubation to rats. Weight gain, toxicity signs, enzymatic studies (transaminases and phosphatases) and histological evaluation of several organs indicated that the extract was devoid of acute toxicity. These acute studies demonstrated that an aqueous extract of marcela obtained after a 2% infusion is safe and did not cause any detrimental effects in vivo under the conditions investigated in this study.