Hepatoprotective activity of Verbena litoralis, Verbena montevidensis and their main iridoid, brasoside

Ethnopharmacological relevance: Verbena montevidensis and Verbena litoralis are plants that present morphological similarities. They are both known as gervao and fel-da-terra, among other popular names, and are used in folk medicine to treat diseases related to the liver and stomach. Aims of the study: The aim of the current investigation was to determine the chemical composition and evaluate the hepatoprotective properties and cytotoxicity of the methanolic and aqueous extracts of V. montevidensis, V. litoralis and their main iridoid in HepG2 cells. Materials and methods: Aqueous and methanolic extracts from the dried aerial parts of V. montevidensis and V. litoralis were obtained. The methanolic extract of V. montevidensis afforded an iridoid as the main compound. The extracts and isolated compound were examined for the hepatoprotective effect and cytotoxicity in human hepatoblastoma HepG2 cells by MIT reduction and neutral red uptake methods. Results: The methanolic and aqueous extracts of both species showed the presence of iridoid and phenylethanoids as the main compounds. The iridoid brasoside was isolated and identified by spectroscopic methods. The phenylethanoid was characterized by HPLC, comparing the UV profile and retention time with an authentic sample. The results of the biological assays indicate that both aqueous and methanolic extracts of V. montevidensis and V. litoralis as well as brasoside were hepatoprotective against ethanol-induced damage in HepG2 cells. The effect can be attributed to the main compounds present since both classes are recognized for this activity. Conclusions: Our results contribute towards validation of the traditional use of V. montevidensis and V. litoralis in the treatment of liver disorders.