Background: Centaurea americana, Krameria ramosissima, Juglans mollis and Turnera diffusa are used by traditional healers in the northeastern region of Mexico to protect against liver damage. However, the hepatoprotective properties of these plants have not been investigated scientifically. This study reports on the protective effects of these plants using an in vitro assay.
Material and methods: Extracts of plants were tested for antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method. The effects of extracts from these plants on a human hepatoma cell line (Huh7) were evaluated according to cell viability and aspartate aminotransferase and malondialdehyde levels before and after exposure of the cells to carbon tetrachloride (CCl(4)).
Results: All extracts reduced DPPH levels by more than 50%. C. americana flower and stem/leaf extracts, the aerial part of T. diffusa, and the nut, leaf and bark of J. mollis extracts were used to assess hepatoprotective activity. The extract of the aerial part of K. ramosissima was toxic. Pretreatment of Huh7 cells with extracts from the flower of C. americana (FCA), the stem/leaf fraction of C. americana (S/LCA), the leaf of J. mollis (LJM) and the bark of J. mollis (BJM) prior to the CCl(4) challenge, protected against CCl(4)-induced liver damage, as evidenced by a significant decrease in the activity of the medium enzyme. The FCA, S/LCA, LJM and BJM extracts showed significant antilipid peroxidant effects in vitro. In conclusion, the hepatoprotective effects of the FCA, S/LCA, LJM and BJM extracts observed in this study may result from their antioxidative properties.