Comparative Metabolite Profiling of Betula pendula Roth and Betula pubescens Ehrh. Leaf Extracts Reveals Antioxidant and Hepatoprotective Potential.

The present study compares the polyphenolic composition, as well as the antioxidant and hepatoprotective potential of extracts obtained from the leaves of Betula pendula Roth and Betula pubescens Ehrh. The extracts were prepared using 90% v/v ethanol and the phytochemical contents were assessed using spectrophotometric assays, while independent metabolites were identified and quantified using an LC/MS/ESI method. The antioxidant potential was evaluated by the DPPH radical and FRAP scavenging assays. Cytotoxicity was evaluated using human LX-2 hepatic stellate cells and HepG2 hepatocellular carcinoma cells. Cell viability assays were performed to determine the potential cytotoxic effects of the two extracts on cellular viability and overall metabolic activity. In vivo, hepatoprotective potential was assessed in a CCl4-induced model of hepatotoxicity. Results revealed the presence of flavonoids and polyphenolic compounds in the leaves of both species, with a more significant potential for the B. pendula leaf extracts. The cell viability assays showed that both extracts maintained high cell viability in LX-2 cells, whereas B. pubescens induced a more pronounced reduction in HepG2 cell viability than B. pendula under the tested experimental conditions. In vivo, CCl4 increased ALT activity to 193.0 ± 8.5 U/L, whereas B. pendula and B. pubescens at 200 mg/kg reduced ALT to 30.4 ± 6.6 and 117.4 ± 24.3 U/L, respectively. CCl4 also increased hepatic MDA levels from 202.7 ± 31.8 to 717.1 ± 31.6, which were reduced to 430.7 ± 100.5 and 448.7 ± 65.8 following treatment with B. pendula and B. pubescens at 200 mg/kg, respectively.