Isolation and cytotoxic activity of buchariol from Salvia leriifolia Benth

The search of natural products for cancer therapy represents an area of great interest in which plants have been the most important source. In the continuing search for cytotoxic compounds from plants in the present investigation we reported the cytotoxic activity of sesquiterpenoid 4,10-epoxy-6alpha-hydroxyguaiane, named buchariol, isolated from S. leriifolia Benth. The genus Salvia (Lamiaceae) comprises about 700 herbs and shrubs, growing in the temperate and warmer zones of the world [1]. Plants belonging to this genus show high diversity in their secondary metabolites [2] as well as in pharmacological effects. Salvia leriifolia aerial parts collected in Sabzewar (Iran) were extracted with MeOH at room temperature. The extract was dissolved in H2O and partitioned with n-hexane, dichloromethane, ethyl acetate and n-butanol. Fractionation of dichloromethane extract led the isolation of buchariol (20.06 mg).The cytotoxicity was evaluated using the sulforodamine B (SRB) assay [3]. The test is based on the estimation of cell number indirectly by providing a sensitive index of total cellular protein content which is linear to cell density. Buchariol exhibited a strong cytotoxic activity against COR-l23 and C32 cell lines with IC50 value of 0.5 and 0.6 μg/mL, respectively. Moreover, the sesquiterpenoid buchariol inhibited the proliferation of A549 cell line with an IC50 value of 4.6 μg/mL. References: 1. Chadefaud M et al. Traite de Botanique (Systematique). Masson et Compagnie Editeurs: Paris, (1960); 2. Lu Y et al. Phytochemistry (2002) 59:117; Monks, A. et al. (1991) J. Nat. Cancer Institute, 83:757-66.