Cytotoxic Activities of Different Iranian Solanaceae and Lamiaceae Plants and Bioassay-Guided Study of an Active Extract from Salvia lachnocalyx

Abstract

Methanol (MeOH), dichloromethane (DCM) and 80% MeOH extractions of fourteen medicinal plants of the families Solanaceae and Lamiaceae collected from different area of Iran were tested for their cytotoxic potential against MOLT-4 human cancer cell lines. Cytotoxicity of the tested plants indicated that 11 plants had one or two active extracts (IC₅₀≤50): MeOH extracts of the shoots of Thymus trautvetteri, Solanum luteum and stems of Lycium shawii; DCM extracts of the shoots of Thymus kotschyanus, Salvia persepolitana, Ballota aucheri, Nepeta glomerulosa, Hyoscyamus tenuicaulis, Salvia lachnocalyx, Salvia sharifii as well as the stems of Salvia verticillata and the roots of Salvia multicaulis and S. lachnocalyx; 80% MeOH extracts of the shoots of T. trautvetteri, S. luteum and the stems of L. shawii. The DCM extract of the aerial parts of S. lachnocalyx as one of the most active species was subjected to the cytotoxic bioassay-guided fractionation and purification using combination of chromatography methods. The bioassay-guided fractionation of DCM extract of the shoots of S. lachnocalyx led to the isolation of two cytotoxic compounds: (2Z,6Z,10Z,14E)-geranylfarnesol (1), a novel natural product, and spathulenol (2). Both of the isolated compounds, especially 1 (IC₅₀ range: 9.6 −20.2 μg/mL), showed good cytotoxic effects against 3 human cancer cell lines, MOLT-4, MCF-7 and HT-29.