The goal of the current study was to assess the effects of saline irrigation on the secondary metabolites and essential oil contents of three significant aromatic and medicinal plants, Pelargonium graveolens L., Mentha longifolia L., and Chrysanthemum frutescens L., using different NaCl levels (0, 50, 75, and 100 mM). Our results indicated that the levels of total phenols, flavonoids, tannins, saponins, and alkaloids in the methanolic extracts increased in response to salinity in the three investigated plants. The GC-MS analysis of the essential oils (EOs) showed that some major compounds increased significantly at the high salinity levels (75 and 100 mM NaCl). The EOs anticancer activity of the three plants against the human hepatocellular carcinoma cell line (HepG2) and human colorectal carcinoma (HCT-116) revealed that the P. graveolens L. EO exhibited the most potent cytotoxic effect with IC 50 values of 0.66 and 1.87 µg/ml, at 50 mM NaCl, respectively. The treated M. longifolia L. EOs showed the most potent cytotoxic effect against HepG2 and HCT-116 at 75 mM NaCl with IC 50 values of 2.32 and 7.47 µg/ml, respectively. Otherwise, M. longifolia L. crude extracts and EOs exhibited the highest DPPH free radical scavenging activity.
Samy et al. (Fri,) studied this question.