Chemical composition of essential and fixed oils of Tagetes erecta fruits (Iran) and their implications in inhibition of cancer signaling.

The current research was conducted to explore, for the first time, Tagetes erecta L. (family Asteraceae) fruits from northwest Iran in terms of the chemical composition of essential and fixed oils, their cytotoxic activities, and the inhibitory effect of essential oil on the PI3K/AKT/mTOR signaling pathway. The volatile oil was obtained through hydrodistillation (Clevenger apparatus). According to gas chromatography-mass spectrometry analysis, the essential oil was rich in cyclic monoterpenoids, 2-isopropyl-5-methyl-3-cyclohexen-1-one (19.99%), D-limonene (12.75%), terpinolene (11.64%) and also the saturated fatty acid palmitic acid (19.09%). Furthermore, the seeds of T. erecta were extracted using hexane by the maceration method. The analysis of fatty acid profile of the fixed oil by gas chromatography-flame ionization detector (GC-FID) demonstrated that the most predominant fatty acids in fixed oil were linoleic acid (59.53%), palmitic acid (13.70%), stearic acid (10.20%), and oleic acid (9.20%). The cytotoxic activity of essential oil, crude oil, and fraction A (obtained from fixed oil) were evaluated by using the MTT assay on MCF7 (human breast cancer cell line), PC3 (human prostate cancer cell line), and U87MG (human glioblastoma cell line). Finally, the effect of essential oil on inhibiting the PI3K/Akt/mTOR signaling pathway was evaluated using real-time PCR. The essential oil exhibited vigorous cytotoxic activity on the U87MG cell line, with an IC value of 32.65 μg/mL. Interestingly, the essential oil significantly inhibited the PI3K/AKT/mTOR cascade compared to the non-treated group. Our results suggest that the essential oil holds promise as an anticancer agent for glioblastoma cell lines. To the best of our knowledge, this study is the first to report on the profile of the essential oil of T. erecta fruits and its implications for targeting the PI3K/AKT/mTOR signaling pathway.