Extracts from felina 32 hemp inflorescences in cancer: an in vitro study.

Cannabis sativa L. is a plant traditionally cultivated as a source of fibers and nutrients. Recently, the interest toward its medical uses is growing, owing to the highlighted therapeutic potential of its numerous phytoconstituents, including anticancer properties [1]. In this context, our work aimed at evaluating the antiproliferative properties of C. sativa var. Felina 32 inflorescences, collected in June and September, in relation to non-psychoactive cannabinoid and caryophyllane sesquiterpene content. Inflorescences were subjected to Bligh-Dyer extraction, to obtain two terpenoid-rich organic fractions, namely JOF (June Organic Fraction) and SOF (September Organic Fraction). Extracts were analysed by gas chromatography/mass spectrometry (GC/MS) to determine the major non-psychoactive cannabinoids and caryophyllane sesquiterpenes. The cytotoxicity of JOF, SOF and the major compounds detected at GC/MS, alone or in combination, was evaluated in different cancer cell lines. The endocannabinoid system involvement in the antiproliferative effects of the samples was assessed using CB1 and CB2 receptor inhibitors. Immunofluorescence and western blotting analysis were performed to confirm the mechanistic hypothesis. Results highlighted cannabidiol, cannabichromene, β-caryophyllene, β-caryophyllene oxide and α-humulene as the major compounds, with higher amount in SOF compared to JOF. The extracts and the pure compounds inhibited cancer cell proliferation, with higher potency towards MDA-MB-468 cells. Interestingly, the pure compound combinations induced cytotoxic effects similar to those of the extracts. After treatment with CB1 and CB2 inhibitors, the cytotoxicity of JOF, SOF and cannabidiol was not reduced; conversely, a slight lowering of β-caryophyllene and cannabichromene cytotoxicity was highlighted, thus suggesting that CB2 receptor activation can partly contribute to their activity. This hypothesis was deepened by evaluating the effect of JOF, SOF and pure compounds on the CB2 protein expression. In conclusion, Felina 32 hemp inflorescences can be an interesting bioactive phytocomplex with antiproliferative properties, likely due to the synergistic interactions between nonpsycoactive terpenoids and caryophyllane sesquiterpenes.