Variation of Malva sylvestris essential oil yield, chemical composition and biological activity in response to different environments across Southern Italy

Mallow (Malva sylvestris L.) grows wild in many countries, and the amount of drug required as functional food or even pharmafood, due to its both medicinal and industrial importance, is produced almost entirely from wild harvest. We studied the effect of environment on crop yield, biological activity and chemical composition of the essential oils of different mallow samples, that were cultivated at sixteen experimental sites in South-central Italy (Molise) in different growing environments. GC-MS analysis of the essential oils revealed the presence of phenolics and fatty acids that were the main compounds in all the samples but their percentages in each plant were greatly different. Antioxidant activities of the essential oils were evaluated by DPPH radical-scavenging activity and FRAP assay. Antimicrobial activity was determined by using the broth dilution method. Samples were also evaluated for their anti-inflammatory properties verifying their inhibitory effects on nitric oxide production in LPS-stimulated RAW 264.7 cells. All essential oils inhibited NO production in cell supernatants in a dose-dependent manner. Moreover, antiproliferative activity was assessed on three human cancer cell lines: breast cancer cells MCF-7 and SKBr3, and melanoma cells C32. Our study demonstrates that the crop performance was greatly influenced by the pedo-climatic conditions, and particularly fertility of the environment and the crop management (water supply) that increased also mallow crop yield. The results of this study provide new knowledge to produce adequate quality of mallow oil.