Harvesting season dependent variation in chemical composition and biological activities of the essential oil obtained from Inula graveolens (L.) grown in Chebba (Tunisia) salt marsh

The chemical composition and the biological activities of aromatic plants may be influenced by seasonal changes. Therefore, the essential oil of Inula graveolens (IGEO), collected at Chebba salt marsh, was studied in terms of yields, compositions and biological activities, throughout four different seasons, namely spring, summer, autumn and winter (April, July, October and January, respectively). GC/MS analysis identified 30 compounds. Mostly quantitative rather than qualitative, variation was observed in the oil composition of each sample. It had been revealed a predominant presence of bornyl acetate and borneol, as well as significant differences of several compound amounts in function of the seasonal change. Biological activities were also related to the harvest season; hence, IGEO from spring gave the best antioxidant activity results and IGEO from autumn seemed to be the most potent against pathogenic microorganisms, while oils from summer and winter were the strongest inhibitors of acetylcholinesterase and tyrosinase.A matrix linking IGEO major compounds to biological was composed to identify relationships between concentrations of the volatile molecules and the biological activities of the samples. Furthermore, the seasonal variation of these main volatile constituents was also investigated through principal compound analysis (PCA). The obtained results revealed that each biological activity depends on the seasonal fluctuation of the amounts of certain chemical compounds.     

Chemical composition and biological evaluation of the volatile constituents from the aerial parts of Nephrolepis exaltata (L.) and Nephrolepis cordifolia (L.) C. Presl grown in Egypt

The essential oil from the aerial parts of Nephrolepis exaltata and Nephrolepis cordifolia obtained by hydro-distillation were analyzed by gas chromatography/ mass spectrometry. The essential oils exhibited potential antibacterial and antifungal activities against a majority of the selected microorganisms. NEA oil showed promising cytotoxicity in breast, colon and lung carcinoma cells. The results presented indicate that NEA oil could be useful alternative for the treatment of dermatophytosis.

Comparative investigation of hydro-distilled volatile constituents from aerial parts (A) of Nephrolepis exaltata (NE) and Nephrolepis cordifolia (NC) (Family Nephrolepidaceae) was carried out. Gas chromatography/mass spectrometry revealed that oils differ in composition and percentages of components. Oxygenated compounds were dominant in NEA and NCA. 2,4-Hexadien-1-ol (16.1%), nonanal (14.4%), β-Ionone (6.7%) and thymol (2.7%) were predominant in NEA. β-Ionone (8.0%), eugenol (7.2%) and anethol (4.6%) were the main constituents in NCA. Volatile samples were screened for their antibacterial and antifungal activities using agar diffusion method and minimum inhibitory concentrations. The cytotoxic activity was evaluated using viability assay in breast (MCF-7), colon (HCT-116) and lung carcinoma (A-549) cells by the MTT assay. The results revealed that NEA oil exhibited potential antimicrobial activity against most of the tested organisms and showed promising cytotoxicity.