Chemical composition and biological activities of Eruca vesicaria subsp. longirostris essential oils

Context To date, there are no reports to validate the Tunisian traditional and folklore claims of Eruca vesicaria (L) Cav. subsp. longirostris (Brassicaceae) for the treatment of disease. Objective Investigation of the chemical composition antimicrobial and antioxidant activity of essential oils from Eruca longirostris leaves, stems, roots and fruits. Materials and methods The essential oils of E. longirostris from leaves, stems, roots and fruits were obtained after 4 h of hydrodistillation. Chemical compositions were determined using a combination of GC/FID and GC/MS. The in vitro antimicrobial activity of the volatile constituents of E. longirostris was performed in sterile 96-well microplates against three Gram-positive, four Gram-negative bacteria and one strain as yeast. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration values were reported. Furthermore, the antioxidant activity was evaluated by DPPH and ABTS assays. Results The main compound for fruits, stems and roots was the erucin (96.6%, 85.3% and 83.7%, respectively), while β-elemene (35.7%), hexahydrofarnesylacetone (23.9%), (E)-β-damascone (15.4%), erucin (10.6%) and α-longipinene (9.6%) constituted the major compounds in the essential oil of the leaves. The experimental results showed that in all tests, essential oil of fruits showed the better antioxidant activity than the others. On the other hand, the oils of stems, fruits and roots showed significant antimicrobial activity with MIC values ranging from 0.125 to 0.31 mg/mL against Candida species, Gram-positive and Gram-negative bacteria, mainly Salmonella enterica. Conclusions The present results indicate that essential oils of E. longirostris can be used as a source of erucin

Phytochemical characterization, antioxidant, antimicrobial and pharmacological activities of Feijoa sellowiana leaves growing in Tunisia

In this study, headspace solid-phase microextraction coupled to GC–MS was applied to identify the volatile bioactive compounds in the leaves of Feijoa sellowiana growing in Tunisia. Thirty-one components were identified, representing 99.9% of the total volatiles. The major constituents were limonene (36.2%), β-caryophyllene (27.8%), aromadendrene (12.5%), and α-copaene (6.6%). Also, the F. sellowiana leaves extract (FSLE) was phytochemically characterized. Antioxidant activity was estimated by different in vitro assays, such as ABTS cation radicals scavenging, iron-chelating capability, ability to inhibit lipid peroxidation, superoxide inhibition and DNA protection assay. The antibacterial and antifungal activities of FSLE were also investigated by the disc diffusion and microdilution methods. In vitro inhibition of diabetes key enzymes (α-glucosidase and α-amylase) was evaluated. The study of kinetics inhibition showed that the FSLE demonstrated a strong inhibition of both α-glucosidase (IC50=8.0 ± 0.2 μg/ mL) and α-amylase (IC50=70.20 ± 0.8 μg/mL) in non-competitive manner. The acute toxicity of FSLE on Wistar rats at the doses of 200, 500 and 2000 mg/kg body weight (BW) was investigated. Our findings revealed that leaves extract at such doses as up to 2000 mg/kg did not cause any signs of toxicity or deaths in rats. Based on hematological and biochemical analyses of hepato-biliary and renal functions, we concluded that the FSLE is tolerated by rats. The analgesic effect of FSLE was assayed using the acetic acid writhing test in mice. At 100 mg/ kg, the FSLE showed a higher analgesic activity (88.08 ± 0.73%) than that of acetylsalicylic acid (ASL) (62.69 ± 0.26%) used as positive control