Evaluation of Antioxidant Activity and Biotransformation of Opuntia Ficus Fruit: The Effect of In Vitro and Ex Vivo Gut Microbiota Metabolism.

Opuntia ficus-indica biological effects are attributed to several bioactive metabolites. However, these actions could be altered in vivo by biotransformation reactions mainly via gut microbiota. This study assessed gut microbiota effect on the biotransformation of O. ficus-indica metabolites both in vitro and ex vivo. Two-time aliquots (0.5 and 24 h) from the in vitro assay were harvested post incubation of O. ficus-indica methanol extract with microbial consortium, while untreated and treated samples with fecal bacterial culture from the ex vivo assay were prepared. Metabolites were analyzed using UHPLC-QTOF-MS, with flavonoid glycosides completely hydrolyzed in vitro at 24 h being converted to two major metabolites, 3-(4-hydroxyphenyl)propanoic acid and phloroglucinol, concurrent with an increase in the gallic acid level. In case of the ex vivo assay, detected flavonoid glycosides in untreated sample were completely absent from treated counterpart with few flavonoid aglycones and 3-(4-hydroxyphenyl)propanoic acid in parallel to an increase in piscidic acid. In both assays, fatty and organic acids were completely hydrolyzed being used as energy units for bacterial growth. Chemometric tools were employed revealing malic and (iso)citric acids as the main discriminating metabolites in vitro showing an increased abundance at 0.5 h, whereas in ex vivo assay, (iso)citric, aconitic and mesaconic acids showed an increase at untreated sample. Piscidic acid was a significant marker for the ex vivo treated sample. DPPH, ORAC and FRAP assays were further employed to determine whether these changes could be associated with changes in antioxidant activity, and all assays showed a decline in antioxidant potential post biotransformation.

Glucosinolates profile, volatile constituents, antimicrobial, and cytotoxic activities of Lobularia libyca.

CONTEXT: Brassicaceae plants are associated with protection against cancers due to their glucosinolate contents. OBJECTIVES: We investigate fresh leaves, roots and ripe seeds of Lobularia libyca (Viv.) C.F.W. Meissn. (Brassicaceae) to identify their glucosinolate constituents, antimicrobial and cytotoxic activities Materials and methods: The glucosinolates were identified using GC-MS analysis of their hydrolysis products and LC-MS analysis in the case of seeds. Disc diffusion (1 mg/disc) and minimum inhibitory concentration (0-160 µg/mL) methods were used to evaluate the antimicrobial activity of seed hydrolysate. In vitro cytotoxicity against colorectal HCT-116, hepatic HUH-7, breast MCF-7 and lung A-549 cells was evaluated for seed hydrolysate (0.01-100 µg/mL) using the sulforhodamine B assay and doxorubicin as a standard Results: Three glucosinolates were identified for the first time in this plant and genus Lobularia. Glucoiberverin was the major compound accumulated in the seeds and leaves, while glucoiberin and glucoerucin were detected only in the seeds. No glucosinolates were detected in roots under the same experimental conditions. Other volatile constituents, e.g., terpenes and fatty acids were only identified in the seeds. The seed hydrolysate showed significant antimicrobial activities against Candida albicans and Pseudomonas aeruoginosa (MIC = 64 and 82 µg/mL, respectively). The seed hydrolysate exhibited a marked selective cytotoxicity in vitro against colorectal, hepatic and breast cancer cell lines. The IC50 values were 0.31, 2.25 and 37 µg/mL, respectively. DISCUSSION AND CONCLUSION: The results indicated the antimicrobial activity of L. libyca and the selective effect of the seed hydrolysate as a cytotoxic drug that is potentially more active than doxorubicin against HCT-116.

Comparative study of volatile oil content and antimicrobial activity of pecan cultivars growing in Egypt.

The volatile oils obtained from the leaves of four pecan cultivars growing in Egypt were evaluated for their chemical composition and antimicrobial activity. The selected cultivars (cv.) were Carya illinoinensis (Wangneh.) K. Koch. cv. Wichita, C. illinoinensis cv. Western Schley, C. illinoinensis cv. Cherokee, and C. illinoinensis cv. Sioux. The gas chromatography-mass spectrometry analyses revealed that the volatile oils from samples of the different cultivars differ in composition and percentage of their components. ß-Curcumene was found as the major constituent of the cv. Wichita oil, whereas germacrene D was the major component of cv. Sioux, cv. Cherokee, and cv. Western Schley. The antimicrobial activity was assayed using the Kirby-Bauer Method by measuring the zone of inhibition of growth. All volatile oils displayed an antimicrobial activity against the tested bacterial strains. On the other hand, only the volatile oil of cv. Wichita showed an antifungal effect on Aspergillus flavus. This work has identified candidates of volatile oils for future in vivo studies to develop antibiotic substitutes for the diminution of human and animal pathogenic bacteria. Nevertheless, the variations of the volatile oil components and antimicrobial potencies of the different studied cultivars, necessitate identifying the cultivars used in future studies.

Seasonal variation in the essential oil composition of Origanum majorana L. cultivated in Egypt.

The hydrodistilled essential oil content of Origanum majorana L. (Lamiaceae) ranged from 2.5-3% with the maximal value (3%) in spring. Analysis of the oil by GC/MS resulted in the identification of 15, 15, 11, and 14 components in the oils prepared in spring, summer, autumn, and winter, respectively. The composition of the essential oils differed quantitatively and qualitatively according to the time of collection. Thymol (38.4%) and cis-sabinene hydrate (25.3%) were the major components in spring plants. Terpinen-4-ol (37.4%, 20.5%, 16.3%) was a major component in the summer, autumn and winter oils, respectively, cis-Sabinene hydrate (54.4%) was major in winter plants while terpinolene (43.1%) was the main component in autumn plants. Other components detected in lower amounts in all oil samples were sabinene and p-cymene (up to 7.4% and 13.9% in autumn), and alpha-terpinene (up to 13.3% in summer).