Citrus Peels Phenolic Derivatives Alleviate Benzo[α]pyrene-Induced Inflammatory Injury of Human Intestinal Epithelial Cells Through NLRP3 and AhR Signaling Pathways

Benzo[α]pyrene (BaP) is ubiquitous in foods, and possesses a fatal cytotoxicity. In current study, ten Citrus peels (Chenpi) phenolic derivatives (CPDs) were isolated in a cell model of human intestinal epithelial (Caco-2) cells under BaP-exposure by a bio-assay guided method. Among them, methyl (3,4,5-trimethoxybenzoyl) valylphenylalaninate (Citrus peels phenolic derivative-2, CPD-2) performed the most protective activity by promoting the antiinflammatory potential on BaP-induced Caco-2 cells. CPD-2 inhibited BaP-induced intracellular ROS over-production and inflammatory epithelial cytokine, IL-4, IL-8, TNF-α, IL-1β and IL-18 over-expression, but not IL-6. CPD-2 also inhibited BaP-induced NLRP3 inflammasome and AhR signaling pathway activation. Overall, CPD-2 attenuates BaP-induced apoptotic death via promoting the antiinflammatory potentials by inhibiting the NLRP3 and AhR signaling pathways activation of Caco-2 cells. Finally, the Citrus peels phenolic derivatives was observed for the first time against BaP-induced inflammation and oxidative stress in human intestinal epithelial cells.

Antioxidant and Anti-Cancer Effect of Ethanolic Extract of Citrus Fruits on Hep G2 and MCF-7 Cell Lines

Background/objective: Cancer is a complex genetic disease that occurs due to mutation in genes that control apoptosis and cell growth. Uncontrolled cell growth leads to the formation of tumors. Free radical causes mutation in genes and DNA sequence, however antioxidants can stabilize these harmful effects. Citrus fruits are the rich source of antioxidants. owing to this property this study was planned to evaluate the potential of the citrus fruits for the treatment of the cancer. Aim: This study aimed to evaluate antioxidant as well anticancer potential of five different citrus strains (Citrus deliciosa, Citrus maxima, Citrus limetta, Citrus sinensis and Citrus reticulata). Methods: Peel of all the citrus fruits were collected, grinded and ethanolic extracts were prepared separately, to evaluate radical scavenging ability by employing DPPH method followed by MTT assay of the cancer cell lines to explore the anticancer potential of the extracts. Results: It was observed that citrus peels exhibited good radical scavenging activity and inhibited tumor growth. Maximum effect was produced by Citrus reticulata, and least results were obtained with Citrus sinensis. Conclusion: It was concluded that antioxidant and anti-cancer effects of citrus peels may be due to be owing to the presence of antioxidants (ascorbic acid, flavonoids, phenols, limonene). This research might open new horizon in the treatment of cancer chemotherapy.

Recent study on the anticancer activity of nobiletin and its metabolites

The exploration of naturally occurring phytochemicals with antitumor potential has been the focus of many studies. Nobiletin, a polymethoxyflavone (PMF) exclusively derived from citrus peels, has been reported as a promising candidate for the prevention and/or treatment of cancers. Additionally, multiple demethylated derivatives of nobiletin from in vivo biotransformation, including 3′-demethylnobiletin (3′-DMN), 4′-demethylnobiletin (4′-DMN), 3′,4′-didemethylnobiletin (3′,4′-DDMN) and 5-demethylnobiletin (5-DMN), among others, have been found to show anti-cancer activity. In this review, the anticancer activity of nobiletin and its derivatives in cancer prevention are comprehensively described.

Changes in the Population of Schizosaccharomyces japonicus in Carissa edulis Vahl (Simple-spined Carissa) Juice Treated with Extracts of Citrus aurantifolia Christm. (lime) and Citrus limon Burm F. (lemon) Peels as Natural Preservatives during Storage

Aim: This study was aimed at evaluating the changes in the population of Schizosaccharomyces japonicus in locally produced simple-spine Carissa juice and the effects of lemon peel, lime peel and combination of lime and lemon peels extract as preservatives on the juice samples. Methodology: Fruit juice produced was treated with different concentrations of citrus peels extracts (lemon, lime and lime+lemon) and their shelf lives were determined at room temperature for 30 days. The effects of the different preservatives on the pH of the juices were assessed and the Yeast count of the juice samples treated with the various concentrations of the citrus peels and the untreated samples were assessed using standard microbiological methods. The sugar fermentation and assimilation test of the isolate was also determined. Results: Yeast population increased in the juice samples that were without treatments (control) from 5.6×103±200 to 1.52×104±200 cfuml-1 indicating significant increase (p≥0.05). Treated juice samples showed significant decrease (p≤0.05) in yeast population in the order of 300>200>100 mg/ml of the natural preservatives. Juice samples treated with highest concentration (300 mg/ml) of combined lime+lemon peels recorded the least colony forming units of 2.0×103±100 ml-1 during the storage period. This showed that the highest concentration (300 mg/ml) of combined lime+lemon peels had more effects on yeast load reduction in the Carissa juice. The results of the preservative properties of the citrus peels revealed the combined preservative (lime+lemon) as the best among the individual preservatives of lime and lemon. The sugar fermentation and assimilation tests showed that Schizosaccharomyces japonicus is a good fermenter of most sugars and can also assimilate sugars for its growth. The pH (3.40±0.01 and 4.09±0.01) of the treated fruit juices were within the acidic ranges that support the growth of yeast cells in culture. Conclusion: From the findings, organic extracts of citrus peels can be used to extend the shelf-life of Carissa juice for up to three weeks.