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.

Stimulation of Phenolic Compounds Accumulation and Antioxidant Activity in In Vitro Culture of Salvia Tebesana Bunge in Response to Nano-TiO2 and Methyl Jasmonate Elicitors

In the present study, we first attempted to achieve an efficient procedure for optimizing callogenesis from apical meristem and leaf explants of S. tebesana on MS media containing different concentrations of BAP alone and in combination with 2,4-D. Then, the inducing effect of nano-TiO2 (10, 60, and 120 mg L− 1) and methyl jasmonate (50, 100, and 200 µM), as abiotic elicitors were studied on the enhancement of phenolic compounds, rosmarinic acid, and some individual flavonoids as well as antioxidant capacity of callus extracts. According to the results, the highest callogenesis rate (100 and 93.33, respectively) and DW (0.55 ± 0.03 and 0.36 ± 0.02 g, respectively) per responsive explant were achieved from apical meristem on MS media containing "BAP 1 + 2,4-D 1" mg L− 1 and from leaf explant on the medium supplemented with "BAP 0.5 + 2,4-D 1" mg L− 1. The elicitation with 10 and 60 mg L− 1 nano-TiO2 (respectively for apical meristem and leaf), and 50µM MeJa could significantly promote the production of predominant phenolic derivatives in S. tebesana calli, where the highest content of total phenolics, O-diphenols, phenolic acid, flavonoid, flavone and flavonol, proanthocyanidin was recorded. Additionally, in increasing the amount of rosmarinic acid of callus, nano-TiO2 treatment was more effective than the elicitation with MeJa. Also, the highest content of Apigenin (0.33 ± 0.02 µg g− 1 DW) was detected after MeJa-elicitation (50µM), while the maximum level of Quercetin (2.61 ± 0.09 µg g− 1 DW) and Rutin (13.79 ± 08 µg g− 1 DW) were obtained after exposure to 60 mg L− 1 nano-TiO2, both from leaf-derived calli. While a significant positive correlation was recorded between antioxidant assays (DPPH and FRAP) and phenolic derivatives of treated calli; a very strong correlation occurred between the content of rosmarinic acid of apical meristem-derived calli and DPPH and FRAP values (r2 = -0.921 and r2 = -0.913, P < 0.01 respectively). Our results showed that the combination of in vitro culture and elicitation would be a good technique to successfully produce and enhance the content of pharmacologically valuable metabolites in S. tebesana.

Chemistry and Pharmacology of Cyperaceae Stilbenoids: A Review

Cyperaceae is a cosmopolitan plant family with approx. 5000 species distributed worldwide. Several members of this family are used in traditional medicines for the treatment of different diseases. In the last few decades, constituents with great chemical diversity were isolated from sedges, and a wide range of biological activities were detected either for crude extracts or for pure compounds. Among the isolated compounds, phenolic derivatives are the most important, especially stilbenoids, and flavonoids. To date, more than 60 stilbenoids were isolated from 28 Cyperaceae species. Pharmacological investigation of Cyperaceae stilbenoids revealed that several compounds possess promising activities; mainly antiproliferative, antibacterial, antioxidant and anthelmintic effects. Isolation, synthesis and pharmacological investigation of stilbenes are increasing constantly. As Cyperaceae species are very good sources of a wide variety of stilbenes, and several of them occur in large amount worldwide, they are worthy for phytochemical and pharmacological investigations. Moreover, stilbenes are important from chemotaxonomical point of view, and they play a key role in plant defense mechanisms as well. This review summarizes the stilbenoids isolated from sedges, and their biological activities.

SECONDARY METABOLITES FROM THE STEM BARKS OF RHIZOPHORA MUCRONATA LAMK

Using various chromatographic separations, three phenolic derivatives (1‒3) and three phytosteryl glycosides (4‒6) were isolated from a methanolic extract of R. mucronata stem barks. Their structures were elucidated to be cinchonain Ia (1), breynioside B (2), polystachyol (3), β-sitosterol 3-O-β-D-glucopyranoside (4), β-sitosterol 3-O-β-D-(6'-O-palmitoyl) glucopyran-oside (5), and β-sitosterol 3-O-β-D-(6'-O-stearoyl)glucopyranoside (6) by detailed analysis via spectroscopic techniques (1D, 2D NMR, and ESI-MS data) as well as comparison with those reported. This is the first report of compounds 1‒6 from the Rhizophora genus.