Hydrolysable Tannins and Biological Activities of Meriania hernandoi and Meriania nobilis (Melastomataceae)

Anti-Inflammatory Effect of Meriania hexamera Sprague by Targeting Syk Kinase in NF-κB Signaling

Inflammation is a protective mechanism against harmful stimuli. There are two types of inflammation, acute and chronic, and severe diseases such as cardiovascular disease and cancer can be caused by chronic inflammation. Therefore, this research was conducted to discover new anti-inflammatory drugs. Meriania hexamera Sprague is a common herb in the Amazon region in South America. It is used as a traditional medical herb by natives, but no studies to date have investigated its anti-inflammatory activity. Using lipopolysaccharide (LPS), pam3CSK4 (Pam3), and poly(I:C), we studied the M. hexamera Sprague-Methanol Extract's (Mh-ME) in vitro anti-inflammatory functions. Using RAW264.7 cells, we detected the released nitric oxide (NO) and mRNA expression extent of inducible nitric oxide synthase (iNOS) with pro-inflammatory proteins like tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and iterleukin-1 beta (IL-1β). It was found that Mh-ME suppressed the inflammatory activities in a dose-dependent manner. In the luciferase assay, the nuclear factor kappa light chain enhancer of the activated B cells (NF-κB) pathway was inhibited by Mh-ME. Mh-ME especially acted as an inhibitor of Syk kinase according to the results from CETSA. We also confirmed that Mh-ME mitigates acute gastritis derived from HCl/EtOH in ICR mice, ameliorating the expression of IL-1β and tumor necrosis factor-alpha (TNF-α). In conclusion, Mh-ME is an herb with anti-inflammatory effects that targets Syk in the NF-κB pathway, suggesting that Mh-ME could be used as an anti-inflammatory herbal medicine.

Identification and Characterization of Glucosyltransferase That Forms 1-Galloyl-β-d-Glucogallin in Canarium album L., a Functional Fruit Rich in Hydrolysable Tannins

Hydrolysable tannins (HTs) are useful secondary metabolites that are responsible for pharmacological activities and astringent taste, flavor, and quality in fruits. They are also the main polyphenols in Canarium album L. (Chinese olive) fruit, an interesting and functional fruit that has been cultivated for over 2000 years. The HT content of C. album fruit was 2.3-13 times higher than that of berries with a higher content of HT. 1-galloyl-β-d-glucose (βG) is the first intermediate and the key metabolite in the HT biosynthesis pathway. It is catalyzed by UDP-glucosyltransferases (UGTs), which are responsible for the glycosylation of gallic acid (GA) to form βG. Here, we first reported 140 UGTs in C. album. Phylogenetic analysis clustered them into 14 phylogenetic groups (A, B, D-M, P, and Q), which are different from the 14 typical major groups (A~N) of Arabidopsis thaliana. Expression pattern and correlation analysis showed that UGT84A77 (Isoform0117852) was highly expressed and had a positive correlation with GA and βG content. Prokaryotic expression showed that UGT84A77 could catalyze GA to form βG. These results provide a theoretical basis on UGTs in C. album, which will be helpful for further functional research and availability on HTs and polyphenols.

Components study on antitussive effect and holistic mechanism of Platycodonis Radix based on spectrum-effect relationship and metabonomics analysis

The antitussive effect of Platycodonis Radix is closely related to the components in saponins fraction of Platycodonis Radix extract (SFPRE); however, these active components and their holistic mechanism remain unknown. Hence, a new method by integrating spectrum-effect relationship analysis with metabolomics analysis was applied to study the active components and their holistic mechanism simultaneously. For spectrum-effect relationship analysis, chemical fingerprints of ten batches of SFPRE were developed using UHPLC-LTQ-Orbitrap MSn; antitussive effect were evaluated using a classic mice-cough model induced by ammonia liquor. Spectrum-effect relationship was analyzed by partial least squares regression (PLSR) analysis. For metabolomics analysis, the altered metabolites related to cough in serum were identified by UHPLC-Q-TOF/MS and orthogonal partial least squares-discriminant analysis (OPLS-DA); metabolic pathway analysis was depended on MetaboAnalyst 4.0, KEGG database, METLIN database and HMDB database. Our findings showed that 10 identified components of Polygalacin D (peak 26), Deapio-platycodin D (peak 21), Platycodin D (peak 23), β-Gentiotriosyl platycodigenin (peak 37), Platycoside G3 (peak 17), Platycoside C (peak 25), Platycodin D3 (peak 16), 3-O-β-D-glucopyranosyl platycodigenin (peak 33), Platycoside F (peak 19) and 3″-O-acetyl platycodin D3 (peak 15), and 2 unidentified components (peak 45 and 44) possessed antitussive effects. The metabolomics analysis result showed that 19 metabolites were potential biomarkers related to the cough, 16 of which could be restored to normal levels by SFPRE. These biomarkers were involved in arachidonic acid metabolism, linoleic acid metabolism and glycerophospholipid metabolism. The current study may facilitate the development of antitussive medicines with fewer side-effects based on Platycodonis Radix.

Characterization, antioxidant, and cytotoxic effects of some Egyptian wild plant extracts

Background

Natural products from plants are very safe as compared to synthetic ones, so the aim of this study was to assess the in vitro antioxidant and antitumor activities of the ethanolic extracts of four Egyptian wild plant species (Varthemia candicans, Peganum harmala, Suaeda vermiculata, and Conyza dioscoridis), as well as polyphenols and flavonoid contents with gas chromatography–mass spectrometry (GC-MS). The antioxidant activity of the four plant extracts was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) to determine 50% inhibition of DPPH radical scavenging activity and reducing power by phosphomolybdate assay. In addition, the chemical composition of the four sample extracts was investigated using GC-MS. The total phenolic and flavonoid levels were also determined. Then, the antitumor activity of the plant extracts against HepG2 cells was determined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

Results

The results showed that Varthemia candicans extract was the highest one regarding both polyphenols and flavonoid contents. Moreover, the extract of Suaeda vermiculata exhibited the lowest half maximum inhibitory concentration (IC50) against DPPH, thus indicating its highest effectiveness. All studied plant extracts decreased the viability of HepG2 cells, in a dose- and time-dependent manner, and the lowest IC50 was for Suaeda vermiculata.

Conclusion

The investigated plant extracts showed potent antioxidant and antitumor activities in vitro due to their phytochemical contents.