Gallotannin Isolated from Pericarp of Water Caltrop Ameliorates High-Fat Diet-Induced Nonalcoholic Fatty Liver Disease in Mice

New sesquiterpenes and viridin derivatives from Penicillium sp. Ameliorates NAFLD by regulating the PINK1/Parkin mitophagy pathway

Fungi from the plant rhizosphere microbiome are considered an important source of bioactive novel natural compounds. In this study, three new sesquiterpenes, penisterpenoids A-C (1-3), and three new viridin derivatives, peniviridiols A-C (4-6), along with twenty one known compounds (7-27), were isolated from the rhizosphere fungus Penicillium sp. SMU0102 of medicinal plant Bupleurum chinense DC. Their structures were elucidated by extensive spectroscopic analysis. The absolute configurations of compounds 1-6 were determined by experimental and calculated ECD spectra, DP4 + probability analysis, modified Mosher's method, and X-ray crystallography. All new compounds were screened for their cytotoxic and lipid-lowering activities in vitro. Among them, compound 1 (20 μM) remarkably alleviated lipid accumulation both in FFA-induced LO2 cells and TAA-induced zebrafish NAFLD models. Furthermore, compound 1 enhanced ATP production and mitochondrial membrane potential (MMP), suppressed reactive oxygen species (ROS) formation, restored mitochondrial structure, and induced autophagosome formation. Moreover, compound 1 significantly upregulated the expression of representative proteins for the mitochondrial homeostasis, including OPA1, DRP1, MFF, and Fis1, as well as mitophagy representative proteins PINK1, Parkin, and P62. Further mechanistic investigations indicated that compound 1 primarily alleviated lipid accumulation through selective activation of the PINK1/Parkin mitophagy signaling pathway.

Gallic acid regulates primary root elongation via modulating auxin transport and signal transduction

Gallic acid is an important secondary metabolite in plants, with great value in medicine, food, and chemical industry. However, whether and how this widely existing natural polyphenolic compound affects the growth and development of plants themselves remains elusive. In this study, we revealed that exogenous application of gallic acid has a dual effect on the elongation of primary root in Arabidopsis. While lower concentrations of gallic acid slightly stimulate primary root growth, excessive gallic acid profoundly reduces primary root length and root meristem size in a dose-dependent manner, probably via suppressing cell division in root meristem as indicated by CYCB1;1::GUS. Moreover, as suggested by the DR5::GFP line analysis and confirmed by the LC-MS assay, auxin contents in root tips were dramatically decreased upon excessive gallic acid treatment. Additional application of IAA partially rescued the shortened primary root and root meristem upon excessive gallic acid treatment, suggesting that auxin is required for excessive gallic acid-caused root growth inhibition. Then, we further revealed that excessive gallic acid down-regulated the expression of auxin transporters PIN1, PIN2, PIN3, and PIN7, and triple mutant pin1 pin3 pin7 exhibited a reduced sensitivity to gallic acid treatment. Meanwhile, excessive gallic acid decreased the degradation of AXR3/IAA17 protein as revealed by HS::AXR3NT-GUS reporter line. Auxin signaling mutant tir1 afb2 afb3 and axr3-3 were also less sensitive to excessive gallic acid treatment in terms of primary root length and root meristem size. Taken together, these findings suggested that excessive gallic acid inhibits primary root growth by modulating auxin transport and signaling in Arabidopsis.

Benefits of Monascus anka solid-state fermentation for quinoa polyphenol bioaccessibility and the anti-obesity effect linked with gut microbiota

In our previous study, a polyphenol-utilization targeted quinoa product was developed via solid-state fermentation with Monascus anka. In this study, we investigated the polyphenol-related novel functions of the fermented product further. Compared with unfermented quinoa, M. anka fermented quinoa alleviated the trapping effect of the macromolecules, especially in the colonic fermentation stage, resulting in enhanced polyphenol bioaccessibility. Lachnoclostridium, Megasphaera, Megamonas, Dialister, and Phascolarctobacterium might contribute to polyphenol liberation and metabolism in fermented quinoa. Additionally, fermented quinoa polyphenols presented an efficient anti-obesity effect by enhancing hepatic antioxidant enzyme activities, suppressing fatty acid synthesis, accelerating fatty acid oxidation, and improving bile acid synthesis. Moreover, fermented quinoa polyphenol supplementation alleviated gut microbiota disorder induced by a high-fat diet, resulting in a decreased ratio of Firmicutes/Bacteroidota, and increased relative abundances of Lactobacillus and Lachnoclostridium. The obtained results suggested that the principal anti-obesity effect of fermented quinoa polyphenols might act through the AMPK/PPARα/CPT-1 pathway. In conclusion, M. anka solid-state fermentation effectively enhanced the bioaccessibility of quinoa, and the fermented quinoa polyphenols showed considerable anti-obesity effect. Our findings provide new perspectives for the development of dietary polyphenol-based satiety-enhancing functional foods.