Previous studies have revealed the microbial metabolism of dietary choline in the gut, leading to its conversion into trimethylamine (TMA), a precursor of the cardiovascular inflammatory marker trimethylamine N-oxide (TMAO). Polymethoxyflavones (PMFs), exemplified by tangeretin, demonstrate efficacy in mitigating TMAO-induced cardiovascular inflammation. However, the specific mechanism by which these compounds exert their effects, particularly in modulating the gut microbiota, remains uncertain. This investigation focused on tangeretin, a representative PMFs, exploring its influence on the gut microbiota and the choline-TMA conversion process. Experimental results showed that tangeretin treatment attenuated the population of CutC-active bacteria, specifically Clostridiaceae and Lactobacillus, induced by choline chloride in rat models. This inhibition resulted in reduced efficiency in choline conversion to TMA, thereby ameliorating cardiovascular inflammation resulting from prolonged choline consumption. In conclusion, tangeretin's preventive action against cardiovascular inflammation is intricately linked to its targeted modulation of TMA-producing bacterial activity.

The emergence of multi-drug resistant bacteria has severely increased the burden on the global health system, and such pathogen infections are considered a great threat to human well-being. Antimicrobial peptides, due to their potent antimicrobial activity and low possibility of inducing resistance, are increasingly becoming the focus of much interest. Herein, a novel dermaseptin peptide, named Dermaseptin-SS1 (SS1), was identified from a skin secretion-derived cDNA library of the South/Central American tarsier leaf frog, Phyllomedusa tarsius, using a ‘shotgun’ cloning strategy. Chemically-synthesised peptide SS1 was found to be broadly effective against Gram-negative bacteria with low haemolytic activity in vitro. A designed synthetic analogue of SS1, named peptide 14V5K, showed a lower salt sensitivity with more rapid bacteria-killing compared to SS1. Both peptides employed the membrane-targeting mechanism to kill Escherichia coli. The antiproliferative activity of SS1 and its analogues, against lung cancer cell lines, was found to be significant.