Theaflavins ameliorate obesity through enhanced antioxidant capacity, a suppressed hepatic BCAA degradation pathway, and gut microbiota modulation.

Theaflavins exhibited potent free-radical scavenging capacity in vitro.

• TFs were tested for antioxidant activity using in vitro free-radical scavenging assays.
• This antioxidant capacity was described as 'potent' in the context of their mechanism of action against obesity-related oxidative stress.

Theaflavins dose-dependently attenuated HFD-induced weight gain, dyslipidemia, and glucose intolerance in vivo.

• The study used a high-fat diet (HFD)-induced obesity mouse model.
• TF administration was applied at multiple doses, showing a dose-dependent response for weight gain attenuation.
• Improvements were observed across multiple metabolic parameters including dyslipidemia and glucose intolerance.

TF administration alleviated hepatic steatosis, ultrastructural damage, and improved liver function in HFD-fed mice.

• Hepatic steatosis was assessed histologically, and ultrastructural damage was evaluated, both showing improvement with TF treatment.
• Liver function markers were improved following TF administration.
• These findings indicate protection against HFD-induced hepatic injury at both structural and functional levels.

Theaflavins suppressed hepatic oxidative stress in HFD-fed mice.

• TF administration reduced markers of hepatic oxidative stress induced by HFD.
• This suppression of oxidative stress was identified as one of the multifaceted mechanisms by which TFs alleviate obesity.

Theaflavins downregulated the HFD-induced overexpression of the valine, leucine, and isoleucine (BCAA) degradation pathway in the liver.

• Six specific genes/proteins in the BCAA catabolism pathway were downregulated: HADH, HMGCL, ACSF3, ACADS, ALDH3A2, and ACAA2.
• Downregulation was confirmed at both mRNA and protein levels.
• This suppression of the hepatic BCAA degradation pathway was identified as a key mechanism underlying TF-mediated metabolic improvement.

Theaflavins improved HFD-induced gut dysbiosis by enriching butyrate-producing genera and reducing harmful taxa.

• Beneficial genera enriched by TF treatment included Akkermansia and Gastranaerophilales_norank, identified as butyrate-producing genera.
• Harmful taxa reduced by TF treatment included Enterococcus and Streptococcus.
• Gut microbiota composition was analyzed using 16S rRNA sequencing or similar gut microbiota analysis methods.

Correlation analysis revealed significant associations between TF-induced microbial shifts, ameliorated metabolic phenotypes, and suppressed hepatic BCAA catabolism.

• Correlation analysis was used to integrate findings from gut microbiota, metabolic phenotypes, and hepatic BCAA pathway data.
• Significant associations were found linking microbial composition changes to metabolic improvements and reduced BCAA catabolism.
• These correlations supported an integrated, multi-mechanistic model of TF action against obesity.