Fermented Houttuynia cordata Thunb. Attenuates Dextran Sulfate Sodium-Induced Colitis in Mice, Associated with Preserved Gut Barrier Integrity and Reduced Colonic TLR4 Expression

Information from the abstract

Houttuynia cordata is commonly consumed as an herb and traditional medicinal ingredient in Asian regions. Although fermented products of H. cordata are gaining popularity as natural health products, their effects in experimental models of colitis remain unclear. This study investigated the protective effects of fermented H. cordata extract (FHE) and fermented H. cordata juice (FHJ) in dextran sulfate sodium (DSS)-induced colitis mice. The bioactive compounds in FHE and FHJ were analyzed via HPLC, confirmed via MS, and compared with those in non-fermented H. cordata extract. The fermented products contained higher levels of gallic acid, quercetin, isoquercitrin, and organic acids, including lactic, glucuronic, butyric, and acetic acids, whereas their caffeic acid, rutin, total phenolic, and total flavonoid contents were lower. In an animal study, male C57BL/6 mice were administered 500 or 1000 mg/kg of FHE and 200 or 400 mg/kg of FHJ as low and high doses for 23 days, with 2.5% DSS in the drinking water on days 15–21 followed by drinking water without DSS on days 22–23. Pretreatment with FHE and FHJ ameliorated the severity of the induced colitis, as indicated by reduced weight loss, decreased disease activity index, restored colon length (8.82 ± 0.29 cm with FHJ 400 mg/kg versus 7.53 ± 0.08 cm in the DSS group, p < 0.001), and protection against histopathological injury, most evidently with the FHE 500 mg/kg and FHJ 400 mg/kg treatments. Intestinal barrier integrity was maintained as shown by decreased permeability to FITC-dextran (570 ± 56 ng/mL with FHJ 400 mg/kg versus 1963 ± 183 ng/mL with DSS group, p < 0.001), elevated levels of colonic Muc2 mRNA (with FHJ at both doses), and upregulation of the tight junction proteins ZO-1 (with FHE at 1000 mg/kg) and claudin-1 (with FHE at both doses and FHJ at 400 mg/kg). Moreover, pretreatment with both FHE and FHJ diminished colonic mRNA expression of TNF-α and IL-1β, whereas IL-6 was reduced under the FHE treatment only, accompanied by reduced colonic TLR4 expression with FHE at 1000 mg/kg and with FHJ at both doses. The phosphorylated-total ratios of IκB-α and NF-κB p65 did not differ significantly between groups. FHE and FHJ played protective roles against DSS-induced colitis, which is associated with the preservation of gut barrier function and reduced colonic TLR4 expression.

Why this record is monitored

This record has an Impact Signal of 78/100 based on recency, source, collaboration, and bibliographic signals. It prioritizes monitoring and is not a judgment of research quality.

Related topics: Inflammatory Bowel Disease · Probiotics and Fermented Foods · Gut microbiota and health