Bioaccessibility, safety, and antidiabetic effect of phenolic-rich extract from fermented Psidium guajava Linn. leaves

• Main Authors: Zhenfeng Huang, You Luo, Xuesen Xia, Anping Wu, Zhenqiang Wu
• Format: Article
• Language: English
• Published: Elsevier 2021-11-01
• Series: Journal of Functional Foods
• Subjects: Phenolic-rich extract; Fermented guava leaves; Bioaccessibility; Safety; Antidiabetic effect
• Online Access: http://www.sciencedirect.com/science/article/pii/S1756464621003728

Fermentation results in the release and biotransformation of phenolic compounds in guava leaves. This study aimed to evaluate the bioaccessibility, safety and antidiabetic effect of phenolic-rich extract from fermented guava leaves (PE-fgl) using Monascus anka and Bacillus sp. BS2. The total phenolics and flavonoids were 51.18% and 16.60% bioaccessible after gastrointestinal digestion, respectively. High bioaccessibility was observed, particularly for ellagic acid, isoquercitrin, quercetin-3-O-β-D-xylopyranoside, quercetin-3-O-α-L-arabinofuranoside and avicularin, resulted in high recovery of α-glucosidase inhibition activity and antioxidant capacity. Moreover, PE-fgl was practically nontoxic with a median lethal dose (LD50) greater than 5000 mg/kg and was without evidence of toxicity following subchronic administration up to the dose limit of 2000 mg/kg. Furthermore, PE-fgl significantly improved serum glucose and lipid levels as well as antioxidant capacity in diabetic mice. Liver, kidney and pancreas damage was also significantly alleviated. These results suggested that PE-fgl could be a nontoxic candidate for diabetes treatment.