Supplementation of papaya leaf juice has beneficial effects on glucose homeostasis in high fat/high sugar induced obese and prediabetic adult mice

Authors: NYAKUNDI, BENARD - University Of Hawaii; Wall, Marisa; YANG, JINZENG - University Of Hawaii

Submitted to: BMC Complementary Medicine and Therapies
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2023
Publication Date: 1/3/2024
Citation: Nyakundi, B.B., Wall, M.M., Yang, J. 2024. Supplementation of papaya leaf juice has beneficial effects on glucose homeostasis in high fat/high sugar induced obese and prediabetic adult mice. BMC Complementary Medicine and Therapies. 24. Article 18. https://doi.org/10.1186/s12906-023-04320-1.
DOI: https://doi.org/10.1186/s12906-023-04320-1

Interpretive Summary: Plant extracts with an abundance of phytochemicals have potential as therapeutics for metabolic disorders, such as diabetes. In this study, we investigated the effects of papaya leaf (PL) juice supplementation on blood glucose levels in diet-induced obese and prediabetic adult mice. Results showed that supplementation of PL juice with a restricted diet for 30 days reduced fasting plasma glucose in obese prediabetic mice, compared to the group fed a restricted diet alone. PL juice with a restricted diet had positive impacts on normalizing glucose homeostasis, enhancing insulin sensitivity, improving lipid profile, and reversing fatty liver disease compared to a restricted diet alone.

Technical Abstract: Prediabetes is characterized by a cluster of glycemic parameters higher than normal but below the threshold of type 2 diabetes mellitus (T2DM). Plant extracts with an abundance of phytochemicals have recently gained popularity as therapeutic uses for metabolic disorders. This study investigated the effects of papaya leaf (PL) juice supplementation on blood glucose levels in diet-induced obese and prediabetic adult mice. B65JL F1 mice (n=20) at 12-14 months old were fed a high fat/sugar diet (HFHS) for 120 days. Mice were switched to restricted rodent chow of 3g feed/30g body weight/day, supplemented with 3g/100mL PL juice for 30 days. HFHS diet remarkably increased body weight from 32.5±1.6 to 50.3±4.1g, and fasting plasma glucose levels up to 192.7±10.1 mg/dL. HFHS diet slightly increased insulin resistance and induced hepatic steatosis, and hyperlipidemia. Combination of PL juice and restricted diet significantly reduced body weight and fasting blood glucose levels to 43.75±1.4 g and 126.25±3.2 mg/dl, respectively, which are lower than the group fed with a restricted diet alone. PL juice with a restricted diet significantly improved lipid profile: cholesterol from 204 to 150mg/dL, LDL-c from 110.4 to 50 mg/dL, and triglyceride from 93.7 to 60 mg/dL. Skeletal muscle Glut4 and p-AKT (ser473) proteins showed significantly higher levels in PL-treated mice than in controls. This study demonstrated that supplementation of PL juice with a restricted diet has great impacts on normalizing glucose homeostasis, enhancing insulin sensitivity, improving lipid profile, and reversal of hepatic steatosis compared to a restricted diet alone.