Chenpi (Citrus reticulatae Pericarpium), the dried peel of tangerine widely used in traditional Chinese medicine, has long been valued for both medicinal and dietary applications. Modern research increasingly highlights its bioactive compounds—including polysaccharides, polymethoxyflavones, volatile oils, and flavonoids—and their potential roles in metabolic health. Recent studies suggest that Chenpi polysaccharides may exert anti-obesity effects by modulating gut microbiota composition and promoting the production of microbial metabolites such as acetate. These mechanisms appear to influence insulin sensitivity, lipid metabolism, inflammatory responses, and hepatic fat accumulation. In addition to polysaccharides, Chenpi extracts and herbal formulations containing Chenpi have also demonstrated promising anti-obesity and metabolic regulatory activities in experimental models. This article summarizes recent findings on Chenpi polysaccharides and related extracts, focusing on their interactions with gut microbiota and their potential roles in the management of obesity, metabolic syndrome, and associated metabolic disorders.
Chenpi and Its Bioactive Components
As a traditional Chinese medicinal material, Chenpi (Citrus reticulatae Pericarpium, CRP) has both medicinal and dietary value. According to traditional Chinese medicine theory, Chenpi has the functions of regulating qi, strengthening the spleen, drying dampness, and resolving phlegm. The main components of Chenpi include volatile oils, flavonoids, vitamins, pectin, polysaccharides, and alkaloids. Modern pharmacological studies have also shown that Chenpi has hepatoprotective, antioxidant, anti-inflammatory, and lipid-lowering effects. In 2002, tangerine peel (Chenpi) was approved as a substance with both medicinal and food use
In recent years, research on gut microbiota has become a major focus. Diet can influence the gut microbiota in different ways. Increasing evidence suggests that gut microbiota is closely related to metabolism, host gene expression, and other physiological processes. Chenpi has been demonstrated to regulate the composition and abundance of gut microbiota, fecal short-chain fatty acids (SCFAs), intestinal barrier function, and gastrointestinal inflammation.
A recently published study explored the anti-obesity effects of citrus prebiotics—Chenpi polysaccharides—and clarified their gut microbiota-dependent mechanism.
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Anti-Obesity Effects of Chenpi Polysaccharides
In a high-fat diet (HFD)-induced obesity mouse model, supplementation with Chenpi polysaccharides significantly reduced body-weight gain, improved insulin sensitivity, and alleviated hepatic steatosis and systemic inflammation. After the gut microbiota was depleted using antibiotics, these beneficial effects disappeared, indicating that the activity of Chenpi polysaccharides depends on gut microbiota.
16S rRNA sequencing and targeted metabolomics analysis showed that Chenpi polysaccharides enriched acetate-producing Bacteroides species and increased acetate levels. In addition, administration of acetate could mimic the effects of Chenpi polysaccharides, reducing hepatic lipid accumulation and body-weight gain in mice fed a high-fat diet. Overall, these findings suggest that the anti-obesity effects of Chenpi polysaccharides are associated with modulation of gut microbiota and may be mediated through increased microbial acetate production. This also highlights their potential as a natural dietary intervention for obesity management.
Furthermore, acetate can enhance insulin sensitivity, reduce adipocyte hypertrophy, and alleviate hepatic steatosis. Chenpi polysaccharides can also downregulate inflammatory cytokines in both systemic circulation and adipose tissue, thereby improving metabolic homeostasis. Taken together, these effects can mitigate high-fat diet-induced obesity and its associated metabolic dysfunctions, including insulin resistance and non-alcoholic fatty liver disease (NAFLD).
Previous studies have shown that activation of Toll-like receptor 4 (TLR4) regulates inflammation and endoplasmic reticulum (ER) stress in NAFLD. Recent research has also demonstrated that Chenpi polysaccharides significantly reduce macrophage infiltration in vivo and inhibit the expression of pro-inflammatory factors and genes associated with ER stress. In addition, Chenpi polysaccharides exhibit specific affinity for myeloid differentiation factor 2 (MD-2), thereby suppressing lipopolysaccharide (LPS)-induced inflammation through interaction with the TLR4 signaling pathway. Therefore, Chenpi polysaccharides may also represent a promising strategy for the treatment of NAFLD.
Chenpi Polysaccharides and Improvement of Metabolic Syndrome
Metabolic syndrome is characterized by a cluster of metabolic abnormalities, including central obesity, insulin resistance, hypertension, and dyslipidemia. It is an important risk factor for atherosclerotic cardiovascular disease and type 2 diabetes. Alarmingly, the prevalence of metabolic syndrome has increased dramatically over recent decades, consistent with the rising global prevalence of obesity.
A recent study published in Carbohydrate Polymers reported that Chenpi polysaccharides not only exhibit anti-obesity effects but can also alleviate high-fat diet-induced metabolic syndrome (MetS) through regulation of gut microbiota.
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Researchers isolated three subfractions (PCRCPI–III) from Chenpi polysaccharides. Their ability to alleviate metabolic syndrome depended on structural characteristics, with PCRCPI showing the most significant therapeutic effects. Oral administration of PCRCPI in mice improved metabolic phenotypes, and this process depended on gut microbiota. It was characterized by selective enrichment along an extended taxonomic lineage: Lactobacillales – Lactobacillaceae – Lactobacillus – Lactobacillus murinus.
Colonization with live Lactobacillus strains enhanced the metabolic benefits of PCRCPI, particularly when combined with Lactobacillus murinus. Together they synergistically improved insulin sensitivity and activated the hepatic PPAR signaling pathway. In addition, PCRCPI increased microbially derived deoxycholic acid, which can activate PPAR-mediated fatty-acid oxidation in hepatocytes. These findings suggest that PCRCPI may represent a promising therapeutic candidate for metabolic syndrome, with a potential mechanism involving stimulation of beneficial Lactobacillus proliferation.
The anti-obesity effects of Chenpi polysaccharides are largely attributed to their prebiotic properties. In studies related to the anti-obesity effects of Chenpi, not only Chenpi polysaccharides but also Chenpi extracts have demonstrated beneficial effects.
Additional Research on the Anti-Obesity Effects of Chenpi
1) Anti-Obesity Effects of Chenpi Extracts
Chenpi has been reported to be rich in 5-hydroxy polymethoxyflavones (5-OH PMFs). One study used a high-fat diet-induced obesity/diabetes mouse model to investigate the effects of Chenpi extract on metabolic indicators. Supplementation with 0.25% and 0.5% Chenpi extract in the diet for 15 weeks significantly prevented HFD-induced obesity, hepatic steatosis, and diabetic symptoms in mice. These beneficial effects were associated with activation of AMP-activated protein kinase (AMPK) in adipose tissue. The results suggest that Chenpi extract enriched in 5-OH PMFs can effectively prevent obesity and type 2 diabetes, possibly through improvement of lipid metabolism via AMPK pathway activation.
Another study using 3T3-L1 preadipocytes showed that Chenpi extract inhibited adipogenesis in a concentration-dependent manner and significantly reduced the expression of adipogenic transcription factors and proteins associated with lipid metabolism. In ob/ob mice, oral administration of Chenpi extract significantly suppressed body-weight gain without affecting food intake. It also restored liver function indicators and improved lipid profiles by reducing total cholesterol, triglycerides, and low-density lipoprotein levels.
2) Anti-Obesity Effects of Chenpi-Containing Formulations
A study reported that a traditional Chinese herbal formula consisting of Chenpi, coix seed, radish, lotus leaf, kelp, and hawthorn—known as Chenpi-Tiao-Yiyiren Decoction (TTD)—showed therapeutic effects in the clinical treatment of metabolic syndrome. Research indicated that TTD restored gut microbiota homeostasis and bile acid (BA) levels in HFD-induced MetS mice.
TTD significantly reduced body-weight gain, fasting blood glucose levels, serum triglyceride levels, and hepatic steatosis in mice. Moreover, TTD corrected gut microbiota dysbiosis, particularly by significantly reducing the Firmicutes/Bacteroidetes ratio. Fecal microbiota transplantation (FMT) confirmed that gut microbiota mediated the therapeutic effects of TTD.
In addition, it has been reported that a mixture of citrus polymethoxyflavones, green tea polyphenols, and lychee extracts can attenuate adipogenesis in 3T3-L1 adipocytes and reduce obesity-induced adipose tissue inflammation in mice.
References
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Kong C.Y., Li Z.M., Han B., et al. Modulation of gut microbiota by tangerine peel polysaccharide: A promising strategy for obesity management via acetic acid production. Food Research International. 2026;229:118460.
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Huang G., Li B., Li C., et al. Structure-function relationship of polysaccharides derived from Pericarpium Citri Reticulatae 'Chachiensis': highlighting the effects on metabolic syndrome by regulating gut microbiota. Carbohydrate Polymers. 2026;379:124936.
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Guo J., Tao H., Cao Y., et al. Prevention of Obesity and Type 2 Diabetes with Aged Citrus Peel (Chenpi) Extract. Journal of Agricultural and Food Chemistry. 2016;64(10).
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Wang L., Li W., Li Y., et al. Dried tangerine peel polysaccharide (DTPP) alleviates hepatic steatosis by suppressing TLR4/MD-2-mediated inflammation and endoplasmic reticulum stress. Bioorganic Chemistry. 2024;147:107369.
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Kim H., Lee M.G., Shin M.S. Anti-Obesity Effects of Acid-Processed Citrus reticulata Blanco Peel Extract Enriched in Highly Bioactive Polymethoxyflavones: Inhibition of 3T3-L1 Adipocyte Differentiation and Therapeutic Efficacy in ob/ob Mice. Nutrients. 2025;17(21):3322.
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Pan M.H., Li M.Y., Tsai M.L., et al. A mixture of citrus polymethoxyflavones, green tea polyphenols and lychee extracts attenuates adipogenesis in 3T3-L1 adipocytes and obesity-induced adipose inflammation in mice. Food & Function. 2019;10(12):7667-7677.