Longan Berry Extract
Also known as: Longan, Longan fruit, Longan berry, Dimocarpus longan Lour.
Overview
Longan berry extract is derived from the fruit, flowers, seeds, or pulp of the longan tree, a subtropical fruit native to Southeast Asia. It contains bioactive compounds such as polyphenols (e.g., proanthocyanidin A2, (-)-epicatechin, gallic acid, ellagic acid), vitamins, minerals, and polysaccharides. Traditionally used in East Asian medicine for conditions like insomnia, palpitation, and forgetfulness, longan extracts are now studied for antioxidant, anti-inflammatory, anti-cancer, metabolic, and neuroprotective effects. Research on longan extract is emerging but growing, with in vitro, animal, and some limited human studies. The evidence quality varies, with some well-designed animal studies and cellular experiments, but a lack of large-scale randomized controlled trials (RCTs) in humans. Systematic reviews specifically on longan extract are scarce, but related polyphenol and polysaccharide components have been reviewed for their biological activities. While promising, more human research is needed to confirm these benefits.
Benefits
Longan berry extract has several potential benefits supported by varying degrees of evidence. Extracts from longan flowers and seeds have demonstrated inhibitory effects on proliferation and colony formation of various cancer cell lines, including colorectal, lung, liver, cervical, and breast cancers, attributed to polyphenols like proanthocyanidin A2 and gallic acid; however, these findings are primarily from in vitro studies and animal models. In a controlled animal study, longan fruit extract improved fasting blood glucose, glucose tolerance, and insulin sensitivity in diabetic mice, suggesting potential benefits for type 2 diabetes mellitus (T2DM) and appetite control, although human data are lacking. Longan flower extracts are rich in antioxidants and have been shown to suppress inflammatory mediators, potentially contributing to cardiovascular and cancer prevention, but clinical evidence is limited. Polysaccharides from longan fruit pulp exhibit prebiotic properties by stimulating beneficial gut bacteria and increasing short-chain fatty acid production, which can support gut and immune health. However, excessive consumption of sugar-rich longan fruit in mice promoted nonalcoholic fatty liver disease (NAFLD) via gut dysbiosis and inflammation, indicating that high intake of free sugars in the fruit may have detrimental metabolic effects.
How it works
Longan berry extract's mechanism of action involves several pathways. Polyphenols, such as proanthocyanidin A2, (-)-epicatechin, and gallic acid, act as antioxidants by scavenging free radicals, inhibiting inflammatory pathways, and inducing apoptosis or inhibiting proliferation in cancer cells. The extract modulates hypothalamic neurons regulating appetite by upregulating anorexigenic POMC neurons and downregulating orexigenic AgRP neurons, possibly through reduction of ER stress, improving glucose homeostasis and reducing hyperphagia in diabetic models. Modified longan polysaccharides have immunomodulatory effects and act as prebiotics, enhancing beneficial gut microbiota and production of short-chain fatty acids, which influence systemic immunity and metabolism. The bioavailability of polyphenols and polysaccharides varies; enzymatic treatment and fermentation can modify polysaccharide structure to enhance prebiotic activity and absorption.
Side effects
Longan extracts are generally considered safe in traditional use and animal studies at moderate doses. However, high intake of the fruit’s sugars may promote metabolic disturbances such as NAFLD in animal models. No well-documented side effects exist in controlled studies; however, excessive consumption of sugar-rich longan fruit may lead to metabolic issues. No specific data are available regarding drug interactions and contraindications; caution is advised in diabetic patients due to potential glucose-lowering effects. There is a lack of clinical safety data in pregnant or lactating women, children, or patients with chronic diseases. Individuals with diabetes should monitor their blood glucose levels closely when consuming longan or longan extract. Due to the limited safety data in specific populations, caution is advised for pregnant or breastfeeding women, children, and individuals with pre-existing health conditions.
Dosage
No established clinical dosing guidelines exist for longan berry extract due to a lack of RCTs. In animal studies, 50 mg/kg/day of longan fruit extract improved metabolic parameters in diabetic mice. Extracts rich in polyphenols or polysaccharides may differ in activity; enzymatic or fermentation treatment may enhance prebiotic effects. Bioavailability may be enhanced by enzymatic modification of polysaccharides. Given the lack of human data, it is difficult to recommend a specific dosage. Starting with a low dose and gradually increasing it while monitoring for any adverse effects is advisable. Individuals with diabetes should exercise caution due to the potential glucose-lowering effects.
FAQs
Is longan berry extract effective for cancer prevention or treatment?
Evidence is limited to in vitro and animal studies showing anti-cancer potential; no clinical trials confirm efficacy in humans. More research is needed to determine its potential role in cancer prevention or treatment.
Can longan extract help with diabetes?
Animal studies suggest benefits on glucose metabolism and appetite regulation, but human data are needed. Individuals with diabetes should consult with their healthcare provider before using longan extract.
Is it safe to consume longan fruit or extract daily?
Moderate consumption appears safe; excessive intake of sugar-rich fruit may have adverse metabolic effects. It's important to consume longan in moderation as part of a balanced diet.
Does longan extract improve gut health?
Polysaccharides from longan have prebiotic properties that may support gut microbiota and immune function. However, more research is needed to fully understand its effects on gut health.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC3905590/ – This review and collection of in vitro and animal studies indicates that longan flower and seed extracts, rich in polyphenols, can inhibit cancer cell proliferation and inflammation. However, the review notes the absence of human RCTs, emphasizing that the findings are primarily preclinical and require further validation in human studies to confirm their clinical relevance.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC10322219/ – This animal RCT using db/db diabetic mice found that longan fruit extract reduced fasting glucose, improved insulin sensitivity, and modulated hypothalamic neurons, leading to reduced food intake. The study suggests potential benefits for managing diabetes, but the findings are limited by the small sample size, the use of an animal model, and the absence of human data.
- https://onlinelibrary.wiley.com/doi/full/10.1002/fft2.185 – This animal study on C57BL/6J mice revealed that excessive longan fruit intake promoted NAFLD through gut dysbiosis and inflammation. The study highlights the potential risks associated with high doses of longan fruit, particularly concerning metabolic health, and emphasizes that these high doses may not be typical for human consumption.
- https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.914679/full – This review of in vitro and animal studies suggests that longan polysaccharides possess immunomodulatory, antioxidant, and prebiotic effects, with enzymatic treatment enhancing their activity. The review acknowledges that the evidence is mostly preclinical and lacks human RCTs, indicating that further research is needed to confirm these effects in humans.
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