Loquat Seed Extract (Eriobotrya japonica)

Loquat seed extract (Eriobotrya japonica) is rich in triterpene acids—including ursolic acid and oleanolic acid—that suppress NF-κB and p38 MAPK inflammatory signaling while upregulating Nrf2-mediated antioxidant defenses. In vivo studies demonstrate that loquat-derived ursolic acid attenuates amyloid-β burden and memory impairment (PMID 37798424), while loquat fruit peel extract significantly regulates lipid metabolism and reduces liver oxidative stress in mice (PMID 36918050).

Origin & History

Loquat Seed Extract is sourced from the seeds of Eriobotrya japonica, a tree native to Southeast China and widely cultivated across Asia, the Mediterranean, and parts of the U.S. Revered in traditional Chinese medicine, this botanical concentrate is known for its potent antioxidant, antimicrobial, and anti-inflammatory properties, supporting respiratory, digestive, metabolic, and dermatological health.

Historical & Cultural Context

In traditional Chinese medicine, Loquat seed has been prized for generations as a soothing respiratory and digestive remedy, celebrated for clearing heat, moisturizing lungs, and detoxifying the liver. Now gaining recognition in modern herbal therapeutics and skincare, it bridges ancient botanical wisdom and science-backed wellness.

Health Benefits

- **Supports respiratory health**: by acting as an expectorant and reducing bronchial inflammation.
- **Enhances immune resilience**: through triterpenes and polyphenols that modulate immune responses.
- **Provides potent antioxidant**: protection by neutralizing free radicals and reducing oxidative stress.
- **Optimizes metabolic health**: by promoting liver detoxification and improving insulin sensitivity.
- **Supports skin health**: by reducing inflammation and promoting collagen synthesis.
- **Offers neuroprotection by**: combating oxidative damage in neural tissues.
- **Promotes digestive wellness**: by soothing inflammation and supporting gut microbiota.

How It Works

The principal triterpenes ursolic acid and oleanolic acid inhibit the phosphorylation of IκBα and translocation of NF-κB p65, thereby suppressing transcription of pro-inflammatory cytokines TNF-α, IL-6, and IL-8; they concurrently block p38 MAPK and ERK1/2 signaling cascades (PMID 40634939, PMID 27323036). Loquat-derived triterpene acids also antagonize cysteinyl leukotriene receptor 1 (CysLTR1), providing an additional anti-inflammatory mechanism relevant to airway inflammation (PMID 40634939). The extract activates the Keap1-Nrf2-ARE pathway, upregulating phase II antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), which collectively reduce hepatic and systemic oxidative stress (PMID 36918050). Chlorogenic acid and other polyphenolic constituents modulate HPA-axis-related glucocorticoid signaling and BDNF expression, contributing to the extract's observed antidepressant-like activity (PMID 37513484).

Scientific Research

Mokhtari et al. (2023) demonstrated that loquat fruit peel extract significantly regulated lipid metabolism and attenuated liver oxidative stress in mice via in vivo and in silico approaches (J Ethnopharmacol, PMID 36918050). Iwasa et al. (2023) showed that long-term administration of loquat leaves and their principal compound ursolic acid attenuated endogenous amyloid-β burden and rescued memory impairment in a murine model (Sci Rep, PMID 37798424). Lim et al. (2023) found that dried loquat fruit extract containing chlorogenic acid prevented depressive-like behaviors induced by repeated corticosteroid injections in mice (Molecules, PMID 37513484). Yang et al. (2025) identified triterpene acids from loquat fruit screened via CysLTR1-immobilized affinity chromatography that serve as potent alternative anti-inflammatory agents by antagonizing cysteinyl leukotriene receptor 1 (BMC Complement Med Ther, PMID 40634939).

Clinical Summary

Animal studies using 40-400 mg/kg daily for 6 weeks showed significant decreases in total cholesterol, LDL, and triglycerides with onset at 2-3 weeks. In vitro studies demonstrate >66.7% antioxidant inhibition at 1000 ppm, nearly matching pharmaceutical-grade TBHQ. Liver enzyme suppression (GOT, ALP, GGT) and body weight reduction were observed in high-fat diet animal models. Human clinical trial data remains limited, with most evidence derived from animal and cell culture studies.

Nutritional Profile

- Phytochemicals: Triterpenes (ursolic acid, corosolic acid), Polyphenols, Flavonoids (quercetin, kaempferol), Saponins
- Bioactives: Amygdalin (Vitamin B17), Polysaccharides
- Minerals: Potassium, Calcium, Magnesium

Preparation & Dosage

- Common Forms: Standardized extract (powder, capsules), tinctures.
- Traditional Use: While the fruit and leaves were traditionally used in Chinese and Japanese medicine for respiratory and digestive ailments, the seed extract is a modern concentration.
- Modern Use: Incorporated into respiratory supplements, blood sugar-regulating formulations, antioxidant-rich teas, and dermatological products.
- Dosage: 400–800 mg standardized extract daily.

Synergy & Pairings

Role: Polyphenol/antioxidant base (innate energy support)
Intention: Immune & Inflammation | Metabolic Health | Respiratory Health
Primary Pairings: - Licorice Root (Glycyrrhiza glabra)
- Mullein (Verbascum thapsus)
- Ginseng (Panax ginseng)
- Reishi Mushroom (Ganoderma lucidum)

Safety & Interactions

Loquat seeds contain small amounts of cyanogenic glycosides (amygdalin), which can release hydrogen cyanide upon enzymatic hydrolysis; proper extraction and processing are essential to minimize this risk, and raw seed consumption is not recommended. Due to the extract's documented effects on lipid metabolism and blood glucose, concurrent use with statins, fibrates, or antidiabetic medications (e.g., metformin, sulfonylureas) should be monitored by a healthcare provider for possible additive hypoglycemic or hypolipidemic effects. Ursolic acid has been shown to inhibit CYP3A4 activity in vitro, which could theoretically alter the pharmacokinetics of drugs metabolized by this enzyme, including cyclosporine, certain statins, and calcium channel blockers. Pregnant and breastfeeding women should avoid loquat seed extract due to insufficient human safety data.