Preventive and potential therapeutic insights into dietary flavonoid isoquercitrin: From plant sources to female reproductive health

ABSTRACT Isoquercitrin, or quercetin-3-O-β-D-glucopyranoside, is a dietary flavonoid abundantly present in fruits, vegetables, medicinal plants and other plant-derived foods. Known for its broad pharmacological potential, isoquercitrin exhibits antioxidant, anti-inflammatory, neuroprotective, and anticancer activities in preclinical models. This structured narrative review provides a comprehensive overview of current findings related to isoquercitrin, with a particular focus on its food sources, extraction and production methods, including green and enzymatic approaches, responses to food processing, stability, bioaccessibility, bioavailability, metabolic fate, and cellular mechanisms of action. Isoquercitrin demonstrates favorable bioavailability and metabolic stability compared with quercetin, which may contribute to its biological relevance. In addition to systemic effects, emerging preclinical evidence suggests that isoquercitrin may modulate pathways associated with female reproductive physiology. Evidence relating to ovarian function is derived primarily from human-derived cell models, evidence concerning uterine effects remains particularly sparse, and observations regarding oestrogen-deficiency-associated bone remodelling derive mainly from animal studies. Isoquercitrin has also demonstrated cytotoxic and antiproliferative effects against various tumor cell types, including breast, ovarian, colon, and bladder cancer models, while showing comparatively lower effects on healthy cells in some experimental systems. However, most available evidence is based on in vitro studies and animal models, and human intervention data remain limited. This review brings together multidisciplinary evidence on isoquercitrin's biological activities and potential applications, with particular attention to underexplored reproductive-health-related effects. It also highlights key knowledge gaps and future research needs, emphasizing the need for further in vivo and clinical studies before potential therapeutic applications can be established.