Luteolin

Luteolin is a flavone, one of the structural subclasses of the flavonoids, with the formula C15H10O6 and a yellow crystalline appearance. It is widely distributed across the plant kingdom, appearing in mosses, ferns, conifers, and flowering plants, and it often occurs bound to sugars as glycosides such as luteolin-7-O-glucoside rather than in free form ^[1]. The French chemist Michel Eugene Chevreul isolated and named it in 1829 from Reseda luteola, a plant known as weld that had been used as a yellow dye since antiquity; its empirical formula was worked out in 1864, its structure proposed in 1896, and its synthesis achieved around 1900.

Dietary luteolin comes from a range of common foods and herbs, among them celery, broccoli, green pepper, parsley, thyme, peppermint, rosemary, oregano, and chamomile, the last often consumed as a tea. Because intake varies widely with diet, luteolin is also marketed on its own or in combination products as a dietary supplement.

Much of the scientific interest in luteolin concerns its behavior in laboratory models. Preclinical studies describe antioxidant, anti-inflammatory, antimicrobial, and anticancer activities, and reviews summarize its ability to lower reactive oxygen species, dampen pro-inflammatory signaling, and interfere with the growth of cancer cells ^[1][2][4]. Work in skin models has examined luteolin as a modulator of inflammation and photodamage ^[3]. Despite this breadth of preclinical data, there is little clinical evidence that the amounts of luteolin obtained from foods meaningfully change human health outcomes, and reviewers stress that questions of dose, absorption, and long-term safety remain open ^[2].

Luteolin is consumed as a normal part of a plant-rich diet and is sold as a supplement, but it is not an approved drug for any condition. Its status therefore rests on preclinical findings and a modest body of early human research rather than on established medical use.

Luteolin is generally well tolerated at supplement doses, with occasional mild GI upset. It can inhibit some drug-metabolizing enzymes, so caution is warranted with medications that have narrow therapeutic windows. Long-term human safety data is limited but food exposure is reassuring.