The Sunlight Experiment

Compound Monograph

Luteolin

Luteolin — a flavone found in artichoke, Chinese skullcap, yarrow and related plants, best characterised in this database for inhibiting hepatic cholesterol biosynthesis.

Work in progress

Classification

Luteolin is a flavone (flavonoid), part of the phenolics class. Antioxidant compounds built around one or more phenol rings — the flavonoids, tannins, phenolic acids, coumarins, and pigments behind much of a plant's protective chemistry.

Phenolics Flavonoids

Where Does It Come From? (22)

Luteolin is a naturally occurring flavone (flavonoid), found in Arjuna, Globe Artichoke, Damiana and 19 other sources. It is well tolerated orally (low toxicity).

Arjuna Terminalia arjuna Catnip Nepeta cataria Celery Chinese Skullcap Scutellaria baicalensis Chrysanthemum Chrysanthemum morifolium Cornflower Centaurea cyanus Couchgrass Elytrigia repens Dagga Leonotis nepetifolia Damiana Turnera diffusa Dandelion Taraxacum officinale Feverfew Tanacetum parthenium Globe Artichoke Cynara scolymus Guamura Cecropia mexicana Holy Basil Ocimum tenuiflorum Hyssop Hyssopus officinalis Melissa Melissa officinalis OreganoParsley Passionflower Passiflora incarnata Stevia Stevia rebaudiana Thyme Thymus vulgaris Yarrow Achillea millefolium

Research & Evidence

Luteolin is a flavone that appears in the flavonoid fraction of many of the herbs in this database. In most of them it is listed as one constituent among many, but in the artichoke monograph it is singled out for a specific, well-described mechanism.

  • Cholesterol-lowering (hepatic cholesterol biosynthesis) — globe artichoke (Cynara scolymus) has a long-documented cholesterol-lowering effect. While cynarin was the first constituent credited with this action, later work showed it is not the only one: the inhibitory effect on hepatocytes associated with de novo cholesterol biosynthesis is attributed specifically to luteolin, which is reported to inhibit this pathway by roughly 30–80%. This works alongside the herb’s choleretic activity (increasing the excretion of cholesterol via bile), and the overall lipid effect has been confirmed in a randomised, double-blind, placebo-controlled study showing a significant decrease in LDL and an increase in HDL 1Reference 1Kraft · 1997Artichoke leaf extract — Recent findings reflecting effects on lipid metabolism, liver and gastrointestinal tracts.
  • Flavonoid fraction of other herbs — luteolin is otherwise listed among the flavonoids of arjuna, damiana, feverfew (including luteolin 7-glucuronide), passionflower, Chinese skullcap, stevia, and yarrow. In several of these it forms part of the antiallergic, anti-inflammatory, or antioxidant flavonoid group of the whole plant rather than being studied in isolation. (Chinese skullcap’s monograph notes luteolin among the flavones in its antiallergic fraction, but the inline citation attached to that statement points to an unrelated reference, so that specific claim is not carried here.)

This is a focused summary: the genuinely compound-specific, well-matched evidence on the source pages centres on the artichoke cholesterol finding. The reference below is the entry that supports it, and this section will grow as more luteolin-specific research is added.

Monoamine oxidase (MAO) inhibition

Luteolin is a MAO-A-preferring flavone inhibitor: in isolated-enzyme work it inhibited MAO-A with an IC50 around 5 µM, versus roughly 60 µM for MAO-B 2Reference 2Han et al. · 2007Monoamine oxidase inhibitory components from Cayratia japonicaView study →. As with the other dietary flavonoids, the activity is real but modest next to the β-carbolines. See the natural MAO inhibitors guide for the comparison.

Toxicity & Safety

Luteolin is a common dietary flavone present in everyday foods such as celery, parsley, and thyme, and is well tolerated in the amounts supplied by the herbs that contain it. The source monographs do not record specific toxicity for luteolin; any cautions on those pages relate to the whole herbs rather than to this flavonoid. As with any concentrated flavonoid supplement, isolated high-dose use is a separate matter from dietary intake, and anyone who is pregnant, breastfeeding, or taking prescription medication — particularly lipid-lowering or other liver-metabolised medication, given luteolin’s documented effect on hepatic cholesterol synthesis — should seek professional guidance before using concentrated extracts.

References

  1. Kraft, K. (1997). Artichoke leaf extract — Recent findings reflecting effects on lipid metabolism, liver and gastrointestinal tracts. Phytomedicine, 4(4), 369-378.
  2. Han, X. H., Hong, S. S., Hwang, J. S., Lee, M. K., Hwang, B. Y., & Ro, J. S. (2007). Monoamine oxidase inhibitory components from Cayratia japonica. Archives of Pharmacal Research, 30(1), 13-17. https://pubmed.ncbi.nlm.nih.gov/17328236/