The Sunlight Experiment

Compound Monograph

Kaempferol

Kaempferol — a common dietary flavonol found across many medicinal plants, present in the antioxidant flavonoid fraction of herbs such as green tea, hops, gotu kola, and yerba maté.

Work in progress

Classification

Kaempferol is a flavonol (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? (34)

Kaempferol is a naturally occurring flavonol (flavonoid), found in Cashew, Gotu Kola, Hops and 31 other sources. It is well tolerated orally (low toxicity).

Acacia Acacia spp. African Dream Herb Entada rheedii Amaranth Amaranthus blitum Arjuna Terminalia arjuna Bay Bean Canavalia rosea Beans Blue Lotus Flower Nymphaea caerulea Broccoli Calamus Acorus calamus Cashew Anacardium occidentale Chickweed Stellaria media Clove Syzygium aromaticum Coltsfoot Tussilago farfara Fennel Foeniculum vulgare Goldenrod Solidago virgaurea Gotu Kola Centella asiatica Guamura Cecropia mexicana Hibiscus Hibiscus rosa-sinensis Hops Humulus lupulus Horse Chestnut Aesculus hippocastanum Horsetail Equisetum arvense Kale Marshmallow Althaea officinalis Passionflower Passiflora incarnata Raspberry Leaf Rubus idaeus Senna Cassia angustifolia Spinach St. John's Wort Hypericum perforatum Stevia Stevia rebaudiana Stinging Nettle Urtica dioica Tea Camellia sinensis Tribulus Tribulus terrestris Wireweed Sida acuta Yerba Maté Ilex paraguariensis

Research & Evidence

Kaempferol is one of the most widely distributed dietary flavonols, and across this database it shows up in the flavonoid fraction of a wide range of plants. On the source-herb pages it is almost always listed as one constituent among many rather than studied in isolation, so the compound-specific evidence here is limited.

  • Flavonoid content of green tea — green tea is noted to have a higher kaempferol content (along with higher quercetin and catechin content) than white and black teas, while having the lowest gallic acid 1Reference 1Barceloux · 2012Medical toxicology of drug abuse: synthesized chemicals and psychoactive plants. Kaempferol therefore forms part of the antioxidant flavonoid profile that characterises green tea.
  • Antibacterial contribution (yerba maté) — kaempferol is named among the compounds (alongside citric acid, caffeic acid, chlorogenic acid, quercetin, and quinic acid) credited with the bactericidal and inhibitory activity of an aqueous yerba maté extract against methicillin-resistant Staphylococcus aureus (MRSA). The yerba maté monograph does not carry a transcribable reference list for this claim, so it is reported here without a citation marker rather than attributing a fabricated source.
  • General flavonoid fraction — kaempferol is otherwise listed as part of the flavonoid content of cashew, gotu kola, hops, marshmallow, passionflower, stevia, and stinging nettle, contributing to the overall antioxidant character of those whole-plant extracts rather than being singled out for a specific action.

The genuinely compound-specific, citable evidence on the source pages is thin, so this is deliberately a short summary. The single reference below is the entry that supports the green-tea composition claim, and this section will grow as more kaempferol-specific research is added.

Monoamine oxidase (MAO) inhibition

Kaempferol is one of the more active dietary flavonols against monoamine oxidase, reported as a MAO-A-preferring inhibitor with an IC50 around 0.7 µM for MAO-A and much weaker activity on MAO-B in isolated-enzyme work 2Reference 2Sloley et al. · 2000Identification of kaempferol as a monoamine oxidase inhibitor and potential neuroprotectant in extracts of Ginkgo biloba leavesView study →. As with the other flavonoids, this is a genuine but modest activity next to the β-carboline MAO inhibitors. See the natural MAO inhibitors guide for context.

Toxicity & Safety

Kaempferol is a common dietary flavonol present in many everyday foods — kale, spinach, broccoli, beans, and tea — and is well tolerated in the amounts supplied by the herbs that contain it. The source monographs do not record specific toxicity for kaempferol; 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 should seek professional guidance before using concentrated extracts.

References

  1. Barceloux, D. G. (2012). Medical toxicology of drug abuse: synthesized chemicals and psychoactive plants. John Wiley & Sons.
  2. Sloley, B. D., Urichuk, L. J., Morley, P., Durkin, J., Shan, J. J., Pang, P. K. T., & Coutts, R. T. (2000). Identification of kaempferol as a monoamine oxidase inhibitor and potential neuroprotectant in extracts of Ginkgo biloba leaves. Journal of Pharmacy and Pharmacology, 52(4), 451-459. https://pubmed.ncbi.nlm.nih.gov/10813558/