A Review on the Dietary Flavonoid Kaempferol

Abstract

Epidemiological studies have revealed that a diet rich in plant-derived foods has a protective effect on human health. Identifying bioactive dietary constituents is an active area of scientific investigation that may lead to new drug discovery. Kaempferol (3,5,7-trihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one) is a flavonoid found in many edible plants (e.g. tea, broccoli, cabbage, kale, beans, endive, leek, tomato, strawberries and grapes) and in plants or botanical products commonly used in traditional medicine (e.g. Ginkgo biloba, Tilia spp, Equisetum spp, Moringa oleifera, Sophora japonica and propolis). Some epidemiological studies have found a positive association between the consumption of foods containing kaempferol and a reduced risk of developing several disorders such as cancer and cardiovascular diseases. Numerous preclinical studies have shown that kaempferol and some glycosides of kaempferol have a wide range of pharmacological activities, including antioxidant, anti-inflammatory, antimicrobial, anticancer, cardioprotective, neuroprotective, antidiabetic, anti-osteoporotic, estrogenic/antiestrogenic, anxiolytic, analgesic and antiallergic activities. In this article, the distribution of kaempferol in the plant kingdom and its pharmacological properties are reviewed. The pharmacokinetics (e.g. oral bioavailability, metabolism, plasma levels) and safety of kaempferol are also analyzed. This information may help understand the health benefits of kaempferol-containing plants and may contribute to develop this flavonoid as a possible agent for the prevention and treatment of some diseases.

Inhibition of airway epithelial-to-mesenchymal transition and fibrosis by kaempferol in endotoxin-induced epithelial cells and ovalbumin-sensitized mice

“…Numerous pre-clinical studies have shown that kaempferol exerts a wide range of pharmacological properties, such as antioxidant, anti-inflammatory, anti-cancer, cardioprotective, neuroprotective, anti-diabetic, anti-osteoporotic and anti-allergic activities. 18 Flavonols of kaempferol and quercetin inhibit IgEmediated release of pro-inflammatory IL-6, IL-8 and TNF-a from mast cells possibly through inhibition of intracellular calcium influx and PKC theta signaling, being suitable for the treatment of allergic and inflammatory diseases. 28 Our recent studies have demonstrated that kaempferol suppresses eosionphil infiltration and airway inflammation in airway epithelial cells and in mice with allergic asthma.…”

“…Kaempferol is a strong antioxidant preventing oxidative cell damage and inhibiting oxidation of LDL and induction of inflammatory mediators involved in the initial steps of atherosclerotic plaque formation. 18,19 In our previous studies, 20,21 kaempferol suppressed eosionphil infiltration and airway inflammation in airway epithelial cells and in mice with allergic asthma. There are numerous studies dealing with inhibitory effects of polyphenols on airway dysfunction and disorders.…”

Modulation of hyperglycemia and TNFα-mediated inflammation by helichrysum and grapefruit extracts in diabetic db/db mice

“…17 Thus, benecial roles of kaempferol have been reported in inammation, hyperglycemia and diabetes using different in vitro and in vivo models. 18 In addition, some investigations concluded that the anti-inammatory activity of Helichrysum italicum may be explained by enzyme inhibition, free-radical scavenging activity and corticoid-like effects. 19 In this sense, our group previously demonstrated that helichrysum and grapefruit extracts ameliorated hyperglycemia by inhibiting a-glucosidase (a similar mechanism to acarbose) and a-amylase enzyme activities and by decreasing the SGLT1-mediated glucose uptake in the gut.…”

Flowers in Australia: Phytochemical Studies on the Illawarra Flame Tree and Alstonville

“…and other human pathogenic bacteria. [22,23] Alstonville (T. lepidota) is used mostly as an ornamental plant due to their dark purple flowers with no medicinal usage previously reported. However, other species within the genus have been reported to possess various biological activities such as wound healing and to treat cataract.…”