Pharmacological effects

Kaempferol (3,5,7‐trihydroxy‐2‐[4‐hydroxyphenyl]‐4H‐1‐benzopyran‐4‐one) is a yellow bioactive flavonoid, which is present inmany edible plants such as tea, cabbage, broccoli, endive, kale, beans, tomato, strawberries, leek, and grapes. It has a significant role in reducing cancer and can act as a therapeutic agent in the treatment of diseases and ailments such as diabetes, obesity, cardiovascular diseases, oxidative stress, asthma, and microbial contamination disorders. Its efficacy, a broad range of activity, and low toxicity compared with other examined compounds, make it an attractive chemical in the fight against diseases (including cancer).

Mechanism of action

Kaempferol acts through different mechanisms: It induces apoptosis (HeLa cervical cancer cells), decreases cell viability (G2/M phase), downregulates phosphoinositide 3‐kinase (PI3K)/AKT (protein kinase B) and human T‐cell leukemia/lymphoma virus‐I (HTLV-I) signaling pathways, suppresses protein expression of epithelial‐mesenchymal transition (EMT)‐related markers including N‐cadherin, E‐cadherin, Slug, and Snail, and metastasis‐related markers such as matrix metallopeptidase 2 (MMP-2).

Bioactivity

As an anti‐oxidant, kaempferol counteracts production of superoxide ions and lowers the formation of reactive oxygen and nitrogen species. It also scavenges Fenton‐generated hydroxyl radical, peroxynitrite, and hydroxyl radicals. Furthermore, kaempferol suppresses the activity of xanthine oxidase and enhances the activities of catalase, heme oxygenase‐1, and superoxide dismutase.

Biological Activity

Naturally occurring flavonoid found in Gingko biloba and red wines that activates the mitochondrial Ca 2+ uniporter (EC 50 = 7 μ M). Induces caspase-9-mediated apoptosis in a variety of cancer cell lines via downregulation of polo-like kinase 1 (PLK1) expression. Exhibits antioxidant activity and attenuates osteoclastic bone reabsorption in vitro .

Biochem/physiol Actions

Potent inhibitor of osteoclastic bone resorption. The effect is believed to be attributable to both the antioxidant and estrogenic activities of kaempferol.

Anticancer Research

Kaempferol is one of the secondary metabolites found in some plants, plant-derivedfoods, and traditional medicines. It is a flavonoid compound obtained from someedible plants including grapes, tea, strawberries, broccoli, tomato, cabbage, leek,kale, endive, and beans. It inhibits growth and migration of pancreatic cancer cellsby acting on proto-oncogene tyrosine kinase (Src), ERK1/2, and AKT pathways(Singh et al. 2016a). It is being investigated in pancreatic and lung cancers toevaluate its antiangiogenic, anticancer, and radical scavenging activities. It showsmoderate cytostatic activity in PC3, HeLa, and K562 human cancer cells. It isidentified as aryl hydrocarbon receptor antagonist and acts against ABCG2 (ATP-bindingcassette subfamily G member 2)-mediated multidrug resistance bypreventing the ABCG2 upregulation in esophageal carcinoma. It induces theapoptosis of ovarian cancer cell by activating p53 in intrinsic pathway mechanism.It is an inhibitor of breast cancer resistance protein (BCRP), quinine reductase-2,and a substrate of BCRP (Calderon-Montano et al. 2011; Wang et al. 2012).

General Description

Kaempferol is a polyphenolic antioxidant abundantly present in vegetables and fruits. It has a diphenylpropane structure. In many plants, it is present as a glycosidic form namely, kaempferol-3-O-glucoside.