Kaempferol

Kaempferol (3,5,7,4’-tetrahydroxyflavone; C₁₅H₁₀O₆) is among the natural flavonols found in green tea, broccoli, cabbage, kale, endive, beans, leeks, tomatoes, grapes, apples, grapefruit, berries, and propolis, as well as myriad other plant sources, including Brassica and species (J. Agric. Food Chem. 2006;54:2951-6; Cancer Prev. Res. (Phila) 2014;7:958-67; Biochem. Pharmacol. 2010;80:2042-9; Chem. Pharm. Bull. (Tokyo) 2012;60:1171-5; J. Eur. Acad. Dermatol. Venereol. 2013 June 27 [doi:10.1111/jdv.12204]).

It is one of the most commonly found dietary flavonoids and is also present in beer, particularly hops (Carcinogenesis 2010;31:1338-43; J. Eur. Acad. Dermatol. Venereol. 2013 June 27 [doi:10.1111/jdv.12204]). Significantly, kaempferol is known to exhibit anticancer, anti-inflammatory, antioxidant, cytoprotective, and antiapoptotic activity (Cancer Prev. Res. (Phila) 2014;7:958-67; Biochem. Pharmacol. 2010;80:2042-9; Exp. Mol. Med. 2008;40:208-19), and is believed to play a role in protecting plants from ultraviolet (UV)-induced damage (J. Agric. Food Chem. 2012;60:6966-76).

Skin protection: antioxidant and anti-inflammatory activity

Among 35 flavonoids tested by Cos et al. in 2001 for lipid peroxidation-inhibiting activity, kaempferol was identified as having the highest antioxidant selectivity index (Planta Med. 2001;67:515-9).

Work by Kim et al. in 2002 revealed that four kaempferol glycosides are key active ingredients in the flowers of Prunus persica, which has long been used in traditional Chinese medicine to treat skin disorders (J. Cosmet. Sci. 2002;53:27-34). Kim and colleagues have also shown in animal studies that the topical application of P. persica may be effective at thwarting UVB-induced skin damage (J. Cosmet. Sci. 2002;53:27-34).

In addition, kaempferol is a key component in Punica granatum, which has been found to act as an effective protector against UVB-induced photodamage and aging in cultured skin fibroblasts (Int. J. Dermatol. 2010;49:276-82).

In various tests on the effects of natural flavonoids on matrix metalloproteinase (MMP)-1 activity and expression, Lim et al. reported in 2007 that kaempferol and quercetin potently inhibited recombinant human MMP-1, and both flavonols along with apigenin and wogonin were found to be strong inhibitors of MMP-1 induction in 12-O-tetradecanoylphorbol-13-acetate–treated human dermal fibroblasts. All four flavonoids also suppressed the activation of activator protein (AP)-1. Kaempferol also hindered p38 mitogen-activated protein kinase c-Jun N-terminal kinase (JNK) activation. The investigators concluded that kaempferol is among the flavonoids or plant extracts containing them that may be useful as an agent to protect against photoaging and to treat some cutaneous inflammatory conditions (Planta Med. 2007;73:1267-74).

In 2010, Park et al. demonstrated that kaempferol alleviated burn injuries in mice and that expression of tumor necrosis factor–alpha (TNF-alpha) induced by burn injuries was reduced by kaempferol. They concluded that their findings suggest the possible application of kaempferol to treat thermal burn–induced skin injuries (BMB Rep. 2010;43:46-51).

Anti-inflammatory as well as depigmenting activity was found by Rho et al. in 2011 to be associated with kaempferol and kaempferol rhamnosides isolated from Hibiscus cannabinus (Molecules 2011;16:3338-44).

In 2014, Kim et al. found that extracts of Aceriphyllum rossii (native to Korea and China) and its active constituents, quercetin and kaempferol, blocked secretion of beta-hexosaminidase and histamine; lowered the production and mRNA expression of interleukin-4 and TNF-alpha; and reduced prostaglandin E₂ and leukotriene B₄ synthesis as well as the expression of cyclooxygenase-2 (COX-2) and 5-lipoxygenase. These and other findings led the investigators to conclude that A. rossii and its active ingredients kaempferol and quercetin may be effective agents for the treatment of immediate-type hypersensitivity (J. Agric. Food Chem. 2014;62:3750-8).

Anticancer activity

Lee et al. reported in 2010 that the inhibition by kaempferol of phosphatidylinositol 3-kinase (PI3K) activity, a key factor in carcinogenesis, and its concomitant effects may account for the chemopreventive activity of the flavonol (Carcinogenesis 2010;31:1338-43).

At the end of that year, Lee et al. found that kaempferol inhibited UVB-induced COX-2 protein expression in mouse skin epidermal JB6 P+ cells, by blocking Src kinase activity and attenuated the UVB-induced transcriptional activities of COX-2 gene and the transcription factor AP-1. They concluded that kaempferol exerts robust chemopreventive activity against skin cancer by suppressing Src (Biochem. Pharmacol. 2010;80:2042-9).

In 2014, Yao et al. found that kaempferol acted as a safe and potent inhibitor of solar ultraviolet-induced mouse skin carcinogenesis that acted by targeting RSK2 and MSK1 (Cancer Prev. Res. (Phila) 2014;7:958-67).

Significantly, in terms of topical delivery, Chao et al. recently showed that submicron emulsions are effective carriers for the transdermal delivery of kaempferol (Chem. Pharm. Bull. (Tokyo) 2012;60:1171-5).

Conclusion

Kaempferol is one among the many natural flavonols found to exert significant salutary effects. Evidence suggests reasons for confidence that kaempferol can play a role in skin health. More research is necessary to determine the effectiveness of topical products intended to harness the benefits of this flavonoid as proper formulation is challenging.

Dr. Baumann is chief executive officer of the Baumann Cosmetic & Research Institute in the Design District in Miami. She founded the Cosmetic Dermatology Center at the University of Miami in 1997. Dr. Baumann wrote the textbook, “Cosmetic Dermatology: Principles and Practice” (New York: McGraw-Hill, 2002), and a book for consumers, “The Skin Type Solution” (New York: Bantam Dell, 2006). She has contributed to the Cosmeceutical Critique column in Dermatology News since January 2001. Her latest book, “Cosmeceuticals and Cosmetic Ingredients,” was published in November 2014. Dr. Baumann has received funding for clinical grants from Allergan, Aveeno, Avon Products, Evolus, Galderma, GlaxoSmithKline, Kythera, Mary Kay, Medicis Pharmaceuticals, Neutrogena, Philosophy, Topix Pharmaceuticals, and Unilever.

Kaempferol (3,5,7,4’-tetrahydroxyflavone; C₁₅H₁₀O₆) is among the natural flavonols found in green tea, broccoli, cabbage, kale, endive, beans, leeks, tomatoes, grapes, apples, grapefruit, berries, and propolis, as well as myriad other plant sources, including Brassica and species (J. Agric. Food Chem. 2006;54:2951-6; Cancer Prev. Res. (Phila) 2014;7:958-67; Biochem. Pharmacol. 2010;80:2042-9; Chem. Pharm. Bull. (Tokyo) 2012;60:1171-5; J. Eur. Acad. Dermatol. Venereol. 2013 June 27 [doi:10.1111/jdv.12204]).

It is one of the most commonly found dietary flavonoids and is also present in beer, particularly hops (Carcinogenesis 2010;31:1338-43; J. Eur. Acad. Dermatol. Venereol. 2013 June 27 [doi:10.1111/jdv.12204]). Significantly, kaempferol is known to exhibit anticancer, anti-inflammatory, antioxidant, cytoprotective, and antiapoptotic activity (Cancer Prev. Res. (Phila) 2014;7:958-67; Biochem. Pharmacol. 2010;80:2042-9; Exp. Mol. Med. 2008;40:208-19), and is believed to play a role in protecting plants from ultraviolet (UV)-induced damage (J. Agric. Food Chem. 2012;60:6966-76).

Skin protection: antioxidant and anti-inflammatory activity

Among 35 flavonoids tested by Cos et al. in 2001 for lipid peroxidation-inhibiting activity, kaempferol was identified as having the highest antioxidant selectivity index (Planta Med. 2001;67:515-9).

Work by Kim et al. in 2002 revealed that four kaempferol glycosides are key active ingredients in the flowers of Prunus persica, which has long been used in traditional Chinese medicine to treat skin disorders (J. Cosmet. Sci. 2002;53:27-34). Kim and colleagues have also shown in animal studies that the topical application of P. persica may be effective at thwarting UVB-induced skin damage (J. Cosmet. Sci. 2002;53:27-34).

In addition, kaempferol is a key component in Punica granatum, which has been found to act as an effective protector against UVB-induced photodamage and aging in cultured skin fibroblasts (Int. J. Dermatol. 2010;49:276-82).

In various tests on the effects of natural flavonoids on matrix metalloproteinase (MMP)-1 activity and expression, Lim et al. reported in 2007 that kaempferol and quercetin potently inhibited recombinant human MMP-1, and both flavonols along with apigenin and wogonin were found to be strong inhibitors of MMP-1 induction in 12-O-tetradecanoylphorbol-13-acetate–treated human dermal fibroblasts. All four flavonoids also suppressed the activation of activator protein (AP)-1. Kaempferol also hindered p38 mitogen-activated protein kinase c-Jun N-terminal kinase (JNK) activation. The investigators concluded that kaempferol is among the flavonoids or plant extracts containing them that may be useful as an agent to protect against photoaging and to treat some cutaneous inflammatory conditions (Planta Med. 2007;73:1267-74).

In 2010, Park et al. demonstrated that kaempferol alleviated burn injuries in mice and that expression of tumor necrosis factor–alpha (TNF-alpha) induced by burn injuries was reduced by kaempferol. They concluded that their findings suggest the possible application of kaempferol to treat thermal burn–induced skin injuries (BMB Rep. 2010;43:46-51).

Anti-inflammatory as well as depigmenting activity was found by Rho et al. in 2011 to be associated with kaempferol and kaempferol rhamnosides isolated from Hibiscus cannabinus (Molecules 2011;16:3338-44).

In 2014, Kim et al. found that extracts of Aceriphyllum rossii (native to Korea and China) and its active constituents, quercetin and kaempferol, blocked secretion of beta-hexosaminidase and histamine; lowered the production and mRNA expression of interleukin-4 and TNF-alpha; and reduced prostaglandin E₂ and leukotriene B₄ synthesis as well as the expression of cyclooxygenase-2 (COX-2) and 5-lipoxygenase. These and other findings led the investigators to conclude that A. rossii and its active ingredients kaempferol and quercetin may be effective agents for the treatment of immediate-type hypersensitivity (J. Agric. Food Chem. 2014;62:3750-8).

Anticancer activity

Lee et al. reported in 2010 that the inhibition by kaempferol of phosphatidylinositol 3-kinase (PI3K) activity, a key factor in carcinogenesis, and its concomitant effects may account for the chemopreventive activity of the flavonol (Carcinogenesis 2010;31:1338-43).

At the end of that year, Lee et al. found that kaempferol inhibited UVB-induced COX-2 protein expression in mouse skin epidermal JB6 P+ cells, by blocking Src kinase activity and attenuated the UVB-induced transcriptional activities of COX-2 gene and the transcription factor AP-1. They concluded that kaempferol exerts robust chemopreventive activity against skin cancer by suppressing Src (Biochem. Pharmacol. 2010;80:2042-9).

In 2014, Yao et al. found that kaempferol acted as a safe and potent inhibitor of solar ultraviolet-induced mouse skin carcinogenesis that acted by targeting RSK2 and MSK1 (Cancer Prev. Res. (Phila) 2014;7:958-67).

Significantly, in terms of topical delivery, Chao et al. recently showed that submicron emulsions are effective carriers for the transdermal delivery of kaempferol (Chem. Pharm. Bull. (Tokyo) 2012;60:1171-5).

Conclusion

Kaempferol is one among the many natural flavonols found to exert significant salutary effects. Evidence suggests reasons for confidence that kaempferol can play a role in skin health. More research is necessary to determine the effectiveness of topical products intended to harness the benefits of this flavonoid as proper formulation is challenging.

Dr. Baumann is chief executive officer of the Baumann Cosmetic & Research Institute in the Design District in Miami. She founded the Cosmetic Dermatology Center at the University of Miami in 1997. Dr. Baumann wrote the textbook, “Cosmetic Dermatology: Principles and Practice” (New York: McGraw-Hill, 2002), and a book for consumers, “The Skin Type Solution” (New York: Bantam Dell, 2006). She has contributed to the Cosmeceutical Critique column in Dermatology News since January 2001. Her latest book, “Cosmeceuticals and Cosmetic Ingredients,” was published in November 2014. Dr. Baumann has received funding for clinical grants from Allergan, Aveeno, Avon Products, Evolus, Galderma, GlaxoSmithKline, Kythera, Mary Kay, Medicis Pharmaceuticals, Neutrogena, Philosophy, Topix Pharmaceuticals, and Unilever.

Kaempferol (3,5,7,4’-tetrahydroxyflavone; C₁₅H₁₀O₆) is among the natural flavonols found in green tea, broccoli, cabbage, kale, endive, beans, leeks, tomatoes, grapes, apples, grapefruit, berries, and propolis, as well as myriad other plant sources, including Brassica and species (J. Agric. Food Chem. 2006;54:2951-6; Cancer Prev. Res. (Phila) 2014;7:958-67; Biochem. Pharmacol. 2010;80:2042-9; Chem. Pharm. Bull. (Tokyo) 2012;60:1171-5; J. Eur. Acad. Dermatol. Venereol. 2013 June 27 [doi:10.1111/jdv.12204]).

It is one of the most commonly found dietary flavonoids and is also present in beer, particularly hops (Carcinogenesis 2010;31:1338-43; J. Eur. Acad. Dermatol. Venereol. 2013 June 27 [doi:10.1111/jdv.12204]). Significantly, kaempferol is known to exhibit anticancer, anti-inflammatory, antioxidant, cytoprotective, and antiapoptotic activity (Cancer Prev. Res. (Phila) 2014;7:958-67; Biochem. Pharmacol. 2010;80:2042-9; Exp. Mol. Med. 2008;40:208-19), and is believed to play a role in protecting plants from ultraviolet (UV)-induced damage (J. Agric. Food Chem. 2012;60:6966-76).

Skin protection: antioxidant and anti-inflammatory activity

Among 35 flavonoids tested by Cos et al. in 2001 for lipid peroxidation-inhibiting activity, kaempferol was identified as having the highest antioxidant selectivity index (Planta Med. 2001;67:515-9).

Work by Kim et al. in 2002 revealed that four kaempferol glycosides are key active ingredients in the flowers of Prunus persica, which has long been used in traditional Chinese medicine to treat skin disorders (J. Cosmet. Sci. 2002;53:27-34). Kim and colleagues have also shown in animal studies that the topical application of P. persica may be effective at thwarting UVB-induced skin damage (J. Cosmet. Sci. 2002;53:27-34).

In addition, kaempferol is a key component in Punica granatum, which has been found to act as an effective protector against UVB-induced photodamage and aging in cultured skin fibroblasts (Int. J. Dermatol. 2010;49:276-82).

In various tests on the effects of natural flavonoids on matrix metalloproteinase (MMP)-1 activity and expression, Lim et al. reported in 2007 that kaempferol and quercetin potently inhibited recombinant human MMP-1, and both flavonols along with apigenin and wogonin were found to be strong inhibitors of MMP-1 induction in 12-O-tetradecanoylphorbol-13-acetate–treated human dermal fibroblasts. All four flavonoids also suppressed the activation of activator protein (AP)-1. Kaempferol also hindered p38 mitogen-activated protein kinase c-Jun N-terminal kinase (JNK) activation. The investigators concluded that kaempferol is among the flavonoids or plant extracts containing them that may be useful as an agent to protect against photoaging and to treat some cutaneous inflammatory conditions (Planta Med. 2007;73:1267-74).

In 2010, Park et al. demonstrated that kaempferol alleviated burn injuries in mice and that expression of tumor necrosis factor–alpha (TNF-alpha) induced by burn injuries was reduced by kaempferol. They concluded that their findings suggest the possible application of kaempferol to treat thermal burn–induced skin injuries (BMB Rep. 2010;43:46-51).

Anti-inflammatory as well as depigmenting activity was found by Rho et al. in 2011 to be associated with kaempferol and kaempferol rhamnosides isolated from Hibiscus cannabinus (Molecules 2011;16:3338-44).

In 2014, Kim et al. found that extracts of Aceriphyllum rossii (native to Korea and China) and its active constituents, quercetin and kaempferol, blocked secretion of beta-hexosaminidase and histamine; lowered the production and mRNA expression of interleukin-4 and TNF-alpha; and reduced prostaglandin E₂ and leukotriene B₄ synthesis as well as the expression of cyclooxygenase-2 (COX-2) and 5-lipoxygenase. These and other findings led the investigators to conclude that A. rossii and its active ingredients kaempferol and quercetin may be effective agents for the treatment of immediate-type hypersensitivity (J. Agric. Food Chem. 2014;62:3750-8).

Anticancer activity

Lee et al. reported in 2010 that the inhibition by kaempferol of phosphatidylinositol 3-kinase (PI3K) activity, a key factor in carcinogenesis, and its concomitant effects may account for the chemopreventive activity of the flavonol (Carcinogenesis 2010;31:1338-43).

At the end of that year, Lee et al. found that kaempferol inhibited UVB-induced COX-2 protein expression in mouse skin epidermal JB6 P+ cells, by blocking Src kinase activity and attenuated the UVB-induced transcriptional activities of COX-2 gene and the transcription factor AP-1. They concluded that kaempferol exerts robust chemopreventive activity against skin cancer by suppressing Src (Biochem. Pharmacol. 2010;80:2042-9).

In 2014, Yao et al. found that kaempferol acted as a safe and potent inhibitor of solar ultraviolet-induced mouse skin carcinogenesis that acted by targeting RSK2 and MSK1 (Cancer Prev. Res. (Phila) 2014;7:958-67).

Significantly, in terms of topical delivery, Chao et al. recently showed that submicron emulsions are effective carriers for the transdermal delivery of kaempferol (Chem. Pharm. Bull. (Tokyo) 2012;60:1171-5).

Conclusion

Kaempferol is one among the many natural flavonols found to exert significant salutary effects. Evidence suggests reasons for confidence that kaempferol can play a role in skin health. More research is necessary to determine the effectiveness of topical products intended to harness the benefits of this flavonoid as proper formulation is challenging.

Dr. Baumann is chief executive officer of the Baumann Cosmetic & Research Institute in the Design District in Miami. She founded the Cosmetic Dermatology Center at the University of Miami in 1997. Dr. Baumann wrote the textbook, “Cosmetic Dermatology: Principles and Practice” (New York: McGraw-Hill, 2002), and a book for consumers, “The Skin Type Solution” (New York: Bantam Dell, 2006). She has contributed to the Cosmeceutical Critique column in Dermatology News since January 2001. Her latest book, “Cosmeceuticals and Cosmetic Ingredients,” was published in November 2014. Dr. Baumann has received funding for clinical grants from Allergan, Aveeno, Avon Products, Evolus, Galderma, GlaxoSmithKline, Kythera, Mary Kay, Medicis Pharmaceuticals, Neutrogena, Philosophy, Topix Pharmaceuticals, and Unilever.