>> Ferulic Acid
1. Ferulic acid stabilizes a solution of vitamins C and E and doubles its photoprotection of skin.
Lin FH, Lin JY, Gupta RD, Tournas JA, Burch JA, Selim MA, Monteiro-Riviere NA, Grichnik JM, Zielinski J, Pinnell SR., Duke University Medical
"Ferulic acid is a potent ubiquitous plant antioxidant. Its incorporation into a topical solution of 15%l-ascorbic acid and 1%alpha-tocopherol
improved chemical stability of the vitamins (C+E) and doubled photoprotection to solar-simulated irradiation of skin from 4-fold to approximately 8
-fold as measured by both erythema and sunburn cell formation. Inhibition of apoptosis was associated with reduced induction of caspase-3
and caspase-7. This antioxidant formulation efficiently reduced thymine dimer formation. This combination of pure natural low molecular weight
antioxidants provides meaningful synergistic protection against oxidative stress in skin and should be useful for protection against photoaging
and skin cancer."
2. In vitro and in vivo evaluation of caffeic and ferulic acids as topical photoprotective agents.
Saija A, Tomaino A, Trombetta D, De Pasquale A, Uccella N, Barbuzzi T, Paolino D, Bonina F., Department of Pharmacology of Natural Substances
and General Physiology, University of Rome 'La Sapienza', Rome, Italy.
"Topically-applied antioxidant drugs represent a successful strategy for protecting the skin against UV-mediated oxidative damage. However,
they can afford to the skin a satisfactory photoprotection only if able to permeate through the stratum corneum and thus to reach deeper
cutaneous layers. Caffeic and ferulic acids, dissolved in saturated aqueous solutions at pH 3 or 7.2, have been tested for their capability to
permeate through excised human skin mounted in Franz cells. At both pH values, ferulic and, at a lower degree, caffeic acids appeared able to
permeate through the stratum corneum. The known higher lipophilicity of ferulic acid may explain the fact that it permeates through the stratum
corneum better than caffeic acid. However, vehicle pH values proved to have no influence on biophenol skin permeation profile; this observed
lack of pH effect may reflect the drug higher concentration attainable in saturated solutions at high pH. On the basis of the findings obtained in
these in vitro experiments, we designed the schedule of a series of in vivo experiments, carried out to evaluate the ability of caffeic and ferulic
acids to reduce, in healthy human volunteers, UVB-induced skin erythema, monitored by means of reflectance spectrophotometry. Caffeic and
ferulic acids, dissolved in saturated aqueous solution pH 7.2, proved to afford a significant protection to the skin against UVB-induced erythema.
To conclude, we have confirmed, by means of in vitro and in vivo experiments, that caffeic and ferulic acids may be successfully employed as
topical protective agents against UV radiation-induced skin damage; however their skin absorption is not influenced by the pH of the
3. Ferulic Acid.
BAUMANN LS, Skin & Allergy News- 2005 10 (Vol. 36, Issue 10).
"Ferulic acid (4-hydroxy-3-methoxycinnamic acid) is pervasive in the plant world. It is present in the cell walls of grains, fruits, and vegetables,
where it is conjugated with mono-, di-, and polysaccharides and other compounds (Biochem. Biophys. Res. Commun. 1998;253:222??; Biomed.
Pap. Med. Fac. Univ. Palacky Olomouc Czech Repub. 2003;147:137??5; J. Sci. Food Agric. 2004;84:1261??; Free Radic. Biol. Med.
Derived from the metabolism of phenylalanine and tyrosine (Biochem. Biophys. Res. Commun. 1998;253:222??; Free Radic. Biol. Med.
1992;13:435??8), ferulic acid is prevalent in whole grains, spinach, parsley, grapes, and rhubarb. Dietary ferulic acid is now considered a
significant antioxidant substance (Appl. Environ. Microbiol. 2004;70:2367??2). This potent herbal constituent also has been incorporated into
cosmetic lotions and other topical products for the photoprotection it confers (Free Radic. Biol. Med. 1992;13:435??8).
Ferulic acid belongs to the polyphenolic compounds known as hydroxycinnamic acids, which also includes caffeic acid, p-coumaric acid, and
cinnamic acid. These molecules are known to confer cutaneous benefits (J. Cosmet. Sci. 2002;53:321??5). Hydroxycinnamic acids are typically
included in sunscreen formulations.
In terms of direct benefit to the skin, ferulic acid is one of the more promising botanical ingredients. It is a potent antioxidant, protecting skin from
UVB-induced erythema (Biomed. Pap. Med. Fac. Univ. Palacky Olomouc Czech Repub. 2003;147:137??5). It also strongly absorbs UV, like its
related compounds (Int. J. Pharm. 2000;199:39??7). And phospholipid membranes are protected by ferulic acid from UV-induced peroxidation as
the lipid peroxidative chain reaction is interrupted (Biomed. Pap. Med. Fac. Univ. Palacky Olomouc Czech Repub. 2003;147:137??5; J. Sci. Food