Cosmeceutical Critique

Buckwheat Extract


 

Native to North and East Asia, buckwheat has been grown in China for more than 2,000 years and has been used in traditional medicine to treat varicose veins.1,2 This highly adaptable plant – the most common species of which are Fagopyrum esculentum (common buckwheat or sweet buckwheat), and F. tataricum (which grows in more mountainous regions) – has acclimated to cultivation in North America, as well.1 Increasingly popular as a healthy grain option, buckwheat flour has been touted for beneficial effects on diabetes, obesity, hypertension, hypercholesterolemia, and constipation.1 It has also gained attention for its association with some allergic reactions.

SandraKavas/iStock /Getty Images Plus
The reputed antioxidant and photoprotective properties of the botanical, in particular, have led to greater scientific scrutiny. Indeed, buckwheat contains an abundance of flavonoids, as well as flavones, phytosterols, and thiamin-binding proteins, many of which are well known to exhibit antioxidant activity.3 Rutin, the primary flavonoid in F. esculentum, has been demonstrated to decrease total leg volume in venous insufficiency patients.2 Chlorogenic acid and hyperoside are also key constituents of buckwheat, as are the flavonoids quercetin, orientin, vitexin, isoorientin, and isovitexin.3,4 In this column, the focus is on research indicating dermatologic applications for this ancient botanical ingredient.

Wound Healing

In 2008, van den Berg et al. performed an in vitro investigation of the antioxidant and anti-inflammatory qualities of buckwheat honey for consideration in wound healing. American buckwheat honey from New York was found to be the source of the most salient activities, with such properties attributed to its abundant phenolic components. The researchers suggested that these phenols might impart antibacterial activity, while the low pH and high free acid content of the buckwheat honey could contribute to healing wounds.4

Antioxidant Activity

The antioxidant capacity, along with other traits, characterizing the sprouts of common buckwheat (F. esculentum) and tartary buckwheat (F. tataricum) was evaluated by Liu et al. in 2008. Rutin is the main flavonoid found in both species, with fivefold higher levels identified in tartary buckwheat in this study. Ethanol extracts of tartary buckwheat also exhibited greater free radical scavenging activity and superoxide scavenging activity, compared with common buckwheat. Both buckwheat species displayed antioxidant activity on human hepatoma HepG2 cells, with tartary buckwheat more effective in diminishing cellular oxidative stress, which the authors attributed to its greater rutin and quercetin levels.5

Zhou et al. studied the protective effects of buckwheat honey on hydroxyl radical-induced DNA damage in 2012, finding that all studied honeys more effectively protected DNA in non–site specific rather than site-specific systems.6

Photoprotection

In a 2005 screening of 47 antioxidant substances and study of their effects on UV-induced lipid peroxidation, Trommer and Neubert reported that buckwheat extract significantly lowered radiation levels, as did extracts of St. John’s Wort, melissa, and sage. They concluded that their in vitro findings supported the inclusion of such ingredients in photoprotective cosmetic formulations or sunscreens pending the results of in vivo experiments with these compounds.7

In 2006, Hinneburg et al. evaluated the antioxidant and photoprotective activity of a buckwheat herb extract, also comparing its photoprotective characteristics to those of a commercial UV absorber. In an assay with 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH), buckwheat extract exhibited significantly more antioxidant activity than did pure rutin, with buckwheat observed to more effectively block UV-induced peroxidation of linoleic acid as compared with rutin and the commercial UV absorber. The researchers concluded that including antioxidants such as buckwheat extract in photoprotective formulations may serve to maximize skin protection in such products.8

Next Article:

   Comments ()