Notably, G. biloba contains quercetin, one of the most abundant natural flavonoids, as well as other flavonoids such as kaempferol, sciadopitysin, ginkgetin, and isoginkgetin with demonstrated antioxidant and anti-inflammatory activity (Clin. Exp. Dermatol. 2001;26:536-9; Radic. Biol. Med. 1998;25:196-200).
Also in late 2010, investigators assessed the antioxidant activity of plants typically used in Unani medicine, of which the 10 displaying the most promising effects, including R. damascena, were identified for additional analysis. The total phenolic, flavonoid, and ascorbic acid contents were ascertained from methanol (50%) extract preparations of all 10 species and researchers also evaluated the in vitro scavenging of reactive oxygen and nitrogen species and the ability of the plant extracts to prevent oxidative DNA harm. R. damascena was among seven of the 10 extracts to exhibit moderate antioxidant activity and one of three species found to potentially have significant preventive activity against oxidative DNA damage as well as antioxidant activity. The investigators concluded that R. damascena, C. icosandra, and C. scariosus, all of which are commonly used in Unani medicine (practiced in South Asia and founded on traditional Graeco-Arabic medicine) and reportedly deliver substantial benefits in the treatment of various human disorders, are potentially useful as natural antioxidants in pharmaceutical products (BMC Complement. Altern. Med. 2010;16:10-77).
A year earlier, investigators examined the phenolic content as well as the antioxidant and antibacterial activities of R. damascena flower extracts absolute, essential oil, and hydrosol. The major constituents of rose essential oil and hydrosol (great than 55%) were found to be citrenellol and geraniol, with phenylethyl alcohol (78.83%) identified as the primary component of rose absolute. The levels of key antioxidants (i.e, beta carotene, tocopherol, and gamma tocopherol) were found to be higher in rose absolute as compared to hydrosol and rose oil. High levels of phenolics were noted in rose absolute and the essential oil, which exhibited potent antibacterial activity against E. coli, P. aeruginosa, Bacillus subtilis, S. aureus, Chromobacterium violaceum, and Erwinia carotovora (Curr. Microbiol. 2009;59:554-8). Of note, hydrosols, also referred to as floral waters, flower waters, hydroflorates, or distillates, are derived from steam distilling plant materials.
In a recent study on the relaxing effects of rose oil administered by transdermal absorption, 40 healthy volunteers were assessed based on autonomic parameters (i.e., blood pressure, breathing rate, blood oxygen saturation, pulse rate, and skin temperature) as well as self-report after receiving rose oil or placebo. Olfactory stimulation was prevented through the use of breathing masks. Significant reductions in systolic blood pressure, breathing rate, and blood saturation were observed, compared to placebo. The rose oil group also self-reported as calmer, more relaxed, and less alert. The author suggested that this small study lends support for the use of rose oil in aromatherapy for the relief of stress and depression (Nat. Prod. Commun. 2009;4:291-6).
The data that exist on R. damascena are interesting but hardly overwhelming. Much more research is necessary to determine the potential efficacy of this botanical in dermatologic products. The current evidence does offer promise though, and further investigation is clearly warranted to determine the full range of activity offered by R. damascena and how well the antioxidant and antibacterial activities of this herb can be harnessed in topical products.