## 4 Natural Antioxidants and Their Role in Cosmetics
### Selected Plant Species with Antioxidant Activity
#### 4.11.8 Scutellaria bialensis  
_Scutellaria bialensis_, a member of the Lamiaceae family, is widely distributed across North China, Japan, Korea, Mongolia, and Russia. The roots of _S. bialensis_, commonly known in China as Huang-Qin (_Sutellaria radix_), are a cornerstone of traditional Chinese medicine. phytochemical investigations have revealed that the roots are rich in bioactive compounds, including free flavonoids, flavonoid glycosides, phenylethanolamine glycosides, and various other small molecules [229; 230].  
Extracts derived from Baikal skillcap, as well as its primary chemical constituents, have been extensively studied for their diverse pharmacological properties. These include antiviral, antitumor, antibacterial, antioxidant, anti-inflammatory, hepatoprotective, and neuroprotective activities, making this species a promising candidate for therapeutic applications.  
Extracts of _S. bialensis_ have been extensively studied for their antioxidative properties, particularly in the context of UV-induced oxidative damage. Research indicates that these extracts effectively mitigate various pathologies, with a notable focus on skin damage resulting from solar radiation. This protective activity is primarily attributed to their potent free radical scavenging abilities as well as their capacity to inhibit lipid peroxidation [231]. In the literature, the antioxidant activity of bioactive compounds of this species--bialalin, baialein, wogonin, and oroxylin--is often emphasized [230].  
_Scutellaria_ root extract protects human skin from UV radiation. Sunscreen cream supplemented with SR-derived extracts has higher SPF value than a control sunscreen cream without the extracts. The cream was very safe as evidenced by the lack of skin responses. SR extracts can absorb UV radiation because of a high content of flavonoids such as baialcin and balcalein. In addition, many previous studies using animal models have shown antiinflammatory effects of SR extract and its constituents. Thus, SR extract is thought to increase SPF by inhibiting inflammatory events as well as by absorbing UV radiation [232].  
Surveys on concentration of use indicate that Scutellaria Baialensis root extract is used at a maximum of 0.5% in leave-on products, such as moisturizers. Cosmetic formulations containing _S. bialensis_-derived ingredients may be applied to the skin or come into incidental contact with the eyes, as seen in eye shadows containing up to 0.07% root extract.  
Additionally, Scutellaria Baicalensis root and sprout extracts are found in products that contact mucous membranes, with maximum concentrations of 0.0045% in lipsticks and 0.0002% in bath soaps and detergents [32].  
Scutellaria Baicalensis root extract is produced using various extraction methods, including ethanolic extraction (30-90% ethanol), aqueous extraction, and butylene glycolic extraction. Ethanolic extractions involve filtration, concentration, sedimentation, and packaging, with some methods incorporating squalene before final processing. Aqueous extraction includes boiling, filtration, and spray drying or lyophilization to obtain a powdered extract stored at 4 \({}^{\circ}\)C. Another method involves thermal reflux extraction, filtration, and evaporation under reduced pressure to yield a concentrated extract [32].