A Randomized Study to Determine the Sun Protection Factor of Natural Pterostilbene from Pterocarpus Marsupium

Abstract

Ultraviolet (UV) rays and its harmful effects have always been a concern to skin health. Sunscreen and sunblock prevent the harmful effects of UV radiation on the skin. Sun Protection Factor (SPF) is an indication of the sun-protective capacity of an ingredient. There is an ever increasing interest in the cosmetic industry for developing novel functional ingredients from natural sources. The purpose of this study was to determine in-vitro and in vivo SPF of natural 90% pterostilbene extracted from the dried heartwood of Pterocarpus marsupium (Indian Kino). The SPF of purified pterostilbene and a formulation containing 0.4% pterostilbene was determined In Vitro using a UV spectrophotometer. Pterostilbene had an SPF of 21.73 ± 0.06, while the cream formulation had an SPF of 8.84 ± 0.01. The in vivo SPF of the 0.4% pterostilbene cream in humans was found to be 6.2 ± 1.30. Primary skin irritation tests in human subjects showed the formulation was safe and had no irritation potential. Pterostilbene was also found to have significant antioxidant activity as determined by free radical scavenging assays in vitro. These results suggest that natural pterostilbene is an antioxidant and shows SPF value both in-vitro and in the human clinical study and thus could be used as an ingredient in topical sun-protective formulations.

Antioxidant activity and nano delivery of the most frequently applied stilbene derivatives: A brief and recent review

“…However, in the DPPH assay, the antioxidant capacity of PTS was higher than RSV; that is, the potential antioxidant activity of PTS was nine times greater than RSV. 22,16 ABTS assay was showed that the antioxidant capacity of oxy-RSV compounds was higher than PTS, RSV and pynosilvyn compounds. 6…”

“…PTS, one of the stilbene derivatives, exists plentifully in bark fruit skin and blueberries [18][19][20][21] as well as Indian kino plants. 7,22 Meanwhile, 3-hydroxy PTS, which is one of the PTS metabolites, can be isolated from all parts of the Sphaerophysa salsula, a type of shrub widespread in Central Asia and the Western China Sea. 13 These data in aggregate provide a clear and wide variety of stilbene sources.…”

Phytochemical Screening and Antioxidant Activity of Seven Native Species Growing in the Forests of Southern Chilean Patagonia

“…Values are reported as means ± SD of four independent determinations. The inhibition percentage was calculated by the following equation: The sun protection factor (SPF) was calculated according to the method described by Mansur et al [50] and used by other authors [51][52][53]. Briefly, the method consists of measuring the absorbance of the sample between 290 and 320 nm, every 5 nm, and using the following equation: where CF is a correction factor (10), EE (λ) is the erythemal effect spectrum, and I (λ) is the solar intensity spectrum.…”

“…Briefly, the method consists of measuring the absorbance of the sample between 290 and 320 nm, every 5 nm, and using the following equation: where CF is a correction factor (10), EE (λ) is the erythemal effect spectrum, and I (λ) is the solar intensity spectrum. The EE (λ) × I (λ) values are constant for each wavelength of the interval and they are reported in the literature (Table 4) [51][52][53]. All…”

“…The sun protection factor (SPF) is an index used to characterize all substances or mixtures capable of acting as sunscreens. The spectrophotometric method reported by Mansur et al [50] is widely used for this purpose [51][52][53].…”