A Randomized Study to Determine the Sun Protection Factor of Natural Pterostilbene from Pterocarpus marsupium
Cosmetics 2020, 7(1), 16;
In a second clinical study, on natural pterostilbene, published in the Journal “Cosmetics”, Sabinsa corporation demonstrated the effect of PteroWhite® as a natural SPF ingredient. With the current status of chemical sunscreens, and the concerns about their systemic absorption and safety, this study has demonstrated PteroWhite® as a safe alternative. A cream formulation containing 4% of PteroWhite® was evaluated in 12 healthy volunteers as per the ISO 24444:2010 regulations showed an in vivo SPF value of 6.2 ±1.30.
The cream was found to be safe and nonirritant in a repeated patch test conducted in 25 healthy individuals, prior to the SPF study. The cream showed an SPF of 8.84 ±0.01, in vitro, while PteroWhite® as an ingredient had an SPF value of 21.73 ±0.06. Further, the study demonstrated the potent antioxidant effects of PteroWhite® in the in various in vitro and cellular test systems. The study concluded that PteroWhite® could be used as a safe ingredient in topical sun-protective formulations. Further details of the study could be accessed at https://doi.org/10.3390/cosmetics7010016
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 was extracted and purified from the Indian Kino tree (Pterocarpus marsupium)
- Pterostilbene was dissolved in DMSO and diluted in 50% methanol for the assay
- The oxygen radical absorption capacity assay (ORAC) for pterostilbene was assessed
- Hydroxyl radical averting capacity was assessed using fluorescein (FL) as the fluorescent probe
- ROS was estimated using dichloro-dihydro-fluorescein diacetate (DCFH-DA) dye
- The SPF was determined In vitro by spectrophotometer, as described by Yang et al
- The primary skin irritation study was conducted in a total of 25 healthy male and female subjects of all skin types (normal, dry, oily, and combination) in the age group of 18 to 55 years.
- In the SPF determination study subjects in the age group 18–55 years (both ages inclusive) were included
- The minimum dose that produces mild but definite erythema with a clearly defined border when evaluated at 24 h post-exposure was considered as MED
- The efficacy of a sunscreen compound, expressed by the sun protection factor (SPF), is defined as the energy from UV required producing a minimal erythema dose (MED) on protected skin, divided by the UV energy required to produce a MED on unprotected skin
- The arithmetic mean and standard deviation of the total observation was taken for both in vitro and in vivo SPF determination
Results and Discussion:
- Antioxidant Activity of Pterostilbene
- Reactive Oxygen Species Scavenging Capacity of Pterostilbene in vitro
- In vitro SPF of Pterostilbene Cream Formulation of 0.4% Pterostilbene
- In vivo Primary Skin Irritation Test of Pterostilbene Cream Formulation
- In vivo Determination of Sun Protection Factor (SPF) of Pterostilbene Cream Formulation
UV radiation causes skin damage and there is an urgent need to protect from its harmful effects. Natural ingredients usually have the potential to protect against the toxic effects of UV radiation. Natural pterostilbene has shown its potential as a safe and effective ingredient in topical formulations for sunscreens and UV protection. The product may be used in combination with other ingredients toboost the SPF value of sunscreen formulations. Further research is required in the development of new effcacious and safe plant-based natural ingredients and formulations which are effective in protecting skin from harmful radiations.Read More…