APPLICATION OF PEAR (Pyrus communis L.) AND BILBERRY (Vaccinium vitis-idaea L.). LEAF EXTRACTS IN FORMULATION OF SKIN LIGHTENING COSMETICS.

Introduction: Hyperpigmentation is one of the most common aesthetic problems and a target of many cosmetic products. Unfortunately, many of recently used skinlightening active ingredients are unstable in cosmetic formulations and lack expected effectiveness. Moreover, prolonged application of such ingredients often results in side effects, including skin irritation, contact dermatitis, leukoderma, or impaired wound healing. For this reason, modern cosmetology is constantly searching for new, effective and safe substances that reduce hyperpigmentation. The source of such substances are plant extracts. Aim: The presented research assessed the possibility of using pear (Pyrus communis L.) and bilberry (Vaccinium vitis-idaea L.). leaf extracts in skinlightening cosmetics. Leaves of this plant species are currently used mostly as waste material, therefore their utilization in the cosmetic industry might help in more sustainable usage of natural resources. Material and methods: The leaves were extracts in water (W extracts) or water:propylene glycol mixture (1:1,v:v, WG extracts) and compared for their phytochemical content (polyphenols and flavonoids) antioxidant activity (using DPPH and ABTS radical scavenging assays) and skin-lightening potential (using tyrosinase inhibitory assay). Results: Bilberry WG extract showed the highest content of polyphenols and flavonoids among all tested extract (2751,5 µg GAE/mL and 199,3 µg QE/mL, respectively). Bilberry W extracts was the most effective antioxidant in DPPH assay and the WG bilberry extracts was the most active in ABTS assay. The highest tyrosinase inhibitory properties were observed for 1% (v/v) bilberry WG and pear W extracts - both inhibited the tyrosinase activity by 25%. BoThextracts then incorporated in the formulation of cosmetic emulsion. To enhance the skin-lightening potential of the product kojic acid was also implemented in the formulation. Prepared cosmetic was analyzed for its physicochemical properties (colour, smell, viscosity, pH), microbiological safety and stability. Conclusions: Presented results showed in practice that pear and bilberry leaf extracts might be applied in formulations of skin lightening cosmetics. [ABSTRACT FROM AUTHOR]