Formulation and evaluation on human skin of a water-in-oil emulsion containing Muscat hamburg black grape seed extract

Abstract

Background: Vitis vinifera 'muscat hamburg' (Vitaceae) is a blue-black grape variety commonly found in Pakistan. It has been consumed and used in traditional medicine for centuries. Compared to other grapes, M. hamburg records one of the greatest amount of polyphenols and displays potent antioxidant activities, which make it a great candidate for its exploitation in the development of stable cream emulsions destined to improve the skin appearance.

Objective: Evaluate the effects of stable water-in-oil (W/O) emulsion containing 2% M. hamburg grape seed extract ('formulation') on human cheek skin in comparison with the placebo ('base').

Methods: An occlusive patch test, containing either the formulation or the base, was topically tested for 8 weeks during a winter period in young adult and healthy Pakistani male volunteers. The subjects were instructed to use twice a day the base and the formulation on their right and left cheek skin, respectively. Non-invasive measurements on these skin areas were carried out every week to assess any effects produced on melanin, elasticity and sebum. Skin compatibility assay (Burchard test) was used to report any potential skin reactivity. ANOVA, paired sample t-test and LSD test were applied to determine the statistical data significance.

Results: Significant differences (P ≤ 0.05) were found between the placebo and the formulation in terms of their respective skin effects elicited on melanin, elasticity and sebum content. Nevertheless, placebo and formulation exerted similar effects on skin erythema and moisture contents. Importantly, no skin hypersensitivity cases were reported during the whole course of the study.

Conclusion: The developed grape-based cream could be efficiently and safely applied to improve a number of skin conditions (e.g. hyper-pigmentation, premature ageing, acne).

Keywords: Muscat hamburg; antioxidant activity; polyphenols; skin rejuvenation; topical application; water-in-oil emulsions.