Synergistic Effects of Green Tea and Ginkgo Biloba Extracts on the Improvement of Skin Barrier Function and Elasticity

September 2014 | Volume 13 | Issue 9 | Original Article | 1092 | Copyright © September 2014


Patrícia M.B.G. Maia Campos PhD, Mirela D.Gianeti PhD, Daiane G. Mercurio ScM, and Lorena R. Gaspar PhD

Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, São Paulo, Brazil

Abstract
This study aimed to evaluate the effects of cosmetic formulations containing green tea (GT) and/or Ginkgo biloba (GB) extracts by preclinical and clinical studies. For the preclinical study, histological analysis was performed after 5 day-period of formulations application on the dorsum of hairless mice. For the clinical study, the formulations were applied on the forearm skin of 48 volunteers, and assessed before and after 3 hours and after a 15 and 30 day-period of application. Histological analysis showed that the formulation with GT (FGT) and the association of GT and GB (FBlend) significantly enhanced viable epidermis thickness and the number of cell layers, suggesting a moisturizing effect in skin deeper layers and increased cell renewal. The clinical efficacy studies showed that the extracts had a moisturizing effect and improved skin microrelief. In addition they synergistically acted on the skin elasticity and skin barrier function. In conclusion, the formulation containing a combination of green tea and Ginkgo biloba extracts effectively improved skin conditions and the effect of formulation FBlend on the improvement of skin elasticity was more pronounced. Finally, the results of the present study revealed other important clinical benefits of Ginkgo biloba and green tea extracts on the skin besides their already known antioxidant action.

J Drugs Dermatol. 2014;13(9):1092-1097.

INTRODUCTION

The aging process results in progressive drying of the skin, changes in the microrelief and pigmentation patterns, reduced firmness and elasticity, and appearance of wrinkles.1 In this context, many anti-aging products containing natural ingredients with antioxidant properties have been marketed, aiming to improve conditions of the aged skin. In addition, botanical extracts have been widely used for dry skin.2 This way, more investigation on the mode of action and clinical studies are required to prove their effects. Among these natural ingredients, green tea and Ginkgo biloba extracts have been widely employed in cosmetic formulations.3
Green tea extracts contain four catechin derivatives, predominantly epicatechin, epigallocatechin, epicatechin gallate, and epicatechin 3-gallate, which have been studied for their antioxidant, anti-inflammatory, and anticancer properties.4 The green tea polyphenols included in cosmetic formulations show good skin penetration and retention. These properties may favor skin performance5 in terms of inhibition of the acute effects caused by exposure to UVB radiation and reduction of inflammation, consequently avoiding the erythema and immunosuppression induced by solar radiation.6 Components of the green tea extract neutralize reactive oxygen species, thereby preventing lipid peroxidation and photoaging. 6
The use of the Ginkgo biloba extract in anti-aging cosmetics has been recently proposed because it is rich in flavonoids (rutin, quercetin, kaempferol), biflavones (bilobetin and ginkgetin), and terpenoids (ginkgolides, bilobalide), which are responsible for the antioxidant and anti-inflammatory activities of this extract.5,7,8 Therefore, combination of the antioxidant properties of the green tea and Ginkgo biloba extracts in cosmetic formulations could provide great benefits to the skin.7,9 In addition, due to green tea and Ginkgo biloba extracts rich composition,10-12 they could also provide extra benefits to the skin, like moisturizing and protective effects.13,14
Some studies showed that these extracts act on fibroblast proliferation and production of collagen and extracellular fibronectin. 15 It is also described improvement of skin texture and appearance observed by dermatologists16 and moisturizing effects and improvement of skin microrelief.17 However, several issues concerning the effectiveness of botanical extracts in cosmetic formulations need to be scientifically clarified.
On the basis of their composition and related data in literature, it has been proposed that the green tea (Camellia sinensis) and Ginkgo biloba extracts have potential use in cosmetic formulations with anti-aging effects. Hence, the efficacy of topical formulations containing these extracts should be investigated, in order to assess whether the impact of these formulations on the human skin under the real conditions of use. This way, the biophysical techniques have been widely used to evaluate the clinical efficacy of cosmetic products.17,18
The traditional histopathological and histometric techniques lead to excellent results and enable accomplishment of a wide range of studies, ie, analysis of the epithelial tissue, dermis, and cellular characteristics. However, they are invasive techniques.19,20 In this