Split-face placebo controlled evaluation of the in vivo anti-ageing efficacy of LineminusTM cream (Polygonum minus extract) in healthy Asian skin type female subjects

摘要

Although changes in pigmentation distribution are known to be a major characteristic of cutaneous ageing in Asian skin, wrinkling was also shown to be a main feature of skin ageing in Asians. The role of reactive oxygen species and the decrease in anti-oxidant enzymes activity with age was recently confirmed for both intrinsic and extrinsic ageing, making oxidative stress of primary importance in the overall ageing process. Polygonum minus is found in local Malaysian herbs known as “kesum”. Previous studies have demonstrated the anti-oxidant properties of kesum as a food ingredient or medicinal plant. However, little is known about the in vivo anti-oxidant and resulting anti-wrinkle efficacy of Polygonum minus in a cosmetic product. Lineminus TM is an extract developed from Polygonum minus leaves (with 3 pending patents: Malaysia PI2012005685, Malaysia PI20125248, and Malaysia PI2012003882/ PCT/MY2013/000033). The aim of this study was to evaluate the efficacy and safety of Lineminus TM cream versus its placebo in healthy Asian females (split-face). Methods used were shadow casting analysis of crow’s feet silicone replicas, self-assessment and dermatological evaluation. Twenty three healthy Asian females, aged between 48-60 years old, having wrinkles on the crow’s feet area were enrolled. Results showed that application of Lineminus TM cream induced a significant decrease in “number of wrinkles” (-17.6% and -20.1%, p<0.05 ), “total length” (-15.9% and -25.7%, p<0.05 ) after 1 and 2 months and “mean length” after 2 months (-8.6%, p<0.05 ). When variations from skin treated with Lineminus cream were corrected from skin treated with Placebo Cream, there was a statistically significant difference in “number of wrinkles” after 1 month (-12.4%, p<0.05 ) and “mean length” of wrinkles after 2 months (-7.3%, p<0.05 ). Subjects significantly agreed to most questions asked to them about Lineminus TM cream’s efficacy after 1 and 2 months. Finally, the tolerance of both creams was found to be very good. Based on these results it is possible to conclude that Lineminus TM Cream is safe and has an anti-wrinkle effect and that Lineminus TM (Polygonum minus extract) has beneficial cosmetic anti-wrinkle properties. These results also show that in addition to Polygonum minus ’s well-known anti-oxidant efficacy, the plant extract demonstrates as well a significant clinical anti-wrinkle effect with clear reduction of crow’s feet wrinkles.