Ann Dermatol (Seoul) Vol. 21, No. 1, 2009
ORIGINAL ARTICLE
Dietary Aloe Vera Supplementation Improves Facial Wrinkles and Elasticity and It Increases the Type I Procollagen Gene Expression in Human Skin in vivo 1,2,4
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Soyun Cho, M.D., Ph.D. , Serah Lee, M.S. , Min-Jung Lee, M.S. , Dong Hun Lee, M.D. , 1,4 3,4 2,3,4 Chong-Hyun Won, M.D., Ph.D. , Sang Min Kim, Ph.D. , Jin Ho Chung, M.D., Ph.D. Department of Dermatology, 1Seoul National University Boramae Hospital, 2Seoul National University College of Medicine, 3Laboratory of Cutaneous Aging Research, Clinical Research Institute, Seoul National University Hospital, 4Institute of Dermatological Science, Medical Research Center, Seoul National University, Seoul, Korea
Background: No studies have yet been undertaken to determine the effect of aloe gel on the clinical signs and biochemical changes of aging skin. Objective: We wanted to determine whether dietary aloe vera gel has anti-aging properties on the skin. Methods: Thirty healthy female subjects over the age of 45 were recruited and they received 2 different doses (low-dose: 1,200 mg/d, high-dose: 3,600 mg/d) of aloe vera gel supplementation for 90 days. Their baseline status was used as a control. At baseline and at completion of the study, facial wrinkles were measured using a skin replica, and facial elasticity was measured by an in vivo suction skin elasticity meter. Skin samples were taken before and after aloe intake to compare the type I procollagen and matrix metalloproteinase 1 (MMP-1) mRNA levels by performing real-time RT-PCR. Results: After aloe gel intake, the facial wrinkles improved significantly (p＜0.05) in both groups, and facial elasticity improved in the lower-dose group. In the photoprotected skin, the type I procollagen mRNA levels were increased in both groups, albeit without significance; the MMP-1 mRNA levels were significantly decreased in the higher-dose group. Type I procollagen immunostaining was substantially increased throughout the dermis in both groups. Conclusion: Aloe gel significantly improves wrinkles and elasticity in photoaged human skin, with an increase in collagen production in the photoprotected skin and a decrease in the collagen- degrading MMP-1
Received April 21, 2008, Accepted for publication July 20, 2008 *A grant by Korea Food and Drug Administration (2004∼2005). Reprint request to: Jin Ho Chung, M.D., Department of Dermatology, Seoul National University Hospital, 28, Yeongeon-dong, Jongno-gu, Seoul 110-744, Korea. Tel: 82-2-2072-2414, Fax: 82-2-742-7344, E-mail: jhchung@snu.ac.kr
6 Ann Dermatol (Seoul)
gene expression. However, no dose- response relationship was found between the low-dose and high-dose groups. (Ann Dermatol (Seoul) 21(1) 6∼11, 2009) -KeywordsAging, Aloe vera, Matrix metalloproteinase, Procollagen, Wrinkles
INTRODUCTION Skin aging is attributed to intrinsic (chronological) aging and photoaging (extrinsic aging). Photoaging and intrinsic aging are induced by damage to human skin by repeated exposure to ultraviolet (UV) irradiation and the damage due to the passage of time, respectively. An alteration in collagen, which is the major structural component of skin, has been considered to be a cause of skin aging in naturally aged and photoaged skin. With increasing age, there is a sustained reduction of collagen and an elevated secretion of matrix-degrading enzymes called matrix metalloproteinases (MMP) in old skin as compared with young skin1. UV causes photoaging by generating reactive oxygen species, and this subsequently triggers a cascade of signaling mechanisms and this eventually causes a decrease of collagen, and an increase of MMP, inflammation, epidermal DNA damage and apoptosis. During this process, activator protein 1 (AP-1) is activated by UV irradiation and so AP-1-driven MMPs such as MMP-1 and MMP-9 are induced. The UV-induced MMPs can degrade collagen, which results in a collagen deficiency in photodamaged skin and eventually skin wrinkling2.