92 J. Cosmet. Sci., 74, 92–100 (March/April 2023) *Address all correspondence to Danqi Deng, danqid128@sina.com and Jiehao Qian, 825946043@qq.com The Effects of a Peptide Complex Cream for Improving Skin Photoaging QIAO TANG, WENTING CAO, WENFANG WANG, JICHUN YANG, JICHAO QIAN AND DANQI DENG Department of Dermatology and Venereology, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China (Q.T., W.C., W.W., D.D.) Dermatology Department, Medical Center Hospital of Qionglai, Chengdu, China (Q.T.) Department of Epidemiology and Biostatistics, School of Population Medicine and Public Health, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China (J.Y.) Zhuhai Yasha Biotechnology Co, Ltd., Zhuhai, Guangdong, China (J.Q.) Accepted for publication July 1, 2023. Synopsis Bioactive peptides are different peptides composed of natural amino acids in different compositions and arrangements. They are now widely used in skin care products, but there are few studies on anti-photoaging. This article aims to investigate the efficacy of a peptide complex cream in the treatment of skin photoaging. 80 female subjects were recruited and assigned to 2 groups (40 in each group) based on a randomized, double- blind, placebo-controlled, parallel-group protocol, and were topically treated with either a peptide complex cream or a base cream. Subjective assessment was done by a physician and a non-invasive skin examination was performed at weeks 0, 2, 4, 6, 8 during the treatment and then again 4 weeks after the treatment was complete. The results showed that there was no significant improvement in facial wrinkles and color spots in the peptide complex cream group, but there was significant facial improvement (P .05) in both the Dermoscopy Photoaging Scale (DPAS) scores and with acne. The peptide complex cream can safely and effectively improve some skin photoaging symptoms, but the effect on wrinkles and color spots is not obvious in the short term. INTRODUCTION Skin photoaging is a chronic inflammation of the skin caused by long-term exposure to ultraviolet radiation. It is clinically manifested by symptoms such as skin roughness, dryness, increased wrinkles, hyperpigmentation, laxity, and capillary dilation, with a small number of people developing benign or malignant skin tumors.1 The global anti-aging product market was estimated to have reached US $34.2 billion in 2020 and is expected to reach US $47.8 billion by 2027. Therefore, anti-skin photoaging is a very promising area of research.2

93 Peptide Effects on Photoaging The peptide complex cream used in this study is Yashaer Polypeptide Hydrating Cream (Zhuhai Yasha Biotechnology Co., Ltd., Zhuhai, Guangdong, China). The core ingredients include carnosine, palmitoyl pentapeptide-4, and acetyl hexapeptide-8. All 3 core ingredients are present in the cream at a concentration of 2%. Carnosine is a dipeptide (β-alanyl-L- histidine) that induces skin rejuvenation and anti-aging via telomere shortening inhibition, antioxidant activity, and anti-glycosylation (carbonyl scavenging).3 Palmitoyl pentapeptide (Lys-Thr-Thr-Lys-Ser, pal-KTTKS) promotes the production of the extracellular matrix (ECM) along with type I and type III collagen.4 Acetyl hexapeptide-8, also known as Argireline (Ac-Glu-Glu-Met-Gln-Arg-ARG-NH 2 ),has an anti-wrinkle effect similar to that of botulinum neurotoxin, which relaxes muscles and reduces wrinkle formation.5 This study utilized a randomized, double-blind, placebo-controlled, parallel-group method to investigate whether the peptide complex cream had the capability to improve facial wrinkles, pigmentation, roughness, and pores in order to understand the tolerance and adverse reactions of the subjects to the peptide complexes. MATERIALS Yashaer Polypeptide Hydrating Cream, Yashaer base cream, and Yashaer Icy Spring Isolation Emulsion (Zhuhai Yasha Biotechnology Co., Ltd., Zhuhai, Guangdong, China). METHODS SUBJECTS Subjects were enrolled from March 2021 to September 2021. The study was approved by the ethics committee of the Second Affiliated Hospital of Kunming Medical University, and all enrolled subjects signed the informed consent form. In the treatment group, Yashaer Polypeptide Hydrating Cream and sunscreen (Yashaer Icy Spring Isolation Emulsion) were applied to the face. In the control group, Yashaer base cream and sunscreen (Yashaer Icy Spring Isolation Emulsion) were applied to the face. This study was a placebo-controlled superiority clinical trial and the improvement rate of facial wrinkles in the subjects was the primary endpoint of the study. Based on a review of literature and clinical experience, the improvement rate of facial wrinkles was 10% in the control group and 40% in the treatment group. Using a one-sided test with a significance level of α =0.05 and a power of 90%, the total sample size for the two groups was calculated to be N =64. Considering a potential 20% dropout rate, a sample size of N1 =64/0.8 =80 was required. Thus, at least 40 subjects were required in each group for a 1:1 assignment. The inclusion criteria for subjects were: (1) participates in the study voluntarily, is able to provide written informed consent, and is able to voluntarily accept and comply with the trial treatment, follow-up, and assessment requirements (2) meets the diagnostic criteria for photoaging with a Glogau grade of II–III (3) female, aged from 45–55 years (4) indoor workers with no history of prolonged exposure to the sun within the last month (e.g., traveling, visiting the beach, hiking snowy mountains, etc.). The exclusion criteria for subjects were: (1) received relevant cosmetic treatments (e.g., laser, radiofrequency, photons, botulinum toxin injection, hyaluronic acid injection, chemical peeling, etc.) within the last month (2) use of oral or topical use of relevant medications (e.g., tretinoin, steroids, etc.) that can affect test results within the last month (3) pregnant or breastfeeding females