ORIGINAL ARTICLE Lycium barbarum polysaccharide fraction associated with photobiomodulation protects from epithelium thickness and collagen fragmentation in a model of cutaneous photodamage Lia Mara Grosso Neves 1 & Carla Roberta Tim 2 & Elaine Medeiros Floriano 3 & Lucimar Retto da Silva de Avó 4 & João Batista Fernandes 5 & Nivaldo Antonio Parizotto 2,6,7 & Marcia Regina Cominetti 1 Received: 6 April 2020 /Accepted: 18 August 2020 # Springer-Verlag London Ltd., part of Springer Nature 2020 Abstract Ultraviolet radiation (UVR) is the major etiologic agent of cutaneous photoaging, and different strategies are used to prevent and treat this condition. The polysaccharide fraction (LBPF) isolated from Lycium Barbarum fruits (goji berry) contains several active ingredients with antioxidant, immune system modulation, and antitumor effects. In addition, the photobiomodulation (PBM) is widely applied in photoaging treatment. This study investigated the effects of LBPF and PBM against the UVR- induced photodamage in the skin of hairless mice. The mice were photoaged for 6 weeks in a chronic and cumulative exposure regimen using a 300-W incandescent lamp that simulates the UVR effects. From the third to the sixth week of photoaging induction, the animals received topical applications of LBPF and PBM, singly or combined, in different orders (first LBPF and then PBM and inversely), three times per week after each session of photoaging. After completion of experiments, the dorsal region skin was collected for the analysis of thickness, collagen content, and metalloproteinases (MMP) levels. A photoprotective potential against the increase of the epithelium thickness and the fragmentation of the collagen fibers was achieved in the skin of mice treated with LBPF or PBM singly, as well as their combination. All treatments maintained the skin collagen composition, except when PBM was applied after the LBPF. However, no treatment protected against the UVR-induced MMP increase. Taken together, we have shown that the LBPF and PBM promote a photoprotective effect in hairless mice skin against epidermal thickening and low collagen density. Both strategies, singly and combined, can be used to reduce the UVR-induced cutaneous photoaging. Keywords Lycium barbarum . Polysaccharides . Photobiomodulation . Photodamage . Hairless mice Introduction The skin is regularly exposed to conditions of direct oxidative damage, including ultraviolet radiation (UVR) from the sun [1]. UVR-induced photodamage causes undesirable changes in skin appearance that over time lead to increased or acceler- ated physiological reserve loss and protection damage [2]. The UVR initiates a complex cascade of biochemical reactions in * Lia Mara Grosso Neves neves.lmg@gmail.com * Marcia Regina Cominetti mcominetti@ufscar.br 1 Laboratory of Biology of Aging (LABEN), Department of Gerontology, Federal University of São Carlos, São Carlos, SP CEP 13565-905, Brazil 2 Postgraduate Program in Biomedical Engineering, Brazil University, São Paulo, SP CEP 08230-030, Brazil 3 Department of Pathology and Legal Medicine, University of São Paulo, Ribeirão Preto, SP CEP 14049-900, Brazil 4 Department of Medicine, Federal University of São Carlos, São Carlos, SP CEP 13565-905, Brazil 5 Department of Chemistry, Federal University of São Carlos, São Carlos, SP CEP 13565-905, Brazil 6 Joint Graduate Program in Physical Therapy, Federal University of São Carlos, São Carlos, SP CEP 13565-905, Brazil 7 Postgraduate Program in Biotechnology in Regenerative Medicine and Medical Chemistry, University of Araraquara, Araraquara, SP CEP 14801-340, Brazil Lasers in Medical Science https://doi.org/10.1007/s10103-020-03132-w