Fundamental research on the action mechanism of

EXPERIMENTAL AND THERAPEUTIC MEDICINE

Fundamental research on the action mechanism of the 800 nm semiconductor laser on skin blackheads and coarse pores JIE LIN1, LI JING2, HAO ZHU1 and FU-SHENG DONG3 1

Department of Medical Cosmetology, Hebei General Hospital, Shijiazhuang, Hebei 050051; Department of Medical Oncology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011; 3 Department of Oral and Maxillofacial Surgery, Dental Hospital of Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China

2

Received May 31, 2016; Accepted November 9, 2016 DOI: 10.3892/etm.2016.3937 Abstract. ������������������������������������������������ The aim of the study was to determine the mecha� nism of action of the 800 nm semiconductor laser on skin blackheads and coarse pores. A total of 24 healthy purebred short-haired male guinea pigs, weighing 350-400 g, were selected and smeared with 0.5 ml coal tar suspension evenly by injector once daily. Treatment was continued for 14 days to form an experimental area of 8x3 cm on the back of the guinea pigs. The animals were divided into the following groups: Normal control group (NC), low-dose laser treatment group (L-LS), high-dose laser treatment group (H-LS), and Q-switched Nd:YAG treatment group (QC). Samples were extracted 1, 7 and 14 days after surgery and hematoxylin and eosin staining was used to identify the following: Epidermis, dermis, sebaceous gland change and hair follicle damage; the expression of proliferating cell nuclear antigen (PCNA) of sebaceous gland cells using immunohistochemistry; seba� ceous gland cell apoptosis using TUNEL; and the protein expression of caspase-3, Bax and Bcl-2 using western blot analysis. With the extension of time, we observed inflam� matory cell infiltration, an increase in hair follicle distortion and necrosis of the surrounding hair follicles. The expression levels of PCNA of the L-LS, H-LS and QC groups decreased with time. Regarding the respective time points, the NC group was highest, the L-LS and H-LS groups were next highest and the H-LS group was lowest. The difference was statisti� cally significant (P