New Research

LOW-LEVEL LASER THERAPY (904nm) CAN INCREASE COLLAGEN AND REDUCE OXIDATIVE AND NITROSATIVE STRESS IN DIABETIC WOUNDED MOUSE SKIN

Tatmatsu-Rocha JC, Ferraresi C, Hamblin MR, Damasceno Maia F, do Nascimento NR, Driusso P, Parizotto NA

Abstract

BACKGROUND AND OBJECTIVE: Over the last decade we have seen an increased interest in the use of Low-Level Laser Therapy (LLLT) in diseases that involve increased oxidative stress. It is well established that hyperglycemia in diabetes elicits a rise in reactive oxygen species (ROS) production but the effect of LLLT remains unclear. This study aimed to investigate whether LLLT was able to improve oxidative/nitrosative stress parameters in the wound healing process in diabetic mice.

STUDY DESIGN/MATERIALS AND METHODS: Twenty male mice were divided into four groups: non-irradiated control (NIC), irradiated control (IC), non-irradiated and diabetic (NID), irradiated and diabetic (ID). Diabetes was induced by administration of streptozotocin. Wounds were created 120days after the induction of diabetes in groups IC and ID and these groups were irradiated daily for 5days (superpulsed 904nm laser, average power 40mW, 60s). All animals were sacrificed 1day after the last irradiation and histology, collagen amount, catalase activity, nitrite and thiobarbituric acid reactive substances (TBARS) were measured.

RESULTS: Histology showed that collagen fibers were more organized in IC and ID when compared to NID group, and significant differences in collagen content were found in group ID versus NID. Catalase activity was higher in IC group compared to other groups (p<0.001). TBARS levels were higher in IC versus NIC, but were lower in ID versus NID (p<0.001). Nitrite was lower in both irradiated groups versus the respective non-irradiated groups (p<0.001). 

CONCLUSION: Delayed wound healing in diabetes is still a challenge in clinical practice with high social costs. The increased production of collagen and decreased oxidative and nitrosative stress suggests that LLLT may be a viable therapeutic alternative in diabetic wound healing.

Retrieved from: https://www.ncbi.nlm.nih.gov/pubmed/27661759

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PHOTOBIOMODULATORY EFFECTS OF SUPERPULSED 904NM LASER THERAPY ON BIOENERGETICS STATUS IN BURN WOUND HEALING

Yadav A, Gupta A, Keshri GK, Verma S, Sharma SK, Singh SB

Abstract

BACKGROUND AND OBJECTIVE: Burn wounds exhibit impaired healing as the progression through the normal sequential stages of tissue repair gets hampered by epidermal barrier disruption, compromised blood circulation, abrogated defence mechanism, pathologic inflammation, and septicemia. Our earlier results reported that superpulsed 904nm LLLT enhanced healing and attenuated inflammatory response in burn wounds. 

MATERIALS AND METHODS: The present study investigated the effect of superpulsed 904nm LLLT (200ns pulse width; 100Hz; 0.7mW mean output power; 0.4mW/cm(2) average irradiance) on biochemical and molecular markers pertaining to bioenergetics and redox homeostasis on full-thickness burn wounds in experimental rats.

RESULTS: Indicated that superpulsed laser irradiation for 7days post-wounding propelled the cellular milieu towards aerobic energy metabolism as evidenced by significantly enhanced activities of key energy regulatory enzymes viz. HK, PFK, CS and G6PD, whereas LDH showed reduced activity as compared to the non-irradiated controls. LLLT showed a significant increased CCO activity and ATP level. Moreover, LLLT also regulated redox homeostasis as evidenced by enhanced NADPH levels and decreased NADP/NADPH ratio. Western blot analysis demonstrated that LLLT produced an up-regulation of GLUT1, pAMPKα and down-regulation of glycogen synthase1 (GS1).

CONCLUSION: Our findings suggest that superpulsed 904nmLLLT augments burn wound healing by enhancing intracellular energy contents through modulation of aerobic metabolism for maximum energy output. Bioenergetic activation and maintenance of redox homeostasis could be one of the noteworthy mechanisms responsible for the beneficial NIR photobiomodulatory effect mediated through superpulsed 904nm LLLT in burn wound healing.

Retrieved from: https://www.ncbi.nlm.nih.gov/pubmed/27344636