Efficacy of Acupuncture on Pain Mechanisms, Inflammatory Responses, and Wound Healing in the Acute Phase of Major Burns: An Experimental Study on Rats

Abstract

We investigated acupuncture, a potential contributor for burn care, on physiological and pathological pain mechanisms and systemic and local inflammatory responses in a rat experimental burn model. Forty male Sprague-Dawley rats were divided into two groups. One-hour groups (five rats/group) were observed for 1 hour and included Sh1 (sham/observation), ShA1 (sham + acupuncture/observation), Brn1 (burn/observation), and BrnA1 (burn + acupuncture/ observation). Seven-day groups (five rats/group) were observed for 7 days and included Sh7 (sham/observation), ShA7 (sham + acupuncture/observation), Brn7 (burn/observation), and BrnA7 (burn + acupuncture/observation). "Pain-distress scores" were noted daily, and acupuncture was repeated within every wound-dressing change on alternate days. After observation periods, blood samples for interleukin 6 and beta-endorphin and skin biopsies for inflammatory changes and immunohistochemical staining of interleukin 6 were collected for analysis(P <.05). In 1-hour groups, interleukin 6 accumulation in burn wounds of BrnA1 was less than Brn1, with Brn1 having the highest mean blood level (P <.05). Mean beta-endorphin levels were higher in ShA1, Brn1, and BrnA1 than in Sh1 (P <.05). In all 7-day groups, the agonizing period was 48 to 72 hours after burn, with Brn7 most affected (P <.05). Microvessels were multiplied in the Brn7 group, with significantly higher numbers in burn wounds of BrnA7 (P<.05). Burn wounds of BrnA7 had less accumulation of interleukin 6 than Brn7 with the Brn7 group having the highest mean blood level and Sh7, ShA7, and BrnA7 having similarly low levels (P>.05). Beta-endorphin levels in ShA7, Brn7, and BrnA7 were lower than in Sh7 (P <.05). Acupuncture contributed to the management of physiological and pathological pain, modulation of inflammatory responses, and associated enhancement of angiogenesis in the acute phase of burn injury in rats.