Low‐level Laser Therapy Ameliorates CCl4‐induced Liver Cirrhosis in Rats

Abstract This study investigated the effects of low‐level laser therapy ( LLLT ) in the liver function, structure and inflammation in a experimental model of carbon tetrachloride ( CCl 4 )‐induced liver cirrhosis. Wistar rats were divided into Control, LLLT , CCl 4 and CCl 4 + LLLT groups. CCl 4 groups received CCl 4 (0.4 g kg −1 ; i.p.), three times a week, for 12 weeks. A 830 nm LLLT was performed with a continuous wave, 35 mW, 2.5 J cm −2 per point, applied to four points of the liver (right and left upper and lower extremities, in the four lobes of the liver) for 2 weeks. Liver structure and inflammation (cirrhotic areas, collagen deposition, inflammation, density of K upffer and hepatic stellate cells) and function (aspartate aminotransferase, alkaline phosphatase, gamma glutamyltransferase, lactate dehydrogenase, total proteins and globulins) were evaluated. LLLT significantly reduced CCl 4 ‐increased aspartate aminotransferase ( P < 0.001), alkaline phosphatase ( P < 0.001), gamma‐glutamyl transferase ( P < 0.001) and lactate dehydrogenase ( P < 0.01) activity, as well as total proteins ( P < 0.05) and globulins ( P < 0.01). LLLT also reduced the number of cirrhotic areas, the collagen accumulation and the hepatic inflammatory infiltrate. Of note, LLLT reduced CCl 4 ‐increased number of K upffer cells ( P < 0.05) and hepatic stellate cells ( P < 0.05). We conclude that LLLT presents beneficial effects on liver function and structure in an experimental model of CCl 4 ‐induced cirrhosis.