RESUMO
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 Kupffer 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 Kupffer 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.