Effect of low level laser therapy on articular cartilage and synovium in osteoarthritis and adjuvant arthritis models in rats: Histopathology, electron microscopy and oxidative stress markers assessment

ABSTRACT

The effect of low energy level laser [LLL] therapy was assessed on the basis of physical parameter [paw edema] and histopathological examination of knee joints using light and electron microscopes. Serum nitric oxide, malondialdehyde and ceruloplasmin in addition to blood glutathione and erythrocyle superoxide dismutase levels/activities were also determined. The results revealed that LLL possesses antiedematous and antiarthritic effects, being more relevant in adjuvant arthritis [AA] animals. This was evidenced by a marked reduction in paw edema in addition to decrease in villous formation and disappearance of inflammatory cells in the synovium of AA rats. The histopathological picture of the articular cartilage was also improved; however, not reaching statistically significant level. In AA mode1, the anti-arthritic effect of LLL was extended systemically causing significant reduction in the elevated levels of malondialdehyde, ceruloplasmin and supxoxide dismutase by 46%, 22% and 25%, respectively, as compared to the corresponding untreated AA rats. No marked effects were clearly demonstrated in osteoarthritis [OA] model as noticed from the hisropathological and biochemical aspects, except for the presence of intact mitochondria even in cells undergoing apoptosis. LLL confers good anti-arthritic effect in AA model that support its anti-inflammatory and immunosuprresive effects. More research should be performed using different schedules of laser to explore its role in OA