Tamarind seed extract mitigates the liver oxidative stress in arthritic rats

Abstract

Although arthritis is primarily a joint disorder that mainly targets the articular cartilage and subchondral bone, several recent investigations have reported oxidative burst and vital organ damage that are being considered as secondary complications of arthritis. The continuous generation of free radicals like reactive oxygen and nitrogen species is considered as a key culprit in the initiation and propagation of oxidative damage. In addition, activation of T and B cells, macrophages, inflammatory mediators such as TNF-α, IL-1β and IL-6 aggravates the oxidative damage of the vital organs, particularly the liver. The current piece of work demonstrates oxidative stress in the liver of arthritic rats and its amelioration by the procyanidin-rich tamarind seed extract (TSE). The arthritic liver homogenate, mitochondrial and cytosolic fractions were found with increased levels of oxidative stress markers including free radicals. As a consequence, depletion in the levels of glutathione, total thiols, glutathione peroxidase and reductase was evident. Furthermore, the activities of endogenous antioxidant enzymes like superoxide dismutase, catalase and glutathione-S-transferase were found to be significantly altered. The increased and decreased activity of transaminases respectively in serum and liver, along with histological observations, further confirms the liver damage. Unfortunately, the commonly used drugs like NSAIDs and DMARDs have failed to prevent oxidative damage, rather they were found to be the inducers themselves. Interestingly, TSE supplementation was found to significantly inhibit oxidative burst in the liver and maintain homeostasis. Thus, the study clearly demonstrates the protective efficacy of TSE against arthritis-associated oxidative liver damage, including mitochondrial oxidative burst and its associated secondary complications.