Possible Modulatory Effect of Tamarind Seed Coat Extract on Fluoride-Induced Pulmonary Inflammation and Fibrosis in Rats

Fluorosis (fluoride toxicity) seems to be reduced by plant secondary metabolites. Tamarind seed coat extract (TSCE), a mixture of procyanidins and polyphenols, possesses numerous pharmacological activities. Regardless of its beneficial properties, the underlying molecular mechanism against chronic fluorosis in vivo is not known. Hence, the present study is aimed to investigate the efficacy of TSCE against fluoride (F−)-induced pulmonary toxicity in rats. Female Wistar rats were randomly divided into four groups and treated with NaF (300 ppm in drinking water) and TSCE (100 mg/kg/bw by oral intubation) alone and in combination daily for 30 days. The results showed that F− exposure-induced modifications in lung injury markers in both serum and BALF were restored by TSCE supplementation. Additionally, F−-induced changes in oxidative stress (NOX4 and p38α MAPK), inflammation (NF-κB, COX-2, and HO-1), apoptosis (Hsp27, Hsp60, caspase3p20, and PARP1), and fibrosis (TGF-β1, psmad3, Col1αl, and hydroxyproline level) markers in the lungs were modulated by TSCE. Thus, TSCE offers protection against F−-induced pulmonary inflammation and fibrosis in rats.