Aging is a Risk Factor for Rheumatoid Arthritis in Rats: Therapeutic Potential of 4‑(Phenylselanyl)-2H-chromen-2-one

The underlying mechanisms of rheumatoid arthritis (RA) remain inconclusive; nevertheless, several factors may contribute to developing and exacerbating the disease's signs and symptoms. It is well established that the structure and function of the organism decline with age; consequently, the aging process has become a significant risk factor for several human diseases. Thus, the current study investigated aging as a risk factor for RA in rats and the potential of 4-(phenylselanyl)-2H-chromen-2-one (4-PSCO) as a new therapeutic strategy. Arthritis was induced by intraplantar injection (i.pl.) of complete Freund's adjuvant (CFA; 0.1 mL) in the left hind paw of young and aged adult male Wistar rats. The 4-PSCO (1 mg kg^-1) was administered via the intragastric route for 10 days. CFA administration in aged rats aggravated pain sensitivity by increasing oxidative damage in the central and peripheral nervous systems. The treatment with 4-PSCO reversed pain sensibility, reduced the inflammatory process, and restored the body weight and spleen index. Additionally, 4-PSCO reduced oxidative stress in the paw and spinal cord. Our findings highlight 4-PSCO as a promising therapeutic alternative to develop a more effective and safer drug to treat RA and underscore age-related differences as an important factor for RA pathogenesis.