Quercetin modulates Chitinase-3-like protein 1 expression and inflammatory responses in lipopolysaccharide-stimulated...

Ovarian inflammatory challenges can impair buffalo fertility by altering granulosa cell (GC) function and oocyte competence. Chitinase-3-like protein 1 (CHI3L1/YKL-40) has been linked to inflammatory processes in several species, and quercetin is a flavonoid with reported anti-inflammatory and antioxidant actions. This study evaluated whether CHI3L1 is responsive to lipopolysaccharide (LPS) stimulation in buffalo granulosa cells and whether quercetin modulates LPS-induced expression of inflammatory markers. Primary buffalo granulosa cells were cultured in vitro and challenged with LPS with or without quercetin co-treatment. CHI3L1 and pro-inflammatory cytokine transcripts (IL-1β, IL-6, and TNF-α) were quantified by real-time PCR; secreted CHI3L1 in culture supernatants was assessed by ELISA; intracellular reactive oxygen species (ROS) were measured by DCFDA fluorescence; and oocyte maturation was assessed using a granulosa cell-cumulus-oocyte complex co-culture system. LPS increased cytokine transcript abundance and ROS production and was accompanied by a modest reduction in oocyte maturation. CHI3L1 mRNA was upregulated following LPS challenge, whereas secreted CHI3L1 protein did not show a significant increase under the conditions tested. Quercetin attenuated LPS-induced cytokine expression and ROS accumulation and partially improved oocyte maturation outcomes. Collectively, these findings identify CHI3L1 as an LPS-responsive transcript in buffalo granulosa cells and support a protective role for quercetin against LPS-induced inflammatory and oxidative responses in vitro. Further work is required to define the functional role of CHI3L1 and the in vivo relevance of quercetin.