eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2025-09-30 18 3 2298 2304 10.13005/bpj/3256 67833 article Ikram Abbas Aboud Al-Sammaraae 1 Department of Microbiology, College of Veterinary Medicine, University of Baghdad, Iraq. Klebsiella pneumoniae is an opportunistic bacterium associated with severe nosocomial infections, and Multi-drug-resistant represents a considerable risk to public health due to rapidly increasing disease prevalence over the past few decades worldwide .This study aimed to demonstrate the capacity of Quercetin dietary supplement to modulate the immune responses for IL-,⁸ IL-,⁶ and INF-α. Forty mice use in ⁴ groups (n=10), the first three groups were received orally 150,100,and 50 mg /mouse weekly for two months, and the 4th group was administered phosphate buffer saline (PBS) as negative control. After two months, sera were collected from mice before and after challenge (¹⁰ days) with an infectious dose of K. pneumoniae (.¹⁵×108 cfu/ml, I.P) of all groups . The results revealed increased levels of IL-,⁶ IL-,⁸and TNF-α significantly (P≤0.05) at all doses compared to the negative control group and the dose 100mg /ml give the high level at day 60 ,while dose 50mg/ml give the high level after ¹⁰ days post infection, but the three treated groups decreased relatively to the negative control after challenge. This research underscores the promise of Quercetin at dose 150mg/ml as anti-inflammatory and immunomodulatory properties through modulation of IL-,⁶ IL-,⁸ and TNF-α levels, which mitigated excessive inflammation and bolstered host defense mechanisms. The findings indicate that Quercetin may serve as a valuable complementary treatment for infections caused by K. pneumoniae. https://biomedpharmajournal.org/vol18no3/evaluation-of-quercetin-on-proinflammatory-cytokines-against-klebsiella-pneumoniae-in-mice/ Klebsiella pneumoniae Quercetin ELISA Mice Cytokines