Naringenin downregulates inflammation-mediated nitric oxide overproduction and potentiates endogenous antioxidant status during hyperglycemia

Abstract

Nitric oxide (NO) is a key regulating factor for physiological functions, when elevated during inflammatory conditions can lower endogenous antioxidant levels. Increased NO interacts with oxygen or other ROS to generate peroxynitrite, a potent oxidant which induces oxidative stress. Analgesic effects of naringenin (NRN), a flavanone has been demonstrated by inducing antiinflammatory effects in O 2 −• -mediated inflammation. NRN stimulates antioxidant enzymes and also improves glucose uptake. Hence this study was designed to look for therapeutic effects of NRN and in comparison, to metformin (MET) on inflammation-mediated increased NO and decreased antioxidant superoxide dismutase (SOD) in diabetic rat model with compromised glycemic and lipid profile. After single intraperitoneal injection of alloxan (120 mg/kg), the rats were equally divided as Group 1 and 2 which received normal saline and no-treatment respectively while group 3 and 4 received MET 50 mg/kg/day and NRN 50 mg/kg/day respectively. Blood samples were collected at 0, 15 th and 30 th day of treatment period. Results showed that alloxan significantly increased serum level of glucose (P<0.001), NO (P<0.001) and inflammatory biomarkers (TNF-α, IL-6), however, it expressively decreased serum SOD and insulin level. While, NRN significantly downregulated glucose (P<0.05), lipid profile, TNF-α, IL-6 and normalized level of NO (P<0.01). It also improved SOD level as compared to that of MET-treatment. Histopathology of pancreas also showed significant improvement in morphology after NRN treatment. This work delivers that NRN exerts anti-oxidant effect in part by downregulating the inflammation-mediated NO overproduction and improving level of SOD resulting in potentiation of endogenous antioxidant defense.

Interleukin‐6 inhibitory effect of natural product naringenin compared to a synthesised monoclonal antibody against life‐threatening COVID‐19

“…108 As a result, naringenin may provide therapeutic benefits to COVID-19 patients by reducing inflammatory reactions. 109 Including excessive levels of cytokines such as TNF-, IL-1, IL-10, and interferon (IFN) 110 NAR also has been shown to reduce autophagy levels and reduce lung inflammation. 69,111 Overall, we can conclude that naringenin could be a promising COVID-19 therapeutic method.…”