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Type 1 diabetes mellitus (T1DM) results from insulin deficiency due to the destruction of pancreatic β-cells. Previously, our studies showed that inhibition of Keap1/Nrf2 signaling pathway promoted the onset of T1DM, which suggests that finding drugs that can activate the Keap1/Nrf2 signaling may be a promising therapeutic strategy for the T1DM treatment. Astragalus membranaceus (Fisch.) Bunge is a common traditional Chinese medicine that has been frequently applied in Chinese clinics for the treatment of diabetes and other diseases. Formononetin (FMNT), one of the major isoflavonoid constituents isolated from this herbal medicine, possesses diverse pharmacological benefits and T1DM therapeutic potential. However, the exact molecular mechanisms underlying the action of FMNT in ameliorating T1DM have yet to be fully elucidated. This study is to investigate the regulation of FMNT on the Keap1/Nrf2 signaling pathway to ameliorate T1DM based on network pharmacology approach combined with experimental validation. A mouse-derived pancreatic islet β-cell line (MIN6) was used for the in vitro studies. An alloxan (ALX)-induced T1DM model in wild-type and Nrf2 knockout (Nrf2−/−) C57BL/6J mice were established for the in vivo experiments. The protective effects of FMNT against ALX-stimulated MIN6 cell injury were evaluated using MTT, EdU, apoptosis and comet assays. The levels of blood glucose in mice were measured by using a blood monitor and test strips. The protein expression was detected by Western blot analysis. Furthermore, the binding affinity of FMNT to Keap1 was evaluated using cellular thermal shift assay (CETSA), drug affinity responsive target stability (DARTS) assay, and solvent-induced protein precipitation (SIP) assay. The interaction pattern between FMNT and Keap1 was assessed by molecular docking and molecular dynamics simulation techniques. Network pharmacology analysis revealed that FMNT exerted its therapeutic effect against T1DM by mainly regulating oxidative stress response-associated signaling molecules and pathways, such as Nrf2 regulating anti-oxidant/detoxification enzymes and Keap1-Nrf2 signaling pathway. The in vivo results showed that FMNT significantly deceased the ALX-induced high blood glucose levels and conversely increased the ALX-induced low insulin contents. In vitro , FMNT markedly protected MIN6 cells from ALX-induced cytotoxicity, proliferation inhibition and DNA damage and reduced the ALX-stimulated cell apoptosis. FMNT also inhibited ALX-induced overproduction of intracellular ROS to alleviate oxidative stress. In addition, FMNT could bind to Keap1 to notably activate the Keap1/Nrf2 signaling to upregulate Nrf2 expression and promote the Nrf2 translocation from the cytoplasm to the nucleus, resulting in enhancing the expression of antioxidant proteins HO-1 and NQO1. Inhibition of Keap1/Nrf2 signaling by ALX was also markedly abolished in the cells and mice exposed to FMNT. Moreover, these effects of FMNT in ameliorating T1DM were not observed in Nrf2−/− mice. This study demonstrates that FMNT could bind to Keap1 to activate the Keap1/Nrf2 signaling to prevent intracellular ROS overproduction, thereby attenuating ALX-induced MIN6 cell injury and ameliorating ALX-stimulated T1DM. Results from this study might provide evidence and new insight into the therapeutic effect of FMNT and indicate that FMNT is a promising candidate agent for the treatment of T1DM in clinics. [Display omitted] • Formononetin ameliorated alloxan-induced T1DM in wild-type C57BL/6J mice. • Formononetin could not ameliorated alloxan-induced T1DM in Nrf2−/− C57BL/6J mice. • Formononetin protected pancreatic islet β-cells from alloxan-induced cell injury. • Formononetin could bind to Keap1 to activate the Keap1/Nrf2 signaling pathway. [ABSTRACT FROM AUTHOR]

Abstract Ethnopharmacological relevance Chrysanthemum indicum Linne (C. indicum), a healthy food and folk medicine in China for thousands of years, has been reported to exert heat-clearing and detoxifying effects and extensively applied to treat various symptoms such as inflammation diseases, hepatitis and headache. Aim of this study The purpose of the present study was to investigate the protective effect of the supercritical carbon dioxide fluid extract from flowers and buds of C. indicum (CI SCFE) on D -galactose-induced brain and liver damage during aging process and to illuminate the underlying mechanisms. Materials and methods Mice were orally administrated with CI SCFE (100, 150 and 300 mg/kg) after injection with D -galactose. 24 h after the last administration, the blood samples, whole brain and liver tissues were collected for biochemical analysis, histological examination and western blot analysis. The body weight, spleen and thymus indexes, alanine transaminase (ALT), aspartate transaminase (AST), total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), malondialdehyde (MDA) in brain and liver, interleukin-1β (IL-1β), interleukin-6 (IL-6), and necrosis factor-α (TNF-α) were detected. Besides, the expressions of Bax, Bcl-2 and cleaved caspase-3 were determined by western blot assay. Results The results indicated that CI SCFE effectively increased the suppressed body weight, attenuated the decline of thymus and spleen indexes, and reduced the elevated levels of ALT and AST induced by D -gal. Furthermore, CI SCFE might notably alleviate D -gal-induced abnormal alterations in structure and function of brain and liver dose-dependently via renewing normal antioxidant enzymes activities (SOD, CAT, GSH-Px), reducing MDA accumulation, decreasing inflammatory cytokines productions (IL-1β, IL-6, TNF-α), as well as attenuating the increase of Bax/Bcl-2 ratio and cleaved caspase-3 activation in the liver and brain. Conclusions Taken together, our present results suggested that CI SCFE treatment could effectively mitigate the D -gal-induced hepatic and cerebral injury, and the underlying mechanism might be tightly related to the decreased oxidative stress, inflammation and apoptosis, indicating CI SCFE might be an alternative and promising agent for the treatment of aging and age-associated brain and liver diseases. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by failure of spontaneous resolution of inflammation. The stem of Kadsura heteroclite (KHS) is a well-known anti-arthritic Tujia ethnomedicinal plant, which named Xuetong in folk, has long been used for the prevention and treatment of rheumatic and arthritic diseases. The analgesic and anti-inflammatory effects and the potential mechanisms behind such effects of KHS would be investigated by using different animal models. The abdominal writhing episodes of mice induced by intraperitoneal injection of acetic acid and the tail-flick response induced by radiant heat stimulation were used to evaluate the analgesic effect of KHS. The number of abdominal writhing episodes of mice and the latency of tail-flick in rats were measured and recorded. In acute inflammatory models, the ear edema of mice was induced by applying xylene on the ear surface, while the paw edema of male and female rats was induced by subcutaneous injection of carrageenan into the right hind paws of animals. The carrageenan-induced paw swelling in rats were selected as an anti-acute inflammatory mechanism of KHS. Serum levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor (TNF-α) were measured by ELISA, and protein expression of cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) were detected by Western blot. The maximal tolerated single dose of KHS was determined to be 26 g/kg in both sexes of mice. Pharmacological studies showed that KHS at the dose of 200 mg/kg significantly prolonged the reaction time of rats to radiant heat stimulation and suppressed abdominal writhing episodes of mice induced by intraperitoneal injection of acetic acid. KHS at the dose of 200, 400, and 800 mg/kg, showed dose-dependent inhibition of xylene-induced ear swelling in mice. KHS at the dose of 100, 200, 400, and 800 mg/kg demonstrated dose- and time-dependent suppression of paw edema induced by subcutaneous injection of carrageenan in both all rats. Mechanistic studies revealed that the anti-inflammatory effect of KHS was associated with inhibition of the production of pro-inflammatory cytokines IL-1β, IL-6, and TNF-α and effectively decreased the expression of COX and iNOS proteins in the carrageenan-injected rat serum, paw tissues and inflammatory exudates. The positive reference drug, rotundine at a dosage of 100 mg/kg and indomethacin at a dosage of 10 mg/kg were used in both mice and rat models. These results suggested that KHS has significant effects on analgesia and anti-inflammation with decreasing the pro-inflammation cytokines of IL-1β, IL-6, and TNF-α and inhibiting the proteins expression of COX-2 and iNOS. Image 1 [ABSTRACT FROM AUTHOR]