This study aimed to explore the protective roles of malvidin in life-threatened sepsis-associated encephalopathy (SAE) and illustrate the underlying mechanism. SAE mice models were developed and treated with malvidin for subsequently protective effects evaluation. Malvidin restored neurobehavioral retardation, declined serum S100β and NSE levels, sustained cerebrum morphological structure, improved blood-brain barrier integrity with elevated tight junction proteins, and decreased evans blue leakage, and finally protect SAE mice from brain injury. Mechanistically, malvidin prevented cerebrum from mitochondrial dysfunction with enhanced JC-1 aggregates and ATP levels, and ROS accumulation with decreased lipid peroxidation and increased antioxidant enzymes. UCP2 protein levels were found to be decreased after LPS stimulation in the cerebrum and BV-2 cells, and malvidin recovered its levels in a ROS dependent manner. In vivo inhibition of UCP2 with genipin or in vitro interference with siRNA UCP2 both disrupted the mitochondrial membrane potential, decreased ATP levels and intensified DCF signals, being a key target for malvidin. Moreover, dorsomorphin block assays verified that malvidin upregulated UCP2 expression through phosphorylating AMPK in SAE models. Also, malvidin alleviated SAE progression through inhibition of ROS-dependent NLRP3 inflammasome activation mediated serum pro-inflammatory cytokines secretion and mitochondrial pathway mediated apoptosis with weakened apoptosis body formation and tunel positive signals, and decreased Bax, cytochrome C, caspase-3 and increased Bcl-2 protein levels. Overall, this study illustrated that malvidin targeted AMPK-α/UCP2 axis to restore LPS-induced mitochondrial dysfunction and alleviate ROS accumulation, which further inhibits NLRP3 inflammasome activation and mitochondrial apoptosis in a ROS dependent way, and ultimately protected SAE mice, providing a reference for the targeted development of SAE prophylactic approach.

Diabetic cardiomyopathy (DCM) is a major complication of diabetes, characterized by myocardial inflammation, oxidative stress, fibrosis, apoptosis, and RhoA activation, ultimately leading to heart failure. This study aimed to evaluate whether higenamine hydrochloride (HGN), a natural alkaloid with anti-inflammatory and antioxidant properties, could alleviate DCM and elucidate its underlying mechanisms. A DCM model was established via streptozotocin injection in mice, followed by HGN administration. Fasudil, a RhoA inhibitor, was used to assess pathway involvement. Histology, biochemical assays, flow cytometry, immunoblotting, ELISA, and qPCR were employed for evaluation. Results showed that HGN effectively alleviated cardiac histological abnormalities and myocardial injury in DCM mice. Further analysis revealed that HGN attenuated DCM-induced cardiac inflammation, oxidative stress, fibrosis, and apoptosis (p < 0.05). In vitro, HGN also reduced high glucose-induced inflammation, oxidative stress, fibrosis, and apoptosis in H9C2 cardiomyocytes (p < 0.05). Mechanistically, these protective effects were mediated by inhibition of RhoA, through which HGN suppressed the MEK/ERK signalling pathway, thereby mitigating cardiomyocyte injury (p < 0.05). However, the RhoA inhibitor fasudil hydrochloride abolished the cardioprotective effects of HGN in DCM mice, specifically, fasudil hydrochloride reversed the HGN-induced improvements in cTnT, CK, and LDH levels. Additionally, echocardiographic parameters (IVSD, LVPWd, LVPWs, LVIDd, LVIDs, IVSs, EF, and FS) were also reversed to levels seen in untreated DCM mice, further confirming that HGN exerts its therapeutic actions via the RhoA/MEK/ERK axis (p < 0.05). Overall, HGN mitigates cardiac inflammation, oxidative stress, fibrosis, and apoptosis in DCM by inhibiting the MEK/ERK pathway through RhoA. This study provides a scientific basis for developing DCM treatments and highlights the therapeutic potential of HGN. Graphical Abstract