Withaferin A alleviates fulminant hepatitis by targeting macrophage and NLRP3

Abstract

Fulminant hepatitis (FH) is an incurable clinical syndrome where novel therapeutics are warranted. Withaferin A (WA), isolated from herb Withania Somnifera, is a hepatoprotective agent. Whether and how WA improves D-galactosamine (GalN)/lipopolysaccharide (LPS)-induced FH is unknown. This study was to evaluate the hepatoprotective role and mechanism of WA in GalN/LPS-induced FH. To determine the preventive and therapeutic effects of WA, wild-type mice were dosed with WA 0.5 h before or 2 h after GalN treatment, followed by LPS 30 min later, and then killed 6 h after LPS treatment. To explore the mechanism of the protective effect, the macrophage scavenger clodronate, autophagy inhibitor 3-methyladenine, or gene knockout mouse lines NLR family pyrin domain containing 3 (Nlrp3)-null, nuclear factor-erythroid 2-related factor 2 (Nrf2)-null, liver-specific AMP-activated protein kinase (Ampk)a1 knockout (Ampka1ΔHep) and liver-specific inhibitor of KB kinase β (Ikkb) knockout (IkkbΔHep) mice were subjected to GalN/LPS-induced FH. In wild-type mice, WA potently prevented GalN/LPS-induced FH and inhibited hepatic NLRP3 inflammasome activation, and upregulated NRF2 and autophagy signaling. Studies with Nrf2-null, Ampka1ΔHep, and IkkbΔHep mice demonstrated that the hepatoprotective effect was independent of NRF2, hepatic AMPKα1, and IκκB. Similarly, 3-methyladenine cotreatment failed to abolish the hepatoprotective effect of WA. The hepatoprotective effect of WA against GalN/LPS-induced FH was abolished after macrophage depletion, and partially reduced in Nlrp3-null mice. Consistently, WA alleviated LPS-induced inflammation partially dependent on the presence of NLRP3 in primary macrophage in vitro. Notably, WA potently and therapeutically attenuated GalN/LPS-induced hepatotoxicity. In conclusion, WA improves GalN/LPS-induced hepatotoxicity by targeting macrophage partially dependent on NLRP3 antagonism, while largely independent of NRF2 signaling, autophagy induction, and hepatic AMPKα1 and IκκB. These results support the concept of treating FH by pharmacologically targeting macrophage and suggest that WA has the potential to be repurposed for clinically treating FH as an immunoregulator.

Withaferin A in the Treatment of Liver Diseases: Progress and Pharmacokinetic Insights

“…In this GalN/LPS-induced acute liver injury model, WA was found to have both potent preventive and therapeutic effects when mice were dosed with a single intraperitoneal injection of WA at 0.5 h before or 2 h after GalN dosing. By using clodronate liposome pretreatment to deplete macrophage, the hepatoprotective effect of WA was abolished, but by further using global Nlrp3-null mice as well as NLRP3-deficient primary macrophages, the WA effects were partially lost, but not totally abolished (Xia et al, 2021). In this same study, by using gene knockout mouse strains, the hepatoprotective effect of WA was found to be independent of the presence of hepatocyte AMPKα1, NRF2 and hepatocyte Iκκβ (Xia et al, 2021).…”

“…Fulminant hepatitis is a life-threatening clinical syndrome worldwide. WA was recently reported to attenuate GalN/LPS-induced hepatotoxicity in mice, associated with attenuating the inflammatory response via targeting macrophage and NLRP3, while largely independent of NRF2 signaling, autophagy induction, and hepatic AMPKα1 and IκκB signaling (Xia et al, 2021). In this GalN/LPS-induced acute liver injury model, WA was found to have both potent preventive and therapeutic effects when mice were dosed with a single intraperitoneal injection of WA at 0.5 h before or 2 h after GalN dosing.…”

“…By using clodronate liposome pretreatment to deplete macrophage, the hepatoprotective effect of WA was abolished, but by further using global Nlrp3-null mice as well as NLRP3-deficient primary macrophages, the WA effects were partially lost, but not totally abolished (Xia et al, 2021). In this same study, by using gene knockout mouse strains, the hepatoprotective effect of WA was found to be independent of the presence of hepatocyte AMPKα1, NRF2 and hepatocyte Iκκβ (Xia et al, 2021). Given that macrophage depletion abolished the hepatoprotective effects of WA in this model and NLRP3 knockout could not totally, but only partially, abolish the hepatoprotective effect of WA, additional targets located in macrophage, such as macrophage-specific Iκκβ, were suspected to mediate the hepatoprotective effects of WA in this model.…”

Paeoniflorin Protects against ANIT-Induced Cholestatic Liver Injury in Rats via the Activation of SIRT1-FXR Signaling Pathway

“…The NF- κ B/NLRP3 inflammasome pathway is an important pathway for regulating inflammatory factors. Recent studies have shown that NLRP3 may cause liver injury through the activation of NF- κ B-related pathways, and NLRP3 inflammasome is of great significance in regulating the occurrence and development of inflammatory response in liver injury [ 46 , 47 ]. When stimulated by external factors, NF- κ B is activated to regulate the expression of NLRP3, IL-18, TNF- α , and other genes.…”

Nebulizer, Inhaled Remdesivir Nanoparticle Co-administered with Withania Somnifera may Minimize the Hepatotoxicity in COVID-19

“…To minimize the toxicity and to enhance the therapeutic efficacy, remdesivir could be administered as nebulizer inhaled nanoparticle once per day for 5-10 days following the oral administration of W. somnifera at a dose of 500 mg per day for 6 weeks [9]. Many preclinical and clinical study results clearly demonstrates that W. somnifera possesses promising hepatoprotective effects through its antioxidant activity and hence suggested its use as a potential therapeutic agent for hepatic disorders [10][11][12][13][14][15].…”