Ethyl pyruvate: A newly discovered compound against ischemia-reperfusion injury in multiple organs

Breaking the vicious cycle: Targeting the NLRP3 inflammasome for treating sepsis-associated encephalopathy

Sepsis-associated encephalopathy (SAE) is a collection of clinical syndromes resulting from sepsis and characterized by widespread brain dysfunction. The high prevalence of SAE has adverse outcomes on the clinical management and prognosis of sepsis patients. However, currently, there are no effective treatments to ameliorate SAE. The pathogenesis of SAE is complex, including neuroinflammation and microglia activation, destruction of the blood-brain barrier (BBB), neurotransmitter dysfunction, cerebral metabolism and mitochondrial impairment, accumulation of amyloid beta and tauopathy, complement activation, among others. Furthermore, these mechanisms intertwine with each other, further complicating the comprehension of SAE. Among them, neuroinflammation mediated by hyperactivated microglia is considered the primary etiology of SAE. This instigates a detrimental cycle wherein BBB permeability escalates, facilitating direct damage to the central nervous system (CNS) by various neurotoxic substances. Activation of the NLRP3 inflammasome, situated within microglia, can be triggered by diverse danger signals, leading to cell pyroptosis, apoptosis, and tauopathy. These complex processes intricately regulate the onset and progression of neuroinflammation. In this review, we focus on elucidating the inhibitory regulatory mechanism of the NLRP3 inflammasome in microglia, which ultimately manifests as suppression of the inflammatory response. Our ultimate objective is to augment comprehension regarding the role of microglial NLRP3 inflammasome as we explore potential targets for therapeutic interventions against SAE.

Ethyl Pyruvate Decreases Collagen Synthesis and Upregulates MMP Activity in Keloid Fibroblasts and Keloid Spheroids

Keloids, marked by abnormal cellular proliferation and excessive extracellular matrix (ECM) accumulation, pose significant therapeutic challenges. Ethyl pyruvate (EP), an inhibitor of the high-mobility group box 1 (HMGB1) and TGF-β1 pathways, has emerged as a potential anti-fibrotic agent. Our research evaluated EP's effects on keloid fibroblast (KF) proliferation and ECM production, employing both in vitro cell cultures and ex vivo patient-derived keloid spheroids. We also analyzed the expression levels of ECM components in keloid tissue spheroids treated with EP through immunohistochemistry. Findings revealed that EP treatment impedes the nuclear translocation of HMGB1 and diminishes KF proliferation. Additionally, EP significantly lowered mRNA and protein levels of collagen I and III by attenuating TGF-β1 and pSmad2/3 complex expression in both human dermal fibroblasts and KFs. Moreover, metalloproteinase I (MMP-1) and MMP-3 mRNA levels saw a notable increase following EP administration. In keloid spheroids, EP induced a dose-dependent reduction in ECM component expression. Immunohistochemical and western blot analyses confirmed significant declines in collagen I, collagen III, fibronectin, elastin, TGF-β, AKT, and ERK 1/2 expression levels. These outcomes underscore EP's antifibrotic potential, suggesting its viability as a therapeutic approach for keloids.

Ethyl pyruvate attenuates cisplatin-induced ovarian injury in rats via activating Nrf2 pathway

Although cisplatin (CDDP) is an antineoplastic drug widely used for the treatment of various tumors, its toxicity on the reproductive system is a concern for patients. Ethyl pyruvate (EP) possesses potent antioxidant and anti-inflammatory activities. The objective of this study was to evaluate the therapeutic potential of EP on CDDP-mediated ovotoxicity for the first time. Rats were exposed to CDDP (5 mg/kg) and then treated with two doses of EP (20 and 40 mg/kg) for 3 days. Serum fertility hormone markers were evaluated using ELISA kits. Oxidative stress (OS), inflammation, endoplasmic reticulum stress (ERS) and apoptosis markers were also determined. In addition, how CDDP affects the nuclear factor erythroid 2-associated factor 2 (Nrf2) pathway and the effect of EP on this situation were also addressed. EP improved CDDP-induced histopathological findings and restored decreasing levels of fertility hormones. EP treatment also reduced the levels of CDDP-mediated OS, inflammation, ERS and apoptosis. In addition, EP attenuated CDDP-induced suppression in the levels of Nrf2 and its target genes, including heme oxygenase-1, NAD(P)H quinone dehydrogenase-1, superoxide dismutase and glutathione peroxidase. Histological and biochemical results showed that EP can have therapeutic effects against CDDP-induced ovotoxicity with antioxidant, anti-inflammatory and Nrf2 activator activities.

Annao Pingchong decoction alleviate the neurological impairment by attenuating neuroinflammation and apoptosis in intracerebral hemorrhage rats

ETHNOPHARMACOLOGICAL RELEVANCE

Intracerebral hemorrhage (ICH) is a central nervous system disease that causes severe disability or death. Even though Annao Pingchong decoction (ANPCD), a traditional Chinese decoction, has been used clinically to treat ICH in China, its molecular mechanism remains unclear.

AIM OF THE STUDY

To study whether the neuroprotective effect of ANPCD on ICH rats is achieved by alleviating neuroinflammation. This paper mainly explored whether inflammation-related signaling pathways (HMGB1/TLR4/NF-κB P65) plays a role in ANPCD treatment of ICH rats.

MATERIALS AND METHODS

Liquid chromatography-tandem mass spectrometry was used to analyze the chemical composition of ANPCD. ICH models were established by injecting autologous whole blood into the left caudate nucleus of Sprague-Dawley (SD) rats. Modified neurological severity scoring (mNSS) was used to assess the neurological deficits. The levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 were analyzed using enzyme-linked immunosorbent assay (ELISA). Pathological changes in the rat brains were observed using hematoxylin-eosin, Nissl, and TUNEL staining. The protein levels of HMGB1, TLR4, NF-κB p65, B-cell lymphoma 2 (Bcl-2), and Bcl-2-associated X protein (Bax) were measured by western blotting and immunofluorescence analysis.

RESULTS

Ninety-three ANPCD compounds were identified, including 48 active plasma components. Treatment with ANPCD effectively improved the outcome, as observed by the neurological function scores analysis and brain histopathology. Our results showed that ANPCD exerts its anti-inflammatory effects by significantly downregulating the expression of HMGB1, TLR4, NF-κB p65, TNF-α, IL-1β, and IL-6. ANPCD also exerted anti-apoptotic effects by significantly decreasing the apoptosis rate and Bax/Bcl-2 ratio.

CONCLUSION

We found that ANPCD had neuroprotective effect in clinical work. Here, we also found that the action mechanism of ANPCD might be related to attenuate neuroinflammation and apoptosis. These effects were achieved by inhibiting the expression of HMGB1, TLR4 and NF-κB p65.

Phenolic Acids from Fructus Chebulae Immaturus Alleviate Intestinal Ischemia-Reperfusion Injury in Mice through the PPARα/NF-κB Pathway

Intestinal ischemia/reperfusion (II/R) injury is a common life-threatening complication with high morbidity and mortality. Chebulae Fructus Immaturus, the unripe fruit of Terminalia chebula Retz., also known as “Xiqingguo” or “Tibet Olive” in China, has been widely used in traditional Tibetan medicine throughout history. The phenolic acids’ extract of Chebulae Fructus Immaturus (XQG for short) has exhibited strong antioxidative, anti-inflammation, anti-apoptosis, and antibacterial activities. However, whether XQG can effectively ameliorate II/R injuries remains to be clarified. Our results showed that XQG could effectively alleviate II/R-induced intestinal morphological damage and intestinal barrier injury by decreasing the oxidative stress, inflammatory response, and cell death. Transcriptomic analysis further revealed that the main action mechanism of XQG protecting against II/R injury was involved in activating PPARα and inhibiting the NF-κB-signaling pathway. Our study suggests the potential usage of XQG as a new candidate to alleviate II/R injury.