Repurposing of the Nootropic Drug Vinpocetine as an Analgesic and Anti-Inflammatory Agent: Evidence in a Mouse Model of Superoxide Anion-Triggered Inflammation.

Clinically active drugs for the treatment of acute pain have their prescription limited due to the significant side effects they induce. An increase in reactive oxygen species (ROS) has been linked to several conditions, including inflammation and pain processing. Therefore, new or repurposed drugs with the ability of reducing ROS-triggered responses are promising candidates for analgesic drugs. Vinpocetine is a clinically used nootropic drug with antioxidant, anti-inflammatory, and analgesic properties. However, the effects of vinpocetine have not been investigated in a model with a direct relationship between ROS, inflammation, and pain. Based on that, we aimed to investigate the effects of vinpocetine in a model of superoxide anion-induced pain and inflammation using potassium superoxide (KO2) as a superoxide anion donor to trigger inflammation and pain. In the KO2 model, vinpocetine dose-dependently reduced pain-like behaviors (spontaneous pain and hyperalgesia), paw edema, and neutrophil and mononuclear cell recruitment to the paw skin (assessed by H&E staining, fluorescence, and enzymatic assays) and to the peritoneal cavity. Vinpocetine also restored tissue endogenous antioxidant ability and Nrf2 and Ho-1 mRNA expression and reduced superoxide anion production and gp91phox mRNA expression. We also observed the inhibition of IκBα degradation by vinpocetine, which demonstrates a reduction in the activation of NF-κB explaining the diminished production of IL-33, IL-1ß, and TNF-α. Collectively, our data show that vinpocetine alleviates pain and inflammation induced by KO2, which is a mouse model with a direct role of ROS in triggering pain and other inflammatory phenomena. Thus, the results suggest the repurposing of vinpocetine as an anti-inflammatory and analgesic drug.

Kaurenoic acid extracted from Sphagneticola trilobata reduces acetaminophen-induced hepatotoxicity through inhibition of oxidative stress and pro-inflammatory cytokine production in mice.

Acetaminophen (paracetamol) is a widely used analgesic and antipyretic drug that is safe at therapeutic doses. However, acetaminophen overdose can be fatal. Currently, the only treatment available is the N-acetyl cysteine. The diterpene kaurenoic acid (ent-kaur-16-en-19-oic acid, KA) is the major constituent of Sphagneticola trilobata (L.) Pruski. KA presents anti-inflammatory, anti-nociceptive and antioxidant properties. In this study, we evaluated the efficacy of KA in a model of acetaminophen-induced hepatotoxicity. KA increased, in a dose-dependent manner, the survival rate after acetaminophen overdose. KA reduced acetaminophen-induced hepatic necrosis and ALT and AST levels. KA decreased acetaminophen-induced neutrophil and macrophage recruitment, oxidative stress and the production of IL-33, TNF-α and IL-1ß, alongside with normalisation of IL-10 levels in the liver. Therefore, KA showed preclinical efficacy in acetaminophen-induced hepatotoxicity and lethality.

Pyrrolidine dithiocarbamate inhibits mouse acute kidney injury induced by diclofenac by targeting oxidative damage, cytokines and NF-κB activity.

AIMS: Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used and effective anti-inflammatories despite the well-known side effects such as gastrointestinal damage, acute kidney injury (AKI), and cardiovascular dysfunctions. Diclofenac is among the most prescribed NSAIDs due to its efficient analgesic and anti-inflammatory properties. Patients using diclofenac possess 77% risk increase to develop AKI. Activation of NF-κB contributes to diclofenac-induced AKI, which is in line with the use of glucocorticoids as one of the management choices to treat AKI patients. MAIN METHODS: In this work, we investigate the efficacy of pyrrolidine dithiocarbamate (PDTC) in diclofenac-induced AKI in mice given it is a known NF-κB inhibitor. KEY FINDINGS: We observed that diclofenac increased proteinuria and urine neutrophil gelatinase-associated lipocalin (NGAL), blood levels of urea, creatinine, oxidative stress, C-reactive protein (CRP), and pro-inflammatory cytokine after 24 h of a bolus administration. In renal tissue, diclofenac also induced morphological changes consistent with kidney damage, modulated cytokine production, increased oxidative stress and reduced antioxidant defenses. These alterations induced by diclofenac were accompanied by activation of NF-κB in the kidney. Treatment with PDTC dose-dependently reduced diclofenac-induced blood urea, creatinine, and oxidative stress. In addition, PDTC reduced proteinuria and urine NGAL levels and blood CRP and pro-inflammatory cytokines. In the kidney, PDTC inhibited diclofenac-induced morphological changes, pro-inflammatory cytokine production, oxidative stress, and NF-κB activation, and increased antioxidant defenses and anti-inflammatory cytokine IL-10. SIGNIFICANCE: Our data demonstrate that PDTC ameliorates diclofenac-induced AKI and that targeting NF-κB signaling pathway is a promising therapeutic approach for the treatment of diclofenac-induced AKI.