Sasanquasaponin induces increase of Cl‑/HCO3‑ exchange of anion exchanger 3 and promotes intracellular Cl‑ efflux in hypoxia/reoxygenation cardiomyocytes

New Drug Targets and Preclinical Modelling Recommendations for Treating Acute Myocardial Infarction

Acute myocardial infarction (AMI) is the leading cause of morbidity and mortality worldwide and the primary underlying risk factor for heart failure. Despite decades of research and clinical trials, there are no drugs currently available to prevent organ damage from acute ischaemic injuries of the heart. In order to address the increasing global burden of heart failure, drug, gene, and cell-based regeneration technologies are advancing into clinical testing. In this review we highlight the burden of disease associated with AMI and the therapeutic landscape based on market analyses. New studies revealing the role of acid-sensitive cardiac ion channels and other proton-gated ion channels in cardiac ischaemia are providing renewed interest in pre- and post-conditioning agents with novel mechanisms of action that may also have implications for gene- and cell-based therapeutics. Furthermore, we present guidelines that couple new cell technologies and data resources with traditional animal modelling pipelines to help de-risk drug candidates aimed at treating AMI. We propose that improved preclinical pipelines and increased investment in drug target identification for AMI is critical to stem the increasing global health burden of heart failure.

The therapeutic importance of acid-base balance

Baking soda and vinegar have been used as home remedies for generations and today we are only a mouse-click away from claims that baking soda, lemon juice, and apple cider vinegar are miracles cures for everything from cancer to COVID-19. Despite these specious claims, the therapeutic value of controlling acid-base balance is indisputable and is the basis of Food and Drug Administration-approved treatments for constipation, epilepsy, metabolic acidosis, and peptic ulcers. In this narrative review, we present evidence in support of the current and potential therapeutic value of countering local and systemic acid-base imbalances, several of which do in fact involve the administration of baking soda (sodium bicarbonate). Furthermore, we discuss the side effects of pharmaceuticals on acid-base balance as well as the influence of acid-base status on the pharmacokinetic properties of drugs. Our review considers all major organ systems as well as information relevant to several clinical specialties such as anesthesiology, infectious disease, oncology, dentistry, and surgery.

Camellia cake extracts reduce burn injury through suppressing inflammatory responses and enhancing collagen synthesis

Background

Burn injury accidents happen in our daily life, and the burn mortality is especially high in the low-to-middle-income countries. Camellia cake extracts (CCEs) are compound extracts from Camellia cake, and the major ingredients in CCEs may have antimicrobial, anti-oxidative, and anti-inflammatory effects. However, the effects of CCEs on burn inflammation and injury remain unknown.

Objective

This study is to investigate the effects of CCEs in burn injury and explore its mechanism.

Design

First, CCEs were identified to mainly contain camelliaside A and B using Ultra High Performance Liquid Chromatography-Time of Flight Mass Spectrometer (UHPLC-TOF-MS) method. Second, the CCEs' effect on burn was tested. Burn was induced by boiling water in mice, and then CCEs (30, 50, and 100 mg/mL) were applied on the damaged skin at 3, 7, and 14 days after burn induction.

Results

The results showed that CCEs protected the skin from burn-induced inflammation and enhanced the wound healing in a dose-dependent manner. CCEs decreased the expression levels of various cytokines including IL-6, TNF-α, IL-1β, MCP-1, TGF-β, and IL-10, as well as inflammatory related factors iNOS. Moreover, CCEs increased the levels of collagens, including the mRNA of COLα-1 and COL-3, and inhibited the mRNA of MMP-1 and TIMP-1, and increased the collagen staining. CCEs also reversed the impairment of activity levels of anti-oxidative enzymes. Furthermore, CCEs suppressed the gene expression of pro-inflammatory cytokines in LPS-stimulated human skin keratinocyte, possibly through inhibiting NF-κB signaling pathway. In addition, toxicological safety experiments on CCEs showed that the oral median lethal dose (LD50) was 2,000 mg/kg, the percutaneous LD50 was greater than 2,000 mg/kg, and CCEs did not cause gene mutation.

Conclusion

CCEs exert a potent anti-inflammatory effect against burn damage in mice. And toxicological safety experiments suggest that CCEs are safe for usage.

Anion exchanger 3 in dorsal root ganglion contributes to nerve injury-induced chronic mechanical allodynia and thermal hyperalgesia

Objective

To determine the role of anion exchanger 3 (AE3) in dorsal root ganglion (DRG) in nerve injury-induced chronic nociception in the rat.

Methods

Spared nerve injury (SNI) was used to induce neuropathic pain. Von Frey filaments and Hargreaves test were used to assess tactile allodynia and thermal hyperalgesia, respectively. Drugs were given by intrathecal administration. Western blotting was used to determine AE3 expression in DRG.

Key findings

SNI produced long-lasting mechanical allodynia and thermal hyperalgesia. AE3 was found in DRG of sham-operated rats. SNI enhanced baseline AE3 expression in L4 and L5 DRGs at days 7 and 14, respectively. In contrast, SNI did not affect AE3 expression in L6 DRG. AE3 expression returned to baseline levels 21 days after SNI. Intrathecal 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid (DIDS) (5–50 μg) pretreatment prevented SNI-induced allodynia and, at a lesser extent, hyperalgesia. Moreover, DIDS (50 μg) reduced SNI-induced AE3 upregulation in L4, but not L5, DRGs. Intrathecal DIDS (5–50 μg) or anti-AE3 antibody (1 μg), but not vehicle, post-treatment (6 days) partially reversed SNI-induced allodynia and hyperalgesia. DIDS or anti-AE3 antibody post-treatment diminished SNI-induced AE3 upregulation in L4 and L5 DRGs.

Conclusions

Data suggest that AE3 is present in DRG and contributes to mechanical allodynia and thermal hyperalgesia in neuropathic rats.