Electroacupuncture alleviates the relapse of pain-related aversive memory by activating KOR and inhibiting GABAergic neurons in the insular cortex.

Pain-related aversive memory is common in chronic pain patients. Electroacupuncture has been demonstrated to block pain-related aversive memory. The insular cortex is a key region closely related to aversive behaviors. In our study, a potential mechanism underlying the effect of electroacupuncture treatment on pain-related aversive memory behaviors relative to the insular cortex was investigated. Our study used the chemogenetic method, pharmacological method, electroacupuncture intervention, and behavioral detection. Our study showed that both inhibition of gamma-aminobutyric acidergic neurons and activation of the kappa opioid receptor in the insular cortex blocked the pain-related aversive memory behaviors induced by 2 crossover injections of carrageenan in mice; conversely, both the activation of gamma-aminobutyric acidergic neurons and inhibition of kappa opioid receptor in the insular cortex play similar roles in inducing pain-related aversive memory behaviors following 2 crossover injections of carrageenan. In addition, activation of gamma-aminobutyric acidergic neurons in the insular cortex reversed the effect of kappa opioid receptor activation in the insular cortex. Moreover, electroacupuncture effectively blocked pain-related aversive memory behaviors in model mice, which was reversed by both activation of gamma-aminobutyric acidergic neurons and inhibition of kappa opioid receptor in the insular cortex. The effect of electroacupuncture on blocking pain-related aversive memory behaviors may be related to the activation of the kappa opioid receptor and inhibition of gamma-aminobutyric acidergic neurons in the insular cortex.

Effect of fermented Cordyceps sinensis on doxorubicin­induced cardiotoxicity in rats.

Cordyceps sinensis (CS) is a prominent medicinal herb in traditional Chinese medicine, and fermented CS is frequently used as a substitute for natural CS. Doxorubicin (DOX), an antitumor drug used in chemotherapy, is limited by its poor cardiotoxicity. The aim of the present study was to evaluate the protective effect of fermented CS against DOX­induced cardiotoxicity and the potential underlying mechanisms. Male Sprague­Dawley rats (180­200 g) were randomly assigned to seven different treatment groups: Normal control, DOX control, DOX+captopril (0.05 g/kg), 0.75, 1.5 and 3 g/kg DOX+CS, and the CS (1.5 g/kg) control. Histopathological changes, cardiac energy metabolism, cyclic adenosine monophosphate (cAMP) signaling and the associated mRNA expression of AMP­activated protein kinase (AMPK) were then evaluated. Fermented CS decreased the left ventricular weight index, heart weight index and mortality; however, it increased diastolic blood pressure and mean arterial pressure. In addition, it shortened the duration of the QRS complex and Sα­T segment, decreased serum creatine kinase (CK) and aspartate aminotransferase activity, inhibited histopathological changes and reduced brain natriuretic peptide content. Treatment with fermented CS also increased the activities of superoxide dismutase and glutathione peroxidase, reduced malondialdehyde content, increased the mitochondrial activities of Na+K+­adenosine 5'­triphosphate (ATP) ase, Ca2+Mg2+­ATPase and CK, and increased the creatine phosphate/ATP ratio and AMP/ATP ratio. Furthermore, it decreased the ATP/adenosine 5'­diphosphate (ADP) ratio, upregulated AMPKα2 expression, reduced the activity of serum phosphodiesterases (PDEs) and increased myocardial cAMP content. The results of the present study demonstrated that fermented CS attenuated DOX­induced cardiotoxicity by inhibiting myocardial hypertrophy and myocardial damage, ameliorating systolic function and the antioxidant enzyme system, improving cardiac energy metabolism, depressing the activities of PDEs, and by upregulating the cAMP and AMPK signaling pathways. Thus, fermented CS may be a candidate for the prevention of DOX­induced cardiotoxicity, cardiac energy impairment and against a number of cardiac diseases.

Effect of Atractylodes macrocephala rhizoma on isoproterenol­induced ventricular remodeling in rats.

Myocardial infarction (MI) is the primary cause of ventricular remodeling (VR). The aim of the present study was to determine the effect of Atractylodis macrocephalae rhizoma (AMR) on VR induced by isoproterenol (ISO) in rats. Male Sprague Dawley rats were randomly divided into the normal control, ISO­induced and AMR groups. Rats in the ISO­induced and AMR groups were subcutaneously injected with 85 mg/kg/day ISO for two consecutive days. Compared with the ISO­induced group, AMR normalized the levels of hemodynamic parameters, markedly attenuated myocardial pathological damage, decreased the level of N­terminal prohormone of brain natriuretic peptide, and inhibited cardiac hypertrophy and myocardial fibrosis. In addition, AMR inhibited oxidative stress and activation of the rennin­angiotensin­aldosterone system (RAAS) when compared with the ISO­induced group. The results of the present study suggest that AMR may reverse VR via its antioxidative effect and inhibition of RAAS activation.