Punicalagin attenuates isoproterenol-induced myocardial infarction through nuclear factor erythroid 2-related factor 2/silent information regulator transcript-1-mediated inhibition of inflammation and cardiac stress markers in experimental animal models.

Myocardial infarction (MI) is a significant global health issue and the leading cause of death. Myocardial infarction (MI) is characterized by events such as damage to heart cells and stress generated by inflammation. Punicalagin (PCN), a naturally occurring bioactive compound found in pomegranates, exhibits a diverse array of pharmacological effects against many disorders. This study aimed to assess the preventive impact of PCN, with its potential anti-inflammatory and antioxidant properties, on myocardial injury caused by isoproterenol (ISO) in rats and elucidate the possible underlying mechanisms. Experimental rats were randomly categorized into four groups: control group (fed a regular diet for 15 days), PCN group (orally administered PCN at 50 mg/kg body weight (b.w.) for 15 days), ISO group (subcutaneously administered ISO (85 mg/kg b.w.) on days 14 and 15 to induce MI), and PCN+ISO group (orally preadministered PCN (50 mg/kg b.w.) for 15 days and administered ISO (85 mg/kg b.w.) on days 14 and 15). The rat cardiac tissue was then investigated for cardiac marker, oxidative stress marker, and inflammatory marker expression levels. PCN prevented ISO-induced myocardial injury, suppressing the levels of creatine kinase-myocardial band, C-reactive protein, homocysteine, cardiac troponin T, and cardiac troponin I in the rats. Moreover, PCN treatment reversed (P<0.01) the ISO-induced increase in blood pressure, attenuated lipid peroxidation markers, and depleted both enzymatic and nonenzymatic markers in the rats. Additionally, PCN inhibited (P<0.01) ISO-induced overexpression of oxidative stress markers (p-38, p-c-Jun N-terminal kinase, and p-extracellular signal-regulated kinase 1), inflammatory markers (nuclear factor-kappa B, tumor necrosis factor-alpha, and interleukin-6), and matrix metalloproteinases and decreased the levels (P<0.01) of apoptosis proteins in the rats. Nuclear factor erythroid 2-related factor 2/silent information regulator transcript-1 (Nrf2/Sirt1) is a major cellular defense protein that regulates and scavenges oxidative toxic substances through apoptosis. Therefore, overexpression of Nrf2/Sirt1 to inhibit inflammation and oxidative stress is considered a novel target for preventing MI. PCN also significantly enhanced the expression of Nrf2/Sirt1 in ISO-induced rats. Histopathological analyses of cardiac tissue revealed that PCN treatment exhibited a protective effect on the heart tissue, mitigating damage. These findings show that by activating the Nrf2/Sirt1 pathway, PCN regulates oxidative stress, inflammation, and apoptosis, hence providing protection against ISO-induced myocardial ischemia.

[Clinical efficacy of local injection of platelet-rich plasma combined with double-layer artificial dermis in treating wounds with exposed tendon on extremity].

Objective: To investigate the clinical efficacy of local injection of platelet-rich plasma (PRP) combined with double-layer artificial dermis in treating wounds with exposed tendon on extremity. Methods: A retrospective observational study was conducted. From December 2017 to October 2022, 16 patients were admitted to Department of Orthopaedic Trauma of the Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, and 32 patients were admitted to Department of Burns and Plastic Surgery of Guiyang Steel Factory Staff Hospital. All the patients had wounds with exposed tendon on extremity caused by various reasons and met the inclusion criteria. There were 39 males and 9 females, aged 26 to 58 years. The patients were divided into PRP alone group, artificial dermis alone group, and PRP+artificial dermis group, with 16 patients in each group. The wounds were treated with autologous PRP, double-layer artificial dermis, or thei combination of autologous PRP and double-layer artificial dermis, followed by autologous split-thickness scalp grafting after good growth of granulation tissue. On the 7th day after the secondary surgery, the autograft survival was observed, and the survival rate was calculated. The wound healing time and length of hospital stay of patients were recorded. At 3 and 6 months after wound healing, the Vancouver scar scale (VSS) was used to score the pigmentation, height, vascularity, and pliability of scars, and the total score was calculated. Adverse reactions during the entire treatment process were recorded. Data were statistically analyzed with chi-square test, Fisher's exact probability test, one-way analysis of variance, least significant difference test, Kruskal-Wallis H test, Nemenyi test, and Bonferroni correction. Results: On the 7th day after the secondary surgery, there was no statistically significant difference in the autograft survival rate of patients among PRP alone group, artificial dermis alone group, and PRP+artificial dermis group (P>0.05). The wound healing time and length of hospital stay of patients in PRP+artificial dermis group were (20.1±3.0) and (24±4) d, respectively, which were significantly shorter than (24.4±5.5) and (30±8) d in PRP alone group (P<0.05) and (24.8±4.9) and (32±8) d in artificial dermis alone group (P<0.05). At 3 and 6 months after wound healing, the pliability scores of patients in PRP+artificial dermis group were significantly lower than those in PRP alone group (with Z values of 12.91 and 15.69, respectively, P<0.05) and artificial dermis alone group (with Z values of 12.50 and 12.91, respectively, P<0.05). There were no statistically significant differences in pigmentation, vascularity, height scores, and total score of scar of patients among the three groups (P>0.05). In artificial dermis alone group, one patient experienced partial liquefaction and detachment of the double-layer artificial dermis due to local infection of Staphylococcus epidermidis, which received wound dressing change, second artificial dermis transplantation, and subsequent treatment as before. No adverse reactions occurred in the remaining patients during the whole treatment process. Conclusions: Local injection of PRP combined with double-layer artificial dermis is effective in treating wounds with exposed tendon on extremity, which can not only significantly shorten wound healing time and length of hospital stay, but also improve scar pliability after wound healing to some extent in the long term. It is a clinically valuable treatment technique that is worth promoting and applying.