RESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Licorice is widely used clinically as one of the most famous traditional Chinese herbs. Its herb roasted with honey is called honey-processed licorice (HPL). Modern studies have shown that HPL has a stronger cardioprotective ability compared to raw licorice (RL), however the material basis and mechanism of action of the potential cardioprotection have not been fully elucidated. AIM OF THE STUDY: To screen and validate the material basis of cardioprotection exerted by HPL and to preliminarily predict the potential mechanism of action. MATERIALS AND METHODS: UPLC-QTOF-MS/MS was used to analyze HPL samples with different processing levels, and differential compounds were screened out through principal component analysis. Network pharmacology and molecular docking were applied to explore the association between differential compounds and doxorubicin cardiomyopathy and their mechanisms of action were predicted. An in vitro model was established to verify the cardioprotective effects of differential compounds. RESULTS: Six differential compounds were screened as key components of HPL for potential cardioprotection. Based on network pharmacology, 113 potential important targets for the treatment of Dox-induced cardiotoxicity were screened. KEGG enrichment analysis predicted that the PI3K-Akt pathway was closely related to the mechanism of action of active ingredients. Molecular docking results showed that the six differential compounds all had good binding activity with Nrf2 protein. In addition, in vitro experiments had shown that five of the active ingredients (liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin, and licochalcone A) can significantly increase Dox-induced H9c2 cell viability, SOD activity, and mitochondrial membrane potential, significantly reduces MDA levels and inhibits ROS generation. CONCLUSION: Liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin and licochalcone A are key components of HPL with potential cardioprotective capabilities. Five active ingredients can alleviate Dox-induced cardiotoxicity by inhibiting oxidative stress and mitochondrial damage.
RESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Honey-processed licorice (HPL) is the roasted product of licorice. It is recorded in the "Shang Han Lun" that licorice has better protection on heart after honey-processed. However, researches regarding its protective effect on the heart and the distribution of HPL in vivo are still limited. AIM OF THE STUDY: To evaluate the cardio-protection of HPL and explore the law of ten main components distribution in vivo under physiological and pathological conditions for an attempt to clarify the pharmacological substance basis of HPL in treating arrhythmia. MATERIALS AND METHODS: The adult zebrafish arrhythmia model was established by doxorubicin (DOX). Electrocardiogram (ECG) was used to detect the heart rate changes of zebrafish. SOD and MDA assays were used to evaluate oxidative stress levels in the myocardium. HE staining was used to observe the morphological change of myocardial tissues after HPL treatment. The UPLC-MS/MS was adapted to detect the content of ten main components of HPL in heart, liver, intestine, and brain under normal and heart injury conditions. RESULTS: Heart rate of zebrafish was decreased, the SOD activity was attenuated and MDA content was increased in myocardium after administration of DOX. Moreover, tissue vacuolation and inflammatory infiltration were detected in zebrafish myocardium induced by DOX. HPL could ameliorate heart injury and bradycardia induced by DOX to a certain extent by increasing SOD activity and reducing MDA content. In addition, the study of tissue distribution revealed that the content of liquiritin, isoliquiritin, and isoliquiritigenin in the heart was higher in the presence of arrhythmias than those in the normal condition. Under pathological conditions, the heart highly exposed to these three components could elicit anti-arrhythmic effects by regulating immunity and oxidation. CONCLUSION: These findings indicate that the HPL is protective against heart injury induced by DOX, and its effect is associated with the alleviation of oxidative stress and tissue injury. And the cardioprotective effect of HPL under pathological conditions may be related to the high distribution of liquiritin, isoliquiritin, and isoliquiritigenin in heart tissue. This study provides an experimental basis for the cardioprotective effects and tissue distribution of HPL.