Chemical constituents from <i>Uncaria laevigata</i> and their protective effect against myocardial ischemia–reperfusion injury

Uncaria laevigata exhibits potential cardiovascular protective effects, and its active constituents against myocardial ischemia-reperfusion injury (MI-RI) is rarely explored. Herein, eighteen compounds were firstly isolated from hooked stems and branches of Uncaria laevigata, including alkaloids, flavonoids, lignans, triterpenoids, and fatty acids. MI-RI measurement demonstrated that compound 1 (procyanidin C1) and compound 13 (cadambine) exerted good anti-MI-RI activity, not previously reported. At 20 mg/kg, compound 1 reduced the ischaemic area to 11.40%, equivalent to metoprolol, whereas compound 13 achieved 14.36% with a clear dose-dependent improvement. Network pharmacology and molecular docking predicted that compound 1 and 13 were correlated with several signalling pathways, and showed favourable binding affinity with metalloproteinases-1 (TIMP1) (−9.5 kcal·mol−1) and ryanodine receptor 2 (RyR2) (−8.6 kcal·mol−1) respectively. This work provides lead compounds against MI-RI and further exploitation of Uncaria laevigata.