PC12 cells were incubated under OGD for 2 h and then separately incubated with the following reagents for 3 h: MFQ (5 μM), KN-93 (2 μM), and leonurine (50, 100, and 200 μg/mL). Then, the cells were cultured under normal conditions for 24 h. Protein expression was evaluated through Western blot analysis. (A) Protein expression of Cx36. (B) Protein expression of CaMKII and pCaMKII. CON, normal control group; OGD, OGD-for-control group; MFQ+OGD, MFQ-treated group; KN93+OGD, KN93-treated group; LEO LOW+OGD, low-dose leonurine group; LEO MID+OGD, middle-dose leonurine group; LEO HIGH+OGD, high-dose leonurine group. *P < 0.05 compared with the normal control (0 h OGD) group. **P < 0.01 compared with the normal control (0-h OGD) group. #P < 0.05 compared with the OGD-for-control group. ##P < 0.01 compared with the OGD-for-control group.