Effect of herbal cake-partitioned moxibustion on Leptin/JAK2/STAT3 in lipid-lowering pathway of hyperlipidemia rabbits

Objective: To observe the lipid-lowering effect of different transdermal absorption enhancers applied to the herbal cake-partitioned moxibustion in hyperlipidemia model rabbits, and to explore the possible mechanism. Methods: Forty New-Zealand rabbits were randomly divided into 5 groups using the random number table method, with 8 rats in each group. Rabbits in the blank group were fed routinely with normal diet; rabbits in the other groups were fed with high-fat diet for 12 weeks to establish the hyperlipidemia model. Rabbits in the blank and the model groups were not treated. After the model was prepared, rabbits in the non-transdermal absorption enhancer group received herbal cake-partitioned moxibustion without transdermal absorption enhancer; rabbits in the laurocapram group and the borneol group received herbal cake-partitioned moxibustion with laurocapram or borneol respectively. After 4 weeks of treatment, serum was collected for enzyme-linked immunosorbent assay (ELISA), and the liver tissues were isolated for immunohistochemistry, quantitative polymerase chain reaction (qPCR) and Western-blotting (WB) detection. Results: Serum ELISA results showed that leptin was significantly decreased in the model group compared with the blank group ( P <0.05); compared with the model group, leptin was significantly increased in the non-transdermal absorption enhancer, the laurocapram and the borneol groups (all P <0.05); compared with the non-transdermal absorption enhancer group, leptin was significantly increased in the laurocapram group and the borneol group (both P <0.05); there was no significant difference in leptin between the laurocapram and the borneol groups ( P >0.05). The qPCR results of rabbit liver tissues showed that the mRNA expressions of leptin, Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) in the model group were significantly lower than those in the blank group (all P <0.05); compared with the model group, the mRNA expressions of leptin, leptin receptor (LR), JAK2 and STAT3 in the non-transdermal absorption enhancer, the laurocapram and the borneol groups were significantly increased (all P <0.05); compared with the non-transdermal absorption enhancer group, the mRNA expressions of leptin, LR, JAK2 and STAT3 in the laurocapram and the borneol groups were significantly increased (all P <0.05); compared with the laurocapram group, the mRNA expressions of leptin, LR, JAK2 and STAT3 in the borneol group were significantly increased ( P <0.05). The trend of immunohistochemistry and WB detection results was basically consistent with the qPCR assay results. The immunohistochemistry and WB detection results of phosphorylated JAK2 (phospho-JAK2) and phosphorylated STAT3 (phospho-STAT3) were basically consistent with those of JAK2 and STAT3. Conclusion: The molecular expression of Leptin/JAK2/STAT3 pathway in the hyperlipidemia model rabbits was decreased. The molecular expression of Leptin/JAK2/STAT3 pathway was significantly increased after the herbal cake-partitioned moxibustion. The application of laurocapram and borneol, as transdermal absorption enhancers, in the herbal cake-partitioned moxibustion could more obviously up-regulate the factors of the Leptin/JAK2/STAT3 lipid-regulating pathway than the herbal cake-partitioned moxibustion alone.