Optimization of ultrasound extraction of Tribulus terrestris L. leaves saponins and their HPLC DAD ESI-MSn profiling, anti-inflammatory activity and mechanism in vitro and in vivo

Ethnopharmacological relevance: Tribulus terrestris L., as an annual herb plant from Zygophyllaceae, exhibits many biological activities, and its main chemical constituents are saponins. However, the extraction process, chemical compositions, anti-inflammatory effect and mechanism of total saponins from Tribulus terrestris L. leaves are still unclear. Aim of the study: The present study extensively evaluated the extraction process, major components, anti-inflammatory action and mechanism of Tribulus terrestris L. leaves saponins. Materials and methods: The ultrasonic extraction and response surface methods were adopted for optimization of extraction technology of total saponins from Tribulus terrestris L. leaves, and its compositions were detected with LC-MSn method. The anti-inflammatory activity of total saponins was studied by lipopolysaccharide induced RAW 264.7 cells and acute lung injury mice models. Results: The ultrasonic extraction parameters of saponins fraction, including ethanol concentration 30%, extraction time 55 min, ratio of solvent to material 35:1 ml/g and extraction temperature 46 degrees C, were screened by response surface method with the extracting rate 5.49%, and thirty compositions were detected with LC-MS' method. Moreover, saponins fraction can play a stronger anti-inflammatory effect by reducing the phagocytic activity and pulmonary edema, and protection of morphology of RAW 264.7 cells and lung tissues, and decreasing the content of NO and TNF-alpha. Moreover, it was revealed that total saponins extract can exert the anti-inflammatory action by the inhibition of the activation of the TLR4-TRAF6-NF-kappa B signalling pathway. Conclusion: These studies imply that Tribulus terrestris L. leaves saponins may be an important anti-inflammatory drug in clinic.

Automated summary

The study aimed to evaluate the extraction process, major components, anti-inflammatory action and mechanism of Tribulus terrestris L. leaves saponins. The results showed that the saponins fraction extracted from Tribulus terrestris L. exhibited a strong anti-inflammatory effect by inhibiting the TLR4-TRAF6-NF-kappa B signaling pathway activation.