Antioxidant activity against H₂O₂-induced cytotoxicity of the ethanol extract and compounds from Pyrola decorate leaves

Abstract

Context: The leaves of Pyrola decorate H. Andr (Pyrolaceae), known as Luxiancao, have long been used for treating kidney deficiency, gastric haemorrhage and rheumatic arthritic diseases in traditional Chinese medicine.

Objective: The phytochemicals and antioxidant capacities in vitro of P. decorate leaves were investigated.

Materials and methods: Ethanol, petroleum ether, acetidin, n-butyl alcohol and aqueous extracts of Pyrola decorate leaves were prepared by solvent sequential process, and then isolated and purified to obtain phytochemicals. Cell viability was measured by MTT assay. PC12 cells were pretreated for 24 h with different extractions of P. decorate leaves at concentrations of 0.1, 0.5, 1, 5 and 10 mg/mL, then H₂O₂ of 0.4 mM was added in all samples for an additional 2 h. The antioxidant capacities of betulin, ursolic acid and monotropein were determined in PC12 cells against H₂O₂ induced cytotoxicity in vitro as well.

Results: Nine compounds (1–9) were isolated and structurally determined by spectroscopic methods, especially 2D NMR analyses. Ethanol extract treated groups showed inhibitory activity with IC₅₀ value of 10.83 mg/mL. Betulin, ursolic acid and monotropein were isolated from P. decorate, and demonstrated with IC₅₀ values of 6.88, 6.15 and 6.13 μg/mL, respectively.

Discussion and conclusions: In conclusion, Pyrola decorate is a potential antioxidative natural plant and worth testing for further pharmacological investigation in the treatment of oxidative stress related neurological disease.

Keywords:

• Pyrolaceae
• terpenoids
• oxidative stress
• isolation

Acknowledgements

We are thankful to prof. Jiang of Tongji School of Pharmacy, Huazhong University of Science and Technology for the use and technical support of ESI-MS facilities.

Disclosure statement

All authors declare no conflicts of interest.

Additional information

Funding

This work was supported by the Youth Innovative Training Fund for College Students of Wuhan University of Science and Technology [Grant No. 201610488041], the Pearl River S&T Nova Program of Guangzhou [201610010017] and Guangdong Special Support Project for Outstanding Young Scholars.