Gynura procumbens ethanol extract improves vascular dysfunction by suppressing inflammation in postmenopausal rats fed a high-fat diet

Abstract

Context

Gynura procumbens (Lour.) Merr. (Asteraceae) has been reported to have various pharmacological activities including anti-inflammatory effects.

Objective

This study sought to determine whether Gynura procumbens (GP) could improve vascular reactivity by suppressing inflammation in postmenopausal rats fed with five-times heated palm oil (5HPO) diet.

Materials and methods

Forty-eight female Sprague-Dawley rats were randomly divided into sham [non-ovariectomized; grouped as control, GP extracts (250 and 500 mg/kg), atorvastatin (ATV, 10 mg/kg)] and postmenopausal (PM) groups [ovariectomized rats fed with 5HPO; grouped as PM, GP extracts (250 and 500 mg/kg) and ATV (10 mg/kg)]. Each group (n = 6) was either supplemented with GP extract or ATV orally once daily for 6 months.

Results

In comparison with the untreated PM group, 250 and 500 mg/kg GP supplementation to PM groups reduced the systolic blood pressure (103 ± 2.7, 86 ± 2.4 vs. 156 ± 7.83 mmHg, p < 0.05), intima-media thickness (101.28 ± 3.4, 93.91 ± 2.93 vs. 143.78 ± 3.31 µM), vasoconstriction percentage induced by phenylephrine (102.5%, 88.3%, vs. 51.8%), sICAM-1 (0.49, 0.26 vs. 0.56 pg/mL) and sVCAM-1 (0.39, 0.25 vs. 0.45 pg/mL). GP extract supplementation increased vasorelaxation percentage induced by acetylcholine (78.4% vs. 47.3%) and sodium nitroprusside (84.2% vs. 53.7%), increased changes in plasma nitric oxide level (1.25%, 1.31% vs. 1.9%), and suppressed the elevation of TNF-α (0.39 vs. 1.02 pg/mL), IL-6 (0.43 vs. 0.77 pg/mL) and CRP (0.29 vs. 0.69 ng/mL) in the PM groups.

Conclusions

GP extract might improve vascular dysfunction by suppressing the inflammatory response, consequently preventing blood pressure elevation.

Keywords:

• Blood pressure
• ovariectomized
• vasorelaxation
• vasoconstriction
• cholesterol
• interleukin-6
• tumour necrosis factor-alpha
• C-reactive protein

Acknowledgments

The authors would like to thank Mr. Fadhlullah Zuhair, Mdm. Juliana Abdul Hamid, and staff members of the Pharmacology Department, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre (UKMMC), Malaysia for their technical assistance.

Author contributions

KAAN: preparation of the draft, contribution to the conception, design, acquisition of data, analysis, and interpretation of data. NMF, FB, QHMS: contribution to the conception, design of the study, and interpretation of data. IJ: contribution to the interpretation of data. ZJ: data analysis and the final approval of the version for publishing. All authors have read and approved the manuscript prior to submission.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation to any qualified researcher.

Additional information

Funding

This work was funded by the Ministry of Agriculture and Agro-Based Industry, Malaysia under Grant NH1015D076; and the Department of Biochemistry, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre (UKMMC), Malaysia.