Effects and mechanism of total phenols of Magnolia officinalis combined with Maijunan Tablets on blood pressure of spontaneous hypertensive rats / 中草药·英文版

ABSTRACT

Objective: Maijunan (MJA) Tablets is a protected variety of traditional Chinese medicine (TCM) consisted of Pueraria lobata, hydrochlorothiazide (HTCZ), Uncaria rhynchophylla (3661980) and excipient. In the present work, MJA was consisted of the total flavones of P. lobata, HCTZ and total alkaloids of U. rhynchophylla (401175). The combination of MJA and the total phenols of Magnolia officinalis (M-MJA) was consisted of the total flavones of P. lobata, the total phenols of M. officinalis, HCTZ and the total alkaloids of U. rhynchophylla (40401175). The aim of this work was to examine the effect and mechanism of M-MJA on the blood pressure of spontaneous hypertensive rats (SHRs). Methods: Adult male SHRs were randomly divided into control group, MJA group (180 mg/kg·d), and the M-MJA group (218 mg/kg·d) (n = 5). SHRs were orally administered with M-MJA and MJA respectively once a day for 8 weeks, the blood pressure of SHRs was measured every two weeks, and the biochemical indicators related to blood pressures were detected at the last dosing. Results: After oral administration of M-MJA to SHRs once a day for 8 weeks, the systolic and diastolic blood pressures of SHRs were deceased significantly. M-MJA affected renin-angiotensin-aldosterone system by decreasing the levels of Ren, Ang II and ALD, affected the endothelial function by decreasing the levels of ET-1 and 20-HETE, and increasing the level of eNOS, affected the oxidative stress by increasing the protein expression of Nrf2 and the activities of HO-1 and GSH-Px, and decreasing the protein expression of CYP2E1 and CYP4A, as well as the content of MDA. Conclusion: These results indicated that M-MJA could regulate the renin-angiotensin-aldosterone system, improve endothelial function, and inhibit CYP4A activity to reduce the production of 20-HETE, alleviate the oxidative stress disorder of the visceral organs, and eventually exert antihypertensive effect. Additionally, the anti-oxidant ability, regulating the renin-angiotensin-aldosterone system and improving endothelial function of M-MJA are more powerful than that of MJA, suggesting that M-MJA may have a better anti-hypertensive effect than MJA.