Antihypertensive effects of ethanolic fruit extract of Acanthopanax sessiliflorus

Acanthopanax sessiliflorus (Araliaceae) is a shrub present mainly in Korea, China and Japan and is known to be one of the most abundant species. Acanthopanax species have been used as a tonic and prophylactic in oriental herbal medication from olden times [1]. Its fruits have been reported to have anti-tumor and immuno-stimulating activities [2, 3]. In this study, the ethanolic extracts from the fruits of Acanthopnax sessiliflorus (ASF) were evaluated on antihypertensive effects in vivo/ex vivo/in vitro. In the in vivo study, spontaneous hypertensive rats (SHRs) were treated with ASF (200, 400 or 600 mg/kg/day) or captopril (100 mg/kg/day) for 4 weeks. The systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured every 7 days using the tail-cuff plethysmography. Oral administration of ASF reduced SBP and DBP in SHRs in dose-dependent and time-dependent manner.

In the ex vivo study, the vasorelaxant effects on isolated porcine coronary arterial rings were evaluated by using organ chamber and physiological recorders [4]. ASF showed strong vasorelaxant effects in isolated porcine coronary arterial rings with (IC₅₀= 260 µg/mL) or without (IC₅₀= 160 µg/mL) endothelium. In the in vitro study, angiotensin converting enzyme (ACE) inhibition effects were measured in the substrate of hipppuryl-I-histidyl-I-leucine (HHL), antioxidant effects were measure by DPPH assay and productive effects of reactive nitrogen species were measured using DAF-FM DA fluorescence. ASF showed significant ACE inhibition effects (IC₅₀= 184 µg/mL), antioxidant effects (IC₅₀,= 779 µg/mL) and reactive nitrogen species productive effects (p < 0.001 in 200 µg/mL) in dose-dependent manner. These results suggest that ASF has antihypertensive effects via multiple targets and could be used as candidate materials for the treatment of hypertension.

Acknowledgements: This work was carried out with the support of “Cooperative Research Program for Agriculture Science & Technology Development (Project No. PJ01133303)”Rural Development Administration, Republic of Korea.

Keywords: Acanthopanax sessiliflorus, fruits, hypertension, spontaneous hypertensive rats, angiotensin converting enzyme, antioxidant activity.

References:

[1] Lee DY, Seo KH, Lee DS, Kim YC, Chung IS, Kim GW, Cheoi DS, Baek NI. Bioactive 3,4-seco-Triterpenoids from the fruits of Acanthopanax sessiliflorus. J Nat Prod 2012; 75: 1138 – 1144

[2] Lee DY, Seo KH, Jeong RH, Lee SM, Kim GS, Noh HJ, Kim SY, Kim GW, Kim JY, Baek NI. Anti-inflammatory lignans from the fruits of Acanthopanax sessiliflorus. Molecules 2012; 18: 41 – 49

[3] Lee JW, Baek NI, Lee DY. Inhibitory effects of seco-triterpenoids from Acanthopanax sessiliflorus Fruits on HUVEC invasion and ACE activity. Nat Prod Commun 2015; 10: 1517 – 1520

[4] Park SH, Shim BS, Yoon JS, Lee HH, Lee HW, Yoo SB, Wi AJ, Park WS, Kim HJ, Kim DW, Oak MH. Vascular protective effect of an ethanol extract of Camellia japonica Fruit: Endothelium-dependent relaxation of coronary artery and reduction of smooth muscle cell migration. Oxid Med Cell Longev 2015; 2015: 6309565