AIM OF THE STUDY: Ziziphora clinopodioides Lam. (ZC) is widely used in Uyghur folk medicine for the treatment of hypertension diseases in Xinjiang, an autonomous region of China. To provide pharmacological basis for this traditional use, we explored the vasodilating effects of ZC and investigated the underlying mechanisms. MATERIALS AND METHODS: Activity of hexane (ZCHE), dichloromethane (ZCDE) and aqueous (ZCAE) extracts of ZC were evaluated on isolated rat aortic rings pre-contracted with phenylephrine (PE) or high KCl. The mechanisms were evaluated on ZCDE, the most potent extract. RESULTS: ZCDE-induced relaxation in endothelium-intact aortic rings pre-contracted with phenylephrine (PE, 10(-6) M) or high KCl (6×10(-2) M), with respective EC(50) values of 0.27±0.03 and 0.34±0.04 g/l. Mechanic removal of the endothelium did not significantly modify ZCDE-induced relaxation. In endothelium-denuded aorta pre-contracted with PE (10(-6) M), the vasorelaxant effect of ZCDE was significantly decreased by 4-amino-pyridine (10(-3) M), but not by glibenclamide (10(-4) M), iberiotoxin (3×10(-8) M) and thapsigargin (10(-7) M). In Ca(2+) free solution, ZCDE significantly inhibited extracellular Ca(2+)-induced contraction in high KCl and PE pre-contracted rings. Additionally ZDCE inhibited the intracellular Ca(2+) release sensitive to PE (10(-6) M). CONCLUSIONS: The results demonstrate that ZDCE exhibits endothelium-independent vasodilating properties that are mediated by inhibition of extracellular Ca(2+) influx through voltage- and receptor-operated Ca(2+) channels (VDDCs and ROCCs), by inhibition of Ca(2+) release from intracellular stores, and also by the opening of voltage-dependent K(+) channels.
AIM OF THE STUDY: Ziziphora clinopodioides Lam. (ZC) is widely used in Uyghur folk medicine for the treatment of hypertension diseases in Xinjiang, an autonomous region of China. To provide pharmacological basis for this traditional use, we explored the vasodilating effects of ZC and investigated the underlying mechanisms. MATERIALS AND METHODS: Activity of hexane (ZCHE), dichloromethane (ZCDE) and aqueous (ZCAE) extracts of ZC were evaluated on isolated rat aortic rings pre-contracted with phenylephrine (PE) or high KCl. The mechanisms were evaluated on ZCDE, the most potent extract. RESULTS:ZCDE-induced relaxation in endothelium-intact aortic rings pre-contracted with phenylephrine (PE, 10(-6) M) or high KCl (6×10(-2) M), with respective EC(50) values of 0.27±0.03 and 0.34±0.04 g/l. Mechanic removal of the endothelium did not significantly modify ZCDE-induced relaxation. In endothelium-denuded aorta pre-contracted with PE (10(-6) M), the vasorelaxant effect of ZCDE was significantly decreased by 4-amino-pyridine (10(-3) M), but not by glibenclamide (10(-4) M), iberiotoxin (3×10(-8) M) and thapsigargin (10(-7) M). In Ca(2+) free solution, ZCDE significantly inhibited extracellular Ca(2+)-induced contraction in high KCl and PE pre-contracted rings. Additionally ZDCE inhibited the intracellular Ca(2+) release sensitive to PE (10(-6) M). CONCLUSIONS: The results demonstrate that ZDCE exhibits endothelium-independent vasodilating properties that are mediated by inhibition of extracellular Ca(2+) influx through voltage- and receptor-operated Ca(2+) channels (VDDCs and ROCCs), by inhibition of Ca(2+) release from intracellular stores, and also by the opening of voltage-dependent K(+) channels.
Authors: Yung Sing Ch'ng; Yean Chun Loh; Chu Shan Tan; Mariam Ahmad; Mohd Zaini Asmawi; Wan Maznah Wan Omar; Mun Fei Yam Journal: Pharm Biol Date: 2017-12 Impact factor: 3.503
Authors: Cibério L Macêdo; Luiz H C Vasconcelos; Ana C C de Correia; Italo R R Martins; Daysianne P de Lira; Bárbara V de O Santos; Fabiana de A Cavalcante; Bagnólia A da Silva Journal: Molecules Date: 2014-11-27 Impact factor: 4.411
Authors: Taseer Ahmad; Adil Javed; Taous Khan; Yusuf S Althobaiti; Aman Ullah; Farooq M Almutairi; Abdul Jabbar Shah Journal: Pharmaceuticals (Basel) Date: 2022-07-30