Vasorelaxant effects of the extracts and some flavonoids from the buds of Coreopsis tinctoria

Figures & data

Figure 1. The structure of compounds 1–7.

Figure 2. Vasorelaxation effects of CTAD and CTAE in endothelium-denude (E−) aortic rings that were pre-contracted with KCl (60 mM, A) or PE (1 µΜ, B). **p < 0.01, *p < 0.05 with the control group. CTAD and CTAE: 50% and 70% ethanol eluates of ethanol extracts from C. tinctoria with AB-8 resin, respectively. Values are means ± SD (n = 10), expressed as the percentage of the vascular tension induced by KCl (60 mM) or PE (1 µΜ).

Table 1. Vasorelaxant effects of extracts from C. tinctoria against high K⁺-induced contractions in rat aortic rings.

	Relaxation (%)
Group	0.03 g/L	0.10 g/L	0.30 g/L	1.00 g/L	3.00 g/L
Control (E+)	0.08 ± 0.10	0.10 ± 0.24	0.11 ± 0.27	0.17 ± 0.15	0.07 ± 0.12
Ethanol extracts	4.89 ± 4.67	8.03 ± 5.08	25.28 ± 9.07*	44.26 ± 15.01*	71.46 ± 16.22**
CTAA	1.12 ± 3.61	0.30 ± 6.01	0.23 ± 9.22	0.40 ± 12.24	0.77 ± 15.89
CTAB	1.51 ± 3.06	1.85 ± 3.60	0.63 ± 4.91	4.38 ± 5.13*	9.66 ± 7.59*
CTAC	5.21 ± 2.87*	9.24 ± 5.72*	14.60 ± 9.15*	22.02 ± 12.27*	38.97 ± 12.57*
CTAD	4.94 ± 2.40	14.09 ± 12.48	33.33 ± 17.30*	55.81 ± 27.19*	100.49 ± 17.30**
CTAE	8.93 ± 6.18*	26.04 ± 17.58**	58.83 ± 15.01**	80.24 ± 13.33**	110.81 ± 16.33**
CTAF	5.37 ± 4.42*	12.65 ± 7.75**	32.03 ± 17.87**	54.27 ± 22.69**	86.60 ± 14.64**

**p < 0.01, *p < 0.05 with the control group. The rings were pre-constricted with high K⁺ (60 mM). Cumulative concentrations of extracts were subsequently added to the bath. CTAA ∼ CTAF: water, 10%, 30%, 50%, 70% and 95% ethanol eluates of ethanol extracts from C. tinctoria with AB-8 resin, respectively. Values are means ± SD (n = 10 rings).

Figure 3. Concentration-dependent effects of flavanomarein, querceagetin 7-O-β-d-glucoside, marein, okanin, luteolin, quercetin and dihydromelanoxetin on intact rat aorta rings precontracted with KCl (μM). **p < 0.01, *p < 0.05 with the control group. Values are means ± SD (n = 10 rings).

Figure 4. Concentration-dependent effects of quercetin, luteolin and propranolol on intact rat aorta rings precontracted with PE 1 μM. **p < 0.01, *p < 0.05 with control group. Values are means ± SD (n = 10 rings).

Figure 5. Effects of CTAD and CTAE (3 g/L) on the dose–response curve of the percentage contraction in high K⁺–Ca²⁺-free depolarizing solution and cumulative concentration of CaCl₂ (0.25 mM–5.00 mM). **p < 0.01, *p < 0.05 with the control group. CTAD and CTAE: 50% and 70% ethanol eluates of ethanol extracts from C. tinctoria with AB-8 resin, respectively. *p < 0.05 compared with control group (n = 10 rings).

Figure 6. Effects of CTA, CTAD and CTAE on PE-induced transient contractions in Ca²⁺-free solution. **p < 0.01, *p < 0.05 with the control group. CTA: ethanol extracts from C. tinctoria, CTAD and CTAE were 50% and 70% ethanol eluates of CTA with AB-8 resin, respectively. Values represent mean ± SD of 10 determinations.