Effects of Allium cepa and Its Constituents on Respiratory and Allergic Disorders: A Comprehensive Review of Experimental and Clinical Evidence

Table 2

The possible bronchodilatory effects of A. cepa and its constituents on the tracheal smooth muscle and its possible mechanisms.

Study type	Study design	Preparations	Dose	Effects	Ref.
Exp	Murine TSM contracted with Cch	A. cepa extract	10, 100, and 1000 μg/ml	Relaxing activity on TSM	[30]
	Rat TSM contracted with Mch and KCl	A. cepa extract	2, 4, 8, 16, 32, and 64 mg/ml	β2-Adrenergic stimulatory and calcium channel blockade mechanisms	[61]
	Rat trachea contracted with Cch	A. cepa peel	3–30 mg/kg	Inhibition of Ca^2+ channels and phosphodiesterase enzyme-like mechanisms	[85]
	Animals 30 min prior to allergen inhalation	Ethanolic extracts	10 µl/1 ml, orally	Relation effect on TSM	[86]
	A/J mice precontracted with Cch	Qt	3.5, 7.5, and 15 μg/ml	Relaxing activity on TSM; inhibited Ca^2+-permeant LVDCCs, TRPC3, and STIM/Orai channels	[87]
	TSM of mice	Qt	100 nM-1 mM and 50 μM	Relaxant effect on TSM; PDE4 inhibition	[88]
	OVA-sensitized guinea pigs	Qt	20 mg/kg	Relaxant effect on TSM in vivo and in vitro	[89]
	Cch-induced TSM contractions	Qt	10^−6−3 × 10^−4 M	Inhibited nitric oxide synthase; N^G-nitro-L-arginine methyl ester significantly reduced the effect of Qt	[147]

Ref.: references, Exp: experimental, Clin: clinical, TSM: tracheal smooth muscle, OVA: ovalbumin, TQ: thymoquinone, and Cch: carbachol.