Abstract
6-Methoxykaempferol-3-
O-glucoside (6-MKG) was isolated from a Sudanese herb (El-hazha). The pharmacological effects of 6-MKG were tested on isolated non-pregnant or late-pregnant rat uteri
in vitro, whilst docking studies were carried out modelling of the binding of 6-MKG to the rat β
2-adrenoceptor
in silico.
In vitro studies revealed that 6-MKG was able to relax both the non-pregnant and the late-pregnant uterine contractility with 50% of the E
max of terbutaline, whilst the EC
50 for 6-MKG was at least half than that of terbutaline. The β
2-adrenoceptors antagonist 3-(isopropylamino)-1-[(7-methyl-4-indanyl)oxy]butan-2-ol(ICI118,551) competitively antagonised the relaxing effect of 6-MKG. Radioligand binding and cAMP studies confirmed the β
2-adrenoceptors agonistic property of the compound. In
in silico docking studies, 6-MKG bound to rat β
2-adrenoceptors with low ∆G
bind
value (−
11.53
±
0.06
kcal/mol) and it interacted with four residues of the active site (Asp
113, Asn
312, Cys
191and Tyr
316). It is concluded that 6-MKG exerts weak β
2-adrenoceptor agonistic activity and can be considered a natural compound with potential therapeutic significance in the field of premature pregnant uterine contractions and asthmatic problems.
► 6-methoxykaempferol-3-O-glucoside (6-MKG) was isolated and identified early (2004). ► Its pharmacological profile remains controversial. ► This study aimed to proof and determine the pharmacological profile of 6-MKG by
in silico -
in vitro techniques using β
2-adrenoceptor as main target. ► The present study revealed that 6-MKG possesses weak β
2-adrenoceptor agonistic activity. ► 6-MKG was with therapeutic potential for premature labour inhibition and asthma treatment.