Antiproliferative and anti-inflammatory acyl glucosyl flavones from the leaves of Bursera copallifera

Abstract

Bursera copallifera (DC) Bullock (Burseraceae) is a plant species used in folk medicine for the treatment of inflammation (bronchitis, cough). The dichloromethane-methanol extract (DML) of B. copallifera leaves was found to possess important antiproliferative and anti-inflammatory activities. In order to further correlate these activities with the phytochemical components, the bioactivity-guided fractionation of the DML extract allowed the isolation of an active fraction which was constituted of five compounds characterized as luteolin-3’-O-(3“-O-E-p-coumaroyl)-α-L-rhamnopyranoside (1), luteolin-3’-O-(2“-O-E-p-coumaroyl)-α-L-rhamnopyranoside (2), α-amyrin (3), 3-epilupeol (4) and stigmasterol (5). Among the five isolated constituents, the triterpenes 3 and 4, and the sterol 5 have been already well known for their anti-inflammatory properties. Flavone 2 (Luteolin-3’-O-(2“-O-E-p-coumaroyl)-α-L-rhamnopyranoside) was responsible for the antiproliferative activity, showing in vitro cytotoxic activity against MCF-7 human cancer cell line with IC50 value of 13.9 μM. On the other hand flavone (1) exhibited COX-1 inhibition (IC50 = 93 μM). Flavone 1, together with the triterpenes 3 and 4 were the responsible for inhibiting TPA-induced inflammation by inhibiting COX-1 enzyme. Therefore, these results support the traditional use of the infusion made with the leaves of B. copallifera as an anti-inflammatory agent.