Effect of Desmodium adscendens fractions on antigen- and arachidonic acid-induced contractions of guinea pig airways

Abstract

Three fractions (n-butanol, F2, and L5), isolated from an aqueous extract of Desmodium adscendens, a plant used in Ghana for the management of asthma, were evaluated for their pharmacological activity using ovalbumin and arachidonic acid-induced contractions of guinea pig airways. All three fractions inhibited the ovalbumin-induced contractions of indomethacin-pretreated tracheal spirals from sensitized animals dose dependently, but only L5 and n-butanol inhibited such contractions in the absence of indomethacin. The concentrations required to inhibit ovalbumin-induced contractions of lung parenchymal strips were threefold higher than with trachea. The contractile response over a 60-min period was divided into three phases. F2 and n-butanol inhibited all phases, whereas L5 inhibited only the late phase. n-Butanol and L5 inhibited arachidonic acid-induced contractions on indomethacin-pretreated tracheal spirals, a leukotriene-dependent reaction. There was no inhibition of arachidonic acid-induced contractions of lung parenchymal strips, which is largely a thromboxane-dependent reaction. The results suggest that D. adscendens contains several pharmacologically active substances that can inhibit allergic airway smooth muscle contraction at multiple sites, including the synthesis and (or) activity of the bronchoconstrictor leukotrienes.

An ethnomedicinal, phytochemical and pharmacological profile of Desmodium gangeticum (L.) DC. and Desmodium adscendens (Sw.) DC.

“…Several studies have been carried out to verify if the plant relaxes smooth muscle and to understand better its action. It has been suggested that the action mechanism of the plant is due to the depletion of the HST stocks (Addy and Awumey, 1984); the inhibition of the cyclooxygenase and lipoxygenase enzymes (Addy and Burka, 1988); the increase of the prostaglandin synthesis, PGE2 and PGF2a; the opening of the BKCa channels (McManus et al, 1993); or the inhibition of cytochrome P450 NADPH-dependent arachidonic acid metabolism (Addy and Schwartzman, 1992). It inhibits contraction of the guinea pig's ileum and airways (Addy and Awumey, 1984;Burka, 1988, 1989).…”

“…Several studies have been carried out to assess if the plant relaxes smooth muscles and to understand better its action (Addy and Awumey, 1984;Addy and Dzandu, 1986;Addy and Burka, 1987, 1988, 1989, 1990Addy, 1992;McManus et al, 1993;Addy and Schwartzman, 1995;Barreto, 2002).…”

“…Three fractions isolated from an aqueous extract of Desmodium adscendens were evaluated for their pharmacological activity using ovalbumin (OA) and arachidonic acid (AA)-induced contractions of guinea pig airways (Addy and Burka, 1988). The OA-induced contractions of indomethacin-pretreated tracheal spirals from sensitized animals were inhibited by all three fractions dose dependently whereas only L5 and n-butanol inhibited such contractions in the absence of indomethacin.…”

Tracheal relaxation of five Ivorian anti-asthmatic plants: Role of epithelium and K+ channels in the effect of the aqueous-alcoholic extract of Dichrostachys cinerea root bark

“…A skeletal muscle-relaxant effect was also described ex vivo and in vivo for a Baphia nitida ethyl acetate extract (Adeyemi et al, 2006). More interestingly, three fractions isolated from an aqueous extract of Desmodium adscendens were shown to inhibit allergic airway smooth muscle contraction at multiple sites, including the synthesis and/or activity of the bronchoconstrictor leukotrienes (Addy and Burka, 1988).…”

Immunoactive Profile of Aqueous Extracts ofDesmodium adscendensin Mice

“…For example, in Ghana, the plant decoction is prescribed by healers to treat asthma and other diseases associated with smooth-muscle contraction (13). This characteristic of D. adscendens has been proved to inhibit contraction of the guinea pig's ileum and airways (1)(2)(3). In addition, its traditional use in hepatic affection, particularly viral hepatitis (16), and anti-allergic effects in vivo (3,4) were verified.…”