Inhibition of Leukotriene B₄Formation in Rat Peritoneal Neutrophils by an Ethanolic Extract of the Gum Resin Exudate ofBoswellia serrata

Abstract

Suspensions of rat peritoneal polymorphonuclear leukocytes (PMNL) elicited with glycogen were stimulated by calcium and ionophore to produce leukotrienes and 5-HETE from endogenous arachidonic acid (AA). We investigated the effect of ethanolic extracts of the gum resin exudate of Boswellia serrata. A concentration-dependent inhibition of LTB4 and 5-HETE production by different charges of exudate extracts were found. All products of the 5-lipoxygenase (5-LOx) from endogenous arachidonic acid (AA) in PMNL were reduced to the same extent by the extracts tested. The ethanolic extract of the gum resin also decreased 5-LOx mediated metabolisation of exogenously added AA to LTB4 and 5-HETE. Since steroidal-type anti-inflammatory drugs do not exert an immediate effect in the test system used, we conclude that the activity of the 5-LOx itself represents the side of inhibition by the gum resin extract. Therefore, an inhibition of 5-LOx catalysed mediator synthesis might be involved in the previously reported anti-inflammatory activity in vivo.

Anti-Inflammatory Actions of Pentacyclic Triterpenes

“…A BA containing crude extract and BAs, especially AKBA, inhibited 5-LO product formation from endogenous arachidonic acid in intact neutrophils, as well as from exogenous substrate in a ceIl-freee system and the activity of purified human 5-LO with IC50 values of 1.5pM, 8pM, and 15pM, respectively (18,25,26). Many PTs (including UA, OA, amyrin), but not 4-ring compounds, bind to 5-LO protein.…”

Development and optimization of boswellic acid-loaded proniosomal gel

“…The anti-inflammatory action of BAs has been attributed due to the inhibition of 5-lipoxygenase in a selective, nonredox, and non-compititive way (Ammon et al, 1991) as compared to other inhibitors of the enzyme 5-lopoxygenase which posess disadvantages because of their non-selectivity, in this manner BAs have advantages of less danger and constrained symptoms when contrasted with other antiinflammatory medications (Ammon et al, 1993;Safayhi et al, 1995;Siemoneit et al, 2009). Earlier studies have suggested that both KBA and AKBA interfere with production of leukotrienes by inhibition 5-lipoxygenase; however, more recent research has shown that other BAs specially b-boswellic acid also play an important role, targeting the microsomal prostaglandin (PG) E2 synthase-1 (mPGES-1) as well as cathepsin G (CatG) thereby complementing the inflammatory action of KBA and AKBA (Tausch et al, 2009;Abdel et al, 2011;Siemoneit et al, 2011;Skarke et al, 2012).…”

Mechanisms underlying the anti-inflammatory actions of boswellic acid derivatives in experimental colitis

“…These acids derive from the resin of Boswellia trees known as frankincense (24). Pharmacological analyses have revealed acetyl-11-keto-␤-boswellic acid (AKBA) to be the most powerful of the acids contained in ethanolic extracts of Boswellia serrata, with in vitro experiments demonstrating cytostatic and proapoptotic actions of AKBA (2,16,28,33,34). We have been able to confirm the anti-inflammatory properties of these compounds in an experimental model of colitis in rats (21).…”