Edema-inducing activity of phospholipase A2 purified from human synovial fluid and inhibition by aristolochic acid

Abstract

A neutral-active, Ca2+-dependent phospholipase A2 (PLA2) purified 11,000-fold from human synovial fluid (HSF) induced edema when injected into the mouse foot pad. The edema produced by HSF-PLA2 was dose-dependent and was positively correlated with the dose-dependent in vitro expression of PLA2 activity. Maximum edema was achieved within 45 min after the injection and persisted for at least 6 h. Aristolochic acid [8-methoxy-6-nitrophenanthro(3,4-d)-1,3-dioxole-5-carboxylic acid], a major chemical component derived from various species of Aristolochia plant, produced a dose-dependent inhibition of in vitro phospholipid hydrolysis by HSF-PLA2, porcine pancreatic PLA2, snake venom (Naja naja) PLA2, and PLA2 isolated from human platelet. The sensitivity of these PLA2s to inhibition by aristolochic acid varied markedly: HSF-PLA2 greater than N. naja PLA2 greater than human platelet PLA2 greater than porcine pancreatic PLA2. The inhibition of HSF-PLA2 by aristolochic acid was independent of substrate concentration (18-144 microM) and Ca2+ concentration (0.1-4.0 mM). These observations indicate that inhibition of HSF-PLA2 by aristolochic acid may result from direct interaction with the enzyme. When aristolochic acid was mixed with HSF-PLA2 and then injected into the mouse foot pad, edema was inhibited in a dose-dependent manner and was positively correlated with in vitro inhibition of PLA2 activity. Alkylation of HSF-PLA2 with p-bromophenacyl bromide concomitantly inhibited both enzyme and edema-inducing activity. These results clearly demonstrate that the neutral-active, Ca2+-dependent PLA2 isolated from human synovial fluid is proinflammatory and that catalytic activity is positively correlated with in vivo proinflammatory effects.

Mass spectrometry analysis of the phospholipase A2 activity of snake pre‐synaptic neurotoxins in cultured neurons

“…4). Following pre-incubation with the generic cellular PLA 2 inhibitor AA (Vishwanath et al 1988;Rosenthal et al 1989;Chandra et al 2002), no reduction in the LysoPLs production by Tetx was detected, whereas a small decrease (significative with p < 0.05) was observed in the case of Ntx. This latter observation might be because of the slight inhibition of the Ntx enzymatic activity itself by AA as detected by performing an in vitro PLA 2 assay (not shown).…”

Involvement of secretory phospholipase A2 activity in the zymosan rat air pouch model of inflammation

“…anti-inflammatory activity in animals, probably due to PLA2 inhibition (Mayer et al, 1988;Vishwanath et al, 1988;Potts et al, 1992;Miyake et al, 1993;Marshall et al, 1994;Tramposch et al, 1994;Gil et al, 1994), although there is no direct evidence for PLA2 participation in experimental models of inflammation and its pharmacological modulation. Scalaradial, a marine natural product exhibits the in vitro pharmacological profile of a potent PLA2 inhibitor acting on extracellular and intracellular enzymes (de Carvalho Jacobs, 1991;Farina et al, 1994); however, to date no data on its possible inhibitory effects on PLA2 in vivo have been reported.…”

“…In fact, some of these enzymes have demonstrated proinflammatory effects when injected into animals (Vadas & Pruzanski, 1986;Vishwanath et al, 1988;Neves et al, 1993). Nevertheless, evaluation of the precise physiological role of PLA2 enzymes has been limited by the difficulties in characterizing PLA2 and the lack of suitable inhibitors.…”

Microarray analysis reveals the inhibition of nuclear factor-kappa B signaling by aristolochic acid in normal human kidney (HK-2) cells

“…AA can block H 2 O 2 -induced platelet aggregation and suppress hydroxyl radicalinduced platelet activation through the arachidonic acid pathMicroarray analysis reveals the inhibition of nuclear factor-kappa B signaling by aristolochic acid in normal human kidney (HK-2) cells Ya-yin CHEN 1, 2 , Su-yin CHIANG 1 , Hsiu-ching WU 3 , Shung-te KAO 1, 2 , Chien-yun HSIANG 4, # , Tin-yun HO 1, # , Jaung-geng LIN 1, #, * www.nature.com/aps Chen YY et al Acta Pharmacologica Sinica npg way [7,8] . AA was found to possess anti-inflammation effects as demonstrated by its ability to inhibit phospholipase A 2 (PLA 2 ) when administered by intramuscular or intraperitoneal injection [9,10] . Furthermore, AA was also reported to inhibit Group I PLA 2 in humans with sepsis [11] .…”

“…[7,8] . AA was found to possess anti-inflammation effects as demonstrated by its ability to inhibit phospholipase A 2 (PLA 2 ) when administered by intramuscular or intraperitoneal injection [9,10] . Furthermore, AA was also reported to inhibit Group I PLA 2 in humans with sepsis [11] .…”