Edema Induced by sPLA2 from Crotalus durissus terrificus Involves PLC and PKC Signaling, Activation of cPLA2, and Oxidative Stress

Abstract

sPLA2 from Crotalus durissus terrificus venom, free of crotapotin (Cdt sPLA2), purified and isolated sPLA2, was able to significantly increase lipid peroxidation, which occurred simultaneously with increased arachidonic acid (AA) metabolism. In addition, MDA and AA levels were elevated at 15 min after Cdt sPLA2 injection and after peak edema (negative control). Thus, oxidative stress and ROS play important roles in the inflammation induced by Cdt sPLA2. On the other hand, edema induced by sPLA2 involves the direct and indirect mobilization of arachidonic acid by the involvement of phosphokinase C (PKC) and phospholipase C (PLC), which indirectly stimulates cytosolic PLA2 (cPLA2). We also observed that the specific antivenin against Cdt venom had no significant effect on the neutralization of induced edema compared to the natural products 5-caffeine-linoleic acid (5CQA) and dexamethasone (AACOCF3). Our results also indicate that there was improvement in the inhibition of edema of natural polyphenolic compounds compared to antivenin or inhibition of the enzymatic activity of sPLA2 due to the fact that 5CQA is a potent antioxidant compound. Thus, our results show a clear correlation between increased arachidonic acid metabolism and oxidative stress.

Bioaffinity Fishing Procedure Using Secretory Phospholipase A2 for Screening for Bioactive Components: Modulation of Pharmacological Effect Induced by sPLA2 from Crotalus durissus terrificus by Hispidulin from Moquiniastrum floribundum

“…Hydroxyl radicals can reduce disulfide bonds in proteins [26]. The results for hispidulin suggest that inflammation or myotoxic activity induced by sPLA2 may involve the formation of hydroxyl radicals as well as free radicals [8,9]. Thus, we were able to identify compounds that inhibit sPLA2 using the bioaffinity technique.…”

“…Our results also showed that hispidulin exerts its anti-inflammatory activity through its intracellular antioxidant action due to the presence of methylation. As such, His has the ability to pass through the plasma membrane and increase the antioxidant defense of the cell [8]. Numerous articles suggest that His exhibits a moderate antioxidant activity for free radical scavenging and neutralization, determined by 1,1-Diphenyl-2-picrylhydrazyl radical, 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl (DPPH), and 2,2 -Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) antioxidant activity monitoring assays [12].…”

“…Using this procedure, we were able to isolate, through one chromatographic run, the compounds presented in the extract. These compounds were identified using NMR ( 1 H, 13 C, and HMBC spectra) as 3-caffeoylquinic acid (1), chlorogenic acid (2), 4-caffeoylquinic acid (3), 3,4-, 3,5-m, and 4,5-dicaffeoylquinic acids (4-6, respectively), 3,4,5-tricaffeoylquinic acid 7, and hispidulin (8). The proposed structures were confirmed by the comparison of the spectroscopic data with those reported in the literature [12,13].…”

“…Both mediators induce an increase in the cytosolic expression of COX-2 and the consequent increase in prostaglandin synthesis [4,5]. The excessive release of free fatty acids by the action of both cytosolic PLA2 as well as secretory sPLA2 increases the activity of COX-2, which can result in formation of more free radicals and pro-inflammatory cytokines, leading to increased oxidative stress and early onset of inflammation [6][7][8]. Thus, sPLA2 is able to induce inflammation through its ability to generate AA, initiating a series of cellular events and inducing an increase in reactive oxygen species (ROS).…”

“…Phenolic compounds are known for their antioxidant activity due to a molecular structure capable of neutralizing or scavenging ROS and chelating metal ions. Thus, searching for natural compounds is important for identifying compounds with therapeutic potential, whether for the development of new antibiotics or new anti-inflammatory drugs [8,9].…”