Inhibition of sPLA2 enzyme activity by cell-permeable antioxidant EUK-8 and downregulation of p38, Akt, and p65 signals induced by sPLA2 in inflammatory mouse paw edema model

Jayachandra, K and Gowda, MDM and Rudresha, GV and Manjuprasanna, VN and Urs, AP and Nandana, MB and Bharatha, M and Jameel, NM and Vishwanath, BS (2022) Inhibition of sPLA2 enzyme activity by cell-permeable antioxidant EUK-8 and downregulation of p38, Akt, and p65 signals induced by sPLA2 in inflammatory mouse paw edema model. In: Journal of Cellular Biochemistry .

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Abstract

The arachidonic acid (AA) metabolic pathway, plays a vital role in the production of eicosanoids by the action of pro-inflammatory secretory phospholipase A2 (PLA2). Release of eicosanoids is known to be involved in many inflammatory diseases. Identification of the inhibitory molecules of this AA pathway enzyme along with the regulation of intracellular signaling cascades may be a finer choice to develop as a powerful anti-inflammatory drug. In this regard, we have screened few cell-permeable antioxidant molecules Tempo, Mito-TEMPO, N,N'-Bis(salicylideneamino)ethane-manganese(II) (EUK)-134, and EUK-8 against pro-inflammatory sPLA2s. Among these, we found EUK-8 is a potent inhibitor with its IC50 value ranges 0.7–2.0 µM for sPLA2s isolated from different sources. Furthermore, docking studies confirm the strong binding of EUK-8 towards sPLA2. In vivo effect of EUK-8 was studied in HSF-sPLA2-induced edema in mouse paw model. In addition to neutralizing the edema, EUK-8 significantly reduces the phosphorylation level of inflammatory proteins such as p38 member of MAPK pathway, Akt, and p65 along with the suppression of pro-inflammatory cytokine (interleukin-6) and chemokine (CXCL1) in edematous tissue. This shows that EUK-8 not only inhibits the sPLA2 activity, it also plays an important role in the regulation of sPLA2-induced cell signaling cascades. Apart from the sPLA2 inhibition, we also examine the regulatory actions of EUK-8 with other downstream enzymes of AA pathway such as 5-LOX assay in human polymorphonuclear leukocytes (PMNs) and COX-2 expression in carrageenan-λ induced paw edema. Here EUK-8 significantly inhibits 5-LOX enzyme activity and downregulates COX-2 expression. These data indicate that EUK-8 found to be a promising multitargeted inhibitory molecule toward inflammatory pathway. In conclusion, mitochondrial targeted antioxidant EUK-8 is not only the powerful antioxidant, also a potent anti-inflammatory molecule and may be a choice of molecule for pharmacological applications.

Item Type:	Journal Article
Publication:	Journal of Cellular Biochemistry
Publisher:	John Wiley and Sons Inc
Additional Information:	The copyright for this article belongs to the John Wiley and Sons Inc.
Keywords:	arachidonic acid; cyclooxygenase; edema and anti-inflammatory; EUK-8; inflammation; lipoxygenase; secretory phospholipase A2
Department/Centre:	Division of Biological Sciences > Centre for Ecological Sciences
Date Deposited:	01 Feb 2023 05:25
Last Modified:	01 Feb 2023 05:25
URI:	https://eprints.iisc.ac.in/id/eprint/79645

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