[SS-120]

Syringic Acid Preconditioning Improves Kidney Ischemia-Reperfusion

¹Department of Urology, Canakkale Onsekiz Mart University, Faculty of Medicine, Canakkale, Turkey.
²Department of Pharmacology, Canakkale Onsekiz Mart University, Faculty of Medicine, Canakkale, Turkey.
³Department of Biochemistry, Canakkale Onsekiz Mart University, Faculty of Medicine, Canakkale, Turkey.
⁴Canakkale Onsekiz Mart University, Student of Faculty of Medicine, Canakkale, Turkey.
⁵Medeniyet University, Faculty of Medicine, Department of Pathology, Istanbul, Turkey.

AIM: Renal ischemia-reperfusion (IR) injury is a common cause of acute kidney injury. The objective of the present study was to determine whether preischemic administration of Syringic Acid (SA) would attenuate renal ischemia-reperfusion injury.
Material-METHOD: Wistar-Albino rats were divided into three groups: (1) Sham-operated group; (2) IR group (30 minute ischemia followed by 1 hour reperfusion); and (3) IR group + SA (Three intraperitoneal doses of 10mg/kg 10% syringic acid were administered). The effects of SA were examined by use of biochemical parameters consisting of ischemia modified albumin (IMA), total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI). In addition, the apoptosis status and histopathological changes including the dilatation of bowman space (DBS), tubular dilatation (TD), tubular cell sloughing (TCS), tubular cell degeneration – necrosis (TCDN), hyaline castes (HC) and interstitial lymphocytic infiltration (ILI) were evaluated

RESULTS: In the IR group, biochemical parameters indicating oxidative stress, IMA, TOS, and OSI, were higher compared to the Sham group. Syringic acid reduced oxidative stress parameters (respectively p=0.002, p=0.021, p=0.010). Although TAS values were lowered in the IR group and higher in the SA pretreated group, no significant changes in TAS values were detected between all the studied groups. The total score was obtained by summing all the scores from morphological kidney damage markers. The total score was increased with IR damage when compared with the Sham group (9.75±0.84, 2.13±0.29; p=0.001). But, the total score significantly fell after administration of SA (4.13±0.71; p=0.001 compared with IR group).

CONCLUSION: Syringic acid preconditioning is effective in reducing tissue damage induced in kidney ischemia-reperfusion injury and the protective effect of SA is mediated via reducing TOS and OSI and preventing apoptosis. Renal histology also showed convincing evidence regarding SA’s protective nature against kidney injury induced during renal ischemia reperfusion. Consequently, SA might be helpful in protecting the kidneys from IR induced damage in humans, probably through the antiapoptotic effect and by reducing the total oxidant status.

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Figure 1

Figure 1. Hematoxylen-Eosin kidney stained sections showed normal structure of the renal cortex and medul¬la of sham operated group (Figure 1A). Thin arrows show tubulus and thick arrows show glomerulus, respectively. This was markedly affected in renal Ischemia reperfusion group (Figure 1B) with severe tubular dilatation(thin arrow), moderate to severe tubular cell degeneration and necrosis (TCDN; red arrows), severe dilatation of Bowman’s space (DBS; thick arrows). In addition to this, generated the number of the hyaline cast was high (Figure 1C). The normal structure was somewhat regained in the Syringic acid pre-treated group (Figure 1D): mild DBS (thick arrows), mild to moderate of TD (thin arrows), minimal TCDN (red arrows).

Table 2

Groups	Apoptosis	DBS	TD	TCS	TCDN	HC	ILI	Total Number
Sham	22.50±11.14	0.38±0.18	0.50±0.26	0.38±0.18	0.38±0.18	0.25±0.16	0.25±0.16	2.13±0.29
IR	252.50±64.9(a)	2.13±0.35(a)	1.75±0.36a	1.13±0.29	0.75±0.16	2.38±0.49(a)	1.63±0.49(a)	9.75±0.84(a)
Syringic Acid	75.00±30.29(b)	1.00±0.37(b)	0.63±0.37(b)	0.50±0.18	0.50±0.18	0.63±0.26(b)	0.88±0.39	4.13±0.71(b)

Apoptosis and histopathological analysis score results.
(a) p< 0.05 compared with sham group
(b) p< 0.05 compared with IR group

Table 1

Groups	IMA	TAS	TOS	OSI
Sham	0.13±0.04	10.54±2.15	7.11±0.88	0.86±0.21
IR	0.71±0.14a	8.33±1.43	15.32±1.98a	2.02±0.25a
Syringic Acid	0.19±0.05a,b	9.85±1.45	9.34±1.05b	1.09±0.24b

Table 1. Serum IMA, TAS, TOS and OSI levels.
a p< 0.05 compared with sham group
b p< 0.05 compared with serum IR group