Effects of curcumin on oxidative stress, inflammation and apoptosis in L-arginine induced acute pancreatitis in mice

Abstract

Background and purpose: Curcumin, an active constituent of rhizomes of Curcuma longa Linn, exhibits a variety of biological activities such as anti-inflammation and anti-oxidant. The present study aims to examine the effects of curcumin on oxidative stress, inflammation and apoptosis in L-arginine induced acute pancreatitis (AP) in mice.

Methods: Male ICR mice were randomly divided into 4 groups. Control group received intraperitoneal injection (i.p.) of 1% DMSO as a vehicle. AP group received two doses of i.p. L-arginine (L-Arg) 450 mg/100 g body weight (BW) at 1-hour interval. AP plus low-dose curcumin group received i.p. curcumin 50 mg/kg BW 1 hour before L-Arg injection and then once daily for 3 days. AP plus high-dose curcumin group received i.p. curcumin 200 mg/kg BW 1 hour before L-Arg injection and then once daily for 3 days. All mice were sacrificed at 72 hours. Pancreatic tissue was obtained for histological evaluation, immunohistochemical studies for nuclear factor-kappa beta (NF-kβ), apoptosis and myeloperoxidase (MPO), and Western blot analyses for 4-Hydroxynonenal (4-HNE). Blood samples were collected for amylase analysis.

Results: Mean body weight was significantly lower in AP group than in control group, while in curcumin group, body weight was maintained. The serum amylase, number of MPO positive cells, NF-kB positive cells, TUNEL positive cells, and 4-HNE expression significantly increased in AP group when compared with control group, but decreased in low and high-dose curcumin groups. Mice in AP group developed severe pancreatic inflammation, edema and fat necrosis. While mice in low and high-dose curcumin groups showed a significant improvement in histopathological scores. There was no significant difference between low and high doses of curcumin.

Conclusion: Curcumin could attenuate acute pancreatitis via anti-oxidant, anti-inflammation and anti-apoptosis property leading to the improvement in pancreatic damage.

Keywords: 4-HNE; Apoptosis; Biochemistry; Cell biology; Curcumin; Myeloperoxidase; Pancreatitis; Physiology; Systems biology.

Fig. 1

The delta body weight between groups. (*P < 0.05 versus control group; ^#P < 0.05 versus AP group).

Fig. 2

Serum amylase level. Data are presented as mean ± SD (*P < 0.05 versus control group; ^#P < 0.05 versus AP group).

Fig. 3

Representative images of pancreatic histopathology by H & E staining (40X). (A) Control group, (B) AP group, (C) Low-dose curcumin group and (D) High-dose curcumin group. Arrows indicate inflammation, edema and fat necrosis.

Fig. 4

a. Representative images of TUNEL staining for evaluation of apoptotic acinar cells (40X). (A) Control group, (B) AP group, (C) Low-dose curcumin and (D) High-dose curcumin. Arrows indicate apoptotic acinar cells. b. The percentage of TUNEL positive cells in each group. Data are presented as mean ± SD (*P < 0.05 versus control group; ^#P < 0.05 versus AP group).

Fig. 4

a. Representative images of TUNEL staining for evaluation of apoptotic acinar cells (40X). (A) Control group, (B) AP group, (C) Low-dose curcumin and (D) High-dose curcumin. Arrows indicate apoptotic acinar cells. b. The percentage of TUNEL positive cells in each group. Data are presented as mean ± SD (*P < 0.05 versus control group; ^#P < 0.05 versus AP group).

Fig. 5

a. Representative images of immunohistochemistry for MPO in mice pancreas (40X). (A) Control group, (B) AP group, (C) Low-dose curcumin and (D) High-dose curcumin. Arrows indicate MPO positive cells. b. Numbers of MPO positive cells per HPF in mice pancreas. Data are presented as mean ± SD (*P < 0.05 versus control group; ^#P < 0.05 versus AP group).

Fig. 5

a. Representative images of immunohistochemistry for MPO in mice pancreas (40X). (A) Control group, (B) AP group, (C) Low-dose curcumin and (D) High-dose curcumin. Arrows indicate MPO positive cells. b. Numbers of MPO positive cells per HPF in mice pancreas. Data are presented as mean ± SD (*P < 0.05 versus control group; ^#P < 0.05 versus AP group).

Fig. 6

a. Representative images of immunohistochemistry for NF-kB expression in mice pancreas (40X). (A) Control group, (B) AP group, (C) Low-dose curcumin and (D) High-dose curcumin. Arrows indicate NF-kβ positive cells. b. The percentage of NF-kβ positive cells in each groups. Data are presented as mean ± SD (*P < 0.05 versus control group; ^#P < 0.05 versus AP group).

Fig. 6

a. Representative images of immunohistochemistry for NF-kB expression in mice pancreas (40X). (A) Control group, (B) AP group, (C) Low-dose curcumin and (D) High-dose curcumin. Arrows indicate NF-kβ positive cells. b. The percentage of NF-kβ positive cells in each groups. Data are presented as mean ± SD (*P < 0.05 versus control group; ^#P < 0.05 versus AP group).

Fig. 7

Western blot analysis of 4-HNE expression in pancreas. (A) Western blot analysis of 4-HNE expression in pancreas. (B) Densitometric analysis of the 4-HNE relative to GAPDH. All data are presented as mean ± SD (*P < 0.05 versus control groups; ^#P < 0.05, ^##P < 0.01 versus AP groups).