The role of curcumin in streptozotocin induced hepatic damage and the trans differentiation of hepat

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ISSN 0040-8166

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Tissue and Cell 48 (2016) 81–88

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The role of curcumin in streptozotocin-induced hepatic damage and the trans-differentiation of hepatic stellate cells Hesham N. Mustafa ∗ Anatomy Department, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia

a r t i c l e

i n f o

Article history: Received 5 December 2015 Received in revised form 19 January 2016 Accepted 7 February 2016 Available online 9 February 2016 Keywords: Curcumin Hepatic stellate cells Streptozotocin Lipid peroxidation Trans-differentiation

a b s t r a c t Diabetic patients frequently suffer from non-alcoholic steatohepatitis. The current study aimed to investigate the role of curcumin and the response of hepatic stellate cells in streptozotocin (STZ)-induced hepatic damage. Sixty male rats were divided into three groups. The normal control injected with a citrate buffer vehicle and the diabetic control group which was injected intraperitoneally (IP) with a single-dose of streptozotocin (50 mg/kg body weight) and a diabetic group was treated with an oral dose of curcumin at 80 mg/kg body weight daily for 60 days. Curcumin effectively counteracts oxidative stress-mediated hepatic damage and improves biochemical parameters. Alpha-smooth muscle actin (␣SMA) was significantly reduced, and insulin antibodies showed strong positive immunoreactivity with curcumin administration. These results optimistically demonstrate the potential use of curcumin, which is attributed to its antiradical/antioxidant activities and its potential ␤-cell regenerative properties. Also, it has the capability to encourage the trans-differentiation of hepatic stellate cells into insulin-producing cells for a period of time. In addition, as it is an anti-fibrotic mediator that inhibits hepatic stellate cell activation and the transition to myofibroblast-like cells, this suggests the possibility of considering curcumin’s novel therapeutic effects in reducing hepatic dysfunction in diabetic patients. © 2016 Elsevier Ltd. All rights reserved.

1. Introduction Diabetic patients frequently suffer from a hepatic impairment recognized as non-alcoholic steatohepatitis which is associated with severe complications such as deposition of glycogen, steatosis, cirrhosis, fibrosis and occasionally hepatic cancer (Bugianesi et al., 2007).

Streptozotocin (STZ) is an N-nitroso-N-methylurea derivative of 2-deoxy-d-glucose which is a diabetogenic agent that damages the islet ␤-cells in the pancreas selectively to produce insulindependent diabetes mellitus (IDDM) (Yang et al., 2010).

Alpha-smooth muscle actin (␣-SMA) is an indicator for the recognition of myofibroblast-like cells plus hepatic stellate cells (HSCs) which are also known as Ito cells (Clement et al., 2010).

In diabetes, the glucose accessibility is increased and this leads to an accelerated formation of advanced glycation end products (AGEs). AGEs interact with the receptor for AGEs (RAGEs) and consequently increase oxidative stress and cellular growth. This

∗ Corresponding author at: King Abdulaziz University, Faculty of Medicine, Anatomy Department, Ground Floor Building No. 8, P.O. Box: 80205, Jeddah 21589, Saudi Arabia. Tel.: +966 566 764 762.

E-mail address: hesham977@hotmail.com http://dx.doi.org/10.1016/j.tice.2016.02.003 0040-8166/© 2016 Elsevier Ltd. All rights reserved.

leads to an increased proliferation of HSCs, which is noticed during hepatic fibrogenesis that is accompanied by the up-regulation of RAGEs. Oxidative stress plays a crucial role in the chronic complications of the diabetic liver, where it is associated with an overproduction of oxygen free radicals and lipid peroxidation (Saravanan and Ponmurugan, 2011).

The use of herbal medicine in defending against STZ-induced liver damage looks promising. Curcumin has been gaining attention because of its health benefits, such as its anti-inflammatory, antioxidant, and immune modulatory effects. Curcumin is the chief curcuminoid of Curcuma Longa, which is a member of the Zingiberaceae family (Kumar et al., 2015).

The polyphenol curcumin improves diabetes-induced dysfunction by decreasing the level of glucose, inhibiting protein-kinase C, and lowering superoxide production (Rungseesantivanon et al., 2010). It reverses insulin resistance, hyperglycemia, and hyperlipidemia by inhibiting the pro-inflammatory transcription factors, signal transducers and stimulating anti-inflammatory signaling pathways (Tang and Chen, 2010).

This study aimed to investigate the probable influence of hepatic stellate cells in the protective capability of curcumin in STZ-induced liver damage. It was also intended to provide an important support in understanding the mechanism of curcumin treatment for hepatic dysfunction.

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2. Materials and methods

2.8. Serum parameters

2.1. Ethical approval

ALT, AST, and ALP, which were increased following hepatocyte injury, were assessed according to the protocol detailed in the manuals of the diagnostic kits (Randox Laboratories Ltd., Crumlin, County Antrim, UK). Serum albumin, total protein, and total bilirubin were determined by spectrophotometer using the corresponding colorimetric kits supplied by Bio Diagnostic Company (Cairo, Egypt) (Lee et al., 2012).

This study was conducted after receiving the approval of the Medical Research Ethics Committee, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.

2.2. Chemicals and Reagents Streptozotocin (STZ) and curcumin were purchased from Sigma–Aldrich Chemicals (St. Louis, MO, USA). Alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) kits were purchased from Randox Laboratories Ltd. (Crumlin, County Antrim, UK). Serum albumin, total protein, and total bilirubin colorimetric kits were supplied by the Bio Diagnostic Company (Cairo, Egypt).

2.3. Animals Sixty male adult albino Wistar rats, weighing 190 ± 20 g, that were used were obtained from the animal house. Animals were housed in a (24 ◦ C ± 3 ◦ C) temperature-controlled room with 40–70% humidity and 12/12 h light/dark cycle. Rats were fed a standard diet and tap water ad libitum throughout the experiment.

The experimental procedures were performed in accordance with the international guidelines for the care and the use of animals in a laboratory.

2.4. Induction of diabetes Fasted rats (12 h) received a single intraperitoneal (IP) injection of freshly prepared STZ (50 mg/kg body weight) dissolved in 0.1 M citrate buffer (pH 4.5). STZ-injected animals were given a 5% glucose solution for 24 h to overcome drug-induced hypoglycemia. On the third day after STZ injection, glucose levels were estimated by obtaining blood samples from the cut tip of the tail using Diagnostic Accu-Chek test strips (Roche Diagnostics, Mannheim, Germany).

Blood glucose levels of 250 mg/dl or more were considered diabetic.

2.5. Experimental design The animals were distributed into 3 groups (20/group). Group 1 (normal control) was injected IP with a citrate buffer vehicle.

Group 2 (diabetic control) received a single IP injection of STZ (50 mg/kg body weight). Group 3 received a single IP injection of STZ (50 mg/kg body weight) and, on the third day after the STZ injection, curcumin was given orally with a dosage of 80 mg/kg body weight and continued daily for 60 days (Zhang et al., 2013). At the end of the experiment, blood samples were collected from the retro-orbital sinus in heparinized capillary tubes for serum analysis. Animals from all groups were sacrificed, and the livers were processed for histological studies.

2.6. Plasma glucose estimation Plasma glucose was measured using an enzymatic colorimetric method with commercially available kits (Randox Laboratories, Ltd., Antrim, UK).

2.7. Plasma insulin estimation Plasma insulin was determined using an insulin enzyme-linked immunosorbent assay (ELISA) kit (code no. AKRIN-010T; Shibayagi Co., Ltd., Gunma, Japan).

2.9. Histological examination Livers were washed with a phosphate buffer solution and then fixed in 10% neutral buffered formalin. Tissues were dehydrated through a graded series of alcohol, cleared in xylene, and embedded in paraffin wax. Tissues were then cut into sections of 3–5 ␮m in thickness using a microtome and stained with hematoxylin and eosin (H&E) for histopathological evaluation and with periodic Acid-Schiff (PAS) for observation of glycogen. For each specimen, at least three to five slides were examined using an Olympus BX53 microscope equipped with a DP73 camera (Olympus, Tokyo, Japan).

2.10. Histopathological evaluation The sections were analyzed for hydropic swelling, parenchymatous degeneration, microvesicular vacuole, macrovesicular vacuole, focal necrosis, inflammatory infiltrations, fibrosis, and sinusoids hyperemia. At the end of the analyses, the findings were presented in a table which showed the degree of degeneration (Guven et al., 2006). Score levels of 0, +1, +2, +3 were equivalent to no, mild, moderate, and severe, respectively. The scores represented values obtained from the tissue sections of six animals from each group with five fields/section (Mustafa et al., 2015).

2.11. Immunohistochemical examination The standard peroxidase immunohistochemistry technique was applied to slides of paraffin-embedded tissue. Sections were de-waxed in xylene, rehydrated, and pretreated with 3% of hydrogen peroxide solution to block endogenous peroxidase activity.

Microwave-assisted antigen retrieval was performed for 20 min.

Slides were then incubated overnight at 4 ◦ C with the primary antibody against ␣-SMA (a mouse monoclonal antibody [Dako, Carpinteria, California, USA] with a dilution of 1:50; cellular site was cytoplasmic) as a marker of activated HSCs with varying degrees of intensity in smooth muscles and myofibroblasts. They were similarly incubated with the primary antibody against insulin (a mouse monoclonal antibody [Dako, Carpinteria, California, USA] with a dilution of 1:100; cellular site was cytoplasmic). The sections were incubated with biotinylated IgG and then with streptavidinperoxidase conjugate (Zymed Corp, San Francisco, CA, USA).

Sections were then washed with phosphate-buffered saline (PBS) and incubated with 3, 3 -diaminobenzidine tetrachloride (DAB) substrate chromogen solution (1 drop of DAB chromogen/1 mL of substrate buffer) for 5 min to detect immunoreactivity. All sections were counter-stained with Mayer’s hematoxylin. Negative control sections were prepared by omitting the primary antibody. Positive control standard laboratory slides were used for all stains to prove the success of the technique. All slides were examined under light microscopy, and the presence of labeled cells was documented.

Absence of staining was recognized as a negative result (−), while the presence of brown staining was recognized as positive result (+) (Mustafa et al., 2015).

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Table 1 Body and liver weight of different groups.

Normal control (n = 20) Liver weight (g)

11.14 ± 1.54

Body weight (g)

187.65 ± 6.11

STZ-diabetic control (n = 20)

STZ-diabetes + curcumin (n = 20)

9.91 ± 1.04 P* < 0.01

10.83 ± 0.85 *P > 0.05 **P < 0.05 180.47 ± 3.89 *P < 0.001 **P < 0.001

163.94 ± 4.9 *P < 0.001

Values are means ± SD (n = 20 each group). ANOVA followed by Tukey’s post hoc test. *P: compared to normal control. **P: compared to diabetic control.

Fig. 1. Body and liver weight of different groups. The mean is given in columns, and error bars represent the standard deviation (SD).

2.12. Quantitative morphometric measurements Ten non-overlapping fields for each animal were selected indiscriminately and analyzed. The measurements were done by using Image-Pro Plus v6.0 software (Media Cybernetics, Silver Spring, MD, USA) and the NIH ImageJ (v1.50) program (http://rsb.info. nih.gov/ij/) with an Olympus BX53 microscope (Olympus, Tokyo, Japan). The area percentages of ␣-SMA immunopositive cells and the insulin-positive cells number were evaluated (Hussein et al., 2015).

2.13. Statistical analysis Quantitative data were expressed as the mean ± SD of different parameters for the treated groups. The data were analyzed using one-way analysis of variance (ANOVA) followed by Tukey’s post hoc test. The statistical analysis was performed using IBM SPSS version 23. The values were considered significant when p < 0.05.

albumin and total protein in the diabetic control group, while curcumin treatment showed a significant increase in these parameters compared to those of the diabetic control group. Conversely, the total bilirubin was increased in the diabetic control group and decreased significantly with curcumin treatment (Table 2 and Fig. 3).

3.3. Histopathological findings The normal control group showed normal cytoarchitecture. The diabetic control group showed parenchymatous degeneration and loss of architecture. With curcumin treatment, hepatic changes were reduced (Table 3).

PAS-stained sections of the normal control group showed PASpositive red granules in the cytoplasm of the hepatocytes and more granules around the central vein (Fig. 4A), while those of the diabetic control group showed few PAS-positive granules (Fig. 4B). With curcumin treatment, mild PAS-positive granules were observed (Fig. 4C and Table 3).

3. Results 3.4. Immunohistochemistry-stained sections 3.1. Effect on liver and body weight At the end of 60 days, curcumin treated specimens showed a significant increase in the body and liver weight as compared to the diabetic control (Table 1 and Fig. 1).

3.2. Biochemical parameters The mean glucose level of the diabetic control group was significantly increased while curcumin treatment showed a significant improvement in glucose level (Table 2 and Fig. 2). The mean insulin level of the diabetic control group was significantly decreased while curcumin treatment showed a significant improvement in insulin level (Table 2 and Fig. 2).

Plasma ALT, AST, and ALP levels were elevated in the diabetic control group in comparison to those of the normal control group, while with curcumin treatment all of these parameters are reduced significantly. Furthermore, there was a significant decrease in the

In the normal control group, ␣-SMA staining was observed only in the media of the blood vessels (portal veins, hepatic artery branches, and central veins) (Fig. 5A). While the diabetic control group showed positive ␣-SMA immunoreactivity in the media of the portal vessels and the periportal area and along the perisinusoidal spaces (Fig. 5B and C). In the curcumin treatment group, mild immunoreactivity was observed (Fig. 5D). The area percentage of ␣-SMA positive cells was significantly higher in the diabetic control group, while in the curcumin treatment group it was reduced significantly (Table 4 and Fig. 7).

Insulin-immunostained sections for both the normal control (Fig. 6A) and diabetic control (Fig. 6B) groups showed no or minimal insulin immune positive cells. The curcumin treatment group showed many insulin positive immune cells in the portal area around the bile ductule (Fig. 6C). The number of insulin positive cells was significantly higher in the curcumin treated group (Table 4 and Fig. 7).

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Fig. 2. Plasma glucose and insulin of different groups. The mean is given in columns, and error bars represent the standard deviation (SD).

Table 2 Biochemical parameters of the different groups.

Parameters

Normal control

STZ-diabetic control

STZ-diabetes + curcumin

Plasma glucose (mg/dl)

87.14 ± 4.28

280.12 ± 57.24 *P < 0.001

Plasma insulin (mIU/L)

5.17 ± 0.73

0.54 ± 0.11 *P < 0.001

ALT (U/l)

65.4 ± 1.2

119.6 ± 2.30 *P < 0.001

AST (U/l)

139.13 ± 3.82

321.35 ± 2.80 *P < 0.001

ALP (U/l)

68.10 ± 2.30

85.2 ± 4.60 *P < 0.001

Albumin (g/dl)

4.14 ± 0.60

1.3 ± 0.87 *P < 0.001

Total protein (g/dL)

5.94 ± 0.89

2.03 ± 0.78 *P < 0.001

Total bilirubin (mg/dL)

0.24 ± 0.20

0.78 ± 0.07 *P < 0.001

160.12 ± 63.27 *P < 0.001 **P < 0.001 4.06 ± 0.45 *P < 0.001 **P < 0.001 76.8 ± 4.60 *P < 0.001 **P < 0.001 204.68 ± 1.96 *P < 0.001 **P < 0.001 79.5 ± 8.10 *P < 0.001 **P < 0.01 3.81 ± 0.40 *P > 0.05 **P < 0.001 4.62 ± 0.13 *P < 0.001 **P < 0.001 0.36 ± 0.06 *P < 0.05 *P < 0.001

Values are means ± SD (n = 20 each group). ANOVA followed by Tukey’s post hoc test. *P: compared to normal control. **P: compared to diabetic control.

ALT, alanine aminotransferase; AST, aspartate aminotransferase; ALP, alkaline phosphatase; mg/dl, milligrams per deciliter; mIU/L, milli-international units per liter; U/l, units per liter; g/dl, grams per deciliter.

4. Discussion In the current study, the diabetic control group revealed a reduction in body weight, which is attributed to the muscle destruction or catabolism of structural protein and fat (Salahuddin and Jalalpure, 2010). Curcumin administration improves the body weight, and this indicates the effect of curcumin on the degradation of structural protein, control of muscle wasting, and increase of metabolic processes in the body.

The current data showed a significant decrease in the plasma insulin levels, which coincides with other findings (Abdel Aziz et al., 2013). Improved insulin level supports the hypothesis that curcumin causes ␤-cells neogenesis and protection (Meghana et al., 2007), and this was evidently proven by this study. Furthermore, it is proposed that controlling hyperglycemia encourages further regeneration of ␤-cells (Guz et al., 2001). This may be attributed to the suggestion that dying ␤-cells are regenerated continuously (Montanya et al., 2000).

Hepatocellular injury is credited to reactive oxygen species (ROS) and lipid peroxidation that causes direct damage to hepatocytes by disrupting the membranes, protein, and DNA (Asmah Rahmat, 2015). The injured hepatocytes release aldehyde end products, which causes further hepatocellular damage and emergence of fibrosis (Novo and Parola, 2012). Also, lipid peroxidation causes an inflammatory reaction that involves the occurrence of cytokines,

mainly tumor necrosis factor (TNF-␣), interleukin-1 (IL-1), and consensus interferon (IFN-c) (Sugano et al., 2006). Meanwhile, curcumin treatment alleviates the hepatocellular injuries.

In the present study, the diabetic control group revealed a congestion of the portal triad with inflammation and notable fibrosis near the central vein. This is attributed to tissue degradations that are caused by depletion of the endogenous antioxidant enzyme stores as superoxide dismutase (SOD) and catalase (CAT) (Chang and Chuang, 2010) and promotion of de novo generation of free radicals (Maritim et al., 2003). Consequently, the higher level of antioxidants that exists in curcumin could boost the quenching of some free radicals inside hepatocytes, which defend the hepatic tissue against oxidative stress damage (Afrin et al., 2015), and this is supported by the current findings.

In liver impairment, hepatic stellate cells (Ito cells) undergo trans-differentiation from lipid storing pericytes to myofibroblast-like cells that lead to an increased collagen and extracellular matrix that is the crucial event in hepatic fibrogenesis (She et al., 2005). Curcumin treatment in the current study caused a reduction of ␣-SMA positive cells, which is the marker of Ito cell activation and in turn, indicates inhibition of Ito cells and the improvement of hepatic fibrosis (Erenoglu et al., 2011).

Curcumin suppresses the AGEs mediated by the stimulation of RAGEs gene expression. This leads to inhibition of the RAGE activated pathways which, in turn, prevents oxidative

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Fig. 3. Biochemical parameters of different groups. The mean is given in columns, and error bars represent the standard deviation (SD).

Table 3 Histopathological findings of the liver.

Hydropic swelling Parenchymatous degeneration Microvesicular vacuole Macrovesicular vacuole Focal necrosis Inflammatory infiltrations Fibrosis Sinusoids hyperemia PAS

Normal control

STZ-diabetic control

STZdiabetes + curcumin

0 0 0 0 0 0 0 0 +3

+2 +2 +0.5 +0.5 +2 +1 +1 +2 +1

+1 +1 +1 +1 +0.5 +1 +0.5 +1 +2

N = 20; Scale: No (0), mild (+1), moderate (+2), severe (+3).

stress, inflammation, and hepatic stellate cell activation, a hallmark of non-alcoholic steatohepatitis and hepatic fibrogenesis associated with type 2 diabetes mellitus (Stefanska, 2012). Moreover, AGE-encouraged production of reactive oxygen species and lipid peroxides was attenuated after treatment with curcumin (Stefanska, 2012).

In the current findings, the trans-differentiation of Ito cells into myofibroblast-like cells is attributed to intercellular connections between Ito cells and activated Kupffer cells, damaged hepatocytes, and inflammatory cytokines (Hellerbrand, 2013). Other factors that cause this trans-differentiation include the platelet-derived growth factor (PDGF), epidermal growth factor (EGF), and transforming growth factor ␤1 (TGF-␤1) that are released after activation of Kupffer cells (Nosseir et al., 2012).

In hyperglycemic conditions, the diabetic control group in the current study showed minimal insulin immune reactions of hepatic stellate cells. This indicates that diabetes encourages the transition of hepatic stellate cells to insulin-producing cells but it cannot maintain their production. Furthermore, it was found that this trans-differentiation occurs early and lasts for two weeks in the diabetic liver (Kim et al., 2007). This transition is attributed to the fact that both the liver and the pancreas originate from the upper primitive foregut endoderm appendages (Lammert et al., 2003) and the late separation of the pancreas and liver during organogenesis might leave pluripotent cells, which are able to give rise to both pancreatic and hepatic lineage (Meivar-Levy and Ferber, 2003).

In supporting this hypothesis, a previous study has discussed the existence of extra-pancreatic insulin-producing cells in the liver in the hyperglycemic condition. However, the number and production of these insulin-producing cells are not enough to improve the hyperglycemic condition (Kojima et al., 2004). The current results support the hypothesis that the hypoglycemic effect of curcumin is attributed to preserving functional insulin-producing cells. In the curcumin group in the current study, insulin immune positive cells were increased which supports the suggestion that curcumin may maintain insulin production by trans-differentiated hepatic stellate cells for a period after STZ injection.

These results optimistically demonstrate the potential use of curcumin for the treatment of STZ-induced liver damage because of its antiradical/antioxidant activities, potential ␤-cell regenerative properties, and capability to encourage the transdifferentiation of hepatic stellate cells into insulin-producing cells for a period of time. In addition, as it is an anti-fibrotic mediator that inhibits hepatic stellate cell activation and the transition to

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Fig. 4. (A) Normal control group showed PAS-positive reaction (distribution of liver glycogen) (arrow); (B) diabetic control group showed few PAS-positive reaction (arrow); (C) curcumin treatment group showed mild PAS-positive reaction (arrow) (PAS, scale bar 20 ␮m).

Fig. 5. (A) Normal control group showed minimal immunostaining (arrow); (B) diabetic control group showed positive immunostaining (activated HSCs) in the media of the portal blood vessels and scattered in the periportal area (arrow); (C) the previous group with positive immunostained cells in the perisinusoidal spaces (arrow); (D) curcumin treatment group showed mild immunostaining (arrow) (␣-SMA, scale bar 20 ␮m).

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Table 4 Mean ± SD of the area percentage of ␣-smooth muscle actin positive cells and the number of insulin-positive cells.

Normal control

STZ-diabetic control

STZ-diabetes + curcumin

Area % of ␣-SMA

0.43 ± 0.28

10.20 ± 0.62 *P < 0.001

Number of insulin positive cells

0.00

0.28 ± 0.01 *P > 0.05

1.06 ± 0.87 *P < 0.01 **P < 0.001 5.10 ± 3.50 *P < 0.001 **P < 0.001

Values are means ± SD (n = 20 each group). ANOVA followed by Tukey’s post hoc test. *P: compared to normal control. **P: compared to diabetic control.

Fig. 6. (A) Normal control group showed a negative immune reaction; (B) diabetic control group showed a minimal immune reaction; (C) the curcumin treatment group showed strong positive immunoreactivity (insulin-producing cells) (arrows) (insulin immune reaction, scale bar 20 ␮m).

Fig. 7. Area % of ␣-SMA and number of insulin positive cells. The mean is given in columns, and error bars represent the standard deviation (SD).

myofibroblast-like cells, consequently the way is now open to consider curcumin’s novel therapeutic effects in reducing hepatic dysfunction in diabetic patients.

Conflicts of interest

5. Conclusion

References

The current data suggest that curcumin affects hepatic stellate cell activation, which represents a key event of non-alcoholic steatohepatitis and hepatic fibrogenesis associated with diabetes.

Abdel Aziz, M.T., El-Asmar, M.F., Rezq, A.M., Mahfouz, S.M., Wassef, M.A., Fouad, H.H., Ahmed, H.H., Taha, F.M., 2013. The effect of a novel curcumin derivative on pancreatic islet regeneration in experimental type-1 diabetes in rats (long term study). Diabetol. Metab. Syndr. 5, 75.

None.

88

H.N. Mustafa / Tissue and Cell 48 (2016) 81–88

Afrin, R., Arumugam, S., Soetikno, V., Thandavarayan, R.A., Pitchaimani, V., Karuppagounder, V., Sreedhar, R., Harima, M., Suzuki, H., Miyashita, S., Nomoto, M., Suzuki, K., Watanabe, K., 2015. Curcumin ameliorates streptozotocin-induced liver damage through modulation of endoplasmic reticulum stress-mediated apoptosis in diabetic rats. Free Radic. Res. 49, 279–289.

Asmah Rahmat, A.A., 2015. Effect of pomegranate on histopathology of liver and kidney on generated oxidative stress diabetic induced rats. J. Cytol. Histol. 6, 2.

Bugianesi, E., Vanni, E., Marchesini, G., 2007. NASH and the risk of cirrhosis and hepatocellular carcinoma in type 2 diabetes. Curr. Diab. Rep. 7, 175–180.

Chang, Y.C., Chuang, L.M., 2010. The role of oxidative stress in the pathogenesis of type 2 diabetes: from molecular mechanism to clinical implication. Am. J. Transl. Res. 2, 316–331.

Clement, S., Pascarella, S., Conzelmann, S., Gonelle-Gispert, C., Guilloux, K., Negro, F., 2010. The hepatitis C virus core protein indirectly induces alpha-smooth muscle actin expression in hepatic stellate cells via interleukin-8. J. Hepatol.

52, 635–643.

Erenoglu, C., Kanter, M., Aksu, B., Sagiroglu, T., Ayvaz, S., Aktas, C., Erboga, M., 2011.

Protective effect of curcumin on liver damage induced by biliary obstruction in rats. Balkan Med. J. 28, 352–357.

Guven, A., Yavuz, O., Cam, M., Ercan, F., Bukan, N., Comunoglu, C., Gokce, F., 2006.

Effects of melatonin on streptozotocin-induced diabetic liver injury in rats.

Acta Histochem. 108, 85–93.

Guz, Y., Nasir, I., Teitelman, G., 2001. Regeneration of pancreatic beta cells from intra-islet precursor cells in an experimental model of diabetes. Endocrinology 142, 4956–4968.

Hellerbrand, C., 2013. Hepatic stellate cells-the pericytes in the liver. Pflügers Arch.

465, 775–778.

Hussein, A.M., Mustafa, H.N., Badawoud, M.H., 2015. Ameliorative potentials of a combination of fenugreek and alpha-tocopherol on cadmium induced testicular toxicity: an ultrastructural study. Folia Morphol. (Warsz) 74, 325–334.

Kim, S., Shin, J.S., Kim, H.J., Fisher, R.C., Lee, M.J., Kim, C.W., 2007.

Streptozotocin-induced diabetes can be reversed by hepatic oval cell activation through hepatic transdifferentiation and pancreatic islet regeneration. Lab. Invest. 87, 702–712.

Kojima, H., Fujimiya, M., Matsumura, K., Nakahara, T., Hara, M., Chan, L., 2004.

Extrapancreatic insulin-producing cells in multiple organs in diabetes. Proc.

Natl. Acad. Sci. USA 101, 2458–2463.

Kumar, A., Chetia, H., Sharma, S., Kabiraj, D., Talukdar, N.C., Bora, U., 2015.

Curcumin Resource Database. Database (Oxford) 2015, bav070.

Lammert, E., Cleaver, O., Melton, D., 2003. Role of endothelial cells in early pancreas and liver development. Mech. Dev. 120, 59–64.

Lee, T.H., Kim, W.R., Poterucha, J.J., 2012. Evaluation of elevated liver enzymes. Clin.

Liver Dis. 16, 183–198.

Maritim, A.C., Sanders, R.A., Watkins 3rd, J.B., 2003. Diabetes, oxidative stress, and antioxidants: a review. J. Biochem. Mol. Toxicol. 17, 24–38.

Meghana, K., Sanjeev, G., Ramesh, B., 2007. Curcumin prevents streptozotocin-induced islet damage by scavenging free radicals: a prophylactic and protective role. Eur. J. Pharmacol. 577, 183–191.

Meivar-Levy, I., Ferber, S., 2003. New organs from our own tissues: liver-to-pancreas transdifferentiation. Trends Endocrinol. Metab. 14, 460–466.

Montanya, E., Nacher, V., Biarnés, M., Soler, J., 2000. Linear correlation between beta-cell mass and body weight throughout the lifespan in Lewis rats: role of beta-cell hyperplasia and hypertrophy. Diabetes 49, 1341–1346.

Mustafa, H., El Awdan, S., Hegazy, G., Abdel Jaleel, G., 2015. Prophylactic role of coenzyme Q10 and Cynara scolymus L on doxorubicin-induced toxicity in rats: Biochemical and immunohistochemical study. Indian J. Pharmacol.

47, 649.

Nosseir, D.A., Gawish, S.A., Moustafa, A.M., Firgany, A.E.-D.L., 2012. The possible protective effect of green tea versus interferon-␣ on carbon tetrachloride-induced hepatic fibrosis in albino rat. Egypt. J. Histol. 35, 398–411.

Novo, E., Parola, M., 2012. The role of redox mechanisms in hepatic chronic wound healing and fibrogenesis. Fibrogenesis Tissue Repair 5, S4.

Rungseesantivanon, S., Thenchaisri, N., Ruangvejvorachai, P., Patumraj, S., 2010.

Curcumin supplementation could improve diabetes-induced endothelial dysfunction associated with decreased vascular superoxide production and PKC inhibition. BMC Complement. Altern. Med. 10, 57.

Salahuddin, M., Jalalpure, S.S., 2010. Antidiabetic activity of aqueous fruit extract of Cucumis trigonus Roxb. in streptozotocin-induced-diabetic rats. J. Ethnopharmacol. 127, 565–567.

Saravanan, G., Ponmurugan, P., 2011. Ameliorative potential of S-allyl cysteine on oxidative stress in STZ induced diabetic rats. Chem. Biol. Interact. 189, 100–106.

She, H., Xiong, S., Hazra, S., Tsukamoto, H., 2005. Adipogenic transcriptional regulation of hepatic stellate cells. J. Biol. Chem. 280, 4959–4967.

Stefanska, B., 2012. Curcumin ameliorates hepatic fibrosis in type 2 diabetes mellitus - insights into its mechanisms of action. Br. J. Pharmacol. 166, 2209–2211.

Sugano, M., Yamato, H., Hayashi, T., Ochiai, H., Kakuchi, J., Goto, S., Nishijima, F., Iino, N., Kazama, J.J., Takeuchi, T., Mokuda, O., Ishikawa, T., Okazaki, R., 2006.

High-fat diet in low-dose-streptozotocin-treated heminephrectomized rats induces all features of human type 2 diabetic nephropathy: a new rat model of diabetic nephropathy. Nutr. Metab. Cardiovasc. Dis. 16, 477–484.

Tang, Y., Chen, A., 2010. Curcumin prevents leptin raising glucose levels in hepatic stellate cells by blocking translocation of glucose transporter-4 and increasing glucokinase. Br. J. Pharmacol. 161, 1137–1149.

Yang, Z., Li, K., Yan, X., Dong, F., Zhao, C., 2010. Amelioration of diabetic retinopathy by engrafted human adipose-derived mesenchymal stem cells in streptozotocin diabetic rats. Graefes Arch. Clin. Exp. Ophthalmol. 248, 1415–1422.

Zhang, D.W., Fu, M., Gao, S.H., Liu, J.L., 2013. Curcumin and diabetes: a systematic review. Evid. Based Complement. Alternat. Med. 2013, 636053.