Antioxidant, anti-inflammatory and protective potential of gallic acid against paraquat-induced liver toxicity in male rats

The protective effects of gallic acid and SGK1 inhibitor on cardiac damage and genes involved in Ca2+ homeostasis in an isolated heart model of ischemia/reperfusion injury in rat

Serum and glucocorticoid-induced kinase 1 (SGK1) is an enzyme that may play a vital role in myocardial ischemia/reperfusion (I/R) injury. This enzyme may affect sarcoplasmic reticulum Ca2+ ATPase (SERCA2), ryanodine receptor (RyR2) and sodium/calcium exchanger (NCX1) during myocardial ischemia/reperfusion injury. The objective of this investigation was to analyze the effects of the combination of GSK650394 (SGK1 inhibitor) and gallic acid on the calcium ions regulation, inflammation, and cardiac dysfunction resulting from ischemia/reperfusion (I/R) injury in the heart. Sixty male Wistar rats were randomly divided into six groups, pretreated with gallic acid or vehicle for 10 days. Then the heart was isolated and exposed to I/R. In the SGK1 inhibitor groups, GSK650394 was infused 5 min before ischemia induction. After that, Ca2+ homeostasis, inflammatory factors, cardiac function, antioxidant activity, and myocardial damage were evaluated. The findings suggested that the use of two drugs in combination therapy produced more significant improvements in left ventricular end diastolic pressure, left ventricular systolic pressure, RR-interval, ST-elevation, inflammation factors, and antioxidant enzymes activity as compared to the use of each drug. Despite this, there was a significant decrease observed in heart marker enzymes (including lactate dehydrogenase (LDH), troponin-I (cTn-I), creatine kinase-MB (CK-MB) and creatine phosphokinase (CPK) when compared to the ischemic group. Additionally, the expression of RyR2, NCX1, and SERCA2 genes showed a noteworthy increase as compared to the ischemic group. The findings of this study propose that using both of these agents on myocardial I/R injury could have superior advantages compared to using only one of them.

Gallic acid rescues uranyl acetate induced-hepatic dysfunction in rats by its antioxidant and cytoprotective potentials

BACKGROUND

The liver was identified as a primary target organ for the chemo-radiological effects of uranyl acetate (UA). Although the anti-oxidant and anti-apoptotic properties of gallic acid (GA) make it a promising phytochemical to resist its hazards, there is no available data in this area of research.

METHODS

To address this issue, eighteen rats were randomly and equally divided into three groups. One group was received carboxymethyl cellulose (vehicle of GA) and kept as a control. The UA group was injected intraperitoneally with UA at a single dose of 5 mg/kg body weight. The third group (GA + UA group) was treated with GA orally at a dose of 100 mg/kg body weight for 14 days before UA exposure. UA was injected on the 15th day of the experiment in either the UA group or the GA + UA group. The biochemical, histological, and immunohistochemical findings in the GA + UA group were compared to both control and UA groups.

RESULTS

The results showed that UA exposure led to a range of adverse effects. These included elevated plasma levels of aspartate aminotransferase, lactate dehydrogenase, total protein, globulin, glucose, total cholesterol, triglycerides, low-density lipoprotein cholesterol, and very-low-density lipoprotein and decreased plasma levels of high-density lipoprotein cholesterol. The exposure also disrupted the redox balance, evident through decreased plasma total antioxidant capacity and hepatic nitric oxide, superoxide dismutase, reduced glutathione, glutathione-S-transferase, glutathione reductase, and glutathione peroxidase and increased hepatic oxidized glutathione and malondialdehyde. Plasma levels of albumin and alanine aminotransferase did not significantly change in all groups. Histopathological analysis revealed damage to liver tissue, characterized by deteriorations in tissue structure, excessive collagen accumulation, and depletion of glycogen. Furthermore, UA exposure up-regulated the immuno-expression of cleaved caspase-3 and down-regulated the immuno-expression of nuclear factor-erythroid-2-related factor 2 in hepatic tissues, indicating an induction of apoptosis and oxidative stress response. However, the pre-treatment with GA proved to be effective in mitigating these negative effects induced by UA exposure, except for the disturbances in the lipid profile.

CONCLUSIONS

The study suggests that GA has the potential to act as a protective agent against the adverse effects of UA exposure on the liver. Its ability to restore redox balance and inhibit apoptosis makes it a promising candidate for countering the harmful effects of chemo-radiological agents such as UA.

Effect of Gallic Acid Pretreatment and SGK1 Enzyme Inhibition on Cardiac Function and Inflammation in a Rat Model of Ischemia-Reperfusion Injury

Background

Serum and glucocorticoid-induced kinase 1 (SGK1) is an enzyme that may play an important role in ischemic-reperfusion (I/R) injury and myocardial dysfunction. Although many studies have been conducted on individual antioxidants, little attention has been paid to the effects of co-administration of an antioxidant with an SGK1 inhibitor on cardiac function after I/R.

Methods

This study aimed to determine the effects of gallic acid (as an antioxidant) combined with an SGK1 inhibitor on I/R-induced cardiac dysfunction and inflammation. Sixty male Wistar rats were randomized into 6 groups, pretreated with gallic acid or vehicle for 10 days. Subsequently, the heart was isolated and exposed to I/R. In groups that received the SGK1 inhibitor, the heart was perfused with the SGK1 inhibitor GSK650394, 5 min before induction of ischemia. After that, cardiac function, inflammatory factors, and myocardial damage were evaluated.

Results

The combination of these two compounds improved cardiac contractility, heart rate, rate pressure product, left ventricular developed pressure, left ventricular systolic pressure, perfusion pressure, and QRS voltage significantly (P < 0.05). In addition, concomitant therapy of these two agents reduced tumor necrosis factor-alpha and interleukin-6, and the activity of creatine kinase-MB, lactate dehydrogenase, and troponin-I (P < 0.05).

Conclusion

The results indicated that administration of gallic acid with the SGK1 inhibitor may have a potentiating effect on the improvement of cardiac dysfunction and I/R-induced inflammation.

Protective effects of gallic acid and SGK1 inhibitor on oxidative stress and cardiac damage in an isolated heart model of ischemia/reperfusion injury in rats

Objectives

Oxidative stress and serum and glucocorticoid-induced Kinase 1 gene (SGK1) perform a central role in the consequences of ischemia in the heart. This research aimed to investigate the effect of coadministration of gallic acid and the GSK650394 (as SGK1 gene inhibitor) on the ischemic complications of a rat model of cardiac ischemia/reperfusion (I/R) injury.

Materials and Methods

Sixty male Wistar rats were divided into 6 groups with or without pretreatment with gallic acid for 10 days. After that, the heart was isolated and perfused with Krebs-Henseleit solution. A 30 min of ischemia was performed followed by a 60 min reperfusion. In 2 groups, GSK650394 was infused 5 min before ischemia induction. Ten minutes after reperfusion commencement, cardiac marker enzyme (CK-MB, LDH, and cTn-I) activities were measured in the cardiac perfusate. At the end of reperfusion, the activity of anti-oxidant enzymes (Catalase, Superoxide dismutase, and Glutathione peroxidase), lipid peroxidation (MDA), total anti-oxidant capacity (TAC), intracellular reactive oxygen species (ROS), infarct size, and SGK1 gene expression were measured in the heart tissue.

Results

The results indicated that dual therapy with both drugs significantly improved endogenous anti-oxidant enzyme activity and TAC more than each drug alone. However, the heart marker enzymes (CK-MB, LDH, and cTn-I), MDA, ROS, infarct size, and SGK1 gene expression were reduced significantly compared with the ischemic group.

Conclusion

The results of this study suggest that concomitant administration of both drugs in the case of cardiac I/R injury may have a more beneficial effect than each one alone.

The role of GRP78/ATF6/IRE1 and caspase-3/Bax/Bcl2 signaling pathways in the protective effects of gallic acid against cadmium-induced liver damage in rats

Objectives

Cadmium (CD) causes widespread and severe toxic effects on various tissues. Studies have shown that apoptosis, inflammation, and endoplasmic reticulum stress play a role in organ damage caused by CD. Phenolic compounds with strong antioxidant effects are found in various fruits and vegetables. One of these compounds is Gallic acid (GA), which is found both free and hydrolyzable in grapes, pomegranate, tea, hops, and oak bark. Result of various studies show that GA has active antioxidant, anti-inflammatory, and anti-apoptotic properties. In our study, we investigated the mechanism of the protective effect of GA on CD-induced hepatotoxicity in rats.

Materials and Methods

In this study, 50 adult male Sprague Dawley rats weighing approximately 200-250 g were used and the rats were divided into 5 groups: Control, CD, GA50+CD, GA100+CD, and GA100. The rats were treated with GA (50 and 100 mg/kg body weight), and Cd (6.5 mg/kg) was administrated to the rats for 5 consecutive days. The liver enzymes, TB levels in serum samples, oxidative stress, inflammation, ER stresses, apoptosis marker, histopathology, 8-OHDG, and caspase-3 positivity were analyzed.

Results

CD administration significantly increased liver enzyme levels (AST, ALT, ALP, and LDH), MDA, IL-1-β, IFN-γ, TNF-α, IL-10, IL-6, GRP78, CHOP, ATF6, p -IRE1, sXBP, Bax mRNA expression, Caspase 3, and 8-OHdG expression (P<0.05). These values were found to be significantly lower in the Control, GA100+CD, and GA100 groups compared to the CD group (P<0.05). CD administration significantly decreased the expression levels of TB, IL-4, SOD, GSH, CAT, GPX, and Bcl-2 mRNA (P<0.05). These values were found to be significantly higher in the Control, GA100+CD, and GA100 groups compared to the CD group (P<0.05).

Conclusion

The results of the present study indicated that GA prevented Cd-induced hepatic oxidative stress, inflammation, ER stress, apoptosis, and tissue damage in rats.