Ameliorative Effect of Thymoquinone and Thymoquinone Nanoparticles against Diazinon-Induced Hepatic Injury in Rats: A Possible Protection Mechanism

The health benefits of thymoquinone (TQ) have been a significant focus of numerous studies. However, more research is needed to ascertain whether its nano-form can effectively treat or prevent chronic diseases. In this study, we investigated how thymoquinone and its nanoparticles can mitigate liver damage induced by diazinon in male Wistar rats and explored the intracellular mechanisms involved. Forty-two Wistar male rats (n = 42) were randomly allotted into seven groups. Group 1 served as the control. Group 2 (vehicle) consisted of rats that received corn oil via a gastric tube daily. In Group 3 (TQ), rats were given a daily oral administration of TQ (40 mg/kg bw). Group 4 (thymoquinone nanoparticles, NTQ) included rats that received NTQ (0.5 mg/kg bw) orally for 21 days. Group 5 (DZN) involved rats that were administered diazinon (DZN, 15 mg/kg bw) orally. In Group 6 (TQ + DZN), rats first received TQ orally, followed by DZN. Group 7 (NTQ + DZN) consisted of rats receiving NTQ orally, then DZN. After 21 days of treatment, the rats were euthanized. After oral administration of DZN, liver enzymes were significantly elevated (p < 0.05). Additionally, there were noticeable increases in oxidative injury markers, such as nitric oxide, malondialdehyde, redox oxygen radicals, and overall increases in hydrogen peroxide and liver protein carbonyl concentrations. This was accompanied by the upregulation of apoptotic markers (Bax, caspase9, caspase 3, bax/Bcl2 ratio), inflammatory cytokines (TNF-α, IL-6), and DNA damage. There was also a noteworthy decrease (p < 0.05) in the activities of antioxidant enzymes and anti-apoptotic markers. However, the oral administration of thymoquinone or its nanoparticle form mitigated these diazinon complications; our histopathological findings corroborated our biochemical and molecular observations. In conclusion, the significant antioxidant properties of thymoquinone, or its nanoparticle form, in tandem with the downregulation of apoptotic markers and inflammatory cytokines, provided a protective effect against hepatic dysfunction caused by diazinon.

Syringic Acid Attenuates Cardiomyopathy in Streptozotocin-Induced Diabetic Rats

Objectives

Diabetic cardiomyopathy (DC) has become one of the serious complications in diabetic cases. In this study, we aimed to explore the syringic acid (SYR) protective effect against diabetes-induced cardiac injury in experimental rats.

Methods

Rats were divided in control and streptozotocin-induced diabetic rats which were subdivided into diabetic controls, and three test groups (SYR at 25, 50, and 100 mg/kg) and the nondiabetic group received 100 mg/kg of SYR. All treatments were given SYR for 6 weeks. SYR effects on cardiac diagnostic markers, heart lipid peroxidation, protein carbonylation, antioxidant system, and changes of the heart mitochondrial mass and biogenesis were measured.

Results

Diabetes induction prompted CK-MB, LDH levels in serum, cardiac catalase, and superoxide dismutase activity, as well as cardiac TBARs and carbonylated protein. SYR administration (100 m/kg) attenuated CK-MB and LDH levels. Also, 50 and 100 mg/kg of SYR reduced cardiac TBARs and carbonylated protein in diabetic rats. These treatments did not show any effects on GSH content, mtDNA, and mitochondrial biogenesis indices (PGC1- α, NRF1, NRF2, and TFAM) in heart tissue.

Conclusions

SYR treatment showed protective effects on diabetic cardiomyopathy in rats by reducing lipid peroxidation and protein carbonylation. The possible mechanisms could be related to antioxidant activity of this phenolic acid. SYR might play a role of a protective factor in cardiac challenges in diabetes.

Multi-organ Toxicity Attenuation by Cerium Oxide and Yttrium Oxide Nanoparticles: Comparing the Beneficial Effects on Tissues Oxidative Damage Induced by Sub-acute Exposure to Diazinon

BACKGROUND

Excessive use of diazinon, as an organophosphate pesticide (OP), contributes to cytotoxic and pathologic cellular damage and, in particular, oxidative stress. However, metal-oxide nanoparticles (NPs), such as cerium oxide (CeO2) and yttrium oxide (Y2O3), with the property of free radical scavenging demonstrated beneficial effects in the alleviation of oxidative stress biomarkers.

OBJECTIVE

The aims of this study include evaluating beneficial effects of CeO2 NPs, Y2O3 NPs, and their combination against diazinon-induced oxidative stress in different tissues of brain, heart, lung, kidney, liver, and spleen.

METHODS

Eight randomized groups of 6 adult male Wistar rats were formed. Each group of rats administered a different combination of diazinon, CeO2 and Y2O3 NPs daily and levels of oxidative stress markers, such as reactive oxygen species (ROS), lipid peroxidation (LPO), total thiol molecules (TTM) and total anti-oxidant power (TAP) and catalase enzyme, were measured after 2 weeks of the treatment.

RESULTS

Measurements of the mentioned markers in the brain, heart, lung, kidney, liver, and spleen showed that the administration of NPs could significantly alleviate the oxidative stress induced by diazinon. However, the findings of this study illustrated that the combination of both CeO2 and Y2O3 NPs led to a better reduction in oxidative stress markers.

CONCLUSION

Sub-acute exposure of diazinon in rats led to increased levels of oxidative stress markers in pivotal tissues such as the brain, heart, lung, kidney, liver, and spleen. CeO2 and Y2O3 NPs neutralize the oxidative stress to compensate diazinon-induced tissue damages. Lay Summary: Organophosphate pesticides (OPs), which are mainly used for pest control, are responsible for the entry of pesticides into the human food cycle. Organophosphate such as diazinon increases the molecular biomarkers of oxidative stress inside the cells of vital tissues such as the heart, liver, lungs, etc. Metal oxide nanoparticles (NPs) such as cerium oxide (CeO2) and yitrium oxide (Y2O3) can have free radical scavenging potential under oxidative stress and through various mechanisms. Although these nanoparticles reduce oxidative stress, it should be borne in the design of the study that additional doses of these substances reverse the beneficial effects.

Neuroprotective Effect of Syringic Acid by Modulation of Oxidative Stress and Mitochondrial Mass in Diabetic Rats

Diabetes is a metabolic complaint associated with oxidative stress and dysfunction of mitochondria. One of the most common complications of diabetes mellitus is neuropathy. This study evaluated the possible neuroprotective effects of syringic acid (SYR), a natural polyphenolic derivative of benzoic acid, on oxidative damage and mitochondria in the brain, spinal cord, and sciatic nerve of streptozotocin-induced diabetic rats. Different groups of rats including normal control, diabetics (induced by streptozotocin), diabetic groups treated with 25, 50, and 100 mg/kg of SYR, and non-diabetic group treated with only 100 mg/kg of SYR were treated for 6 weeks. Learning and memory function, physical coordination, and acetylcholinesterase (AChE) and antioxidant indexes, as well as mRNA expression of mitochondrial biogenesis, were measured in the brain, spinal cord, and sciatic nerves. Diabetic rats treated with 100 mg/kg SYR exhibited significantly improved learning, memory, and movement deficiency (p < 0.05). SYR 100 mg/kg also significantly upregulated the brain mRNA expression of PGC-1α and NRF-1, the key regulators of energy metabolism, oxidative phosphorylation, and mitochondrial biogenesis. In addition, SYR 100 mg/kg and SYR 50 mg/kg increased the mtDNA/nDNA ratio in the brain and the spinal cord of diabetic rats, respectively (p < 0.05). SYR attenuated the lipid peroxidation in all the tissues, but not significant effects were observed on GSH, AChE, catalase, and superoxide dismutase activity. In all the tests, nonsignificant differences were observed between the control and SYR 100 mg/kg groups. Moreover, SYR reduced inflammation and demyelination in sciatic nerves. This is the first study to reveal the regulation of mitochondrial biogenesis and energy metabolism by SYR, beyond its antioxidant role in the diabetic rats' brain and spinal tissues.

The effect of ellagic acid on spinal cord and sciatica function in a mice model of multiple sclerosis

Multiple sclerosis (MS) is a well-known neurodegenerative disorder, causing toxicity in different organs, such as spinal cord tissue. The goal of this study was to investigate the protective effect of ellagic acid (EA) against spinal cord and sciatica function in cuprizone (Cup)-induced demyelination model. Animals were divided into six equal groups. The first group received tap water as the control. Cup group was treated with Cup (0.2% w/w in fed). EA 100 group was orally treated with EA (100 mg/kg). EA + Cup groups were orally treated with three doses of 5, 50, and 100 mg/kg of EA plus Cup (0.2% w/w). All groups received treatment for 42 days. Open field, rotarod, and gait tests were done to evaluate the behavioral changes following Cup and/or EA treatment. Also, lipid peroxidation, reactive oxygen species (ROS) content, antioxidant capacity, superoxide dismutase (SOD), and catalase enzymes activity in spinal cord was evaluated. Luxol fast blue (LFB) staining also the behavioral tests were performed to evaluate the model. Cup increased ROS levels and oxidative stress in their spinal cord tissues. Also, Cup reduced antioxidant capacity, SOD, and catalase activity. EA (especially at 100 mg/kg) prevented these abnormal changes. EA co-treatment dose-dependently was able to ameliorate behavioral impairments in mice that received Cup. EA might act as a protective agent in MS by modulating spinal cord function.

Paraoxon-induced damage in rat hippocampus is associated with alterations in the expression of apoptosis-related proteins

To determine the possible role of apoptosis in the development of paraoxon-induced brain damage, we evaluated expression of apoptosis-related proteins, the extent of neuronal damage, and activation of astrocytes in rat hippocampus. Adult male Wistar rats were intraperitoneally injected with one of three doses of paraoxon (0.3, 0.7, or 1 mg/kg) or corn oil (vehicle). After 14 or 28 days, expression of apoptosis-related proteins, including B-cell leukemia/lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), and caspase-3, as well as the number of neurons and glial fibrillary acidic protein (GFAP) positive cells in hippocampus were examined by western blot, cresyl blue staining, and immunohistochemistry, respectively. After 14 and 28 days, Bax and caspase-3 proteins were significantly increased in rats receiving 0.7 and 1 mg/kg of paraoxon. A significant decrease in Bcl-2 protein levels was also observed in 0.7 and 1 mg/kg groups after 14 days and in 1 mg/kg group after 28 days. Animals treated with 1 mg/kg of paraoxon showed a significant decrease in the number of neurons in the CA1 area. Also, those treated with 0.7 and 1 mg/kg of paraoxon showed an increase in the number of GFAP positive cells in both CA1 and CA3 areas as well as a significant decrease in survived neurons in the CA3 area. Our results indicated that neuronal damage induced by convulsive doses of paraoxon in rat hippocampus is mediated in part through apoptosis mechanism. Activation of astrocytes might lead to reduced extent of damage and damage and consequently increased neuronal survival.

Protective effect of captopril against diazinon induced nephrotoxicity and neurotoxicity via inhibition of ROS-NO pathway

Diazinon (Dz) is a widely used insecticide. It can induce nephrotoxicity and neurotoxicity via oxidative stress. Captopril, an angiotensin-converting enzyme inhibitor, is known for its antioxidant properties. In this study, we used captopril for ameliorating of Dz-induced kidney and brain toxicity in rats. Animals were divided into five groups as follows: negative control (olive oil), Dz (150 mg kg^-1), captopril (60 and 100 mg kg^-1) and positive control (N-acetylcysteine 200 mg kg^-1) were injected intraperitoneally 30 min before Dz. After 24 h, animals were anesthetized and the brain and kidney tissues were separated. Then oxidative stress factors were evaluated. Also, blood was collected for assessment of blood urea nitrogen (BUN), creatinine (Cr) and nitric oxide (NO) levels. Dz significantly increased oxidative stress markers such as reactive oxygen species (ROS), lipid peroxidation, and protein carbonyl as well as glutathione (GSH) oxidation in both tissues. Increased levels of the BUN, Cr and NO were observed after Dz injection. Interestingly, captopril administration significantly decreased ROS production in both tissues. Captopril significantly protected kidney and brain against lipid peroxidation and GSH oxidation. Administration of captopril could markedly inhibit protein carbonyl production in kidney and brain after Dz injection. Furthermore, captopril ameliorated the increased level of BUN, Cr and NO. These results suggested that captopril can prevent Dz-induced oxidative stress, nephrotoxicity and neurotoxicity because of its antioxidant activity.