N-acetylcysteine dose-dependently improves the analgesic effect of acetaminophen on the rat hot plate test

Elderly mice with history of acetaminophen intoxication display worsened cognitive impairment and persistent elevation of astrocyte and microglia burden

Acetaminophen (APAP) is a leading cause of acute liver failure. The effect of APAP metabolite's effects in the periphery are well characterized; however, associated consequences in the brain remain poorly understood. Animal studies on this subject are few and reveal that frequent APAP intake can trigger cerebral abnormalities that vary depending on the subject's age. Alarmingly, experimental efforts have yet to examine associated consequences in elderly hosts, who correspond to the highest risk of medication overload, impaired drug clearance, and cognitive deficits. Here, we interrogated the cerebral and peripheral pathology of elderly mice submitted to monthly episodes of APAP intoxication since a young adult age. We found that weeks after the final episode of recurrent APAP exposure, mice exhibited worsened non-spatial memory deficit whereas spatial memory performance was unaltered. Interestingly, one month after the period of APAP intoxication, these mice showed increased glial burden without associated drivers, namely, blood-brain barrier disruption, cholesterol accumulation, and elevation of inflammatory molecules in the brain and/or periphery. Our experimental study reveals how recurrent APAP exposure affects the cognitive performance and cellular events in elderly brains. These data suggest that APAP-containing pharmacological interventions may foreshadow the elevated risk of neuropsychiatric disorders that afflict elderly populations.

The impact of intraoperative N-acetylcysteine on opioid consumption following spine surgery: a randomized pilot trial

Aim: N-acetylcysteine (NAC) decreases inflammation and could augment perioperative analgesia. Materials & methods: This prospective pilot trial examined postoperative opioid consumption at 12 h following intraoperative NAC. In phase I, 20 adults scheduled for posterior spine surgery were randomized to NAC (0, 50, 100 and 150 mg/kg) to determine the optimal dose. In phase II, 30 patients were randomized to placebo or NAC (150 mg/kg). Opioid consumption, pain ratings and time to opioid rescue were recorded. Results: Postoperative opioid consumption was reduced in the NAC group 19.3% at 12 h and 20% at 18 and 36 h. Opioid consumption was reduced 22-24% in the NAC group at all times after adjusting for intraoperative opioid administration. NAC subjects reported lower pain scores relative to placebo. Conclusion: Subjects randomized to NAC consumed less postoperative opioids and reported less pain versus placebo. Larger randomized controlled trials are needed to further evaluate NAC for analgesia. Clinical Trial Registration: NCT04562597 (ClinicalTrials.gov).

Hepatic regenerative response to long-term consumption of cinnamon-rich diet in aged rats

Objective

The present study aimed to investigate the impact of cinnamon on liver regeneration in a rat model of partial hepatectomy (PH).

Materials and Methods

Thirty-two old male Sprague-Dawley rats (12 weeks old) were randomly divided into two equal groups (n=16). One group was fed with a standard diet (control) while the other group was fed with the same diet containing 1% cinnamon for 41 weeks. Then, all animals were subjected to the PH procedure and their livers were studied on postoperative days 2, 10 and 28. The liver contents of hepatic growth factor (HGF), insulin, malondialdehyde (MDA), nitric oxide metabolites (NOx), superoxide dismutase (SOD) and tumor necrosis factor-alpha (TNF-α) were evaluated. Also, the serum levels of liver function markers (alanine aminotransferase (ALT) and aspartate aminotransferase (AST), MDA, NOx and SOD activity were measured.

Results

The regenerated liver weight was significantly higher in cinnamon-treated animals than the controls on both day 10 and 28 post hepatectomy. The hepatic MDA levels in the cinnamon-treated animals were significantly lower than the control rats. Cinnamon led to a significant increase of SOD on day 2 after hepatectomy in serum and liver content. The basal level of HGF in the liver of cinnamon-consuming rats was significantly higher than in the control rats. Hepatic insulin level was significantly increased relative to baseline and control on day 2 in the cinnamon-consuming rats. Hepatic TNF-α levels dramatically decreased on postoperative days (POD) 2 relative to baseline in the control and cinnamon-treated rats.

Conclusion

Long-term cinnamon consumption enhanced liver regeneration outcomes in old rats.

Comparative Effect of the Active Substance of Thyme with N-Acetyl Cysteine on Hematological Parameters and Histopathological Changes of Bone Marrow and Liver in Rat Models of Acetaminophen Toxicity

Acetaminophen has always been at the center of attention as a non-steroidal anti-inflammatory drug, which is generally associated with the serious side effects on liver and the hematological parameters. This study aimed to compare the effect of N-acetyl cysteine (NAC) and thyme extract on rat models of acetaminophen-induced toxicity. The present experimental study was conducted on 48 Wistar rats randomized into six groups, including the control group (no treatment); the Ac group (470 mg/kg of acetaminophen); the Ac + 100Ex, Ac + 200Ex, and Ac + 400Ex groups (acetaminophen + thyme extract at doses of 100, 200, 400 mg/kg); and Ac + NA group (acetaminophen + NAC). After weighing, a blood sample was taken from heart at the end of the period. The measured parameters were hematological, liver biochemical, and oxidative stress profiles. A part of the liver tissue was also fixed for the pathological examinations. The bone marrow was aspirated to check for cellular changes as well. The lowest mean of the final weight and liver weight to body weight ratio was observed in the Ac group. Weight loss was compensated in Ac + NA and Ac + 200Ex groups (P = 0.035). White blood cell (WBC), red blood cell (RBC), Hemoglobin (Hgb), and Hematocrit (HCT) in Ac and Ac + 400Ex groups showed significant differences from those of the other test groups (P < 0.001). Aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP) enzymes in Ac + 200Ex and Ac + NA groups showed a significant decrease compared to those of the other treatment groups (P = 0.043). Total antioxidant capacity (TAC) and glutathione peroxidase (GPx) had the lowest levels in Ac and Ac + 400Ex groups, while malondialdehyde (MDA) had the highest content. In this regard, the liver histopathological indices (necrosis, hyperemia, and hemorrhage) in the Ac + 200Ex and Ac + NA groups reached their lowest grades in the treatment groups. The mean number of erythroid and myeloid cells in the Ac group reached the lowest (17.40 ± 3.48). The microscopic appearance of the bone marrow cells was different from normocytosis in the control group to hypocytosis in the Ac and Ac + 400Ex groups. Thymol, as an effective ingredient in thyme extract at a dose of 200 mg/kg compared to NAC, had a unique effect on reducing bone marrow and liver cell-tissue changes due to the acetaminophen toxicity.

Role of ROS/JAK2/STAT3 signaling pathway in di-n-butyl phthalate-induced testosterone synthesis inhibition and antagonism of lycopene

Di-n-butyl phthalate (DBP) causes adverse effects on male reproduction, especially testosterone synthesis inhibition. However, the specific mechanism of DBP-induced testosterone synthesis inhibition and its effective intervention measures of prevention and treatment are scarce presently. Lycopene (LYC) plays beneficial roles in male infertility because of its antioxidant activity. Nevertheless, it is unclear whether LYC could prevent DBP-induced male reproductive toxicity. By in vitro and in vivo investigations, this study demonstrated that DBP activated ROS/JAK2/STAT3 signaling pathway, promoted mitophagy and apoptosis, which in turn inhibited testosterone synthesis. Additionally, another major finding was that LYC supplement could reverse the above change, presenting as the restraint of ROS/JAK2/STAT3 signaling pathway, reduction of mitophagy and apoptosis, and improvement of testosterone synthesis. Our study facilitates deeper understandings of the mechanism in DBP-induced testosterone synthesis inhibition, and identifies LYC as the effective prevention and control strategies for DBP poisoning.

Platelet-Rich Plasma Gel-Loaded Collagen/Chitosan Composite Film Accelerated Rat Sciatic Nerve Injury Repair

Peripheral nerve injury (PNI) is a common clinical disease caused by severe limb trauma, congenital malformations, and tumor resection, which may lead to significant functional impairment and permanent disability. Nerve conduit as a method for treating peripheral nerve injury shows good application prospects. In this work, the COL/CS composite films with different mass ratios of 1:0, 1:1, and 1:3 were fabricated by combining physical doping. Physicochemical characterization results showed that the COL/CS composite films possessed good swelling properties, ideal mechanical properties, degradability and suitable hydrophilicity, which could meet the requirements of nerve tissue engineering. In vitro cell experiments showed that the loading of platelet-rich plasma (PRP) gel on the surface of COL/CS composite films could significantly improve the biocompatibility of films and promote the proliferation of Schwann cells. In addition, a rat model of sciatic nerve defect was constructed to evaluate the effect of COL/CS composite films on peripheral nerve repair and the results showed that COL/CS composite films loaded with PRP gel could promote nerve regeneration and functional recovery in rats with sciatic nerve injury, indicating that the combination of PRP gel with the COL/CS composite film would be a potential approach for the treatment of peripheral nerve injury.

Enlarging the Stokes Shift by Weakening the π-Conjugation of Cyanines for High Signal-to-Noise Ratiometric Imaging

The signal-to-noise ratio (SNR) is one of the key features of a fluorescent probe and one that often defines its potential utility for in vivo labeling and analyte detection applications. Here, it is reported that introducing a pyridine group into traditional cyanine-7 dyes in an asymmetric manner provides a series of tunable NIR fluorescent dyes (Cy-Mu-7) characterized by enhanced Stokes shifts (≈230 nm) compared to the parent cyanine 7 dye (<25 nm). The observed Stokes shift increase is ascribed to symmetry breaking of the Cy-Mu-7 core and a reduction in the extent of conjugation. The fluorescence signals of the Cy-Mu-7 dyes are enhanced upon confinement within the hydrophobic cavity of albumin or via spontaneous encapsulation within micelles in aqueous media. Utilizing the Cy-Mu-7, ultra-fast in vivo kidney labeling in mice is realized, and it is found that the liver injury will aggravate the burden of kidney by monitoring the fluorescence intensity ratio of kidney to liver. In addition, Cy-Mu-7 could be used as efficient chemiluminescence resonance energy transfer acceptor for the reaction between H₂ O₂ and bisoxalate. The potential utility of Cy-Mu-7 is illustrated via direct monitoring fluctuations in endogenous H₂ O₂ levels in a mouse model to mimic emergency room trauma.

Effects of N-Acetyl-L-Cystein Antioxidant on Ex Vivo Culture of Vitrified Premature Mouse Ovarian Tissue

Optimization of practical ways to obtain mature follicles from cryopreserved ovarian tissues, especially in patients suffering from ovarian dysfunction, is very important. In vitro ovarian tissue culture allows faster screening of follicle development and reduces follicle isolation damage. During ovarian tissue culture, controlling oxidative stress is critical to support better follicular development and less damage. Immature Naval Medical Research Institute (NMRI) mouse ovaries (8-days-old) were randomly distributed into four cultured groups; non-vitrified, vitrified, non-vitrified N-acetyl-L-cysteine (NAC)⁺, and vitrified NAC⁺. Ovaries of vitrified groups along with non-vitrified ovaries were cultured on agar gel in the presence or absence of NAC for 5 days. Afterward, morphological evaluations, mRNA expressions of Gdf9, Bmp6, Lif, Amh, Bax, and Bcl2 genes, malondialdehyde, and total antioxidant capacities were compared between four groups at the first and last day of culture. Good preservation of tissue integrity and an increase of follicular development were observed in all groups. In addition, the expression of Gdf9, Lif, Bax, and Bcl2 genes were increased and Amh was decreased in groups cultured in the presence of NAC compared to groups cultured without NAC. Although total antioxidant capacity was not significantly different between the experimental groups, the lipid peroxidation and apoptotic index were significantly reduced in the presence of NAC. Thus, it appears that NAC antioxidant acts as a contributory factor for the ex vivo culture of ovarian tissue and reduces oxidative stress, apoptotic index, and improves follicular development, especially in non-vitrified groups.

Hepatoprotective Effect of Oplopanax elatus Nakai Adventitious Roots Extract by Regulating CYP450 and PPAR Signaling Pathway

O. elatus Nakai is a traditional medicine that has been confirmed to exert effective antioxidant and anti-inflammatory functions, and is used for the treatment of different disorders. However, its potential beneficial effects on drug induced hepatotoxicity and relevant molecular mechanisms remain unclear. This study investigated the protective effect and further elucidated the mechanisms of action of O. elatus on liver protection. O. elatus chlorogenic acids-enriched fraction (OEB), which included chlorogenic acid and isochlorogenic acid A, were identified by HPLC-MS/MS. OEB was administrated orally daily for seven consecutive days, followed by a single intraperitoneal injection of an overdose of APAP after the final OEB administration. The effects of OEB on immune cells in mice liver were analyzed using flow cytometry. APAP metabolite content in serum was detected using HPLC-MS/MS in order to investigate whether OEB affects CYP450 activities. The intestinal content samples were processed for 16 s microbiota sequencing. Results demonstrated that OEB decreased alanine aminotransferase, aspartate aminotransferase contents, affected the metabolism of APAP, and decreased the concentrates of APAP, APAP-CYS and APAP-NAC by inhibiting CYP2E1 and CYP3A11 activity. Furthermore, OEB pretreatment regulated lipid metabolism by affecting the peroxisome proliferator-activated receptors (PPAR) signaling pathway in mice and also increased the abundance of Akkermansia and Parabacteroides. This study indicated that OEB is a potential drug candidate for treating hepatotoxicity because of its ability to affect drug metabolism and regulate lipid metabolism.

Effect of red beetroot juice on oxidative status and islet insulin release in adult male rats

INTRODUCTION

Beetroot is rich in inorganic nitrate and it has been shown that inorganic nitrate has beneficial effects on metabolic syndrome. This study aims to investigate the effect of red beetroot juice (RBJ) on carbohydrate metabolism in adult insulin-resistant rats.

MATERIALS AND METHODS

Sixteen male Wistar rats (32 weeks old) were divided into two equal groups: control and RBJ. Treatment with drinking water (control) and 100% RBJ (RBJ) was lasted for 5 weeks. At the end of the 4th week the intraperitoneal glucose tolerance test was performed and at the end of the study period animals were sacrificed and blood and tissue (aorta, heart, and liver) samples were collected. Furthermore, pancreatic islets were isolated and their insulin secretion activity was investigated in different glycemic conditions.

RESULTS

Compared to the control group, RBJ-treated rats showed lower blood glucose and insulin levels in the glucose tolerance test. Serum and tissue levels of nitric oxide in the RBJ group were significantly higher than those in the control group. The liver peroxidation and serum aspartate transaminase levels were significantly increased in the RBJ-treated animals compared to the control group. The islets of RBJ group exhibited lower insulin secretion, especially in 16.7 mM glucose concentration (supraphysiologic condition) than control group.

CONCLUSIONS

RBJ consumption improves glucose metabolism in rats via increasing nitric oxide metabolites in an insulin-independent manner. However, future studies are needed to minimize the potential hepatic adverse consequences.

Neuroprotective effects of Olea europaea L. fruit extract against cigarette smoke-induced depressive-like behaviors in Sprague-Dawley rats

Depression is broadly acclaimed as a mental health anomaly and despite advancements in the development of antidepressant drugs, they are linked with side effects. Dietary modifications and medicinal plants like olives can be used as effective strategies due to their antioxidant, immune-modulatory, antiinflammatory, and anticonvulsant properties. Considering the compositional alterations in olive fruits during ripening, the antidepressant potential of olive fruits at different degrees of ripeness, that is, un-ripened (green) and ripened (black) was investigated. Rats were randomly divided into five groups: G₀ (Normal diet), G₁ (Normal diet + smoke exposure (SE), G₂ (Normal diet + SE + Citalopram), G₃ (Normal diet + SE + Green olive extract), and G₄ (Normal diet + SE + Black olive extract). Depressive-like behaviors were induced in all groups through cigarette smoke exposure except G₀ . Green and black olive extracts prevented depressive behaviors by reducing the immobility time of rats in forced swim test and tail suspension test while increased the latency to respond in hot plate assay. Moreover, lipid peroxidation in brain tissue was reduced with citalopram, green, and black olive extracts. Additionally, treatments also enhanced the antioxidant pool of brain tissues. Histological examination revealed that olive extracts and citalopram prevented cigarette smoke-induced moderate to severe necrosis and congestion in the brain parenchyma and elucidated antidepressant potential by improving the expression of monoamine oxidase-A, solute carrier family 6 member 4, and brain-derived neurotrophic factor genes. Conclusively, olives may act as a promising antidepressant agent in ameliorating cigarette smoke-induced depressive-like behaviors. PRACTICAL APPLICATIONS: Olive extracts at both ripening stages revealed an antidepressant-like effect almost similar to the standard antidepressant drug and also prevented oxidative damages. Therefore, from the current findings, it can be recommended that food ingredients with antidepressant potential like olives should be incorporated in future interventions to combat depression/psychiatric anomalies and diet therapy should be encouraged to alleviate lifestyle-related disorders.

Use of a combination of N-acetylcysteine and clonazepam to treat burning mouth syndrome

OBJECTIVE

This study was intended to evaluate the clinical efficacy of a combination of N-acetylcysteine (NAC) and clonazepam for treatment of burning mouth syndrome (BMS).

STUDY DESIGN

A total of 160 patients with BMS were divided into 3 groups: group 1 received NAC (400 mg/d), group 2 received clonazepam (0.5 mg/d), and group 3 received both NAC and clonazepam. We evaluated symptom relief after 8 weeks of treatment using a visual analog scale (VAS). To assess oral health-related quality of life, we used the validated Korean version of an oral health impact profile (OHIP-14K).

RESULTS

The overall response rates of the 3 groups were 60.3%, 51.3%, and 80.0%, respectively. The mean VAS and OHIP-14K scores significantly decreased in all groups after the 8-week treatments. The VAS score changes were -12.2 ± 19.5, -10.0 ± 14.1, and -21.0 ± 24.6, respectively (P = .001), in the 3 groups and the OHIP-14K changes were -2.3 ± 9.2, -4.4 ± 6.9, and -8.7 ± 10.3, respectively (P = .020). Group 3 showed significantly larger differences in VAS and OHIP-14K scores than group 2, before and after treatment.

CONCLUSIONS

In the treatment of BMS, the NAC/clonazepam combination therapy was more effective than either monotherapy.

The Effect of Cinnamaldehyde on iNOS Activity and NO-Induced Islet Insulin Secretion in High-Fat-Diet Rats

Introduction

Obesity and insulin resistance are associated with alterations in nitric oxide level and insulin secretion. Previous studies demonstrated that cinnamaldehyde (CNMA) improved islet insulin secretion and restored nitric oxide (NO) level, but its underlying mechanisms have not been investigated. This study aimed to investigate the effect of CNMA on inducible nitric oxide synthase (iNOS) activity and NO-induced islet insulin secretion in high-fat-diet (HFD) treated rats.

Materials and Methods

Forty male Wistar rats (12 weeks old) were randomly divided into four equal groups, namely, control, CNMA, HFD, and HFD + CNMA. Control and CNMA groups were treated with standard laboratory animals' diet, while HFD and HDF + CNMA groups were fed with an HFD diet enriched with 25% W/W tail fat for 16 weeks. CNMA was administrated orally (20 mg/kg body weight, daily) during the study period. Islet insulin secretion and the inducible NOS activity in the presence or absence of L-NAME (NO synthase inhibitor, 5 mmol/L) were evaluated.

Results

L-NAME-suppressed insulin secretion in control, HFD, and HFD + CNMA groups; however, in the CNMA group, it could not exhibit such effect (P < 0.01). Islets of HFD-treated animals showed significantly higher iNOS activity than controls. CNMA treatment significantly suppressed iNOS activities in CNMA and HFD + CNMA groups compared with control and HFD, respectively.

Conclusion

These results suggest that the beneficial effect of CNMA on insulin secretion might be due to its inhibitory effect on iNOS activity.