Protective effects of thymoquinone and melatonin on intestinal ischemia-reperfusion injury

Comprehensive and updated review on anti-oxidant effects of Nigella sativa and its constituent, thymoquinone, in various disorders

Several pharmacological effects were described for Nigella sativa (N. sativa) seed and it has been used traditionally to treat various diseases. In this review article, the updated and comprehensive anti-oxidant effects of N. sativa and its main constituent, thymoquinone (TQ), on various disorders are described. The relevant articles were retrieved through PubMed, Science Direct, and Scopus up to December 31, 2023. Various extracts and essential oils of N. sativa showed anti-oxidant effects on cardiovascular, endocrine, gastrointestinal and liver, neurologic, respiratory, and urogenital diseases by decreasing and increasing various oxidant and anti-oxidant marketers, respectively. The main constituent of the plant, TQ, also showed similar anti-oxidant effects as the plant itself. The anti-oxidant effects of different extracts and essential oils of N. sativa were demonstrated in various studies which were perhaps due to the main constituent of the plant, TQ. The findings of this review article suggest the possible therapeutic effect of N. sativa and TQ in oxidative stress disorders.

Protective and therapeutic potential of melatonin against intestinal diseases: updated review of current data based on molecular mechanisms

INTRODUCTION

Intestinal diseases, a leading global cause of mortality and morbidity, carry a substantial socioeconomic burden. Small and large intestines play pivotal roles in gastrointestinal physiology and food digestion. Pathological conditions, such as gut dysbiosis, inflammation, cancer, therapy-related complications, ulcers, and ischemia, necessitate the urgent exploration of safe and effective complementary therapeutic strategies for optimal intestinal health.

AREAS COVERED

This article evaluates the potential therapeutic effects of melatonin, a molecule with a wide range of physiological actions, on intestinal diseases including inflammatory bowel disease, irritable bowel syndrome, colon cancer, gastric/duodenal ulcers and other intestinal disorders.

EXPERT OPINION

Due to anti-inflammatory and antioxidant properties as well as various biological actions, melatonin could be a therapeutic option for improving digestive disorders. However, more researches are needed to fully understand the potential benefits and risks of using melatonin for digestive disorders.

A proprietary black cumin oil extract (Nigella sativa) (BlaQmax®) modulates stress-sleep-immunity axis safely: Randomized double-blind placebo-controlled study

Objective

Stress, sleep, and immunity are important interdependent factors that play critical roles in the maintenance of health. It has been established that stress can affect sleep, and the quality and duration of sleep significantly impact immunity. However, single drugs capable of targeting these factors are limited because of their multi-targeting mechanisms. The present study investigated the influence of a proprietary thymoquinone-rich black cumin oil extract (BCO-5) in modulating stress, sleep, and immunity.

Methods

A randomized double-blinded placebo-controlled study was carried out on healthy volunteers with self-reported non-refreshing sleep issues (n = 72), followed by supplementation with BCO-5/placebo at 200  mg/day for 90  days. Validated questionnaires, PSQI and PSS, were employed for monitoring sleep and stress respectively, along with the measurement of cortisol and melatonin levels. Immunity markers were analyzed at the end of the study.

Results

In the BCO-5 group, 70% of the participants reported satisfaction with their sleep pattern on day 7 and 79% on day 14. Additionally, both inter- and intra- group analyses of the total PSQI scores and component scores (sleep latency, duration, efficiency, quality, and daytime dysfunction) on days 45 and 90 showed the effectiveness of BCO-5 in the improvement of sleep (p < 0.05). PSS-14 analysis revealed a significant reduction in stress, upon both intra (p < 0.001) and inter-group (p < 0.001) comparisons. The observed reduction in stress among the BCO-5 group, with respect to the placebo, was significant with an effect size of 1.19 by the end of the study (p < 0.001). A significant correlation was also observed between improved sleep and reduced stress as evident from PSQI and PSS. Furthermore, there was a significant modulation in melatonin, cortisol, and orexin levels. Hematological/immunological parameters further revealed the immunomodulatory effects of BCO-5.

Conclusion

BCO-5 significantly modulated the stress-sleep-immunity axis with no side effects and restored restful sleep.

Effects of melatonin on intestinal function and bacterial compositions in sucking piglets

Melatonin has been reported to affect intestinal function by targeting microbiome, morphological structure, barrier integrity and nutrient absorptive system. While the effect of melatonin on intestinal development in newborn infants is obscure, thus, this study firstly attempted to investigate the hypothesis that melatonin treatment improves intestinal development in sucking piglets. 14 healthy newborn piglets received 10 ml melatonin solution (1 mg/ml) or drinking water (n = 7) for 21 days. The results showed that oral administration of melatonin increased liver relative weight (p < 0.05) but failed to affect growth performance in sucking piglets (p > 0.05). Immunostaining jejunal samples from melatonin group showed high expressions of nnos and claudin1, indicating that melatonin improved intestinal neural development and barrier integrity. Also, melatonin promoted intestinal absorptive function evidenced by the increased serum proline concentration in melatonin-treated piglets compared with the control (p < 0.05). Gut microbiota compositions were tested by 16S rDNA sequencing and the results showed that melatonin increased the relative abundance of Actinobacteria compared with the control (p < 0.05) at the phylum level. However, Selenomonadales was markedly reduced compared with the control at the order level (p < 0.05). Gut and faecal volatile fatty acids were tested to evaluate the microbiota metabolism, but no difference was noticed in volatile fatty acid concentrations (p > 0.05). Melatonin improved intestinal development by affecting neural development, barrier integrity, nutrient absorption and microbiota in sucking piglets.

Antioxidant Phytochemicals for the Prevention of Fluoride-Induced Oxidative Stress and Apoptosis: a Review

Fluorosis is a major public health problem globally. The non-availability of specific treatment and the irreversible nature of dental and skeletal lesions poses a challenge in the management of fluorosis. Oxidative stress is known to be one of the most important mechanisms of fluoride toxicity. Fluoride promotes the accumulation of reactive oxygen species by inhibiting the activity of antioxidant enzymes, resulting in the excessive production of reactive oxygen species at the cellular level which further leads to activation of cell death processes such as apoptosis. Phytochemicals that act as antioxidants have the potential to protect cells from oxidative stress. Evidence confirms that clinical symptoms of fluorosis can be mitigated to some extent or prevented by long-term intake of antioxidants and plant products. The primary purpose of this review is to examine recent findings that focus on the amelioration of fluoride-induced oxidative stress and apoptosis by natural and synthetic phytochemicals and their molecular mechanisms of action.

Effect of exogenous melatonin on the antioxidant defense system in the liver and small intestine of the Syrian hamster (Mesocricetus auratus)

Background. Due to the growing light pollution and the development of new territories, including northern ones, the search for drugs that increase the adaptive capacity of the organism is promising.The aim. We studied the effects of the exogenous melatonin (100 µg/day/animal) on antioxidant status of liver and small intestine in Syrian hamsters (Mesocricetus auratus) in the light conditions of North-West of Russia (Petrozavodsk, northern lighting – NL).Materials and methods. Female hamsters were exposed to a 12/12 light/dark cycle (LD; n = 12) or NL for 3 months. In NL light conditions hamsters were divided into two groups: NL-control (received placebo; n = 12) and NL-mel (received melatonin; n = 12). The study was conducted from the period of the summer solstice – June 25 (NL: 19.36/4.24) to September 25 (NL: 12/12) (autumn equinox).Results. Animals were kept in the NL conditions had decreased the levels of GSH and activities of antioxidant enzymes (superoxide dismutase (SOD) and catalase) at initial stage of experiment as well as increased TBA reactive substances (TBARS) level at the beginning and after a month of the experiment in the liver in comparison to control (LD). It was observed that in the small intestine the activities of SOD and the levels of GSH (initial and intermediate stages) and TBARS (end of the experiment) were significantly higher in NL in comparison to LD. Liver and small intestine TBARS concentrations after one and three months of the experiment were decreased in NL-mel in comparison to NL-control.Conclusion. The results of the study indicate the sensitivity of the antioxidant defense system in the tissues of the liver and small intestine of Syrian hamster to the photoperiod and exogenous melatonin. The present study revealed that exogenous melatonin was able to reduce the level of TBARS and increase the activity of SOD and CAT in the light conditions of North-West of Russia.

Inhibition of Prolyl Oligopeptidase Prevents Consequences of Reperfusion following Intestinal Ischemia

BACKGROUND

Intestinal ischemia/reperfusion injury (IRI) remains a clinical event that contributes to high morbidity and mortality rates. Intestinal epithelium is exposed to histological and vascular changes following tissue ischemia. Prolyl endopeptidase (PREP), involved in inflammatory responses, could be targeted for recovery from the permanent consequences following intestinal ischemia. Our aim was to investigate the role of PREP inhibitor KYP-2047 in tissue damage, angiogenesis, and endothelial barrier permeability after intestinal IRI in mice.

METHODS

KYP-2047 treatments were performed 5 min prior to intestinal damage. Intestinal IRI was induced in mice by clamping the superior mesenteric artery and the celiac trunk for 30 min, followed by 1 h of reperfusion.

RESULTS

PREP inhibition by KYP-2047 treatment reduced intestinal IR-induced histological damage and neutrophil accumulation, limiting inflammation through decrease of NF-ĸB nuclear translocation and fibrotic processes. KYP-2047 treatment restored barrier permeability and structural alteration following intestinal IRI, attenuating neovascular processes compromised by ischemia/reperfusion. Additionally, loss of epithelial cells during intestinal ischemia occurring by apoptosis was limited by KYP-2047 treatment, which showed strong effects counteracting apoptosis and DNA damage.

CONCLUSIONS

These findings provide the first evidence that PREP inhibition through KYP-2047 inhibitor use could be a validate strategy for resolving alterations of intestinal epithelium the pathophysiology of intestinal disease.

Consumption of Anacardium Occidentale L. (Cashew Nuts) Inhibits Oxidative Stress through Modulation of the Nrf2/HO-1 and NF-kB Pathways

Ischemia/reperfusion injury is a severe disorder associated with a high mortality. Several antioxidant and pharmacological properties of cashew nuts (Anacardium occidentale L.) and its metabolites from different countries have recently been described. It is a medicinal plant with important therapeutic effects. This study aimed to verify the effect of an oral administration of cashew nuts in a rat model of ischemia/reperfusion (I/R). Adult male rats were subjected to intestinal I/R injury by clamping the superior mesenteric artery for 30 min and then allowing animals to 1 h of reperfusion. Rats subjected to I/R of the gut showed a significant increase in different biochemical markers. In particular, we evaluated lipid peroxidation, tissue myeloperoxidase activity, protein carbonyl content, reactive oxygen species generation and decreased antioxidant enzyme activities. Western blot analysis showed the activation of the NRF2 and NF-kB pathways. Increased immunoreactivity to nitrotyrosine, PARP, P-selectin, and ICAM-1 was observed in the ileum of rats subjected to I/R. Administration of cashew nuts (100 mg/kg) significantly reduced the mortality rate, the fall in arterial blood pressure, and oxidative stress and restored the antioxidant enzyme activities by a mechanism involving both NRF2 and NF-kB pathways. Cashew nuts treatments reduced cytokines plasma levels, nitrotyrosine, and PARP expression as well as adhesion molecules expressions. Additionally, cashew nuts decreased the intestinal barrier dysfunction and mucosal damage, the translocation of toxins and bacteria, which leads to systemic inflammation and associated organs injuries in particular of liver and kidney. Our study demonstrates that cashew nuts administration exerts antioxidant and pharmacological protective effects in superior mesenteric artery occlusion–reperfusion shock.

The effects of hydrogen-rich saline solution on intestinal anastomosis performed after intestinal ischemia reperfusion injury

AIM

We investigated the effects of hydrogen-rich saline solution (HRSS) on intestinal anastomosis performed after intestinal ischemia reperfusion injury (IRI).

MATERIALS AND METHODS

Thirty Wistar albino female rats were randomly divided into five groups. Only laparotomy was performed in the Sham group. In the other four groups, an intestinal IRI was performed for 45 min by clamping the superior mesenteric artery. After intestinal IRI, anastomosis was performed by cutting the intestine from the proximal 15 cm of the ileocecal valve at the first and 24th hours. HRSS was given intraperitoneally 5 ml/kg before reperfusion and for four more days in the HRSS¹ and HRSS²⁴groups, while no treatment was given to the I/R¹ and I/R²⁴ groups. After 5 days, all groups underwent relaparotomy. The anastomotic bursting pressures were measured in all groups, except the Sham group. The tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), myeloperoxidase (MPO) and malondialdehyde (MDA) levels were measured in the tissues taken from the anastomosis line. The tissue sections were evaluated histopathologically and the apoptosis index was determined by applying the TUNEL method. The results were analyzed one-way analysis of variance (ANOVA) and Pearson's chi-squared test.

RESULTS

Although the MPO, MDA, IL-6 and TNF-α tissue values were not statistically significant among the groups, the degree of tissue damage and apoptosis levels were lower and the anastomotic bursting pressures values were higher in the HRSS¹ and HRSS²⁴ groups compared to the I/R¹ and I/R²⁴ groups.

CONCLUSION

HRSS is effective in reducing the intestinal damage caused by an IRI: HRSS has the potential to reduce the detrimental effects of intestinal anastomosis performed after an intestinal IRI.

The Therapeutic Effect of Nigella sativa Seed on Indomethacin-induced Gastric Ulcer in Rats

Background:

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to relieve pain and reduce inflammation. However, gastric complications remain a major problem limiting their clinical usage. This study was carried out to evaluate the therapeutic effect of Nigella sativa seed (N. sativa seed) hydroalcoholic extract on indomethacin-induced gastric ulcer in rats and its possible mechanism.

Methods:

This study was carried out on forty-eight male Wistar rats. Gastric ulcer was induced by indomethacin (35 mg/kg). N. sativa seed extract (100, 200, and 400 mg/kg) and ranitidine (50 mg/kg) was administered orally for five days after ulcer induction. Ulcer index, gastric acid secretion, gastric mucus content, total thiol, malondialdehyde (MDA), and total hexose, and protein content in gastric juice were determined.

Results:

The ulcer index in groups of N. sativa seed was significantly lower as compared to indomethacin group. N. sativa seed significantly decreased MDA and protein content, but increased total thiol, total hexose, and mucus content as compared to indomethacin group. N. sativa seed did not affect gastric acid secretion.

Conclusion:

These findings showed that the gastroprotective effect of N. sativa seed against indomethacin- induced ulcer was mainly exerted by antioxidant activity, stimulation of gastric mucus secretion and also increased total hexose in the gastric mucosa.

Thymoquinone reduces ischemia and reperfusion-induced intestinal injury in rats, through anti-oxidative and anti-inflammatory effects

OBJECTIVES

The aim of the present study was to investigate the effect of thymoquinone on ischemia/reperfusion (I/R) injury at 150 min or/and 24 h of reperfusion in male Wistar Rats.

MATERIAL AND METHODS

The therapeutic value of thymoquinone on cellular damage caused by reactive oxygene species or inflammatory processes during intestinal ischemia/reperfusion was investigated using pharmacological function studies on smooth muscle contractile responses of acetylcholine (Ach) and KCl, along with myeloperoxidase activity, malondialdehyhde, glutathione and cytokine levels such as tumor necrosis factor (TNF)-α and interleukin (IL)-1β in serum and ileum tissue of rats. Thymoquinone was administered at a dose of 50 mg/kg orally for three times: 30 min, 24 h and 48 h prior to the surgical procedure. Soon after reperfusion timing (150 min or 24 h), the contractility traces to KCl and acetylcholine of the ileum smooth muscle were recorded through isolated organ bath.

RESULTS

Pretreatment with thymoquinone reversed the disrupted contractility of the ileum smooth muscle at the 24 h reperfusion. Increased malondialdehyde and depleted glutathione levels and high myeloperoxidase activity determined in the ileum I/R tissue returned to reasonable amounts by pretreatment of Thymoquinone, which attenuated malondialdehyde quantity, restored glutathione level and inhibited myeloperoxidase activity. In addition, both serum and tissue TNF-α and IL-1β activities were modulated by thymoquinone at 24 h of intestinal I/R.

CONCLUSION

The results indicate that thymoquinone may have therapeutic value due to its immunomodulating, radical scavenging and/or antioxidant effects in intestinal I/R injury including oxidant damage mechanisms.

Combination Therapy of Allopurinol and Dantrolene and Its Role In The Prevention of Experimental Ischemia Reperfusion Injury Of The Small Intestine

BACKGROUND

The effect of different drugs on ischemia and reperfusion (I/R; induced oxygen free radical damage) was examined in small bowel tissue because the intestine is extremely sensitive to this pathology. Different drugs (allopurinol and dantrolene) can remove oxygen free radicals or inhibit the mechanisms leading to their generation, thus reducing mucosal lesions. We investigated the protective potential of combination therapy in the intestine against I/R damage.

METHODS

Forty-eight male Wistar rats were separated into 8 groups: one sham (control), one I/R (ischemia 60 min + reperfusion at 24 h), and 6 groups treated with allopurinol, dantrolene, or combination therapy. The grade of injury in the small bowel was established by the lipid peroxidation (MDA) and antioxidant enzymatic activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in tissue samples. Moreover, the collected samples were subjected to histological study.

RESULTS

Combination therapy preserved normal enzymatic levels compared to the I/R groups (p < 0.05) for all parameters studied. The animals treated with combination therapy showed less severe small bowel damage than I/R group in accordance with the histological results.

CONCLUSIONS

Results obtained in the experimental process indicate that the administration of antioxidants protects against intestinal damage by I/R. Overall, combination therapy may protect intestinal tissue from I/R injury.

Melatonin in drug addiction and addiction management: Exploring an evolving multidimensional relationship

Melatonin is a pleiotropic signalling molecule that regulates several physiological functions, and synchronises biological rhythms. Recent evidences are beginning to reveal that a dysregulation of endogenous melatonin rhythm or action may play a larger role in the aetiology and behavioural expression of drug addiction, than was previously considered. Also, the findings from a number of animal studies suggest that exogenous melatonin supplementation and therapeutic manipulation of melatonin/melatonin receptor interactions may be beneficial in the management of behavioural manifestations of drug addiction. However, repeated exogenous melatonin administration may cause a disruption of its endogenous rhythm and be associated with potential drawbacks that might limit its usefulness. In this review, we examine the roles of melatonin and its receptors in addictive behaviours; discussing how our understanding of melatonin’s modulatory effects on the brain rewards system and crucial neurotransmitters such as dopamine has evolved over the years. Possible indications(s) for melatonergic agents in addiction management, and how manipulations of the endogenous melatonin system may be of benefit are also discussed. Finally, the potential impediments to application of melatonin in the management of addictive behaviours are considered.

Protective effect of glutamine on the main and adjacent organs damaged by ischemia-reperfusion in rats

Intestinal ischemia and reperfusion (I/R) causes cellular and tissue damage to the intestine and remote organs such as the liver. Increased production of ROS and nitric oxide and dysregulation of cytoprotective enzymes may be involved in intestinal I/R. The aim was to evaluate the protective effects of glutamine on the intestine and liver of rats with intestinal I/R injury. Twenty male Wistar rats (300 g) were divided into four groups: sham-operated (SO), glutamine + SO (G + SO), I/R, and glutamine + I/R (G + I/R). Occlusion of the SMA for 30 min was followed by 15-min reperfusion. Glutamine (25 mg/kg/day) was administered once daily 24 and 48 h before I/R induction. Blood and tissue of were collected for aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, histopathological analysis, immunohistochemistry of IL-1β and TNF-α, thiobarbituric acid reactive substance (TBARS) and nitric oxide, Nrf2/keap1, superoxide dismutase (SOD), NADPH quinone oxidoreductase1 (NQO1), inducible nitric oxide synthase (iNOS), heat shock protein (HSP70), glucose-regulated protein 78 (GRP78), and activating transcription factor 6 (ATF-6) by western blot. Statistic analysis by ANOVA-Student-Newman-Keuls test (mean ± SE) significantly was p < 0.05. Tissue damage, AST, ALT, IL-1β, TNF-α, TBARS, NO, Keap1, iNOS, GRP78, and ATF-6 expression were significantly lower in the G + I/R group as compared to the I/R group. Expression of Nrf2, SOD, NQO1, and HSP70, was significantly higher in the G + I/R group as compared to I/R group. Pre-treatment with glutamine provided protection against oxidative damage in the intestine and liver in an experimental model of intestinal I/R.

Risperidone-Induced Renal Damage and Metabolic Side Effects: The Protective Effect of Resveratrol

Objective

The aim of the study was to investigate the possible protective qualities of resveratrol (RSV) against the side effects of risperidone (RIS) in an experimental model in rat kidneys with histologic and biochemical assessments.

Materials and Methods

Experimental procedures were performed on 35 female Sprague Dawley rats. Rats were randomly divided into five groups: control, untreated rats (n = 7) were in group 1; group 2 was given 2 mg/kg/day RIS (n = 7); group 3 was treated with 2 mg/kg/day RIS and 20 mg/kg/day RSV (n = 7); group 4 was treated with 2 mg/kg/day RIS and 40 mg/kg/day RSV (n = 7); and group 5 was treated with 2 mg/kg/day RIS and 80 mg/kg/day RSV (n = 7). All treatments were administered for two weeks by gavage. On treatment day 15, kidney tissues were removed for analysis.

Results

The results showed that RSV treatment reduced weight gain induced by RIS. In addition, RSV increased the total antioxidant status (TAS) and decreased serum creatinine (Cr), blood urea nitrogen (BUN), oxidative stress index (OSI), and total oxidant status (TOS) levels significantly (p < 0.05).

Conclusion

This study revealed that treatment with RSV might protect kidney tissues against the side effects of RIS. RSV could be an effective course of therapy to enhance therapeutic efficacy.

Antioxidant potential of Himanthalia elongata for protection against ischemia-reperfusion injury in the small bowel

BACKGROUND

Seaweed has been associated with the prevention and/or treatment of various diseases related to oxidative stress because of its antioxidant activity. We investigated the protective potential of extract of Himanthalia elongata against ischemia-reperfusion (I/R) injury in the intestine of rats.

METHODS

Seventy-two (72) male Wistar albino rats were randomly assigned into 12 groups as follows: sham, I/R only, I/R plus vehicle at 3 time points, and I/R plus extract at 3 time points. The degree of intestinal injury was determined by oxidative stress using lipid peroxidation, superoxide dismutase, catalase, and glutathione peroxidase after mesenteric ischemia-reperfusion. A histological study was also performed.

RESULTS

The algae extract helps to maintain normal enzymatic levels because, for all the studied parameters, groups treated with the extract showed significant differences (P < .05) compared with the I/R groups, and there were no differences compared with the sham group. The histological study showed that damage to the intestinal mucosa was less severe in animals treated with extract of H elongata after up to 24 hours of reperfusion compared with the I/R group.

CONCLUSION

These results suggest that the extract of H elongata can protect intestinal tissue against ischemia-reperfusion injury.