Reducing oxidative stress by κ-carrageenan and C60HyFn: The post-thaw quality and antioxidant status of Azari water buffalo bull semen

Azeri water buffalo is a species of great interest due to the high quality of its products such as milk. Due to the decreasing trend of its number and risk of extinction in the future, our attention is directed towards ensuring the preservation of its genetic reserves by keeping its sperm. Using antioxidants in semen extender is one of the ways to reduce the detrimental effects of freezing process on post-thawed quality of spermatozoa. This study was conducted to determine the effect of κ-carrageenan (k-CRG) and C60HyFn supplemented semen extender on the quality of post-thawed Azari water buffalo spermatozoa. A total of 30 semen samples were obtained from three buffaloes using an artificial vagina (twice a week for five weeks = 10 replicates). The samples (n = 3) from each replicate were pooled and divided into equal aliquots to prepare 14 extender groups, including control (C), k-0.2, K-0.4, K-0.6, K-0.8 (containing 0.2, 0.4, 0.8 mg K-CRG/mL, respectively), C-0.1, C-0.2, C-0.4, C-0.8, C-1, C-5, C-10, C-20, and C-40 (containing 0.1, 0.2, 0.4, 0.6, 0.8, 1, 5, 10, 20, 40 μM C60HyFn, respectively), and then frozen. After thawing, motility and velocity parameters, plasma membrane integrity (PMI) and functionality (PMF), DNA damage, Hypo-osmotic swelling (HOS) test, malondialdehyde (MDA), total antioxidant capacity (TAC), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase glutathione activities and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging were evaluated. In vivo fertility was compared between k-0.6, C-1 and control groups. 60 buffalo were inseminated 24 h after the onset of estrus. The diagnosis of pregnancy was performed rectally at least 60 days after fertilization. Total and progressive motility and velocity parameters were improved by k-0.4, k-0.6, k-0.8, C-0.4, C-0.8, C-1, C-5, and C-10 groups) compared to the other groups. Plasma membranes integrity and PMF were improved by k-0.4, k-0.6, C-0.4, C-0.8, C-1, C-5, and C-10 groups compared to other groups, while in terms of sperm DNA damage K-0.4, K-0.6, K-0.8, C-0.2, C-0.4, C-0.8, C-1, C-5, and C-10 groups showed better results compared to the control group. The evidence also showed that k- 0.4, k-0.6, k-0.8, C-0.4, C-0.8, C-1, C-5, and C-10 groups could improve TAC, and decrease MDA levels. Also, k-0.4, k-0.6, k-0.8, C-0.2, C-0.4, C-0.8, C-1, C-5, and C-10 groups could improve GPx, CAT, and GSH levels, but no significant difference was found regarding SOD compared to the other groups. DPPH scavengers were tested by K-0.6, K-0.8 and C-1, C-5, C-10, C-0.8, C-0.4 and C-0.2 groups and compared to other groups improved. The fertility rate [70% (14/20)] was higher in C-1 than other groups. To conclude that k-CRG and C60HyFn supplementation can increase the quality parameters of cryopreserved buffalo semen after thawing and that 1 M C60HyFn can increase in vivo fertility of buffalo semen.

REV-ERB activation as a novel pharmacological approach for treating inflammatory pain

Pain is a complex problem affecting millions of people worldwide. The current therapies to reduce pain are limited as many treatment options inadequately address the causes of pain, lead to tolerance of the drug, or have adverse effects including abuse potential. While there are many causes of pain, one underlying mechanism to the pathogenesis and maintenance of pain conditions is chronic inflammation driven by the NLRP3 inflammasome. Several inflammasome inhibitors are currently under investigation however have the potential to suppress the functioning of the innate immune system, which may cause unwanted affects in patients. Here, we show that the nuclear receptor REV-ERB can suppress the activation of the inflammasome when pharmacologically activated with small molecule agonists. Additionally, REV-ERB activation appears to have analgesic potential in a model of acute inflammatory pain, likely as a result of inflammasome suppression.

Persistent peripheral inflammation and pain induces immediate early gene activation in supraspinal nuclei in rats

Pain is a public health concern worldwide and can present simultaneously with anxiety and depression. c-Fos is a marker used to identify activated cells in response to various stimuli. Specifically, it can be used as a brain marker of pain. We examined whether peripheral inflammation produces mechanical allodynia, anxiety- and depression-related behaviors in male rats (Rattus norvegicus, Wistar strain) and if these behaviors can have an impact on c-Fos expression in the supraspinal nuclei involved in pain control. We assessed mechanical thresholds by von Frey monofilaments, depression-like behaviors in the forced swimming test (FST) and anxiety-related behaviors in the open field test (OFT) after the administration of the inflamogen Complete Freund´s Adjuvant (CFA) in rats. We found that CFA increased paw diameter is all rats, however, CFA treatment resulted in a subgroup of rats developing allodynia [CFA- mechanical allodynia (CFA-MA)] and a subgroup of rats not developing allodynia [CFA-no mechanical allodynia (CFA-NMA)]. At the peak of tactile allodynia and inflammation, results were coupled with an increase in c-Fos expression in several supraspinal brain nuclei, i.e. basolateral amygdala, periaqueductal gray matter and rostroventromedial medulla in CFA-MA rats. Moreover, we found a correlation between c-Fos levels and mechanical thresholds. No modification in c-Fos expression was observed in CFA-NMA rats. CFA did not modulate behaviors in the OFT or FST. In summary, we show that mechanical allodynia but not peripheral inflammation activates c-Fos in several supraspinal nuclei, which sheds new light on brain regions involved in the control of pain following peripheral injury and decouples this effect from mere peripheral inflammation. This model may be used to study resistance to pain development in future studies.

Evidence for Endogenous Opioid Dependence Related to Latent Sensitization in a Rat Model of Chronic Inflammatory Pain

Studies performed in a mouse model of chronic inflammatory pain induced by intraplantar injection of complete Freund's adjuvant (CFA) have shown that constitutive activation of the endogenous opioid signaling, besides serving as a mechanism of endogenous analgesia that tonically represses pain sensitization, also generates a state of endogenous opioid dependence. Since species-related differences concerning pain biology and addictive behaviors occur between mice and rats, the present study explored whether the coexistence of endogenous opioid analgesia and endogenous opioid dependence also characterizes a homologous rat model. To this aim, CFA-injured Wistar rats were treated with either 3 mg/kg or 10 mg/kg of the opioid receptor inverse agonist naltrexone (NTX) during the pain remission phase and monitored for 60 min for possible withdrawal behaviors. At 3 mg/kg, NTX, besides inducing the reinstatement of mechanical allodynia, also caused a distinct appearance of ptosis, with slight but nonsignificant changes to the occurrence of teeth chatters and rearing. On the other hand, 10 mg/kg of NTX failed to unmask pain sensitization and induced significantly lower levels of ptosis than 3 mg/kg. Such an NTX-related response pattern observed in the rat CFA model seems to differ substantially from the pattern previously described in the mouse CFA model. This supports the knowledge that mice and rats are not identical in terms of pharmacological response and stresses the importance of choosing the appropriate species for preclinical pain research purposes depending on the scientific question being asked.

Visualization of trigeminal ganglion sensory neuronal signaling regulated by Cdk5

The mechanisms underlying facial pain are still incompletely understood, posing major therapeutic challenges. Cyclin-dependent kinase 5 (Cdk5) is a key neuronal kinase involved in pain signaling. However, the regulatory roles of Cdk5 in facial pain signaling and the possibility of therapeutic intervention at the level of mouse trigeminal ganglion primary neurons remain elusive. In this study, we use optimized intravital imaging to directly compare trigeminal neuronal activities after mechanical, thermal, and chemical stimulation. We then test whether facial inflammatory pain in mice could be alleviated by the Cdk5 inhibitor peptide TFP5. We demonstrate regulation of total Ca2+ intensity by Cdk5 activity using transgenic and knockout mouse models. In mice with vibrissal pad inflammation, application of TFP5 specifically decreases total Ca2+ intensity in response to noxious stimuli. It also alleviates inflammation-induced allodynia by inhibiting activation of trigeminal peripheral sensory neurons. Cdk5 inhibitors may provide promising non-opioid candidates for pain treatment.

Trifluoro-icaritin alleviates chronic inflammatory pain through α7nAChR-mediated suppression of HMGB1/NF-κB signaling in the spinal cord of rats

Inflammatory pain is a chronic, persistent and serious disease that greatly impacts public health, which is often accompanied by allodynia, hyperalgesia, and spontaneous pain. It is evident that α7 nicotinic acetylcholine receptor (α7nAChR) plays a key role in cholinergic anti-inflammatory pathway and exhibits the inhibition of neuroinflammation in chronic pain. Trifluoro-icaritin (ICTF), a derivative of icaritin from the extract of a genus of Epimedium plant, is identified to possess profound anti-inflammatory activity. However, whether ICTF has anti-nociceptive effect on inflammatory pain and its potential mechanisms remain poorly elucidated. Intraperitoneal injection (i.p.) of ICTF to complete Freund's adjuvant (CFA)-induced inflammatory pain rats once daily for 21 consecutive days. Pain-related behaviors were evaluated with paw withdrawal threshold (PWT), paw withdrawal latency (PWL), and CatWalk gait analysis. Expression of pain-related signaling molecules in the spinal cord were detected using qRT-PCR, western blot assay, and immunofluorescence staining. This results showed that ICTF (3.0mg/kg, i.p.) effectively alleviated mechanical allodynia and thermal hyperalgesia not 0.3 and 1.0mg/kg in CFA rats. Subsequently, we further observed that ICTF (3.0mg/kg) dramatically decreased the mRNA and protein levels of HMGB1, NF-κB p65, and IL-1β but markedly enhanced α7nAChR and IL-10 expression in the spinal cord of CFA rats, and Immunofluorescence staining also showed that ICTF (3.0mg/kg) significantly increased the expression of α7nAChR and reduced IBA1 in the spinal cord of CFA rats, along with suppressing the alterations of gait parameters induced by CFA. Moreover, Intrathecal injection (i.t.) of α7nAChR antagonist alpha-bungarotoxin (α-Bgtx, 1.0μg/kg) not only reversed the anti-nociceptive effect of ICTF on pain hypersensitivity, but also inhibited the down-regulation of HMGB1, NF-κB p65, and IL-1β as well as the up-regulation of α7nAChR and IL-10 protein expression induced by ICTF treatment. Altogether, our results illustrate that ICTF enables to ameliorate CFA-induced inflammatory pain through α7nAChR-mediated inhibition of HMGB1/NF-κB signaling pathway in the spinal cord of rats, suggesting that ICTF may be exploited as a potential painkiller against chronic inflammatory pain.

Benefits of electroacupuncture and a swimming association when compared with isolated protocols in an osteoarthritis model

Background and aim

Osteoarthritis (OA) is characterized by pain and inflammation. Electroacupuncture (EA) and swimming (SW) are non-pharmacological interventions recommended for treating OA. The study evaluated the benefits of electroacupuncture (EA) and swimming (SW) association when compared with isolated protocols in an OA rodent model. Experimental.

Procedures

An ankle monoarthritis model was induced in rats by applying Complete Freund's Adjuvant (CFA). After seven days of induced OA, the groups were submitted to EA (ST36 and the GB 30 Acupoint), SW, or the EA + SW protocol. The nociceptive behavior was measured by the Von Frey test, the Cold Stimulation test, and the Paw Flick Immersion test. Inflammatory activity was evaluated by measuring TNF levels, myeloperoxidase, NAGase, immunological parameters and the histology from the subcutaneous tissue.

Results

Compared to CFA group, EA decreased the nociceptive scores in the cold stimulation test (p < 0.05), and it also increased the latency time in thermal cold (p < 0.01) and heat hyperalgesia (p < 0.001). Also, EA reduced NAGase (p < 0.01). SW reduced the edema (p < 0.05) and did not increase the inflammatory infiltrates or congestion, neither in the histological measurements nor by analyzing the levels of TNF. The association of EA + SW decreased the neutrophils and the monocytes, MPO (p < 0.05), and the glutamate levels in the cerebrospinal fluid (CSF, p < 0.001).

Conclusion

There were statistical differences between combination therapy and monotherapy as seen by the inflammatory parameters, which could be associate to the delay of the chronification osteoarthritis retardation. However, EA + SW did not show benefits when compared to isolated protocols in nociceptive behavior.

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Electroacupuncture (EA) extended the latency time in the thermal hyperalgesia assay.

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The swimming protocol did not increase the inflammatory infiltrates.

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EA and swimming decreased the glutamate levels in the cerebral spinal fluid.

The Occurrence of Pain-Induced Depression Is Different between Rat Models of Inflammatory and Neuropathic Pain

Various pain conditions may be associated with depressed mood. However, the effect of inflammatory or neuropathic pain on depression-like behavior and its associated time frame has not been well established in rat models. This frontward study investigated the differences in pain behavior, depression-like behavior, and serotonin transporter (SERT) distribution in the brain between rats subjected to spared nerve injury (SNI)-induced neuropathic pain or complete Freund’s adjuvant (CFA)-induced inflammatory pain. A dynamic plantar aesthesiometer and an acetone spray test were used to evaluate mechanical and cold allodynia responses, and depression-like behavior was examined using a forced swimming test and sucrose preference test. We also investigated SERT expression by using positron emission tomography. We found that the inflammation-induced pain was less severe than neuropathic pain from days 3 to 28 after induced pain; however, the CFA-injected rats exhibited more noticeable depression-like behavior and had significantly reduced SERT expression in the brain regions (thalamus and striatum) at an early stage (on days 14, 21, and 28 in two groups of CFA-injected rats versus day 28 in SNI rats). We speculated that not only the pain response after initial injury but also the subsequent neuroinflammation may have been the crucial factors influencing depression-like behavior in rats.

Effects of Resveratrol on Receptor Expression and Serum Levels of Estrogen and Progesterone in the Rat Endometritis Model

Endometritis is characterized by inflammation of the endometrial lining that leads to reduced reproductive potential. Restoring the impaired hormonal balance is an important component of endometritis treatment. The purpose of the current study was to evaluate the effects of resveratrol on estrogen and progesterone hormone status in endometritis. Mature female Sprague Dawley rats were used, and endometritis was induced by intrauterine infusion of Escherichia coli. Animals were treated with resveratrol alone or combined with marbofloxacin. Compared to the non-treated endometritis group, resveratrol treatment reduced serum oestradiol levels, increased serum progesterone levels, enhanced estrogen receptor (ER) expression in the uterine stroma, decreased ESR1 gene expression, and raised ESR2 gene expression. Resveratrol administration combined with marbofloxacin also increased ER expression in the uterine gland and progesterone receptor expression in the uterine epithelium. The findings of this study suggest that the actions of resveratrol on progesterone levels and estrogen receptor expression might be responsible for its beneficial effect in rats with endometritis.

The effects of the molecular weight of chitosan on the tissue inflammatory response

The molecular weight of chitosan (CS) may affect its physical properties and its ability to induce an appropriate host response. The biocompatibilities of CS membranes of low (LMWCS) and high (HMWCS) molecular weight were investigated by inserting these materials into the subcutaneous tissue of rats for 1-28 days and evaluating leukocyte infiltration, granulation tissue, fibrosis, arginase-1 immunostaining, as well as nuclear factor-κB (NF-κΒ) and fibroblast growth factor (FGF)-2 expressions. Both CS membranes induced a peak of leukocyte infiltration on the first day of insertion and stimulated granulation and fibrous tissue generation when compared to control. LMWCS induced more collagen deposition a week earlier, when compared to the control and HMWCS membrane. The membranes also increased arginase-1 immunostaining, a M2 macrophage marker. M2 macrophage is recognized as anti-inflammatory and pro-regenerative. NF-κB is an essential biomarker of the inflammatory process and induces the expression of several pro-inflammatory cytokines. The LMWCS membrane reduced inflammation, as indicated by a reduced nucleus/cytoplasm NF-κB ratio in surrounding tissue from days 7 to 14 when compared to control. On the first day, the expression of FGF-2, a biomarker of inflammatory resolution, was increased in the tissue of the LWMCS group, when compared with HMWCS, which was consistent with the type I collagen deposition. Thus, LWMCS was associated with a prior reduction of the inflammatory response and improved wound healing.

Electroacupuncture Relieves Pain and Attenuates Inflammation Progression Through Inducing IL-10 Production in CFA-Induced Mice

The therapeutic effect of electroacupuncture (EA) on inflammatory pain has been well recognized clinically, but the mechanism is unclear. Interleukin-10 (IL-10), which is produced by regulatory T (Treg) cell, is a key anti-inflammatory cytokine for relieving inflammatory pain. Therefore, the aim of this study is to investigate whether EA could inhibit CFA-induced pain and attenuate inflammation progression by regulating the activation of immunocyte and inducing the expression of IL-10. In this study, mice were treated with EA (2/100 Hz, 2 mA) for five consecutive days after 1 day of CFA injection. The behavioral tests were measured and analyzed after the daily EA treatment; then, hind paw, spinal cord, and spleen tissues were prepared for assessment. The results showed that EA treatment significantly increased the mechanical threshold and thermal latency after CFA injection and boosted the expression of IL-10 in paw and spinal cord tissues. EA treatment promoted Treg cells; suppressed macrophage and neutrophils cells; reduced the expression of IL-1β, NLRP3, and TNF-α; and ultimately relieved inflammatory pain. The findings suggested that the analgesic and anti-inflammatory effect of EA treatment could be partially associated with suppression of pro-inflammatory cytokines mediated by induction of IL-10.

Farrerol ameliorate adjuvant-induced ankle injury via alteration of PPAR-γ signal pathway

This study evaluated the anti-inflammatory activity against lipopolysaccharide (LPS)-mediated mouse macrophages (in vitro) and assessed the protective effect of farrerol on arthritis caused by complete freund adjuvant (CFA) in rats. For the evaluation of the pharmacological effect of farrerol on the activity of nitric oxide (NO) and cyclooxygenase, pro-inflammatory cytokines including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1β, RAW 264.7 cells were used. A 0.1 ml CFA was injected subcutaneously for the induction of arthritis. The paw volume, body weight and arthritic score were estimated at regular intervals. Pro-inflammatory cytokines, inflammatory mediators, and antioxidant parameters were also estimated. Farrerol suppressed NO production and COX-catalyzed prostaglandin (PGE₂ ) in RAW 264.7. Farrerol also downregulated the p-p65, p-IκBα expression and upregulated the PPAR-γ expression in RAW 264.7 cells. Treatment of farrerol increased body weight substantially, and reduced paw edema and arthritic score. Farrerol treatment also significantly improved the level of hemoglobin (Hb), count of red blood cells (RBC), and decreased the rate of erythrocyte sedimentation (ESR), white blood cell (WBC) parameters, while the generation of pro-inflammatory cytokines inhibited. Together, farrerol also suppressed the pro-inflammatory cytokines TNF-α, IL-6, and IL-1β. Obtained results directed that the farrerol exerted its therapeutic effect against CFA-induced arthritic rats through anti-inflammatory mechanism by regulation of the PPAR-γ. PRACTICAL APPLICATIONS: Increase the arthritis disease worldwide day-by-day. The current research study showed the anti-arthritic effect of farrerol (flavonoid phytoconstituent) of Rhododendron dauricum Linn. In this study, farrerol considerably inhibited the NF-κB to show the anti-arthritic effect. The finding showed the potential effect against acute and chronic inflammation via inhibition of inflammatory mediators and oxidative stress. The result suggests the anti-inflammatory and antioxidant effect of farrerol. On the basis of result, we can say that farrerol can be the beneficial drug to treat the arthritis.

Sleep spindles as a diagnostic and therapeutic target for chronic pain

Pain is known to disrupt sleep patterns, and disturbances in sleep can further worsen pain symptoms. Sleep spindles occur during slow wave sleep and have established effects on sensory and affective processing in mammals. A number of chronic neuropsychiatric conditions, meanwhile, are known to alter sleep spindle density. The effect of persistent pain on sleep spindle waves, however, remains unknown, and studies of sleep spindles are challenging due to long period of monitoring and data analysis. Utilizing automated sleep spindle detection algorithms built on deep learning, we can monitor the effect of pain states on sleep spindle activity. In this study, we show that in a chronic pain model in rodents, there is a significant decrease in sleep spindle activity compared to controls. Meanwhile, methods to restore sleep spindles are associated with decreased pain symptoms. These results suggest that sleep spindle density correlates with chronic pain and may be both a potential biomarker for chronic pain and a target for neuromodulation therapy.

Thiazolidine Derivatives Attenuate Carrageenan-Induced Inflammatory Pain in Mice

BACKGROUND

Peripheral inflammation leads to the development of persistent thermal hyperalgesia and mechanical allodynia associated with increased expression of interleukin-1β (IL-1β) in the spinal cord. The aim of the present study was to investigate the effects of thiazolidine derivatives, 1b ([2-(2-hydroxyphenyl)-1,3-thiazolidin-4-yl](morpholin-4-yl)methanone) and 1d (2-hydroxy-4-{[2-(2-hydroxyphenyl)-1,3-thiazolidine-4-carbonyl]amino}benzoic acid), on thermal hyperalgesia, mechanical allodynia and on IL-1β expression during carrageenan-induced inflammation in the spinal cord in mice. Inflammatory pain was induced by injecting 1% carrageenan into the right hind paw of the mice.

METHODS

The animals were administered thiazolidine derivatives, 1b and 1d (1 mg/kg, 3 mg/kg, or 10 mg/kg), intraperitoneally 30 minutes before carrageenan administration. The animals' behavior was evaluated by measuring thermal hyperalgesia, mechanical allodynia, and motor coordination. The IL-1β expression was measured by enzyme-linked immunosorbent assay. Acute and sub-acute toxicity studies were conducted to evaluate the toxicity profile of compounds.

RESULTS

Treatment with the thiazolidine derivative, 1b and 1d, attenuated carrageenan-induced thermal hyperalgesia and mechanical allodynia at doses of 1 mg/kg, 3 mg/kg, and 10 mg/kg. No motor coordination deficits were observed in animals. The compounds also reduced IL-1β expression in the spinal cord of mice. Acute and sub-acute toxicity studies revealed that both compounds were safe.

CONCLUSION

The compounds exhibit promising activity against inflammatory pain due to their ability to produce anti-hyperalgesic and anti-allodynic effects and to inhibit IL-1β expression in the spinal cord.

Dobera glabra (Forssk.) Poir. (Salvadoraceae); phenolic constituents of the aqueous leaves extract and evaluation of its anti-inflammatory, analgesic activities

BACKGROUND

The plant kingdom is considered one of the most common sources for structural and biological diversity. In particular, the wild category acquires our attention to investigate the phytochemical and the biological evaluations.

METHODS

Dobera glabra was exposed to phytochemical examination using HPLC-ESI-MS analysis. Furthermore, the anti-inflammatory activity was evaluated using carrageenan-induced rat paw edema model, whereas both the central and peripheral analgesic activities were tested via hot plate test in rats and acetic acid-induced writhing in mice, respectively.

RESULTS

Twenty phenolic compounds of D. glabra aqueous leaves extract were emphasized by liquid chromatography coupled with mass spectrometry. Moreover, D. glabra exhibited both anti-inflammatory and peripheral analgesic activities. Furthermore, D. glabra significantly decreased the immune expression of MMP-9, TNF-α and TGF-β1 in the hind paw of rats.

CONCLUSION

D. glabra possess peripheral anti-nociceptive and anti-inflammatory effects in rats mediated through its anti-oxidant and anti-inflammatory activities. The activity of D. glabra leaves extract might be attributed to the presence of hydroxy and keto structures.

Amino acid conjugates of 2-mercaptobenzimidazole provide better anti-inflammatory pharmacology and improved toxicity profile

Benzimidazole is an important pharmacophore for clinically active drugs against inflammation and treatment of pain, however, it is associated with gastrointestinal side effects. Here we synthesized benzimidazole based agents with significant analgesic/anti-inflammatory potential but with less gastrointestinal adverse effects. In this study, we synthesized novel, orally bioavailable 2-mercaptobenzimidazole amino acid conjugates (4a-4o) and screened them for analgesic, anti-inflammatory and gastro-protective effects. The synthesized 2-mercaptbenzimidazole derivatives were characterized for their structure using FTIR, 1 H NMR and 13 C NMR spectroscopic techniques. The 2-mercaptobenzimidazole amino acid conjugates have found to possess potent analgesic, anti-inflammatory and gastroprotective activities, particularly with compound 4j and 4k. Most of the compounds exhibited remarkable anti-ulcer and antisecretory effects. Molecular docking studies were carried out to study the binding affinities and interactions of the synthesized compounds with target proteins COX-2 (PDB ID: 3LN1) and H+ /K+ -ATPase (PDB ID: 5Y0B). Our results support the clinical promise of these newly synthesized 2-mercaptobezimidazol conjugates as a component of therapeutic strategies for inflammation and analgesia, for which the gastric side effects are always a major limitation.

Hepatoprotective effect of gentiopicroside in combination with leflunomide and/or methotrexate in arthritic rats

AIMS

This study aimed to examine whether gentiopicroside (GPS) could exert hepatoprotective effects on leflunomide (LEF)- and/or methotrexate (MTX)-treated arthritic rats through anti-inflammatory and antioxidant pathways.

MAIN METHODS

We observed the external symptoms of joints, analysed serum indicators, measured haematological parameters and mRNA levels, and performed HE staining.

KEY FINDINGS

LEF and/or MTX combined with GPS ameliorated oxidative stress by increasing the mRNA levels of the antioxidant gene Nrf2, GCLC, HO-1, and NQO1, increasing the antioxidant enzymes superoxide dismutase (SOD), glutathione (GSH) and catalase (CAT), reducing the oxidant substance malondialdehyde (MDA), reducing the inflammatory response by decreasing the mRNA levels of NF-κB, tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), and inhibiting the secretion of the pro-inflammatory cytokines TNFα, IL-6, IL-1β and reducing C-reactive protein (CRP), as well as alleviating the external symptoms of arthritis.

SIGNIFICANCE

These results show that GPS plays an antioxidant and anti-inflammatory role in LEF- and/or MTX-treated arthritic rats by affecting the Nrf2 and NF-κB signalling pathways, thus exerting hepatoprotective effects.

Development of a Mouse Pain Scale Using Sub-second Behavioral Mapping and Statistical Modeling

Rodents are the main model systems for pain research, but determining their pain state is challenging. To develop an objective method to assess pain sensation in mice, we adopt high-speed videography to capture sub-second behavioral features following hind paw stimulation with both noxious and innocuous stimuli and identify several differentiating parameters indicating the affective and reflexive aspects of nociception. Using statistical modeling and machine learning, we integrate these parameters into a single index and create a "mouse pain scale," which allows us to assess pain sensation in a graded manner for each withdrawal. We demonstrate the utility of this method by determining sensations triggered by three different von Frey hairs and optogenetic activation of two different nociceptor populations. Our behavior-based "pain scale" approach will help improve the rigor and reproducibility of using withdrawal reflex assays to assess pain sensation in mice.

Repeated administration of a flavonoid-based formulated extract from citrus peels significantly reduces peripheral inflammation-induced pain in the rat

Depression-related disorders are the first cause of disability worldwide according to the World Health Organization, and there is limited availability of effective antidepressant medications without side effects. Similarly, pain management is a public health concern particularly due to the increase in use of opioid medications, which have a significant side effect profile. Flavonoids can modulate numerous physiological functions including emotional and anti-nociceptive processes. Gold lotion (GL) is a natural product based on the extract of six citrus peels rich in flavonoids (0.45 mg/ml) with numerous reported biological activities. In the present study, we investigated the effect of repeated administration of GL in a battery of behavioral tests, including the open field test (OFT), forced swim test (FST), and von Frey test (vFT), in rats. While the OFT measured anxiolytic-related effects, the FST evaluated depression-related behavior. The vFT evaluated mechanical allodynia in two rat models of peripheral inflammation induced by carrageenan or complete Freund's adjuvant (CFA) administration. Treatment with GL reduced mechanical allodynia after either carrageenan or CFA administration. On the other hand, repeated GL administration did not modulate any behavior evaluated by OFT or FST. Consumption of GL inhibits behavioral signs of inflammatory pain. Therefore, GL may be a valuable analgesic product to be used for inflammatory pain.

Effects of k-carrageenan supplementation or in combination with cholesterol-loaded cyclodextrin following freezing-thawing process of rooster spermatozoa

This experimental research purposely seeks to explore the effect of supplementing k-carrageenan (k-CRG) or CLC (cholesterol-loaded cyclodextrins) or the combined effect of k-CRG and CLC as supplements of antioxidants to an extender for rooster semen freezing. A total of 75 neat pooled ejaculates were collected twice a week from twenty-five (25) commercial line arbor acres broiler roosters (30 wks) during the experimental period. In each replicate, semen samples (n= 15, three ejaculates per rooster) were pooled and divided into nine equal aliquots, and each aliquot was diluted with one of the following extender supplemented with k-CRG, CLC, and k-CRG + CLC after which it was subjected to cryopreservation process using the "pellet" method. In study I, the supplementation of extenders with k-CRG was in five equal aliquots as follows; (0.2, 0.4, 0.6, 0.8) mg/mL and control group (k-CRG 0) mg/mL while in Study II, there was a combination of both k-CRG + CLC (0.4 mg/mL + 1.5 mg/mL, respectively), 0.4 mg/mL k-CRG, 1.5 mg/mL CLC and control group. Sperm quality parameters, endogenous antioxidant enzymes, lipid peroxidation (MDA) and ROS were all assessed after the freeze-thaw process. Our findings in study I indicated that at post-thaw, an optimum 0.4 mg/mL k-CRG supplementation in the extender improved semen quality parameters, endogenous enzymes, MDA and ROS in comparison to the control group. Interestingly prior to the freeze-thaw process, it was depicted in study II that combined k-CRG + CLC (0.4 mg/mL+1.5 mg/mL) inclusion in the extender provided maximum protection to sperm quality parameters, endogenous enzymes, MDA and ROS in comparison to 1.5 mg/mL CLC and control group at post-thaw. Besides, there was also a significant difference observed in the extenders supplemented with combined k-CRG + CLC (0.4 mg/mL +1.5 mg/mL) when compared to 0.4 mg/mL k-CRG for semen quality parameters and endogenous antioxidant enzymes (SOD, CAT, and GPx) but no significant difference was observed for MDA and ROS. Also, there was a significant difference observed in the extender supplemented with 1.5 mg/mL CLC when compared to the control group for semen quality parameters, SOD, CAT, and MDA but no significant difference for GPx and ROS at post-thaw. In conclusion, k-CRG at an optimal dosage of 0.4 mg/mL proved effective for improving post-thaw sperm quality but its combined addition k-CRG + CLC at an optimal concentration of (0.4 + 1.5) mg/mL in the extender provided greater protection to the rooster spermatozoa at post-thaw.

Protagonist Role of Opioidergic System on Post-Traumatic Stress Disorder and Associated Pain

OBJECTIVE

Post-traumatic stress disorder (PTSD) and chronic pain often co-occur. Studies have shown an interaction between pain and PTSD. In this narrative review, we aim to support conducting comprehensive studies by describing PTSD, pain and determining whether opioidergic system, its agonist and antagonist manipulation could positively or negatively affect PTSD symptoms and concurrent pain.

METHODS

Term searches was done in Google Scholar, Scopus, ScienceDirect, Web of Science and PubMed databases as well as hand searching in key resource journals from 1979-2019.

RESULTS

There are a lot of contradictions and disputes when endogenous opioidergic system and opioidergic antagonist system are studied in PTSD patients. Exogenous morphine administration in PTSD patients can decrease the symptoms of PTSD but it doesn't have a pain reduction effect to an acceptable level. Beta-endorphin as an endogenous opioid is effective in pain reduction in the moment of events but after minutes to hours, the endorphins withdrawal syndrome leads to exaggerated intrusive thoughts and flashbacks of PTSD, which exacerbate the pain. It has also been shown that naloxone, as an opioidergic antagonist, can reduce or increase the PTSD symptoms and its associated pain.

CONCLUSION

Data suggest different roles of opioidergic system and their antagonist in pain control and mood in PTSD. However, further investigations need to be done in order to reveal the role of endogenous opioidergic system and opioidergic antagonist system as a mediator in PTSD patients suffering from acute or chronic pain.

Preliminary assessment of the anti-inflammatory and analgesic effects of methanol leaf extract of Cussonia barteri (Araliaceae) in rodents

Introduction: Potato (Solanum tuberosum L.) is an important vegetable crop in Syria. Potato tuber moth Cussonia barteri is a small tree that grows in the sub-Saharan part of Africa. Various parts of the plant are used for the treatment of a variety of ailments in ethno-medicine.

Objective: To evaluate the anti-inflammatory and analgesic effect of the methanol leaf extract of Cussonia barteri.

Material and methods: The leaves were air-dried, powdered and repeatedly extracted with methanol using a Soxhlet apparatus. The resulting methanol extract (100, 200 and 400 mg/kg) was evaluated for anti-inflammatory activity using carrageenan-induced paw oedema, xylene-induced ear oedema and formalin-induced arthritis tests. Analgesic effect was evaluated using acetic acid-induced mouse writhing, hot plate and tail flick tests.

Results: All doses of the extract significantly (p<0.05) reduced carrageenan-induced paw oedema, however the 400 mg/kg dose gave a sustained effect. The extract significantly inhibited xylene induced ear oedema at all doses. There were no significant (p>0.05) reductions in paw swellings due to formalin. In the acetic acid induced writhing test, the extract significantly (p<0.05) decreased writhing at 400 mg/kg only. Reaction times were not significantly different from the control in the hot plate and tail flick tests.

Conclusion: This study has shown that the methanol extract possesses acute anti-inflammatory and peripherally mediated analgesic effects.

Antinociceptive and anti-arthritic effects of aqueous whole plant extract of Trianthema portulacastrum in rodents: Possible mechanisms of action

ETHNOPHARMACOLOGICAL RELEVANCE

Trianthema portulacastrum L. (Aizoaceae) is used in traditional African Medicine for the treatment of various illnesses including dropsy, inflammation and rheumatism.

AIM OF THE STUDY

This study was designed to investigate the anti-nociceptive and anti-arthritic properties of the aqueous whole plant extract of Trianthema portulacastrum (AETP), possible mechanisms of action and characterize some of the active constituents.

MATERIALS AND METHODS

Antinociceptive activity was evaluated using the acetic acid-induced writhing and hot plate tests in mice. The carrageenan test was used to induce a transient inflammation while arthritis was induced with complete Freund's adjuvant (CFA) in rats. On completion of CFA-induced arthritis macroscopic observations, the rats were euthanized to isolate the spleen, liver and limbs for estimation of oxidative stress and histological analysis.

RESULTS

AETP (10, 50, or 250 mg/kg; p.o.) produced significant (p < 0.05) and dose-dependent inhibition (41.10, 50.40, and 67.10%, respectively) of writhing response elicited by acetic acid. Also, increased pain threshold of supraspinally mediated nociceptive behaviour, with peak maximum possible effect (MPE) obtained at 250 mg/kg (22.98%; 30 min post-treatment). However, the pre-treatment of mice with Nitro-L-arginine (L-NNA) or naloxone reversed AETP-induced antinociception. In another experiment, AETP produced time course inhibition of carrageenan-induced paw oedema with peak effect (50.60%) at 250 mg/kg as well as significant reduction in CFA-induced arthritis by 58.56%, on day 27 and arthritic index (26.84%). Similarly, AETP attenuated CFA-induced MDA generation and deficit in antioxidant enzyme activities. Histological analysis of rat joints revealed a reduction in the synovial hyperplasia and mononuclear infiltration induced by CFA in AETP treated groups.

CONCLUSION

Findings from this study showed that T. portulacastrum possesses anti-nociceptive action through nitrergic and opioidergic signalling as well as anti-arthritic effect through enhancement of antioxidant defense system and inhibition of release or actions of inflammatory mediators.

Natural chromones as potential anti-inflammatory agents: Pharmacological properties and related mechanisms

Chromones are a group of natural substances with a diversity of biological activities. Herein we assessed the pharmacological potential of three chromones (1, 2 and 3) isolated from Dictyoloma vandellianum as anti-inflammatory agents using in vitro and in vivo approaches. During in vitro screening, the production of NO and cytokines by macrophages stimulated with LPS and IFN-γ was inhibited by all chromones at concentrations (5-20 μM) that did not induce cytotoxicity. Analysis of pharmacokinetic parameters (in vitro half-life and intrinsic clearance) using human liver microsomes revealed that 3 has a superior pharmacokinetic profile, compared to 1 and 2. Treatment with 3 (100 mg/kg, ip) did not affect the mice motor performance, while 1 and 2 induced motor deficit. Taking into account the pharmacokinetic profile and absence of motor impairment, 3 was selected for further pharmacological characterization. Corroborating the data from in vitro screening, treatment of cell cultures with 3 (5-20 μM) reduced TNF-α, IL-6 and IL-1β production by stimulated macrophages. In the complete Freund's adjuvant-induced paw inflammation model in mice, 3 (25 and 50 mg/kg, ip) inhibited mechanical hyperalgesia, edema and cytokine production/release (IL-1β, IL-6 and TNF-α). 3 (5-20 μM) also reduced the transcriptional activity of NF-κB in stimulated macrophages. Furthermore, treatment with RU486, a glucocorticoid receptor (GR) antagonist, partially prevented the inhibitory effect of 3 on macrophages, indicating that this chromone exerts its anti-inflammatory effects in part through the activation of GR. The results presented herein demonstrate the pharmacological potential of natural chromones, highlighting 3 as a possible candidate for the drug discovery process targeting new anti-inflammatory drugs.

Antimicrobial, anti-inflammatory and wound healing activity of polyherbal formulation

According to Ayurveda, individual herbs are insufficient to achieve a desired therapeutic effect. When it is optimized as multiple herbs composition in a particular ratio it will give a therapeutic effect in a better way with reduced toxicity. In order to develop such an intervention, the present study was intended to develop a polyherbal drug from methanolic extracts of Plumbago zeylanica Linn, Datura stramonium Linn and Argemone mexicana Linn. The study also aimed to evaluate the impact of polyherbalism on antimicrobial and antioxidant effect, thereafter the ratio of individual plant extracts was optimized accordingly to treat the wound. The poyherbal drug was put on preclinical trial to access the anti-inflammatory and wound healing activity as 2% and 5% polyherbal carbopol-940 gels. The antimicrobial activity was assessed by agar well diffusion and broth dilution method while wound healing activity was evaluated by excision and incision wound models. Topical anti-inflammatory activity was assessed by carrageenan induced paw oedema. The findings of the study revealed the synergistic antimicrobial potential of Polyherbal drug against gram-positive and negative strains. Polyherbal carbopol- 940 gels (2% and 5%w/w) promoted the wound healing and anti-inflammatory effect. The high rate of wound contraction (<0.0001), early epithelialization period (<0.0001) and increased wound breaking strength (<0.0001) were observed in 2% and 5% polyherbal gel treated group when compared to the normal control and negative control group. The antimicrobial and anti-inflammatory effect of Polyherbal drug provoked and promoted the wound healing process through accelerated remodelling of damaged tissue.

Anti-inflammatory effect of an adhesive resin containing indomethacin-loaded nanocapsules

OBJECTIVE

To analyze the anti-inflammatory and analgesic effects of an adhesive resin containing indomethacin-loaded nanocapsules in rat model.

DESIGN

Adhesive resin disks with or without indomethacin-loaded nanocapsules were subcutaneously implanted into right hind paw of rats. A week after surgical procedure, 2% formalin solution was intradermally injected into plantar surface of paw. Nociceptive and inflammatory responses were evaluated by formalin test. Paw edema by pletismometer and mechanical hyperalgesia by von Frey test were performed on day 2, day 4, day 6, day 8, day 10 and day 12 after surgery. IL-6, IL-10, and lactate dehydrogenase (LDH) serum levels were determined by ELISA-sandwich test.

RESULTS

Group containing indomethacin-loaded nanocapsules (NC) presented lower edema in the right hind paw at 24h after formalin injection than those of the control group (CT) (P<0.01). NC group showed decrease in the nociceptive response in phase I (neurogenic pain) compared to CT group (NC - 66.86±22.83s X CT - 130.17±35.83s, P<0.001). NC group presented supporting higher intensity of stimulus on days 8 and 12 (24h and 72h after formalin injection) (P<0.01 and P<0.02 respectively). The IL-6 serum level was also significantly higher in the NC group than CT group (p<0.001).

CONCLUSIONS

These results indicate that an adhesive resin containing indomethacin-loaded nanocapsules has anti-inflammatory and nociceptive activities in a chemical model of acute inflammation. The present investigation confirms an adhesive resin with drug-loaded nanocapsules may be useful for improving therapeutic effect for adhesives to be used in deep cavities.

The thermal probe test: A novel behavioral assay to quantify thermal paw withdrawal thresholds in mice

Rodent models are frequently used to improve our understanding of the molecular mechanisms of pain and to develop novel analgesics. Robust behavioral assays that quantify nociceptive responses to different sensory modalities, such has heat, are therefore needed. Here, we describe a novel behavioral assay to quantify thermal paw withdrawal thresholds in mice, called the thermal probe test, and compared it with other methods commonly used to measure heat thresholds, namely the Hargreaves test and the dynamic and conventional hot plate tests. In the thermal probe test, a slightly rounded 2.5 mm diameter metal probe that heats on contact at a rate of 2.5°C/sec, is applied to the plantar surface of the hind paw in mice at a starting temperature of ∼37°C, and the temperature at which a withdrawal response occurs, designated as the paw withdrawal temperature, is automatically recorded. The thermal probe test is effective at quantifying thermal allodynia in carrageenan-induced inflammation (paw withdrawal temperature 3 h: contralateral, 50.3 ± 0.6°C; ipsilateral, 43.1 ± 1.0°C), burns injury (paw withdrawal temperature 3 d: contralateral, 50.8 ± 0.5°C; ipsilateral, 43.2 ± 0.6°C) and after topical capsaicin (paw withdrawal temperature: vehicle control, 49.7 ± 0.6°C; capsaicin, 44.8 ± 1.2°C), giving comparable results to the Hargreaves test. In addition, the thermal probe test can detect opioid mediated analgesia in carrageenan-induced inflammation. Therefore the thermal probe test is a novel behavioral assay effective for quantifying thermal allodynia and analgesia in mouse models of pain.