LMD and LC-MS-based chemical constituents and pharmacological effects assessment for two different processing methods of the root of Paeonia lactiflora Pall.

The plant of Paeonia lactiflora Pall. belongs to Ranunculaceae, and its root can be divided into two categories according to different processing methods, which included that one was directly dried without peeling the root of the P. lactiflora (PR), and the other was peeled the root of the P. lactiflora (PPR) after boiled and dried. To evaluate the difference of chemical components, UPLC-ESI-Q-Exactive Focus-MS/MS and UPLC-QQQ-MS were applied. The distribution of chemical components in different tissues was located by laser microdissection (LMD), especially the different ingredients. A total of 86 compounds were identified from PR and PPR. Four kind of tissues were isolated from the fresh root of the P. lactiflora (FPR), and 54 compounds were identified. Especially the content of gallic acid, albiflorin, and paeoniflorin with high biological activities were the highest in the cork, but they were lower in PR than that in PPR, which probably related to the process. To illustrate the difference in pharmacological effects of PR and PPR, the tonifying blood and analgesic effects on mice were investigated, and it was found that the tonifying blood and analgesic effects of PPR was superior to that of PR, even though PR had more constituents. The material basis for tonifying blood and analgesic effect of the root of P. lactiflora is likely to be associated with an increase in constituents such as paeoniflorin and paeoniflorin lactone after boiled and peeled. The study was likely to provide some theoretical support for the standard and clinical application.

Efficacy assessment of novel methanimine derivatives in chronic constriction injury-induced neuropathic model: An in-vivo, ex-vivo and In-Silico approach.

The multicomponent etiology, complex clinical implications, dose-based side effect and degree of pain mitigation associated with the current pharmacological therapy is incapable in complete resolution of chronic neuropathic pain patients which necessitates the perpetual requirement of novel medication therapy. Therefore, this study explored the ameliorative aptitude of two novel methanimine imitative like (E)-N-(4-nitrobenzylidene)-4­chloro-2-iodobenzamine (KB 09) and (E)-N-(4-methylbenzylidene)-4­chloro-2-iodobenzamine (KB 10) in chronic constriction injury (CCI) of sciatic nerve induced neuropathic pain in rat model. Standard behavioral tests like dynamic and static allodynia, cold, thermal and mechanical hyperalgesia along with rotarod activity were performed at various experimental days like 0, 3, 7, 14 and 21. Enzyme linked immunosorbent assay (ELISA) on spinal tissue and antioxidant assays on sciatic nerve were executed accompanied by molecular docking and simulation studies. Prolonged ligation of sciatic nerve expressively induced hyperalgesia as well as allodynia in rats. KB 09 and KB 10 substantially attenuated the CCI elicited hyperalgesia and allodynia. They significantly reduced the biomarkers of pain and inflammation like Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in ELISA and while enhanced the GSH, SOD and CAT and diminished the MDA levels during antioxidant assays. KB 09 displayed -9.62 kcal/mol with TNF-α and -7.68 kcal/mol binding energy with IL-6 whereas KB 10 exhibited binding energy of -8.20 kcal/mol with IL-6 while -11.68 kcal/mol with TNF-α and hence both trial compounds ensured stable interaction with IL-6 and TNF-α during computational analysis. The results advocated that both methanimine derivatives might be novel candidates for attenuation of CCI-induced neuropathic pain prospects via anti-nociceptive, anti-inflammatory and antioxidant mechanisms.

Phytochemical Investigation, In silico/In vivo Analgesic, and Anti-inflammatory Assessment of the Egyptian Cassia occidentalis L.

Cassia occidentalis L., from Fabaceae family phytochemical screening, revealed several biologically active principles mainly flavonoids and anthraquinones. GLC analysis of the lipoidal matter afforded 12 hydrocarbons: 9-dodecyl-tetradecahydro-anthracene (48.97 %), 9-dodecyl-tetradecahydro-phenanthrene (14.43 %), and 6 sterols/triterpenes: isojaspisterol (11.99%) and fatty acids were palmitic acid (50 %), and Linoleic acid (16.06%). Column chromatography led to the isolation of fifteen compounds (1-15), elucidated using spectroscopic evidence. First report of undecanoic acid (4) from the family Fabaceae, while p-dimethyl amino-benzaldehyde (15) was first time isolated from a natural origin. Eight compounds isolated for the first time from C. occidentalis L.; ß-amyrin (1), ß-sitosterol (2), stigmasterol (3), camphor (5), lupeol (6), chrysin (7), pectolinargenin (8), and 1, 2, 5-trihydroxy anthraquinone (14) besides five known compounds previously isolated; apigenin (9), kaempferol (10), chrysophanol (11), physcion (12), and aloe-emodin (13). In-vivo evaluation of anti-inflammatory and analgesic effects of C. occidentalis L. extracts where the n-butanol and total extracts showed the highest activities. The percentage of the inhibitory effect of the n-butanol extract was 29.7 at a dose of 400 mg/Kg. Furthermore, identified phytoconstituents were docked into the active sites of enzymes nAChRs, COX-1, and COX-2 to evaluate binding affinity. Phyto-compounds Physcion, aloe-emodin, and chrysophanol were found to have a good affinity for targeted receptors compared to co-crystalized inhibitors, validating the analgesic and anti-inflammatory effects of the phytochemicals.

Assessment of Iris albicans lange as potential antimicrobial and analgesic agent.

Objective of the present work was to evaluate the presence of phytochemical constituents and pharmacological activities (antimicrobial and anti-nociceptive) of crude extract isolated from Iris albicans and its corresponding fractions. Extraction was made with methanol and extract was evaluated for the presence of different bioactive constituents, as per standard protocols. Extract and its corresponding fractions were evaluated for their antimicrobial and anti-nociceptive potential. Well diffusion method was used to evaluate the antibacterial effects while anti-nociceptive effect was studied using in-vivo models (acetic acid induced writhing, hotplate and tail immersion tests) at different dose level (100, 200 and 300 mg/kg of body weight) and compared with diclofenac sodium (dose = 10 mg/kg body weight). Results showed that the I. albicans extracts contained secondary metabolites including alkaloids, phytosterols, flavonoids, saponins, terpenoids, tannins, phenols, steroids, fixed oil, glycosides and carbohydrates. Furthermore, it was observed that different fractions in decreasing polarity order such as chloroform >n-Hexane > Ethyl acetate > Crude Methanol > Aqueous extract exhibited effective antimicrobial response against all test organisms. Results of the study showed that the extracts have significant antimicrobial and analgesic activity, providing evidence for its folklore use.

In the Swim of Cannabis: Developmental Toxicity and Metabolomic Pathway Alterations of Zebrafish Larvae Exposed to THC for the Assessment of Its Potential Environmental and Human Health Impact.

As the pharmacological properties and therapeutic applications of Cannabis sativa L. pace with the upsurge of interest of the scientific community in harnessing its constituent phytocannabinoids, illicit use may raise serious health issues. Tetrahydrocannabinol (THC) is one of the most well-known phytoactive constituents of cannabis and continues to garner scientific and public attention not only because of its pharmacological value but also because over-the-counter products of THC and prescription medications are becoming increasingly available from pharmacies, dispensaries, Internet, local retail stores, or by illicit means. Hence, a multidimensional approach was employed to examine the impact of THC on zebrafish larvae. The acute toxicity, expressed as LC50, was 1.54 mg/L. Adverse effects were observed on the phenotype, such as tail bending, pericardial edema, etc., even at concentrations lower than LC50, and fundamental functions of larvae (e.g., heart rate and cardiac contractility, and rhythm) were significantly affected. Behavioral changes were noticed, which were reflected in locomotor activity and sensitivity to light/dark changes. Finally, an untargeted metabolomic study was carried out to shed light on the metabolic alterations that occurred, providing substantiating evidence of the observed phenotype alterations. Overall, the potentially detrimental effects of THC on a vertebrate model are depicted.

Safety Assessment and Pain Relief Properties of Saffron from Taliouine Region (Morocco).

Saffron is the most expensive spice in the world. In addition to its culinary utilization, this spice is used for medicinal purposes such as in pain management. In this study, the analgesic activity of Crocus sativus stigma extract (CSSE) was evaluated in rodents and its possible physiological mechanism was elucidated. The anti-nociceptive effect of CSSE was evaluated using three animal models (hot plate, writhing, and formalin tests). The analgesic pathways involved were assessed using various analgesia-mediating receptors antagonists. The oral administration of CSSE, up to 2000 mg/kg, caused no death or changes in the behavior or in the hematological and biochemical blood parameters of treated animals nor in the histological architecture of the animals' livers and kidneys. CSSE showed a central, dose-dependent, anti-nociceptive effect in response to thermal stimuli; and a peripheral analgesic effect in the test of contortions induced by acetic acid. The dual (central and peripheral) analgesic effect was confirmed by the formalin test. The anti-nociceptive activity of CSSE was totally or partially reversed by the co-administration of receptor antagonists, naloxone, atropine, haloperidol, yohimbine, and glibenclamide. CSSE influenced signal processing, by the modulation of the opioidergic, adrenergic, and muscarinic systems at the peripheral and central levels; and by regulation of the dopaminergic system and control of the opening of the ATP-sensitive K+ channels at the spinal level. The obtained data point to a multimodal mechanism of action for CSSE: An anti-inflammatory effect and a modulation, through different physiological pathways, of the electrical signal generated by the nociceptors. Further clinical trials are required to endorse the potential utilization of Moroccan saffron as a natural painkiller.

Pharmacodynamics assessment of ß-carboline from the roots of Psammosilene tunicoides as analgesic compound.

ETHNOPHARMACOLOGICAL RELEVANCE: The root of Psammosilene tunicoides (W. C. Wu et C. Y. Wu) is a well-known medicinal herb for the treatment of pain, hemostasia and rheumatoid arthritis among Chinese people. AIM OF THE STUDY: The present study aimed to investigate the antinociceptive activity and mechanism of ß-carboline alkaloids 1-4 which were extracted from the roots of P. tunicoides. MATERIALS AND METHODS: The analgesic effects were evaluated using peripheral and central pain mouse models of nociception, including the formalin test and the tail flick test. The levels of glutamic acid (Glu) and nitric oxide (NO) in cerebellar cortexes and spinal cords (L4-6) were determined. The anti-inflammatory of all compounds were then assessed on RAW264.7 cells. RESULTS: Our results showed that compounds 1-4 had significant analgesic effects on both phases of formalin test of mice. Furthermore, all compounds showed suppressive effects on Glu in the brain and NO levels in the brain cortex and the spinal cord. Except for compound 1, the others could extend the pain threshold of hot water tail-flick in mice. In addition, compounds 2 and 3 (60 µmol/kg) could decrease GABAAα1 protein levels in spinal cord. All compounds exhibited anti-inflammatory effects by inhibiting lipopolysaccharide (LPS)-induced NO production in RAW264.7 cells with half-maximal inhibitory concentration (IC50) 1.1-34.9 µM. CONCLUSION: ß-carboline alkaloids from the roots of P. tunicoides had significant analgesic activity by both central and peripheral mechanisms. Our findings suggested that regulating the release of NO or Glu or GABAα1 are some of the mechanisms of analgesic activity of ß-carboline alkaloids.

Syzygium cumini (L.) Skeels extracts; in vivo anti-nociceptive, anti-inflammatory, acute and subacute toxicity assessment.

ETHNOPHARMACOLOGICAL RELEVANCE: Syzygium cumini (L.) Skeels has been extensively used in the ancient medical system of Pakistan, India, Bangladesh, and Sri Lanka to combat diabetes, inflammation, and renal disorders. These health-promoting aspects of S. cumini are related to bioactive metabolites such as phenolic acids, anthocyanins, tannins, and flavonoids. AIM OF THE STUDY: Earlier to this study, we have reported S. cumini extracts as potential sources of bioactive compounds bearing antioxidant and anti-inflammatory properties. However, prior further suggesting S. cumini fruit extracts for consumption against inflammatory disorders, it was mandatory to validate the claim and explore toxicity of the extracts. This study aims to determine the in vivo anti-nociceptive, anti-inflammatory, acute, and subacute toxicity properties of S. cumini crude extracts, followed by identifying and quantifying bioactive metabolites. MATERIAL AND METHODS: In the present study, the anti-nociceptive and anti-inflammatory potential of S. cumini sequential crude extracts were evaluated using formalin and glutamate-induced paw licking method in mice. The acute and sub-acute toxicity assessment of active extract was performed by oral administration in rats. An acute toxicity trial was performed with two different doses, i.e., 2000 mg/kg and 3000 mg/kg for consecutive 14 days, whereas a sub-acute toxicity study was conducted at doses of 750 mg/kg and 1500 mg/kg for the next 28 days. Identification of bioactive compounds was performed using HPLC, and at the end, in silico docking calculations of identified compounds were performed. RESULTS: The 100% methanolic extract (SCME) protected the mice from painful stimulation of formalin and glutamate in a dose-dependent manner with the maximum effect of 49% and 67% at 200 mg/kg, respectively, followed by moderate and non-influential effects of 50% methanolic extract and dichloromethane (DCM) extracts when compared to control, i.e., normal saline. The results of acute toxicity recorded LD50 of SCME over 3000 mg/kg, and no antagonistic effects were recorded during the subacute study when SCME dispensed at the rate of 750 mg/kg and 1500 mg/kg. SCME was found to induce no adverse effects to kidney, heart, liver, spleen, and paired lungs examined by hematological, serum biochemical, histological analysis. HPLC analysis of S. cumini 100% methanolic extracts revealed the presence of delphinidin 3-glucoside, peonidin-3,5-diglucoside, scopoletin, and umbelliferone at the concentration of 127.4, 2104, 31.3, 10.4 µg/g whereas in 50% methanolic extract, the quinic acid, catechin, and myricetin were present at the concentration of 54.9, 63.7, 12.3 µg/g, respectively. Umbelliferone and scopoletin are newly reported compounds in the present study. In silico docking calculations of these compounds indicated the potential of anti-nociceptive and anti-inflammatory activities. CONCLUSIONS: These findings validate that S. cumini fruit extracts are a rich source of bioactive compounds that needs to be considered to enhance biological activities with lesser side effects.

Assessment of Antimicrobial Agents, Analgesics, and Epidermal Growth Factors-Embedded Anti-Adhesive Poly(Lactic-Co-Glycolic Acid) Nanofibrous Membranes: In vitro and in vivo Studies.

BACKGROUND: Postoperative tissue adhesion is a major concern for most surgeons and is a nearly unpreventable complication after abdominal or pelvic surgeries. This study explored the use of sandwich-structured antimicrobial agents, analgesics, and human epidermal growth factor (hEGF)-incorporated anti-adhesive poly(lactic-co-glycolic acid) nanofibrous membranes for surgical wounds. MATERIALS AND METHODS: Electrospinning and co-axial electrospinning techniques were utilized in fabricating the membranes. After spinning, the properties of the prepared membranes were assessed. Additionally, high-performance liquid chromatography and enzyme-linked immunosorbent assays were utilized in assessing the in vitro and in vivo liberation profiles of the pharmaceuticals and the hEGF from the membranes. RESULTS: The measured data suggest that the degradable anti-adhesive membranes discharged high levels of vancomycin/ceftazidime, ketorolac, and hEGF in vitro for more than 30, 24, and 27 days, respectively. The in vivo assessment in a rat laparotomy model indicated no adhesion in the peritoneal cavity at 14 days post-operation, demonstrating the anti-adhesive capability of the sandwich-structured nanofibrous membranes. The nanofibers also released effective levels of vancomycin, ceftazidime, and ketorolac for more than 28 days in vivo. Histological examination revealed no adverse effects. CONCLUSION: The outcomes of this study implied that the anti-adhesive nanofibers with sustained release of antimicrobial agents, analgesics, and growth factors might offer postoperative pain relief and infection control, as well as promote postoperative healing of surgical wounds.

Preclinical assessment of analgesic, anti-inflammatory and antipyretic potential of Fragaria ananassa and Actinidia deliciosa fruit extract.

Fragaria ananassa (garden strawberry) and Actinidia deliciosa (kiwi) fruits are widely consumed due to their taste and nutritive value however several studies also supports their medicinal uses. Current study was designed to assess the In-Vivo analgesic, anti-inflammatory and antipyretic activity of ethanol extract of Fragaria ananassa (EEFA), Actinidia deliciosa (EEDA) and their 1:1 combination. Albino Wistar rats were divided into five groups (n=5) for each study comprising of vehicle control, reference standards *(aspirin and paracetamol 100 mg/kg/day), EEFA (800 mg/kg/day), EEAD (800 mg/kg/day) and 1:1 combination of EEFA and EEAD (400 + 400mg/kg/day). The results revealed significant anti-inflammatory potential of EEAD and their combination with 79.35% and 82.03% inhibition in carrageenan induced paw edema whereas 52.54% inhibition was produced by EEFA against control. However most powerful analgesic effect was produced by EEFA with 52.23% at 60 min followed by EEAD (48.38%) and EEFA+ EEAD combination (44.09%). Similarly, EEFA, EEAD and their combination also lowered the rectal temperature in highly significant manner (p< 0.01) against control. These results suggested the possible role of garden strawberry and kiwi in treating the ailments related to pain, inflammation and fever however further studies are required to elucidate the constituents responsible for it and their exact mechanism.

Assessment of pharmacological activities of Lygodium microphyllum Cav. leaves in the management of pain, inflammation, pyrexia, diarrhea, and helminths: In vivo, in vitro and in silico approaches.

Lygodium microphyllum Cav. (Family: Lygodiaceae) is a perennial, snake fern and an invasive weed in Florida and also known as old world climbing fern. This study is intended to evaluate the antipyretic, analgesic, anti-inflammatory, antidiarrheal and anthelmintic activity of methanol extract of Lygodium microphyllum Cav. leaves (MELM) by in vivo, in vitro and in silico approaches. In addition, Biovia, PyRx autoDock Vina, UCSF Chimera have been applied to investigate the docking study in order to evaluate the binding interaction and an online tool was used to explore the ADME/T properties of selected bioactive compounds. In acetic acid induced writhing study, MELM inhibited 44.28% and 56.61% of writhes at 200 and 400 (mg/kg) respectively compared to standard drug Diclofenac-Na (10 mg/kg) (74.42% inhibition). In anti-inflammatory experiment by formalin triggered licking method, MELM caused significant (p < 0.05) inhibition of licking in both early phase (42.97%, 63.30%) and late phase (43.35%, 63.03%) at the doses of 200 and 400 mg/kg respectively, whereas reference drug Ibuprofen inhibited paw licking 77.18% in early phase and 76.86% in late phase. MELM also showed promising antipyretic potential where the maximum reduction of fever was produced by MELM 400 mg/kg whose fever lowering capacity is close to the prescribe drug Indomethacin 4 mg/kg, i.p. In Castor oil triggered diarrhea method, MELM delayed the onset time of diarrhea, continuous persistence of wet feces, and decreased the weight of wet feces remarkably. Defection inhibition was achieved 27.56% and 51.72%, for MELM 200 and at 400 (mg/kg) respectively while loperamide 2 (mg/kg) yields 55.17% inhibition of the diarrheal defecation. In anthelmintic bioassay, MELM took 5.83 ± 0.83 and 41.67 ± 1.78 min respectively for paralyzing and death compared to standard drug albendazole; (paralysis time 4.00 ± 0.73 min and death time 31,00 ± 1.71 min). Isoeleutherol, isoquercetin and quercetin were found prominent in molecular docking study and ADME/T analysis verified their drug likeliness. The research validates the moderate analgesic, anti-inflammatory, and remarkable antipyretic, antidiarrheal, anthelmintic activities of the plant extract which can be used an alternative source of novel therapeutics.

Synthesis and Assessment of Fused ß-Carboline Derivatives as Kappa Opioid Receptor Agonists.

The synthesis of 5-formyl-6-aryl-6H-indolo[3,2,1-de][1,5] naphthyridine-2-carboxylates by reaction between 1-formyl-9H-ß-carbolines and cinnamaldehydes in the presence of pyrrolidine in water with microwave irradiation is described. Pharmacophoric modification of the formyl group offered several new fused ß-carboline derivatives, which were investigated for their κ-opioid receptor (KOR) agonistic activity. Two compounds 4 a and 4 c produced appreciable agonist activity on KOR with EC50 values of 46±19 and 134±9 nM, respectively. Moreover, compound-induced KOR signaling studies suggested both compounds to be extremely G-protein-biased agonists. The analgesic effect of 4 a was validated by the increase in tail flick latency in mice in a time-dependent manner, which was completely blocked by the KOR-selective antagonist norBNI. Moreover, unlike U50488, an unbiased full KOR agonist, 4 a did not induce sedation. The docking of 4 a with the human KOR was studied to rationalize the result.

A Realistic Approach for Anti-Inflammatory, Antinociceptive and Antimutagenic Activities, and Risk Assessment of the Aqueous Extract of Platanus orientalis L. Leaves.

BACKGROUND: Oriental planetree (Platanus orientalis L.) leaf was recorded as a remedy against inflammatory problems and to stop the pain, i.e. toothache or knee pain in "The Canon of Medicines" by Avicenna and was also being documented in the Iranian Traditional Medicine. Although such a utilization has not been described in reliable sources, recently use of its leaves as herbal tea has become popular among laypeople. Previous studies have shown that only the nonpolar extract from the leaves may have such efficacy, while possible benefits when it is used as herbal tea have not been investigated. OBJECTIVE: The present study aims to reveal the possible efficacy and safety profile of aqueous extract from P. orientalis leaf. METHODS: Aqueous extract of the leaves was submitted to in vivo and in vitro tests to determine its anti-inflammatory, antinociceptive, antimutagenic activities and also reveal its safety profile. RESULTS: The aqueous extract (400 mg/kg) procured weak and non-significant anti-inflammatory and antinociceptive activities. Meanwhile, the aqueous extract demonstrated antimutagenic activity in very high concentrations. On the other hand, results of safety evaluation showed that no concern had been observed from the viewpoint of public health. CONCLUSION: Despite the popularity of the herbal tea prepared from the leaves of Oriental planetree among the people suffering joint problems to relieve pain, this study has proven that such application would not help them to alleviate their complaints when used as herbal tea.

Leaves of Cleome amblyocarpa Barr. And Murb. And Cleome arabica L.: Assessment of nutritional composition and chemical profile (LC-ESI-MS/MS), anti-inflammatory and analgesic effects of their extracts.

ETHNOPHARMACOLOGICAL RELEVANCE: The Cleomaceae family is known for its richness in secondary metabolites and different Cleome species are used in folk medicine. Cleome amblyocarpa and Cleome arabica are medicinal herbs used in Tunisia and other North Africa countries to treat various diseases such as diabetes, rheumatism, colic, pain and digestive disorders. AIM OF THE STUDY: To our knowledge, few data are available about the nutritional value, phytochemical components and biological effects of C. arabica and C. amblyocarpa cultivated in Tunisia. For this reason, the present survey aimed to determine the nutritional value, bioactive compounds and pharmacological properties of the leaves of these two species of Cleome. MATERIALS AND METHODS: To characterize and determine the bioactive compounds in both extracts of leaves of Cleome species, ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) was used. The various nutritional parameters were analyzed, in particular the amounts of protein, carbohydrates, ash, fiber, and total lipids. Vitamin E and fatty acid profiles were also evaluated by HPLC-DAD-FLD and GC-FID, respectively. The acute toxic effects of leaf extracts in mice at concentrations of 100, 500 and 800 mg/kg body weight have been investigated. The anti-inflammatory effect of leaves extracts was examined by means of the in vitro and in vivo models. The in vivo anti-inflammatory test was assessed by means of the carrageenan induced paw edema in rats. For the in vitro anti-inflammatory assay, the red blood cells membrane stabilization and protein denaturation methods were employed. The analgesic effect of hydroalcoholic extracts of leaves was also assessed by acetic acid induced writhing model in mice. RESULTS: The phytochemical composition and the nutritional values of the leaves of C. amblyocarpa and C. arabica were determined. Our results revealed that the leaves of C. amblyocarpa are rich in flavonoids and glucosinolates. On the other hand, these latter metabolites are not present in the C. arabica extract and the leaves are characterized by the presence of flavones, methoxyflavones and their glycosides. Our findings revealed that the leaves of the two species contain a potential quantity of vitamins; proteins, carbohydrates and dietary fiber, and their hydroalcoholic extracts indicated substantial anti-inflammatory and antinociceptive activities in all the tests. Additionally, the data from the acute toxicity test proved that the leaf extracts did not cause any mortality or signs of toxicity in animals at doses up to 800 mg/kg CONCLUSIONS: The results obtained in this investigation demonstrated that the leaves of C. arabica and C. amblyocarpa are a valuable source of nutrients and active substances. Our observations support the traditional utilize of these two Cleome species for the treatment of painful diseases and as a source of natural anti-inflammatory agents.

Assessment of the anti-allodynic efficacy of a glycine transporter 2 inhibitor relative to pregabalin and duloxetine in a rat model of prostate cancer-induced bone pain.

BACKGROUND: The pathobiology of prostate cancer-induced bone pain (PCIBP) is underpinned by both inflammatory and neuropathic components. Here, we used a rat model of PCIBP to assess the analgesic efficacy of a glycine transporter 2 (GlyT2) inhibitor (N-(6-((1,3-dihydroxypropan-2-yl)amino)-2-(dimethylamino)pyridin-3-yl)-3,5-dimethoxy-4-(4-(trifluoromethyl)phenoxy) benzamide) relative to two clinically available adjuvant drugs that are recommended for the relief of neuropathic pain, viz, pregabalin and duloxetine. METHODS: PCIBP was induced in male Wistar Han rats following intra-tibial injection (ITI) of rat prostate cancer (AT3B) cells into the left tibia. Sham-rats received an ITI of heat-killed AT3B cells. PCIBP rats with fully developed mechanical allodynia in the ipsilateral hindpaws as assessed using von Frey filaments, received single oral (p.o.) bolus doses of the GlyT2 inhibitor (3-30 mg/kg), pregabalin (3-100 mg/kg), duloxetine (3-100 mg/kg), or vehicle. Baseline paw withdrawal thresholds (PWTs) were determined in the ipsilateral (injured side) and contralateral hindpaws immediately prior to dosing and at scheduled times for 3 h post dosing in individual animals. RESULTS: Single oral bolus doses of the GlyT2 inhibitor (3-30 mg/kg) evoked partial pain relief at the doses tested in the ipsilateral hindpaws of PCIBP rats without any discernible behavioural side effects. By contrast, single oral bolus doses of pregabalin at 10-100 mg/kg evoked dose-dependent and complete alleviation of mechanical allodynia. By comparison, single oral bolus doses of duloxetine at doses up to 100 mg/kg lacked efficacy. CONCLUSION: Oral administration of this GlyT2 inhibitor evoked partial pain relief in PCIBP rats and did not evoke central nervous system side effects in contrast to GlyT2 inhibitors reported by others.

Assessment of the anti-hyperalgesic efficacy of J-2156, relative to clinically available analgesic/adjuvant agents in a rat model of mild to moderate chronic mechanical low back pain (LBP).

Chronic mechanical low back pain (cLBP) is a leading cause of disability and a major socio-economic burden internationally. The lifetime prevalence of non-specific LBP is approximately 84%, with the prevalence of cLBP at about 23%. Clinically available analgesic/adjuvant medications often provide inadequate pain relief in patients experiencing cLBP. Hence, the urgency for discovery of effective and better tolerated medications. Fourteen days after the induction of five shallow annular punctures (5X) in the lumbar intervertebral discs at L4/L5 and L5/L6 in male Sprague-Dawley rats, mechanical hyperalgesia was fully developed in the lumbar axial deep tissues at L4/L5 (primary) and L1 (secondary). Importantly, mechanical allodynia in the hindpaws was absent. From day 28, we assessed the face validity of our mild to moderate LBP-5X rat model using four clinically available analgesic/adjuvant drugs, namely gabapentin, morphine, meloxicam and amitriptyline relative to vehicle. Additionally, the anti-hyperalgesic effects of J-2156, a highly selective small molecule somatostatin type 4 receptor agonist was assessed. Single i.p. bolus doses of gabapentin and meloxicam at the highest doses tested (100 and 30 mg/kg, respectively) alleviated secondary hyperalgesia (L1) but not primary hyperalgesia (L4/5). Morphine at 1 mg/kg alleviated both primary and secondary hyperalgesia in these tissues, whereas amitriptyline at the doses tested, lacked efficacy. These findings attest to the face validity of our model. J-2156 at 10 and 30 mg/kg alleviated secondary hyperalgesia in the lumbar axial deep tissues at L1 with a non-significant trend for relief of primary hyperalgesia in the corresponding tissues at L4/L5 in these animals.

Design, synthesis and pharmacological assessment of new pyrazole compounds.

AIMS: This study investigated the antinociceptive and anti-inflammatory effects of new pyrazole compounds LQFM011(5), LQFM043(6) and LQFM044(7) as well as the mechanisms of action and acute in vitro toxicity. MAIN METHODS: The antinociceptive activity was evaluated using the acetic acid-induced abdominal writhing test, formalin-induced pain test and the Randall-Selitto test. The anti-inflammatory activity was evaluated using models of paw oedema and pleurisy induced by carrageenan; cell migration, the levels of tumour necrosis factor α (TNF-α) and myeloperoxidase (MPO) enzyme activity were evaluated. In addition, the ability to inhibit phospholipase A2 (PLA2) in vitro and docking in PLA2 were used. Acute oral systemic toxicity in mice was evaluated through the neutral red uptake assay. KEY FINDINGS: The synthesised compounds (5-7), delivered via gavage (p.o.) at 70, 140 or 280 µmol/kg, decreased the number of writhings induced by acetic acid; the three compounds (280 µmol/kg p.o.) reduced the paw licking time in the first and second phase of the formalin test and decreased the nociceptive threshold variation in the Randall-Selitto test. Furthermore, this dose reduced oedema formation, leucocyte migration (specifically through reduction in polymorphonuclear cell movement) and increased mononuclear cells. MPO activity and the levels of pro-inflammatory cytokines TNF-α were decreased. Evaluation of PLA2 inhibition via the docking simulation revealed more interactions of LQFM043R(6) and LQFM044(7), data that corroborated the half-maximal inhibitory concentration (IC50) of PLA2 inhibition in vitro. Therefore, LQFM011(5), LQFM043(6) and LQFM044(7) were classified with the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) as category 4.

Pharmacological and molecular docking assessment of cryptotanshinone as natural-derived analgesic compound.

Medicinal plants from traditional chinese medicine are used increasingly worldwide for their benefits to health and quality of life for the relevant clinical symptoms related to pain. Among them, Salvia miltiorrhiza Bunge is traditionally used in asian countries as antioxidant, anticancer, anti-inflammatory and analgesic agent. In this context, several evidences support the hypothesis that some tanshinones, in particular cryptotanshinone (CRY), extracted from the roots (Danshen) of this plant exhibit analgesic actions. However, it is surprisingly noted that no pharmacological studies have been carried out to explore the possible analgesic action of this compound in terms of modulation of peripheral and/or central pain. Therefore, in the present study, by using peripheral and central pain models of nociception, such as tail flick and hot plate test, the analgesic effect of CRY in mice was evaluated. Successively, by the aim of a computational approach, we have evaluated the interaction mode of this diterpenoid on opioid and cannabinoid system. Finally, CRY was dosed in mice serum by an HPLC method validated according to European Medicines Agency guidelines validation rules. Here, we report that CRY displayed anti-nociceptive activity on both hot plate and tail flick test, with a prominent long-lasting peripheral analgesic effect. These evidences were indirectly confirmed after the daily administration of the tanshinone for 7 and 14 days. In addition, the analgesic effect of CRY was reverted by naloxone and cannabinoid antagonists and amplified by arginine administration. These findings were finally supported by HPLC and docking studies, that revealed a noteworthy presence of CRY on mice serum 1 h after its intraperitoneal administration and a possible interaction of tested compound on µ and k receptors. Taken together, these results provide a new line of evidences showing that CRY can produce analgesia against various phenotypes of nociception with a mechanism that seems to be related to an agonistic activity on opioid system.

An unbiased and efficient assessment of excitability of sensory neurons for analgesic drug discovery.

Alleviating chronic pain is challenging, due to lack of drugs that effectively inhibit nociceptors without off-target effects on motor or central neurons. Dorsal root ganglia (DRG) contain nociceptive and non-nociceptive neurons. Drug screening on cultured DRG neurons, rather than cell lines, allows for the identification of drugs most potent on nociceptors with no effects on non-nociceptors (as a proxy for unwanted side effects on central nervous system and motor neurons). However, screening using DRG neurons is currently a low-throughput process, and there is a need for assays to speed this process for analgesic drug discovery. We previously showed that veratridine elicits distinct response profiles in sensory neurons. Here, we show evidence that a veratridine-based calcium assay allows for an unbiased and efficient assessment of a drug effect on nociceptors (targeted neurons) and non-nociceptors (nontargeted neurons). We confirmed the link between the oscillatory profile and nociceptors, and the slow-decay profile and non-nociceptors using 3 transgenic mouse lines of known pain phenotypes. We used the assay to show that blockers for Nav1.7 and Nav1.8 channels, which are validated targets for analgesics, affect non-nociceptors at concentrations needed to effectively inhibit nociceptors. However, a combination of low doses of both blockers had an additive effect on nociceptors without a significant effect on non-nociceptors, indicating that the assay can also be used to screen for combinations of existing or novel drugs for the greatest selective inhibition of nociceptors.