[Effects of tetramethylpyrazine on pharmacokinetics in plasma and brain dialysate and neuropathic pain in rat model of spared sciatic nerve injury].

This study aims to explore the effects of tetramethylpyrazine(TMP) on pharmacokinetics in plasma and brain dialysate and neuropathic pain in the rat model of partial sciatic nerve injury(SNI), and to investigate the correlation between the analgesic effect of TMP and its concentrations in the plasma and brain dialysate. Male SD rats were randomized into Sham, SNI, and SNI+TMP groups. Mechanical stimulation with von frey filaments and cold spray method were employed to evaluate the mechanical sensitivity and cold sensitivity of rats. Another two groups, Sham+TMP and SNI+TMP, were used to intubate the common jugular vein and implant microdialysis probes into the anterior cingulate gyrus(ACC), respectively.After intraperitoneal injection of TMP at a dose of 80 mg·kg~(-1), automatic blood collection and intracerebral microdialysis(perfusion rate of 1 µL·min~(-1)) systems were used to collect the blood and brain dialysate for 24 h. HSS T3 C_(18) reversed-phase chromatographic column(2.1 mm×50 mm, 2.5 µm) was used for liquid chromatographic separation. Gradient elution was carried out with the mobile phase of methanol-water(containing 0.005% formic acid) at a flow rate of 0.25 mL·min~(-1). Electrospray ion source was used for mass spectrometry, and the scanning mode was multi-reaction monitoring under the positive ion mode. The ion pairs for quantitative analysis were TMP m/z 137/122 and aspirin m/z 179/137, respectively. DAS 2.11 was used to calculate the pharmacokinetic parameters. The optimal time of TMP to exert the analgesia effect and inhibit cold pain sensitivity was 60 min after treatment. The TMP in the plasma and brain dialysate of SNI rats showed the T_(max) of 15 min and 30 min, the C_(max) of(2 866.43±135.39) and(1 462.14±197.38) µg·L~(-1), the AUC_(0-t) of(241 463.30±28 070.31) and(213 115.62±32 570.07) µg·min·L~(-1), the MRT_(0-t) of(353.13±47.73) and(172.16±12.72) min, and the CL_Z of 0.73 and 0.36 L·min·kg~(-1), respectively. The analgesic effect of TMP had a significant correlation with the blood drug concentration in the ACC, which indicated that this method was suitable for the detection of TMP in rat plasma and brain dialysate. The method is accurate, reliable, and sensitive and can realize the important value of the application of correlation analysis theory of "automatic blood collection-microdialysis/PK-PD" in the research on neuropathic pain.

Discovery of new 2-(3-(naphthalen-2-yl)-4,5-dihydro-1H-pyrazol-1-yl)thiazole derivatives with potential analgesic and anti-inflammatory activities: In vitro, in vivo and in silico investigations.

Joining the global demand for the discovery of potent NSAIDs with minimized ulcerogenic effect, new pyrazole clubbed thiazole derivatives 5a-o were designed and synthesized. The new derivatives were initially evaluated for their analgesic activity. Eight compounds 5a, 5c, 5d, 5e, 5f, 5h, 5m, and 5o showed higher activity than Indomethacin (potency = 105-130 % vs. 100 %). Subsequently, they were picked for further evaluation of their anti-inflammatory activity, ulcerogenic liability as well as toxicological studies. Derivatives 5h and 5m showed a potential % edema inhibition after 3 h (79.39 % and 72.12 %, respectively), with a promising safety profile and low ulcer indices (3.80 and 3.20, respectively). The two compounds 5h and 5m were subjected to in vitro COX-1 and COX-2 inhibition assay. The candidate 5h showed nearly equipotent COX-1 inhibition (IC50 = 38.76 nM) compared to the non-selective reference drug Indomethacin (IC50 = 35.72 nM). Compound 5m expressed significant inhibitory activities and a higher COX-2 selectivity index (IC50 = 87.74 nM, SI = 2.05) in comparison with Indomethacin (SI = 0.52), with less selectivity than Celecoxib (SI = 8.31). Simulation docking studies were carried out to gain insights into the binding interaction of compounds 5h and 5m in the vicinity of COX-1 and COX-2 enzymes that illustrated the importance of pyrazole clubbed thiazole core in hydrogen bonding interactions. The thiazole motif of compounds 5h and 5m exhibited a well orientation toward COX-1 Arg120 key residue by hydrogen bonding interactions. Compound 5h revealed an additional arene-cation interaction with Arg120 that could rationalize its superior COX-1 inhibitory activity. Compounds 5h and 5m overlaid the co-crystallized ligand Celecoxib I differently in the active site of COX-2. Compound 5m showed an enhanced accommodation with binding energy of - 6.13 vs. - 1.70 kcal/mol of compounds 5h. The naphthalene ring of compound 5m adopted the Celecoxib I benzene sulfonamide region that is stabilized by hydrogen-arene interactions with the hydrophobic sidechains of the key residues Ser339 and Phe504. Further, the core structure of compound 5m, pyrazole clubbed thiazole, revealed deeper hydrophobic interactions with Ala513, Leu517 and Val509 residues. Finally, a sensitive and accurate UPLC-MS/MS method was developed for the simultaneous estimation of some selected promising pyrazole derivatives in rat plasma. Accordingly, compounds 5h and 5m were suggested to be promising potent analgesic and anti-inflammatory agents with improved safety profiles and a novel COX isozyme modulation activity.

Phytochemical, Pharmacological, and Molecular Docking Study of Dry Extracts of Matricaria discoidea DC. with Analgesic and Soporific Activities.

Pineapple weed (Matricaria discoidea DC.) is a widespread plant in Europe and North America. In ethnomedicine, it is well-known for its anti-inflammatory and spasmolytic activities. The aim of this research was to develop novel methods of M. discoidea processing to obtain essential oil and dry extracts and to investigate their phytochemical compositions. Moreover, the molecular docking of the main substances and the in vivo studies on their soporific and analgesic activities were conducted. The essential oil and two dry extracts from M. discoidea were prepared. A total of 16 phenolic compounds (seven flavonoids, seven hydroxycinnamic acids, and two phenolic acids) in the dry extracts were identified by means of UPLC-MS/MS. In the essential oil, nine main terpenoids were identified by gas chromatography (GC). It was shown that phenolic extraction from the herb was successful when using 70% ethanol in a triple extraction method and at a ratio of 1:14-1:16. The in vivo studies with rodents demonstrated the analgesic activity of the M. discoidea extracts and improvements in the sleep of animals. The dry extracts of M. discoidea did not show any toxicity. The molecular docking analysis showed a high probability of COX-1,2 inhibition and NMDA receptor antagonism by the extracts.

Chemical composition and potential antioxidant, anti-inflammatory, and analgesic efficacy of Cistus albidus L.

This study aims to assess the chemical composition of the aqueous extract of Cistus albidus L. leaves, as well as the potential of aqueous and hydroethanol extracts of the leaves and seeds as analgesic, anti--inflammatory, and antioxidant agents. The contents of phenolics and inorganic constituents were determined in C. albidus seeds and leaves; antioxidant capacity was assessed by 3 complementary and diverse tests. The carrageenan-induced paw edema technique was used to investigate the anti-inflammatory effect in vivo, and albumin denaturation to evaluate the anti-inflammatory effect in vitro. The acetic acid-induced contortion test, the tail-flick test, and the plantar test were used to assess the analgesic effi cacy in vivo. Chemical analysis was performed by UPLC-MS/MS to quantify several phenolic compounds including catechin (1,627.6 mg kg-1), quercitrin (1,235.8 mg kg-1) and gallic acid (628. 2 mg kg-1). The ICP analysis revealed that potassium and calcium were the main inorganic components in the seeds and leaves of C. albidus. The hydroethanolic extract of the leaves showed the highest content of polyphenols/flavonoids, whereas the highest value of proantho cyanidins was detected in the aqueous extract of the seeds. All extracts showed potent antioxidant activity related to different phenolic compounds (quercetin, gallic acid, astragalin, catechin, and rutin). The aqueous extract of the leaves strongly inhibited paw edema (76.1 %) after 6 h of treatment and showed maximal inhibition of protein denaturation (191.0 µg mL-1 for 50 % inhibition) and analgesic activity in different nociceptive models. The presented data reveal that C. albidus extracts potentially show antioxidant, anti-inflammatory, and analgesic activities that could confirm the traditional use of this plant.

Molecular docking of quercetin: a promising approach for the development of new anti-inflammatory and analgesic drugs.

The aim of this study is to investigate the antinociceptive, anti-inflammatory and antipyretic effects of quercetin. Additionally, molecular docking studies were conducted to evaluate potential interactions between quercetin and various molecular targets. Animal models were used to conduct a comprehensive pharmacological investigation of quercetin. Evaluation of analgesic activity revealed a reduction in the number of abdominal cramps during the twisting test and inhibition of pain during the second phase of the formaldehyde test. Additionally, evaluation of its anti-inflammatory activity showed a reduction in ear oedema. However, it is important to note that quercetin administration has not been shown to significantly reduce yeast-induced hyperthermia. The docking study revealed the high inhibitory potential of quercetin against the COX-2 receptor.

Novel Triazole-Containing "Dipeptides": Synthesis, Molecular Docking and Analgesic Activity Studies.

Dipeptides of a new structure based on ß-triazolalanines and (L)-α-amino acids were synthesized and optimal conditions were developed that ensure both chemical and optical purity of the final products. Molecular docking was carried out and possible intermolecular interactions of dipeptides with potential targets were established. Based on these studies, the analgesic property of chosen dipeptides was studied and it was found that some compounds possess revealed antinociceptive activity in the tail-flick test.

RP-UHPLC-ESI-QTOF-MSn analyses, antioxidant, antimicrobial, analgesic activities and toxicity of Achillea ligustica All.

Fourty five polyphenols were identified in the hydroethanol extract of Achillea ligustica All. by LC-HRMS/MS with caffeoyl-6-oleside (5.74%), eucommin A (4.03%), quercetin-3-O-ß-D-glucoside (3.13%) and cirsimaritin (2.95%) as the major compounds. A good antioxidant potential was shown in DPPH, ABTS and phenanthroline tests and the highest antioxidant activity (A0.5:36.23 ± 3.07 µg/mL), which was close to the standard α-tocopherol, was shown in Reducing power. The extract inhibited the growth of all tested microorganisms with MICs ranging between 10 and 190 µg/mL. In the acute toxicity test, no death was observed at doses of 100, 750 and 1500 mg/Kg with DL50 higher than 2000 mg/Kg. In analgesic in vivo assay, the extract showed a very important capacity to reduce pain, whether central or peripheral, with a certain dose-dependent relationship. For the three tests (tail flick, hot plate and acetic acid assay), the effective dose was 750 mg/kg.

Phytochemical, Technological, and Pharmacological Study on the Galenic Dry Extracts Prepared from German Chamomile (Matricaria chamomilla L.) Flowers.

Galenic preparations of German chamomile are used to treat mild skin diseases, inflammation, and spasms, and they have also been reported to have anxiolytic and sedative effects. The medicinal use of chamomile is well known in ethnomedicine. After obtaining its galenic preparations, there is lots of waste left, so it is expedient to develop waste-free technologies. The aims of this study were to gain knowledge of the ethnomedical status of chamomile in the past and present, develop methods for preparing essential oils and dry extracts from German chamomile flowers using complex processing, reveal the phytochemical composition of such extracts, and verify the analgesic and soporific activity of the extracts. Two methods for the complex processing of German chamomile flowers were developed, which allowed us to obtain the essential oil and dry extracts of the tincture and aqueous extracts as byproducts. A total of 22 phenolic compounds (7 hydroxycinnamic acids, 13 flavonoids, and 2 phenolic acids) were found in the dry extracts by using UPLC-MS/MS. In total, nine main terpenoids were identified in the chamomile oil, which is of the bisabolol chemotype. During the production of chamomile tincture, a raw material-extractant ratio of 1:14-1:16 and triple extraction are recommended for its highest yield. In in vivo studies with mice and rats, the extracts showed analgesic activity and improvements in sleep. The highest sedative and analgesic effects in rodents were found with the dry extract prepared by using a 70% aqueous ethanol solution for extraction at a dose of 50 mg/kg. The developed methods for the complex processing of German chamomile flowers are advisable for implementation into the pharmaceutical industry to reduce the volume of waste during the production of its essential oil and tincture, and to obtain new products.

Polyphenols and extracts from Zingiber roseum (Roxb.) Roscoe leaf mitigate pain, inflammation and pyrexia by inhibiting cyclooxygenase-2: an in vivo and in silico studies.

Zingiber roseum (Roxb.) Roscoe, a perennial herb from the Zingiberaceae family, has a long history of traditional use in the treatment of several ailments including pain, inflammation, fever, cough, arthritis, skin diseases, and liver infections. This study sought to confirm the efficacy of Zingiber roseum (Roxb.) Roscoe leaves methanol extract (ZrlME) as reported in traditional usage by evaluating its analgesic, anti-inflammatory, and antipyretic capabilities. In addition, in silico molecular docking of the metabolites identified in ZrlME was studied to verify the experimental outcomes. ZrlME demonstrated strong dose-dependent analgesic efficacy against all analgesic tests. ZrlME (400 mg/kg) showed higher anti-inflammatory activity than the standard in the carrageenan-induced paw edema test model. A significant reduction of rectal temperature (3.97°F↓) was also recorded at the same dose of ZrLME after 24 h of treatment. Seven polyphenolic metabolites were identified and quantified by HPLC-DAD analysis, including 3, 4- dihydroxy benzoic acid, (-) epicatechin, rutin hydrate, p-coumaric acid, trans-ferulic acid, rosmarinic acid, and myricetin. Strong binding affinities (ranges from -5.8 to -8.5 Kcal/mol) between the aforesaid polyphenols and cyclooxygenase-2 were discovered. Moreover, molecular dynamics simulations (MDS) demonstrated that these polyphenols exhibit significant COX-2 inhibitory activity due to their high stability in the COX-2 active site. In computational prediction, the polyphenols were also found to be nontoxic, and a variety of biological activities, such as antioxidant, analgesic, anti-inflammatory, antipyretic, and hepatoprotective, were observed. The results of this study revealed that ZrlME possesses notable analgesic, anti-inflammatory, and antipyretic properties.

Exploring the impact of seasonal variations on the chemical composition, antinociceptive, and anti-inflammatory properties of Pogostemon heyneanus Benth. essential oil.

Background: Pogostemon heyneanus leaves infusions are relevant in ethnopharmacology for treating colds, coughs, headaches, and asthma. Purpose: The essential oil chemical composition of a Pogostemon heyneanus specimen was monthly monitored from October 2021 to July 2022 to evaluate the climatic influences on its yield and chemical composition and antinociceptive, andanti-inflammatory properties. Methods: The leaves, collected monthly over a 10-month period, were submitted to hydrodistillation. The oils obtained were analyzed by gas chromatography coupled to a mass spectrometer and gas chromatography coupled to flame ionization detector. The P. heyneanus essential oil (PhEO) was tested in vivo to evaluate its peripheral analgesic actions through the abdominal writhing test induced by acetic acid, and peripheral analgesia by tail immersion. Neurogenic and inflammatory pain were evaluated by formalin test, and acute oral toxicity of the oil was also verified. Results: PhEO presented 27 chemical constituents with the highest predominance of patchoulol (43.6%-76.9%), α-bulnesene (0.2%-12.7%), α-guaiene (0.4%-8.9%), seychellene (3.8%-5.1%) and pogostol (0.0%-8.2%). The climatic parameters insolation, humidity, rainfall, and temperature did not influence the essential oil yield or the main chemical constituents, except for pogostol, which presented a strong (r = 0.73) and statistically significant (p < 0.05) correlation with temperature. PhEO did not display toxicity at the maximum 300 mg/kg dosage. The oil showed low peripheral and central analgesic action at 100 mg/kg, while in the neurogenic and inflammatory pain inhibition tests, no actions related to PhEO were observed. In the carrageenan-induced peritonitis test, PhEO did not reduce the migration of leukocytes to the peritoneal cavity compared to the control group. Conclusion: Pogostemon heyneanus is a resistant plant to seasonal influences and a source of patchoulol. Despite ethnopharmacological indications, no in-vivo biological activities such as neurogenic or inflammatory pain were identified in the present work. So, the low influence of the climatic parameters on chemical composition can infer that the low pharmacological activity is also not subject to climatic variations, that is, it does not change due to the climate.

Structurally diverse analgesic diterpenoids from the flowers of Rhododendron molle.

Thirteen diterpenoids (1-13), classified into four structurally diverse carbon skeletons, including 1,5-seco-kalmane (1 and 6), grayanane (2-11), kalmane (12), and rhodomollane (13), were isolated from the flowers extract of Rhododendron molle. Among them, rhodomollinols A - E (1-5) were five new diterpenoids and their structures were elucidated by extensive spectroscopic methods including HRESIMS, UV, IR, 1D and 2D NMR, as well as quantum ECD calculations. Rhodomollinol A (1) is the first representative of a 6-deoxy-1,5-seco-kalmane diterpenoid. The abnormal NMR phenomenon of the presence of only 9 carbon resonances instead of 20 carbons in the 13C NMR spectrum of 1 was observed and elucidated by the quantum NMR calculations. All diterpenoids 1-13 showed significant analgesic activities in an acetic acid-induced writhing model. It's the first time to report the analgesic activity of a rhodomollane-type diterpenoid. At a dose of 1.0 mg/kg, diterpenoids 1-3, 6, 8, 9, and 12 reduced the writhe numbers with inhibition rates over 50%, and 9 exhibited stronger analgesic activity with a writhe inhibition rate of 89.7% than that of the positive control morphine. Importantly, even at the lowest dose of 0.04 mg/kg, rhodomollinols A (1) and B (2), rhodomollein X (7), and 2-O-methylrhodojaponin VI (9) still showed more potent analgesic effects than morphine with the writhe inhibition rates of 51.8%, 48.0%, 61.7%, and 60.0%, respectively. A preliminary structure-activity relationship might provide some clues to design potential analgesics on the basis of structurally diverse Ericaceae diterpenoids.

Exploring the therapeutic potential of Prinsepia utilis Royle seed oil: A comprehensive study on chemical composition, physicochemical properties, anti-inflammatory, and analgesic activities.

ETHNOPHARMACOLOGICAL RELEVANCE: Prinsepiautilis (PU) Royle, native to the Himalayan region, is a deciduous thorny shrub with numerous traditional uses of its roots, leaves and seeds for treatment of conditions such as rheumatic pain, joint pain, arthritis, and inflammation. AIM OF THE STUDY: Keeping in mind the growing demand of products of natural origin as alternate medicine, the present study was undertaken to scientifically validate for the first time the traditional claims of healing pain and inflammation by evaluating the fatty oil isolated from the seeds using established in vitro and in vivo models. MATERIALS AND METHODS: PU Seeds were Soxhlet extracted using n-hexane and fatty oil was isolated. Chemical composition of the oil was established with the aid of Gas Chromatography-Flame Ionization Detection (GC-FID) and Gas Chromatography-Mass Spectrometry (GC-MS). The oil was then subjected to in vitro anti-inflammatory activity by following the established protocols of trypsin inhibitory and bovine serum albumin denaturation assays. The acute toxicity of the oil was also studied using OECD guidelines 423. The anti-inflammatory property of the oil was further evaluated using carrageenan-induced and formalin-induced edema in the rat paw. Moreover, hot plate latency and tail immersion assay were employed to evaluate analgesic activity of the oil. To establish the quality of the oil, various physicochemical properties were also studied. RESULTS: GC-FID and GC-MS analysis of the oil revealed the presence of linoleic acid (59.06 ± 0.00%), oleic acid (28.11 ± 0.01%), palmitic acid (9.51 ± 0.01%) and stearic acid (3.32 ± 0.01%). In vitro trypsin inhibitory and bovine serum albumin denaturation assay revealed dose-dependent notable activity of the oil with IC50 value of 63.57 µg/mL and 518.14 µg/mL, respectively. The physico-chemical characterization demonstrated that the oil possesses a low acidity and a high oxidative stability index. The oil was found to be non-toxic and displayed effective anti-inflammatory activities with significant inhibition till 4 h in carrageenan-induced and formalin-induced rat paw edema at maximum tested dose of 200 mg/kg b.w. The oil also exhibited significant results in hot plate latency and tail immersion assay with positive effects showing up to 4 h after dose administration. CONCLUSION: These findings, besides supporting the traditional claims, suggest that P. utilis seed oil has potential therapeutic applications as a natural anti-inflammatory and analgesic agent. Further studies are warranted to explore its mechanisms of action and potential use in pharmaceutical and nutraceutical industries.

Discovery of highly functionalized grayanane diterpenoids from the flowers of Rhododendron molle as potent analgesics.

A systematical investigation on the chemical constituents of the flowers of Rhododendron molle (Ericaceae) led to the isolation and characterization of thirty-eight highly functionalized grayanane diterpenoids (1-38), including twelve novel analogues molleblossomins A-L (1-12). Their structures were elucidated by comprehensive methods, including 1D and 2D NMR analysis, calculated ECD, 13C NMR calculations with DP4+ probability analysis, and single crystal X-ray diffraction. Molleblossomins A (1), B (2), and E (5) are the first representatives of 2ß,3ß:9ß,10ß-diepoxygrayanane, 2,3-epoxygrayan-9(11)-ene, and 5,9-epoxygrayan-1(10),2(3)-diene diterpenoids, respectively. Molleblossomins G (7) and H (8) represent the first examples of 1,3-dioxolane-grayanane conjugates furnished with the acetaldehyde and 4-hydroxylbenzylidene acetal moieties, respectively. All grayanane diterpenoids 1-38 were screened for their analgesic activities in the acetic acid-induced writhing model, and all of them exhibited significant analgesic activities. Diterpenoids 6, 13, 14, 17, 20, and 25 showed more potent analgesic effects than morphine at a lower dose of 0.2 mg/kg, with the inhibition rates of 51.4%, 68.2%, 94.1%, 66.9%, 97.7%, and 60.0%, respectively. More importantly, even at the lowest dose of 0.04 mg/kg, rhodomollein X (14), rhodojaponin VI (20), and rhodojaponin VII (22) still significantly reduced the number of writhes in the acetic acid-induced pain model with the percentages of 61.7%, 85.8%, and 64.6%, respectively. The structure-activity relationship was summarized and might provide some hints to design novel analgesics based on the functionalized grayanane diterpenoids.

Biological Activity of Hexaazaisowurtzitane Derivatives.

Biologically active compounds of natural or synthetic origin have a complex structure and generally contain various structural groups among which polycyclic cage amines are found. Hexaazaisowurtzitanes are representatives of these amines and studies on their biological activity began less than two decades ago, starting with research on the environmental impact of CL-20. This research helped to evaluate the risks of potential pollution in the habitat environments of living organisms and determine whether the chemical compounds in question could be utilized in pesticides, herbicides, fungicides, or medicinal drugs. The nomenclature of hexaazaisowurtzitane compounds has recently been expanded significantly, and some of them have demonstrated promise in the design of medicinal drugs. This paper review studies the pharmacological activity of the acyl derivatives of hexaazaisowurtzitane. Most of the compounds have been found to possess a high analgesic activity, providing a solution to the pressing issue of pain management in current pharmacology. Analgesic drugs currently used in the clinical practice do not meet all of the efficacy and safety requirements (gastro-, nephro-, hepato-, haematotoxicity, etc.). The material presented in the seven sections of this paper highlights information about hexaazaisowurtzitane derivatives. Furthermore, they have been observed to exhibit anti-inflammatory, anticonvulsant, antihypoxic, and antimetastatic activities, which render them highly promising for evaluation in various fields of medicinal practice.

Synthesis, Hydrolytic Stability and In Vivo Biological Study of Bioconjugates of the Tetrapeptides FELL Containing Pyrrole Moiety.

BACKGROUND: Bioconjugates are promising alternatives for the multiple targeting of any disease. Pyrrole heterocycle is well known with many activities and is a building block of a lot of medical drugs. On the other hand, peptides are short molecules with many advantages such as small size, ability to penetrate the cell membrane and bond-specific receptors, vectorizing potential, etc. Thus, hybrid molecules between peptide and pyrrole moiety could be a promising alternative as an anti-pain tool. METHODS: New bioconjugates with a general formula Pyrrole (α-/ß-acid)-FELL-OH (NH2) were synthesized using Fmoc/OtBu peptide synthesis on solid support. HPLC was used to monitor the purity of newly synthesized bioconjugates. Their structures were proven by electrospray ionization mass spectrometry. The Paw Pressure test (Randall-Selitto test) was used to examinate the analgesic activity. Hydrolytic stability of targeted structures was monitored in three model systems with pH 2.0, 7.4 and 9.0, including specific enzymes by means of the HPLC-UV method. RESULTS: The obtained results reveal that all newly synthesized bioconjugates have analgesic activity according to the used test but free pyrrole acids have the best analgesic activity. CONCLUSIONS: Although free pyrrole acids showed the best analgesic activity, they are the most unstable for hydrolysis. Combination with peptide structure leads to the hydrolytic stabilization of the bioconjugates, albeit with slightly reduced activity.

Analgesic effect of Centaurium erythraea and molecular docking investigation of the major component swertiamarin.

Centaurium erythraea Rafn is employed in Algerian traditional medicine for treating pain. The analgesic activity of the ethanolic extract (EE) from the flowering aerial parts of this plant was examined, and molecular docking of the main bioactive compound was performed. The EE, characterised by the iridoid swertiamarin, was administered to Wistar albino rats in pain models. Peripheral analgesic activity was evaluated using the acetic acid-induced writhing test, and a hot plate test was performed for central antinociceptive activity evaluation. Treatment with EE significantly decreased rats' writhing induced by acetic acid suggesting peripheral analgesic activity. Furthermore, the elevation of mean basal reaction time in the hot plate method indicated central analgesic activity. Molecular docking studies showed good docking energy with acceptable binding interactions of swertiamarin with cyclooxygenase-2 protein. This supports the analgesic activity of C. erythraea EE, justifying the traditional use of the plant as an analgesic herbal remedy.

Discovery of (S)-flurbiprofen-based novel azine derivatives as prostaglandin endoperoxide synthase-II inhibitors: Synthesis, in-vivo analgesic, anti-inflammatory activities, and their molecular docking.

The anti-inflammatory and analgesic drugs currently used are associated with several adverse effects and found to be highly unsafe for long-term use. Currently, nineteen novel bis-Schiff base derivatives (1-19) of flurbiprofen have been designed, prepared and assessed for in-vivo analgesic, anti-inflammatory and in vivo acute toxicity evaluation. The structures of the acquired compounds were deduced through modern spectroscopic techniques including HR-ESI-MS, 13C-, and 1H NMR. Amongst the series, compounds 7, 9, and 10 attributed potent activities with 93.89, 92.50, and 90.47% decreased edema, respectively compared to flurbiprofen (90.01%), however, compounds 11 and 15 exhibited significant activity of 90.00% decrease. Out of them, fourteen compounds (1-6, 8, 12-14, and 16-19) displayed good activity in the range of 68.96-86.95%. In case of an analgesic study, all the derivatives significantly (p 0.001) increased the pain threshold time particularly compound 7 had the best analgesic effect (24 ± 2.08 s) in comparison with flurbiprofen (21.66 ± 2.02 s) using hot plate test. Similarly, in the acetic acid-induced writhing test, compound 7 determined a potent inhibitory effect (60.47 %) close to flurbiprofen (59.28%). All the synthesized derivatives were found safe up to the dose of 30 mg/kg, in acute toxicity study. On a molecular scale, the synthesized compounds were modeled through a ligand-based pharmacophore study and molecular docking to have insight into the different possible interactions leading to high inhibition levels against the COX-2 enzyme.

Comprehensive Analysis of the Chemical and Bioactivity Profiles of Endemic Crataegus turcicus Dönmez in Comparison with Other Crataegus Species.

Crataegus turcicus is a plant endemic to Türkiye. For the first time, this study aimed to comparatively assess its flower-bearing branches, leaves, and fruits with other well-known Crataegus species (C. monogyna, C. pentagyna, and C. orientalis) in terms of chemical composition and bioactivity studies to evaluate its potential use as a food supplement. Firstly, the contents of total phenolics (TPC), flavonoids (TFC), proanthocyanidin (TPAC), and anthocyanin (TAC) in different plant parts of Crataegus species were evaluated. The highest TPAC was found in the hydroalcoholic extract of C. turcicus flower-bearing branches. Moreover, all plant parts had comparatively higher amounts of TPC, TFC, and TAC compared to other Crataegus species. The chemical screening by high-performance thin-layer chromatography (HPTLC) resulted that C. turcicus parts were rich with chlorogenic acid, neochlorogenic acid, quercetin and vitexin derivatives, epicatechin, procyanidin, etc., and their quantities were evaluated by high-performance liquid chromatography (HPLC). In terms of several in vitro antioxidant activity outcomes, the flower-bearing branches of C. turcicus showed the highest antioxidant activity by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) test among the assessed antioxidant assays. Additionally, hydroalcoholic extracts of C. turcicus significantly decreased LPS-induced nitric oxide, tumor necrosis factor-alpha, and interleukin-6 production more potently than indomethacin (positive control). In addition to its remarkable anti-inflammatory activity, C. turcicus showed analgesic activity by reducing prostaglandin E2 levels.

Synthesis, In Silico Logp Study, and In Vitro Analgesic Activity of Analogs of Tetrapeptide FELL.

BACKGROUND: The inflammatory process represents a specific response of the organism's immune system. More often, it is related to the rising pain in the affected area. Independently of its origin, pain represents a complex and multidimensional acute or chronic subjective unpleasant perception. Currently, medical doctors prescribe various analgesics for pain treatment, but unfortunately, many of them have adverse effects or are not strong enough to suppress the pain. Thus, the search for new pain-relieving medical drugs continues. METHODS: New tetrapeptide analogs of FELL with a generaanalgesic-Glu-X3-X4-Z, where X = Nle, Ile, or Val and Z = NH2 or COOH, containing different hydrophobic amino acids at positions 3 and 4, were synthesized by means of standard solid-phase peptide synthesis using the Fmoc/OtBu strategy in order to study the influence of structure and hydrophobicity on the analgesic activity. The purity of all compounds was monitored by HPLC, and their structures were proven by ESI-MS. Logp values (partition coefficient in octanol/water) for FELL analogs were calculated. Analgesic activity was examined by the Paw-pressure test (Randall-Selitto test). RESULTS: The obtained results reveal that Leu is the best choice as a hydrophobic amino acid in the FELL structure. CONCLUSIONS: The best analgesic activity is found in the parent compound FELL and its C-terminal amide analog.

Investigation of Paracetamol Entrapped Nanoporous Silica Nanoparticles in Transdermal Drug Delivery System.

An effort was made to administer paracetamol drug through transdermal patch, as no such formulation of this drug has been developed yet. The primary cause for the lack of such formulations is paracetamol's poor aqueous solubility. As a result, the current research concentrated on preparing nanomedicines, or drug-loaded nanoparticles, for delivery via transdermal formulations. Nanoparticles can improve the solubility of weakly aqueous soluble or even aqueous insoluble drugs by changing the crystalline structure of loaded medicines to an amorphous state and serving as drug permeation boosters. Silica nanoparticles (SNPs) were synthesized through sol-gel technique to achieve the aforementioned goal. DLS data revealed that the average particle size was around 100-200 nm, which was sufficient to penetrate the skin barrier. XRD analysis showed that the SNPs were amorphous, and the drug molecules lost their crystallinity after encapsulation into the nanoparticles, causing the enhancement of dissolution of drug molecules in physiological pH (pH-7.4). Different kinetic models were employed for the ex vivo dissolution data to evaluate the suitable kinetic model followed by the drug release in both burst and sustained phase. In vivo analgesic study was executed on mice applying each of the transdermal formulations to examine the performances of the patches.