A novel ω-conotoxin Bu8 inhibiting N-type voltage-gated calcium channels displays potent analgesic activity

ω-Conotoxins inhibit N-type voltage-gated calcium(Ca_(v)2.2)channels and exhibit efficacy in attenuating neuropathic pain but have a low therapeutic index.Here,we synthesized and characterized a novelω-conotoxin,Bu8 from Conus bullatus,which consists of 25 amino acid residues and three disulfide bridges.Bu8 selectively and potently inhibits depolarization-activated Ba^(2+ )currents mediated by rat Ca_(v)2.2 expressed in HEK293 T cells(IC_(50)=89 nmol/L).Bu8 is two-fold more potent thanω-conotoxin MVIIA,aω-conotoxin currently used for the treatment of severe chronic pain.It also displays potent analgesic activity in animal pain models of hot plate and acetic acid writhing but has fewer side effects on mouse motor function and lower toxicity in goldfish.Its lower side effects may be attributed to its faster binding rate and higher recovery ratios.The NMR structure demonstrates that Bu8 contains a small irregular tripleβ-strand.The structure-activity relationships of Bu8 Ala mutants and Bu8/MVIIA hybrid mutants demonstrate that the binding mode of Ca_(v)2.2 with the amino acid residues in loop 1 and loop 2 of Bu8 is different from that of MVIIA.This study characterizes a novel,more potentω-conotoxin and provides new insights for designing Ca_(v)2.2 antagonists.

Studies on Extraction and Activity of Peptides from Haemadipsa hainana

[Objectives]Peptides was extracted from Haemadipsa hainana and its activity was studied.[Methods]Electric stimulation,water extraction and ultrasonic extraction were used to extract the peptides from H.hainana.Then the protein content and molecular weight distribution of H.hainana peptides were detected by the BCA method and SDS-PAGE method,respectively.The antithrombin activity and analgesic activity of the three peptide extracts of H.hainana were detected by Markwardt thrombin titration method and mouse hot plate experiment,respectively.[Results]There extraction methods of electric stimulation,water extraction and ultrasonic extraction were used to extract the peptide extract of H.hainana,and the yields were as follows:water extraction>electrical stimulation>ultrasonic extraction.The three peptide extracts from H.hainana had antithrombin activity,and the antithrombin activity was as follows:water extraction>ultrasonic extraction>electrical stimulation.Through the hot plate experiment in mice,it was verified that the three peptide extracts of H.hainana had analgesic activity,and the analgesic activity was water extraction>electric stimulation>ultrasonic extraction.The analgesic activity of high-dose(100 mg/kg)group of H.hainana obtained by water extraction was slightly weaker than that of tramadol.[Conclusions]This study confirmed that the peptide extract of H.hainana had certain antithrombin and analgesic activity,laying a foundation for the subsequent development and application of H.hainana.

Development and Evaluation of Stable Paracetamol Loaded Solid Dispersion with Enhanced Analgesic and Hepatoprotective Property

Paracetamol (PCM) is enlisted in the WHO model list as an essential medicine for pain and palliative care, but at overdose, it causes hepatic damage. This study was designed to assess the analgesic efficacy and hepatoprotective property of a solid dispersion (SD) loaded with PCM. A number of PCM loaded formulations (PSDs) were fabricated using silica alone or in combination with polyethylene glycol and/or Na-citrate followed by in-vitro dissolution profiling. Selected PSDs with improved dissolution profile were subjected to solid-state characterization (DSC, PXRD, FTIR, and SEM), stability study along with investigation of in-vivo analgesic efficacy and effect on hepatocytes. Among these, PSD10 showed a rapid and significantly higher in-vitro drug release than pure PCM. This improvement was distinct to other PSDs also. Solid-state characterization of PSD10 authenticated the conversion of crystalline PCM to amorphous form upon formulation. Subsequent oral administration of PSD10 in Swiss albino mice showed 1.44-fold greater analgesic efficacy than pure PCM at dose 30 mg/kg. Besides, at acute toxic dose, liver histology of PSD10 mice was comparable with NC mice indicating hepatic protection upon formulation, whereas the PCM mice showed extensive hepatic necrosis which was also endorsed by significantly higher values of SGPT, SGOT, and ALP than PSD10 mice. Finally, an accelerated stability study of PSD10 performed according to the guideline of ICH noticed no remarkable deviation in its dissolution performance as well as crystalline nature. Thus, this newly developed PSD10 may be a safe and promising alternative for pain management and palliative care.

Pharmacodynamic study in multi-animal models on the efficacy and optimal dosage of antiviral oral liquid for children

Antiviral Oral Liquid(AOL)is an adult medicine in the Chinese Pharmacopoeia used to treat upper respiratory infections such as influenza.It has shown promising clinical efficacy in relieving flu-like symptoms such as fever,inflammation,and pharyngalgia both in adults and children.However,the instruction manual does not specify the exact usage and dosage of AOL for children.In this article,we set 6 dosage ranges:0.2,0.5,0.7,0.9,1.1,1.4 mL/kg/d,according to its dosage for adults and the conversion method between adult and children dosage.And six animal models were used to evaluate the effectiveness of AOL in different doses.The results indicated that AOL could reduce the lung index,virus load,and expression of proinflammatory cytokines in the lung.AOL could improve pathological changes and prolong the survival time of mice infected by the Influenza A virus(H1N1)A/PR/8/34 strains at 0.5–0.9 mL/kg/d concentrations in different degrees.The four dose groups of 0.7–1.4 mL/kg/d could significantly inhibit the ear shell swelling caused by xylene and reduce the rabbit body temperature induced by lipopolysaccharide(P<0.01,P<0.05).All the five dosage groups of 0.2–1.1 mL/kg/d could inhibit the increase of peritoneal capillary permeability induced by glacial acetic acid(P<0.01).AOL at 0.7 and 0.9 mL/kg/d reduced the painful writhing times in young mice induced by glacial acetic(P<0.01).These results indicated that the optimal dose of AOL in antiviral,antipyretic,anti-inflammatory,and analgesic effects is 0.7 mL/kg/d.

Anti-inflammatory Effects of Baicalin (In Vitro and In Vivo)

Baicalin(BA)is commonly used to treat inflammatory diseases and shows anti-inflammatory effects.The present study aimed to evaluate the analgesic and anti-inflammatory activities of BA both in vitro and in vivo.In animal models,acetic acid-induced writhing was used to assess analgesic activity.In addition,a variety of tests including xylene-induced ear edema test,minimum inhibitory concentration(MIC)assays and acetic acid-induced peritoneal capillary hyperpermeability test were used to evaluate antiinflammatory activity of BA.BA at 0.2 and 0.1 mg·mL-1 doses expressed analgesic as well as anti-inflammatory activities in mice.In acetic acid induced writhing test,BA applying three times,twice and once a day significantly inhibited the acetic acid-induced writhing response within 15 min by 7.80%(*p<0.05),7.50%(**p<0.01)and 6.25%(**p<0.01).In xylene-induced ear edema test,BA at 0.2,0.1 and 0.05 mg·mL-1 decreased ear edema by 45.50%(**p<0.01),15.20%(*p<0.05)and 9.10%(*p<0.05).In acetic acidinduced peritoneal capillary hyperpermeability test,BA exhibited significant inhibition(*p<0.05 versus control)of inflammation.In MIC assays,the MIC values of baicalin for S.aureus and Escherichia coli were 125 mg•mL-1,and the MIC values for the control bacteria ATCC25922 and ATCC25923 were 62.5 mg·mL-1.These findings suggested baicalin might contain analgesic and antiinflammatory agents which supported its use in traditional medicine.

Bispecific sigma-1 receptor antagonism and mu-opioid receptor partial agonism:WLB-73502,an analgesic with improved efficacy and safety profile compared to strong opioids

Opioids are the most effective painkillers,but their benefit-risk balance often hinder their therapeutic use.WLB-73502 is a dual,bispecific compound that binds sigma-1(S1R)and mu-opioid(MOR)receptors.WLB-73502 is an antagonist at the S1R.It behaved as a partial MOR agonist at the G-protein pathway and produced no/unsignificantβ-arrestin-2 recruitment,thus demonstrating low intrinsic efficacy on MOR at both signalling pathways.Despite its partial MOR agonism,WLB-73502exerted full antinociceptive efficacy,with potency superior to morphine and similar to oxycodone against nociceptive,inflammatory and osteoarthritis pain,and superior to both morphine and oxycodone against neuropathic pain.WLB-73502 crosses the blood-brain barrier and binds brain S1R and MOR to an extent consistent with its antinociceptive effect.Contrary to morphine and oxycodone,tolerance to its antinociceptive effect did not develop after repeated 4-week administration.Also,contrary to opioid comparators,WLB-73502 did not inhibit gastrointestinal transit or respiratory function in rats at doses inducing full efficacy,and it was devoid of proemetic effect(retching and vomiting)in ferrets at potentially effective doses.WLB-73502 benefits from its bivalent S1R antagonist and partial MOR agonist nature to provide an improved antinociceptive and safety profile respect to strong opioid therapy.

Antidiarrheal properties of different extracts of Chinese herbal medicine formula Bao-Xie-Ning

OBJECTIVE： Bao-Xie-Ning （BXN）, a traditional Chinese herbal medicine （CHM） formula composed of Fructus Evodiae, Flos Caryophylli and Cortex Cinnamomi, and used for the treatment of infant diarrheal illness, was subject to systematic assessment for its putative multiple pharmacodynamic effects and pharmacological antidiarrheal mechanisms. METHODS： High-performance liquid chromatography-diode array detector-electrospray ionization- mass spectrometric/mass spectrometry was developed and validated for identification and quantification of the main constituents in different extracts of BXN. Male Kunming mice weighing 20 to 25 g were used for detecting the antidiarrheal activity of the extracts. Ethanolic extract （EE）, volatile oil extract （VOE）, and aqueous extract （AE） of BXN were respectively subjected to pharmacodynamic and pharmacological comparison in assessing antidiarrheal effects with senna-induced diarrhea, castor oil-induced diarrhea, acetic acid-induced writhing assay, and isolated duodenum test. RESULTS： The highest yields of three detected components of BXN, rutaecarpine, eugenol and cinnamaldehyde were observed in EE. EE showed the most remarkable antidiarrheal activity in dose-dependent and time-dependent manners in both senna- and castor oil-induced diarrhea models, and presented dose-dependent analgesic activity in acetic acid-induced algesthesia model. In addition, EE extract of BXN also exhibited strong antimobility action on the intestine and strongest depression on spontaneous contraction of isolated duodenum. CONCLUSION： Ethanol extraction is an efficient method to extract the active constituents of BXN. BXN extract demonstrated multiple pharmacological activities affecting the main mechanisms of diarrhea, which validated BXN＇s usage in the comprehensive clinical treatment of diarrhea.

Analgesic and Anti-inflammatory Effects of Ginger Oil

Objective Ginger(Zingiber officinale) is widely used as a spice in cooking and as a medicinal herb in traditional herbal medicine.The present study was to investigate the analgesic and anti-inflammatory activities of ginger oil in experimental animal models.Methods The analgesic effect of the oils was evaluated by the 'acetic acid' and 'hot-plate' test models of pain in mice.The anti-inflammatory effect of the oil was investigated in rats,using rat paw edema induced by carrageenan,adjuvant arthritis,and vascular permeability induced by bradykinin,arachidonic acid,and histamine.Indomethacin(1 mg/kg),Aspirin(0.5 g/kg) and Dexamethasone(2.5 mg/kg) were used respectively as reference drugs for comparison.Results The ginger oil(0.25-1.0 g/kg) produced significant analgesic effect against chemically-and thermally-induced nociceptive pain stimuli in mice(P < 0.05,0.01).And the ginger oil(0.25-1.0 g/kg) also significantly inhibited carrageenan-induced paw edema,adjuvant arthritis,and inflammatory mediators-induced vascular permeability in rats(P < 0.05,0.001).Conclusion These findings confirm that the ginger oil can be used to treat pain and chronic inflammation such as rheumatic arthritis.

Analgesic alkaloids from Urticae Fissae Herba

Objective:To investigate the analgesic substances in the aerial part of Urtica fissa(Urticae Fissae Herba),commonly used for rheumatoid and rheumatism arthritis.Methods:The analgesic constituents were isolated with the active guidance of hot plate and acetic acid writhing models,and identified by comprehensive spectroscopic analysis.Results:Thirteen alkaloids(1–13),two lignans(14,15),and three amides(16–18)were isolated from the active fractions.Among them,compound 1 was a new alkaloid,and compound 6 was a new natural product.The activity evaluation in vivo indicated that various pyrrole alkaloids(1,3,6,and 12)possessed significant analgesic activities,they could significantly inhibit the mice pain response induced by acetic acid and hot plate at the dosage of 2 mg/kg BW.Conclusion:The study revealed that the pyrrole alkaloids played important roles in the analgesic activities of Urticae Fissae Herba.

Note Microwave synthesis and pharmacological activity of Mannich base cyclohexanone derivatives

We have synthesized mannich base cyclohexanone using microwave irradiation method,and studied their pharma-cological activity.Based on analytical and spectral(IR,NMR and Mass) data,a number of mono as well as double mannich base cyclohexanones have been synthesized from primary and secondary amines and formaldehyde,and then purified and characterized. The required 3-aryl-2,4-diacetyl-5-hydroxy-5-methylcyclohexanone was prepared from appropriate aldehyde and acetylacetone. The synthesized compounds were screened for analgesic activity via standard approaches,and they have shown positive analgesic activity.

(+)/(-)-Yanhusamides A-C,three pairs of unprecedented benzylisoquinoline-pyrrole hetero-dimeric alkaloid enantiomers from Corydalis yanhusuo

A chemical investigation on the aqueous extract of Corydalis yanhusuo tubers led to the isolation and structural elucidation of three pairs of trace enantiomeric hetero-dimeric alkaloids,(+)/(-)-yanhusamides A-C(1-3),featuring an unprecedented 3,8-diazatricylco[5.2.2.0^(2,6)]undecane-8,10-diene bridged system.Their structures were exhaustively characterized by X-ray diffraction,comprehensive spectroscopic data analysis,and computational methods.Guided by the hypothetical biosynthetic pathway for 1-3,a gram-scale biomimetic synthesis of(±)-1 was achieved in 3 steps using photoenolization/Diels-Alder(PEDA)[4+2]cycloaddition.Compounds 1-3 exhibited potent inhibition of NO production induced by LPS in RAW264.7 macrophages.The in vivo assay showed that oral administration of 30 mg/kg of(±)-1 attenuated the severity of rat adjuvant-induced arthritis(AIA).Additionally,(±)-1 induced a dose-dependent antinociceptive effect in the acetic acid-induced mice writhing assay.

Aconapelsulfonines A and B,seco C_(20)-diterpenoid alkaloids deriving via Criegee rearrangements of napelline skeleton from Aconitum carmichaelii

Two sulfo nated seco C_(20)-diterpenoid alkaloids,aconapelsulfonines A(1) and B(2),were isolated from an aqueous extract of the raw material of "Fu Zi"(the Aconitum carmichaelii lateral roots),of which the structures were elucidated by various spectroscopic data,combined with X-ray crystallogra phic analysis.The unprecedented skeletons are biogenetically proposed to be derived via Criegee rearrangements of the napelline-type architecture.The two compounds exhibited dose-depended analgesic activities on an acetic acid-induced mice writhing test.

Two unique C21-diterpenoid alkaloids from Aconitum carmichaelii

Two sulfonated diterpenoid alkaloids possessing different but related novel carbon skeletons,named aconidenusulfonine A(1)and 12,16-secoaconidenusulfonine A(2),respectively,were isolated as minor components from an aqueous extract of the lateral roots of Aconitum carmichaelii("Fu Zi").The structures of 1 and 2,representing the first two C21-diterpenoid alkaloids from nature,were determined by analysis of various spectroscopic data and chemical transformation,of which 1 was further proved by single-crystal X-ray diffraction.Especially,1 exhibited dose-depended analgesic activity consistent with the clinical function of Fu Zi.