Antinociceptive and anti-inflammatory activities of Tabernaemontana catharinensis

In this work we describe the analgesic, anti-inflammatory and toxic activities as well as the phytochemical profile of the ethanol extract from Tabernaemontana catharinensis A. DC. (Apocynaceae) stem bark. Analgesic evaluation was carried out against chemical and thermal stimuli. Anti-inflammatory activity was investigated on carrageenan-induced edema in rats and toxicological studies (LD₅₀) were conducted in mice. Phytochemical analyses were performed by standardized methodology. In an analgesic assay, acetic acid-induced writhings were significantly inhibited by extract doses of 37.5?mg/kg (40.97%), 75?mg/kg (77.70%) and 150?mg/kg (88.98%). A central analgesia was also observed using T. catharinensis extract at all doses tested, particularly noticed at 60 and 90?min following administration. The extract significantly reduced edema development by 30.35% (37.5?mg/kg), 34.46% (75?mg/kg), and 56.42% (150?mg/kg) when assessed 180?min following carrageenan intraplantar injection, demonstrating an effective anti-inflammatory action. The LD₅₀ value was 2200?mg/kg. Phytochemical analyses of ethanol extract from Tabernaemontana catharinensis stem bark showed the presence of alkaloids and terpenoids, which may be responsible for the observed pharmacological activities described in this work.     

Anticholinesterase,antioxidant, analgesic and anti-inflammatory activity assessment of Xeranthemum annuum L. and isolation of two cyanogenic compounds

Context: Xeranthemum annuum L. (Asteraceae) (XA) is an ornamental and medicinal species with limited bioactivity and phytochemical data.

Objective: Identification of anticholinesterase, antioxidant, anti-inflammatory and analgesic effects of the flower and root–stem (R-S) extracts of XA.

Materials and methods: Anticholinesterase (at 100?μg mL^?1) and antioxidant (at 1000?μg mL^?1) effects of various extracts were evaluated via microtiter assays, while anti-inflammatory and analgesic effects of the R-S extracts were tested using carrageenan-induced hind paw oedema (100 and 200?mg kg^?1) and p-benzoquinone (PBQ) writhing models (200?mg kg^?1) in male Swiss albino mice. The R-S ethanol extract of XA was subjected to isolation studies using conventional chromatographic methods.

Results: Most of the extracts showed inhibition over 85% against butyrylcholinesterase and no inhibition towards acetylcholinesterase. The flower chloroform and the R-S ethyl acetate extracts were most effective (97.85?±?0.94% and 96.89?±?1.09%, respectively). The R-S ethanol extract displayed a remarkable scavenging activity against DPPH (77.33?±?1.99%) and in FRAP assay, while the hexane extract of the R-S parts possessed the highest metal-chelating capacity (72.79?±?0.33%). The chloroform extract of the R-S caused a significant analgesic effect (24.4%) in PBQ writhing model. No anti-inflammatory effect was observed. Isolation of zierin and zierin xyloside, which were inactive in anticholinesterase assays, was achieved from the R-S ethanol extract.

Discussion and conclusion: This is the first report of anticholinesterase, antioxidant, analgesic and anti-inflammatory activities and isolation of zierin and zierin xyloside from XA. Therefore, XA seems to contain antioxidant and BChE-inhibiting compounds.     

Antimalarial,antiplasmodial and analgesic activities of root extract of Alchornea laxiflora

Context: Alchornea laxiflora (Benth.) Pax. &; Hoffman (Euphorbiaceae) root decoctions are traditionally used in the treatment of malaria and pain in Nigeria.

Objective: To assess the antimalarial, antiplasmodial and analgesic potentials of root extract and fractions against malarial infections and chemically-induced pains.

Material and methods: The root extract and fractions of Alchornea laxiflora were investigated for antimalarial activity against Plasmodium berghei infection in mice, antiplasmodial activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of Plasmodium falciparum using SYBR green assay method and analgesic activity against experimentally-induced pain models. Acute toxicity study of the extract, cytotoxic activity against HeLa cells and GCMS analysis of the active fraction were carried out.

Results: The root extract (75–225?mg/kg, p.o.) with LD₅₀ of 748.33?mg/kg exerted significant (p?P. berghei infection in suppressive, prophylactive and curative tests. The root extract and fractions also exerted moderate activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of P. falciparum with the ethyl acetate fraction exerting the highest activity with IC₅₀ value of 38.44?±?0.89?μg/mL (Pf 3D7) and 40.17?±?0.78?μg/mL (Pf INDO). The crude extract was not cytotoxic to HeLa cells with LC₅₀ value >100?μg/mL. The crude extract and ethyl acetate fraction exerted significant (p?Discussion and conclusions: These results suggest that the root extract/fractions of A. laxiflora possess antimalarial, antiplasmodial and analgesic potentials and these justify its use in ethnomedicine to treat malaria and pain.     

Effects of an ethanol extract and the diterpene,xylopic acid,of Xylopia aethiopica fruits in murine models of musculoskeletal pain

Context: Fruits of Xylopia aethiopica (Dunal) A. Rich. (Annonaceae) are used traditionally to manage arthritis, headache and other pain disorders.

Objective: The analgesic properties of the X. aethiopica ethanol fruit extract (XAE) and xylopic acid (XA) were evaluated in musculoskeletal pain models.

Materials and methods: Acute muscle pain was induced in gastrocnemius muscle of Sprague–Dawley rats with 3% carrageenan (i.m.). Rats received XAE (30–300?mg/kg), XA (10–100?mg/kg) or morphine (1–10?mg/kg) after 12?h. Effects of XAE and XA on muscle pain were assessed by measuring post-treatment grip strength of the rats. Chronic muscle pain was similarly induced, but drug treatment was on the eighth day and effects of XAE and XA assessed with Randall–Selitto test for hyperlagesia. Acute-skeletal pain was induced in knee joints of rats with 3% carrageenan-kaolin mixture and effects determined 12-h later. Similar induction protocol was used for chronic knee pain with treatment and measurement as done for chronic muscle pain.

Results: XAE and XA significantly and dose-dependently ameliorated both acute muscle (ED₅₀ mg/kg: XAE?=?22.9; XA?=?6.2) and skeletal hyperalgesia (XAE?=?39.9; XA?=?17.7) induced by 3% carrageenan. Similarly, chronic skeletal hyperalgesia was reduced by XAE and XA treatment similar to morphine (ED₅₀: XAE?=?13.0; XA?=?4.6). This reduction was also seen in chronic muscle hyperalgesia (ED₅₀: XAE?=?79.1; XA?=?42.7). XAE and XA significantly reduced the spread of hyperalgesia to contralateral limbs in both models of chronic hyperalgesia.

Conclusion: These findings establish analgesic properties of the ethanol fruit extract of X. aethiopica and xylopic acid in musculoskeletal pain.     

An evaluation of the anti-inflammatory,antipyretic and analgesic effects of hydroethanol leaf extract of Albizia zygia in animal models

Context: The leaves of Albizia zygia (DC.) J.F. Macbr. (Leguminosae-Mimosoideae) are used in Ghanaian traditional medicine for the treatment of pain, inflammatory disorders and fever (including malaria).

Objectives: The present study evaluated the anti-inflammatory, antipyretic and analgesic effects of the hydroethanol leaf extract of Albizia zygia (AZE) in animal models.

Materials and methods: The anti-inflammatory and antipyretic effects of AZE were examined in the carrageenan-induced foot oedema model and the baker’s yeast-induced pyrexia test respectively. The analgesic effect and possible mechanisms of action were also assessed in the formalin test.

Results: AZE (30–300?mg/kg, p.o.), either preemptively or curatively, significantly inhibited carrageenan-induced foot edema in 7-day-old chicks (ED₅₀ values; preemptive: 232.9?±?53.33?mg/kg; curative: 539.2?±?138.28?mg/kg). Similarly, the NSAID diclofenac (10–100?mg/kg, i.p.) significantly reduced the oedema in both preemptive (ED₅₀: 21.16?±?4.07?mg/kg) and curative (ED₅₀: 44.28?±?5.75?mg/kg) treatments. The extract (30–300?mg/kg, p.o.) as well as paracetamol (150?mg/kg, p.o.) also showed significant antipyretic activity in the baker’s yeast-induced pyrexia test (ED₅₀ of AZE: 282.5?±?96.55?mg/kg). AZE and morphine (1–10?mg/kg, i.p.; positive control), exhibited significant analgesic activity in the formalin test. The analgesic effect was partly or wholly reversed by the systemic administration of naloxone, theophylline and atropine.

Conclusion: The results suggest that AZE possesses anti-inflammatory, antipyretic and analgesic properties, which justifies its traditional use. Also, the results show the involvement of the opioidergic, adenosinergic and the muscarinic cholinergic pathways in the analgesic effects of AZE.     

Anti-inflammatory,analgesic and antioxidant activities of 3,4-oxo-isopropylidene-shikimic acid

Context 3,4-Oxo-isopropylidene-shikimic acid (ISA) is an analog of shikimic acid (SA). SA is extracted from the dry fruit of Illicium verum Hook. f. (Magnoliaceae), which has been used for treating stomachaches, skin inflammation and rheumatic pain.

Objective To investigate the anti-inflammatory, analgesic and antioxidant activities of ISA.

Materials and methods Analgesic and anti-inflammatory activities of ISA were evaluated using writhing, hot plate, xylene-induced ear oedema, carrageenan-induced paw oedema and cotton pellets-induced granuloma test, meanwhile the prostaglandin E₂ (PGE₂) and malondialdehyde (MDA) levels were assessed in the oedema paw tissue. ISA (60, 120 and 240?mg/kg in mice model and 50, 120 and 200?mg/kg in rat model) was administered orally, 30?min before induction of inflammation/pain. Additionally, ISA was administered for 12 d in rats from the day of cotton pellet implantation. The active oxygen species scavenging potencies of ISA (10^?3–10^?5 M) were evaluated by the electron spin resonance spin-trapping technique.

Results ISA caused a reduction of inflammation induced by xylene (18.1–31.4%), carrageenan (7.8–51.0%) and cotton pellets (11.4–24.0%). Furthermore, ISA decreased the production of PGE₂ and MDA in the rat paw tissue by 1.0–15.6% and 6.3–27.6%, respectively. ISA also reduced pain induced by acetic acid (15.6–48.9%) and hot plate (10.5–28.5%). Finally, ISA exhibited moderate antioxidant activity by scavenging the superoxide radical and hydroxyl radical with IC₅₀ values of 0.214 and 0.450?μg/mL, respectively.

Discussion and conclusion Our findings confirmed the anti-inflammatory, analgesic and antioxidant activities of ISA.     

In vivo anti-inflammatory properties of aerial parts of Nasturtium officinale

Context: Nasturtium officinale R. Br. (watercress) has long been used in Iranian folk medicine to treat hypertension, hyperglycemia, and renal colic. Moreover, anticancer, antioxidant, and hepatoprotective properties of N. officinale have been reported.

Objective: In this study, anti-inflammatory activity of the hydro-alcoholic extract from aerial parts of N. officinale was investigated.

Materials and methods: Oral administration of the hydro-alcoholic extract of N. officinale (250, 500 and 750?mg?kg^?1) was investigated on two well-characterized animal models of inflammation, including carrageenan- or formalin-induced paw edema in rats. Then, the topical anti-inflammatory effect of N. officinale (2 and 5?mg/ear) was studied on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse ear edema. Finally, biopsy of the paw or ear was performed for pathological evaluation.

Results: Acute toxicity tests of N. officinale in rats established an oral LD₅₀ of >5?g?kg^?1. The extract of watercress (250, 500 and 750?mg?kg^?1) significantly inhibited carrageenan-induced paw edema 1, 2, 3 and 4?h after carrageenan challenge (p??1) also showed considerable activity against formalin-evoked paw edema over a period of 24?h (p?N. officinale (5?mg/ear) reduced TPA-induced ear edema (p?Discussion and conclusion: Our findings indicate potent anti-inflammatory activity of N. officinale in systemic and topical application and propose its potential as an anti-inflammatory agent for treatment of inflammatory conditions.     

Bioassay-guided isolation of anti-inflammatory and antinociceptive compound from Plumbago zeylanica leaf

Plumbago zeylanica Linn. (Plumbaginaceae) is used in the treatment of various inflammatory ailments in traditional medicines. In order to validate these ethnobotanical practices, the anti-inflammatory and antinociceptive activities of various leaf extracts (petroleum ether (60–80°), chloroform, acetone, ethanol, and aqueous) were studied using in vivo experimental models at two dose levels (200 and 400?mg/kg, p.o.). Anti-inflammatory activity was tested using the carrageenan induced rat hind paw edema method while analgesic activity was studied using the hot plate and formalin induced models. Diclofenac (100?mg/ kg) was used as the reference standard in both anti-inflammatory and analgesic models and morphine (10?mg/ kg, i.p.) was used as the reference standard in the formalin induced analgesic model. The acetone extract significantly (p?<?0.01) reduced inflammation in the rats when compared to the control group. As for the analgesia effect, the acetone and petroleum ether extracts significantly (p?<?0.01) decreased the pain stimulus only in the later phase of the formalin test, suggesting that the drug could be peripherally acting. Bioassay-guided fractionation of the acetone extract led to the isolation and identification of plumbagin. Structure elucidation of plumbagin confirmed it as 5-hydroxy-2-methyl-1,4-naphthoquinone, a naphthaquinone derivative, through spectral techniques.     

In vitro immunomodulatory activity and in vivo anti-inflammatory and analgesic potential with gastroprotective effect of the Mediterranean red alga Laurencia obtusa

Context: Red algae have been recognized as a rich natural source of compounds possessing interesting biological and pharmacological activities.

Objective: This work investigates anti-inflammatory, analgesic and gastroprotective activities of MeOH/CH₂Cl₂ crude extract and its fractions F1 (50% MeOH) and F2 (80% MeOH) from the whole alga plant Laurencia obtusa Hudson (Rhodomelaceae).

Materials and methods: Anti-inflammatory activity was evaluated in vitro using cytometric bead array (CBA) technology to follow up the secretion of tumour necrosis factor alpha (TNF-α) in lipopolysaccharide activated THP-1 monocytic cells at doses of 10–250?μg/mL and in vivo using carrageenan-induced paw oedema in Wistar rats at doses of 25, 50, 100 and 200?mg/kg. Crude extract and fractions were tested at the doses of 25, 50, 100 and 200?mg/kg for peripheral and central analgesic activity by acetic acid-induced writhing test and hot-plate method, respectively, in Swiss albino mice. Gastroprotective activity was evaluated using HCl/ethanol-induced gastric ulcer test in rats at doses of 25, 50, 100 and 200?mg/kg.

Results: Crude extract, F1 and F2 showed an interesting inhibition of TNF-α secretion with IC₅₀ values of 25, 52 and 24?μg/mL, respectively, and a significant anti-inflammatory activity in vivo (p?< 0.01), 3?h after carrageenan injection, the oedema inhibition was 55.37%, 52.18% and 62.86%, respectively, at the dose of 100?mg/kg. Furthermore, they showed a significant peripheral analgesic activity with 53.79%, 55.92% and 57.37% (p?< 0.01) of writhing inhibition, respectively. However, no significant activity was found in the hot-plate test. An interesting gastroprotective effect was observed with crude extract and its fractions F1 and F2 with a gastric ulcer inhibition of 65.48%, 77.42% and 81.29%, respectively, at the dose of 50?mg/kg.

Discussion and conclusion: These results suggest that L. obtusa might be used as a potential source of natural anti-inflammatory and analgesic agents with gastroprotective effect.     

Anti-inflammatory,analgesic, and antioxidant activities of Pisonia aculeata: Folk medicinal use to scientific approach

Context: Pisonia aculeata leaves (Nyctagenaceae), a Folk medicinal plant used in the treatment of several inflammation, pain, and oxidative stress associated diseases.

Objective: To evaluate anti-inflammatory, analgesic, and antioxidant potential of crude methanol extract of P. aculeata leaves (MEPA).

Materials and methods: Analgesic and anti-inflammatory activities of MEPA (250 and 500?mg/kg) were evaluated using writhing, formalin, hot plate, tail flick, carrageenan-induced paw edema test, and membrane stabilizing activity. Free radical scavenging activity, total phenolic and flavonoid contents of MEPA were also determined using standard methods.

Results: Oral administration of MEPA showed significant (p < 0.001) inhibition of paw edema, pronounced at 4?h and 5?h after carrageenan injection, and at 200 µg/mL exerts 77.67 and 38.51% protective effect against hypotonic solution and heat induced hemolysis, respectively. MEPA (250 and 500?mg/kg) produced 35.21 and 79.14% inhibition of acetic acid-induced writhing. Furthermore, MEPA (500?mg/kg) inhibited 49.19% early and 73.14% late phase of formalin-induced hypernociception. In contrast, a lower dose of MEPA did not prevent hot plate induced nociception, while in the tail immersion method, pronounced analgesic activity was observed between 1 and 4?h postdosing. The extract possesses significant in vitro antioxidant activity and a lipid peroxidation inhibition effect. Total phenolic and total flavonoid content in MEPA were 87.99?±?0.87?mg GAE/g and 58.98?±?0.01?mg QE/g, respectively.

Discussion and conclusion: Our findings confirmed the analgesic, anti-inflammatory and antioxidant activities of Pisonia aculeata leaves. Contents of flavonoids and phenolic compounds in extract could be correlated with its observed biological activities.     

Anti-inflammatory and antinociceptive effect of Pachygone ovata leaves

Context: Pachygone ovata (Poir.) Miers ex Hook. F. et Thoms (Menispermaceae) is a rich source of bioactive bisbenzylisoquinoline and aporphine alkaloids.

Objective: This study investigates the in vitro and in vivo anti-inflammatory and antinociceptive potential of Pachygone ovata leaves.

Materials and methods: Lipoxygenase (LOX) assay for anti-inflammatory activity was conducted using MeOH, EA, H and Aq extracts; followed by alkaloid isolation. The anti-inflammatory potential was determined using carrageenan-induced paw oedema and formalin tests for evaluation of Pachygone ovata analgesic effect. Different doses (100, 300 and 400?μg/kg) were administered orally to Wistar rats for a period of one week, once daily.

Results: MeOH and EA extract efficiently inhibited LOX (IC₅₀ 1.43 and 2.15?μg/mL, respectively). MeOH extract had better inhibiting capacity (57%) than indomethacin (51%) in carrageenan induced rats. MeOH extract (300?μg/kg) significantly reduced the increased levels of nitric oxide (8?±?0.57 M), total leukocyte count (4.5?±?0.05 cells 10³/cells) and C-reactive protein (55?±?0.45?mg/mL). There was a decrease in various serum biochemical markers (ALT, AST). Histopathological studies revealed reduction in oedema and decreased cellular infiltration on supplementation with MeOH extract. Furthermore, MeOH extract (300?μg/kg) and alkaloid fraction (400?μg/kg) effected both phases (neurogenic and inflammatory) of formalin injected models.

Discussion and conclusion: Inflammatory mediators play a key role in inflammation; therefore, keeping it in control is of utmost importance. The usefulness of Pachygone ovata leaves on pain and inflammation has been described, probably due to its effect on inflammatory mediators and high alkaloid content.     

Phytochemical screening and analgesic profile of the lyophilized aqueous extract obtained from Chrysobalanus icaco leaves in experimental protocols

Context: Chrysobalanus icaco L. (Chrysobalanaceae) has been used for the treatment of abdominal pain and cramps.

Objective: Assess the chemical and pharmacological profile of the lyophilized aqueous extract from C. icaco leaves (AEC).

Materials and methods: Chromatographic methods were used to assess compounds from AEC. Mice were treated with vehicle (control group) or AEC (100, 200 or 400?mg/kg, p.o.) (group with 7–8 mice) and the analgesic profile was assessed employing the acetic acid-induced writhing, formalin, hot plate tests and hyperalgesia induced by carrageenan (CG) or tumour necrosis factor-alpha. The animal motor performance was assessed using rota-rod and grip strength tests.

Results: The chromatographic profile of AEC demonstrated the presence of terpenoid compounds. The acute pretreatment with AEC, at all doses, produced a significant (p?<?0.01) inhibition of painful bahaviour (11.4?±?3.6; 10.3?±?2.8; 11.3?±?2.2) when compared to the control group (24.7?±?4.7) in acetic acid-induced writhing test. In the formalin test, AEC were effective in the second phase (p?<?0.01) (57.2?±?10.3; 56.3?±?9.2; 54.7?±?8.9) when compared to control group (121.9?±?18.5). No response was observed in the hot plate test. The higher dose of AEC produced a significant (p?<?0.01 or p?<?0.05) inhibitory effect on the mechanical hyperalgesia test. AEC did not affect the motor performance of the mice.

Discussion: The terpenoids from AEC are known for its analgesic and anti-inflammatory properties. So, these results corroborate the experiments using the AEC in inflammatory pain protocols.

Conclusion: Our results suggest that AEC act against inflammatory pain.     

Treatment of Acute Appendicitis with old Chinese Drugs

Abstract

Context: Careya arborea Roxb. (Lecythidaceae) has multiple applications in traditional medicine; it exhibits analgesic, antibacterial, anti-inflammatory, antiulcer, and protective effects. However, the effect of C. arborea on biochemical and immmunological inflammatory mediators has not been explored.

Objective: The present study investigates the anti-inflammatory potential of the methanol extract of C. arborea stem bark and further assesses its possible mechanism on the modulation of inflammatory biomarkers.

Materials and methods: Anti-inflammatory activity of C. arborea methanol extract (CAME) was evaluated (100 and 200?mg/kg, p.o) using indomethacin (10?mg/kg, p.o) as the standard drug in Wistar albino rats. Inflammation was induced by injecting 0.1?ml carrageenan (1% w/v) into the left hind paw. The anti-inflammatory mechanism was studied by measuring malondialdehyde (MDA), C-reactive protein (CRP), nitric oxide (NO), myeloperoxidase (MPO), TNF-α, and IL-1β levels in both control and treated groups. A protocol has also been established to quantify quercetin and betulinic acid content in CAME using HPTLC fingerprint.

Results: Careya arborea significantly (p?Conclusion: Several mechanisms, including the inhibition of pro-inflammatory cytokines, enzymes and mediators release, appear to account for the anti-inflammatory potential of C. arborea.     

Mechanistic assessment of the analgesic,anti-inflammatory and antipyretic actions of Dalbergia saxatilis in animal models

Context: Aqueous root extract of Dalbergia saxatilis, Hook, f., (Leguminosae) (DS) is reported useful for toothache, pains, and fever, but not scientifically proven.

Objective: This study determined its effectiveness in pain, inflammation, and fever, applying scientific models.

Materials and methods: Swiss mice or Sprague–Dawley rats (n?=?5) were pretreated with distilled water, DS (100 or 200?mg/kg), or standard drug for 30?min. The analgesic activity was measured by acetic acid writhing, tail flick, tail immersion, tail clip, hot plate, and formalin pain tests; anti-inflammatory effects were determined via carrageenan and dextran rat paw oedema tests; antipyretic activity was measured by Escherichia coli lipopolysaccharide (ECL) and turpentine in rabbits, and d-amphetamine sulphate (d-AS) pyrexia test in rats.

Results: Writhing frequency inhibition was produced by 200?mg/kg DS (33.10%), aspirin (38.19%) and morphine (93.68%). Unlike morphine, DS did not produce significant prolongation of the reaction times in the hot-plate, tail immersion, tail flick, and tail clip tests. In the first and second phases of formalin test, respectively, % inhibition was: 200?mg/kg DS (25.70% and 0%), aspirin (4.76% and 67.33%), morphine (81.42% and 66.11%); for carrageenan and dextran tests, significant difference was recorded between 200?mg/kg DS and control up to 6?h. Significant reduction in ECL, turpentine and d-AS pyrexia was recorded at 100 and 200?mg/kg DS.

Conclusion: DS produces mild non-steroidal analgesic and anti-inflammatory, as well as significant antipyretic actions involving cyclooxygenase, α₂ adrenoceptor and interleukin-1 β1 due to any of glycosides, saponins or phenolic tannins.     

Antinociceptive effect of the essential oil of tarragon (Artemisia dracunculus)

Context: Tarragon [Artemisia dracunculus L. (Asteraceae)] is used as a commercial flavoring and in perfumery. In traditional folk medicine, tarragon has been used for treatment of pain and gastrointestinal disturbances.

Objective: This study investigated the antinociceptive effect of the essential oil of A. dracunculus (EOAD) in various experimental models.

Materials and methods: The median lethal dose (LD₅₀) of EOAD was estimated using the method of Lorke. The antinociceptive effect was assessed using chemical (formalin and acetic acid) and thermal (hot-plate) nociceptive tests in rats and mice. In all experiments, EOAD was administered intraperitoneally at the doses of 10, 30, 100 and 300?mg/kg.

Results: In the acute toxicity test, the value of estimated LD₅₀ for EOAD was 1250?mg/kg. EOAD (100 and 300?mg/kg) significantly reduced (p?p?Conclusions: This study reported the peripheral and central antinociceptive activity of the EOAD and rationalized the traditional use of the plant in the treatment of different painful conditions.     

Analgesic Effects of Aqueous Extracts of the Leaves of Bryophyllum pinnatum.

Abstract

Bryophyllum pinnatum. Linn (Crassulaceae) is a shrub with simple or trifoliate petiolate leaves used mainly in folk medicine to alleviate pains of various intensities and etiologies. The analgesic potency of the aqueous extract of the leaves of B. pinnatum. was investigated using animal models. Results showed that the aqueous extract of B. pinnatum. was devoid of severe toxic effects (LD₅₀ = 660.9±2.65 mg/kg body weight), increased the pain threshold in rats using the hot plate or thermal methods, inhibited or reduced phenylbenzoquinone-induced writhing or abdominal stretches in mice in a dose-dependent manner, and produced a weak or an inferior anti-inflammatory activity than aspirin. It is concluded that the aqueous extract of B. pinnatum. can demonstrate strong analgesic potency comparable in a times-and dose-dependent manner to a nonsteroidal anti-inflammatory drug.     

The anti-arthritic activity of total glycosides from Pterocephalus hookeri,a traditional Tibetan herbal medicine

Context: Pterocephalus hookeri (C. B. Clarke) Hock., a traditional Tibetan herbal medicine rich in glycosides, has been used to treat several diseases including rheumatoid arthritis.

Objective: To evaluate the anti-arthritic activity of total glycosides from P. hookeri, and its possible mechanisms of action.

Materials and methods: Anti-arthritic activity of total glycosides from P. hookeri (oral administration for 30 days at 14–56?mg/kg) was evaluated using paw swelling, arthritis scores and histopathological measurement in adjuvant-induced arthritis (AA) Sprague-Dawley rats. The NF-κB p65 expression in synovial tissues, and serum superoxide dismutase (SOD) activity, malondialdehyde (MDA) and nitric oxide (NO) levels was measured in AA rats, respectively. Further assessment of anti-inflammatory and analgesic activities of these glycosides were carried out using inflammation and hyperalgesia models induced by xylene, carrageenan, agar and acetic acid, respectively.

Results: Total glycosides (56?mg/kg) decreased the paw swelling (38.0%, p?p?p?p?p?p?p?Discussion and conclusion: Our findings confirmed the anti-arthritic property of the total glycosides from P. hookeri, which may be attributed to its inhibition on NF-κB signalling and oxidative stress.     

Analgesic and anti-inflammatory effects of the methanol root extracts of some selected Nigerian medicinal plants

Context: The roots of Alafia barteri Oliver (Apocynaceae), Combretum mucronatum Schumach (Combretaceae) and Capparis thonningii Schum (Capparaceae) are used in Traditional African Medicine to alleviate painful and inflammatory conditions.

Objective: This study investigated the analgesic and anti-inflammatory effects of the methanol root extracts of Alafia barteri (MeAB), C. mucronatum (MeCM), and Capparis thonningii (MeCT).

Materials and methods: Analgesic activity of the extracts (50, 100, and 200?mg/kg, p.o. 1?h) was evaluated using acetic acid-, formalin- and hot plate-induced pain while anti-inflammatory actions (100 or 200?mg/kg) were investigated using the carrageenan- and xylene-induced edema tests.

Results: MeAB, MeCM, and MeCT (200?mg/kg) inhibited acetic acid-induced abdominal constriction by 55.07, 46.67, and 47.25%, respectively. In the formalin test, the index of pain inhibition of early and late phases was, respectively, 47.83 and 81.98% for MeAB, 56.10 and 63.81% for MeCM, and 42.84 and 63.29% for MeCT (200?mg/kg). MeAB and MeCT pretreatments significantly increased the reaction time by 46.67 and 25.53%, respectively, 120?min post-treatment in the hot-plate test. Naloxone (5?mg/kg, s.c.) pretreatment 15?min before extract administration, significantly (p?MeAB, MeCM, and MeCT showed significant anti-inflammatory activity with 60.44 and 30.39%, 63.74 and 58.08%, and 50.55 and 77.84% (200?mg/kg, 4?h), respectively, inhibition of paw and ear edema.

Discussion and conclusion: The analgesic and anti-inflammatory effects of MeAB and MeCT involve an interaction with opioid pathway and/or inhibition of chemical mediators of pain and inflammation.     

Antinociceptive and anti-inflammatory effects of the ethyl acetate stem bark extract of Bridelia scleroneura (Euphorbiaceae)

Bridelia scleroneura is a member of the Euphorbiaceae family. In folk medicine in Cameroon, the stem bark of this plant is used for relieving abdominal pain, contortion, arthritis and inflammation. In this study, the antinociceptive and anti-inflammatory activities of the ethyl acetate stem bark extract have been evaluated. The putative analgesic effect of the plant extract was examined in abdominal constriction, hot plate, formalin and on pain using tail immersion mouse models and in carrageenan-induced paw edema in rats. The extract (150–600 mg/kg) exhibited a dose-dependent analgesic effect (46.27–78.97%) in acetic acid-induced abdominal constriction in mice. B. scleroneura extract increased the pain latency of nociceptive response to thermal stimuli at the higher dose of 600 mg/kg. B. scleroneuna induced significant dose-dependent reduction of the nociception in both early and late phases of the formalin test. The extract at the dose of 300 mg/kg, increased significantly, by 63.70% and 52.01% the tail-immersion latency time, 1 and 2 h post-dosing. In the carrageenan test, B. scleroneura (150–600 mg/kg, p.o) had dose-dependent and significant effects at different time intervals. This behaviour was similar to indometacin (10 mg/kg) used as a standard drug. These results show that the ethyl acetate stem bark extract of B. scleroneura possesses peripheral and central analgesic properties as well as anti-inflammatory activity against acute inflammation processes, in support of the folk medicinal use of the plant.     

Evaluation of antinociceptive and antidiarrhoeal properties of Manilkara zapota leaves in Swiss albino mice

Context Manilkara zapota (L.). P. Royen. (Sapotaceae) has been used in folk medicine to treat pain, diarrhoea, inflammation, arthralgia, and other disorders.

Objective Screening of Manilkara zapota leaves ethanol extract and its different solvent soluble fractions for possible antinociceptive and antidiarrhoeal activities in Swiss albino mice.

Materials and methods The extract and various fractions (200 and 400?mg/kg body weight; p.o.) were tested for peripheral and central antinociceptive activity by acetic acid-induced writhing and radiant heat tail-flick method, respectively; castor oil-induced diarrhoeal model was used to evaluate antidiarrhoeal activity at both doses. All the samples were administered once in a day and the duration of study was approximately 5?h.

Results Ethanol extract (400?mg/kg), petroleum ether fraction (400?mg/kg), and ethyl acetate fraction (400?mg/kg) showed significant peripheral antinociceptive activity having 59.89, 58.24, and 46.7% (p?<?0.001) of writhing inhibition, respectively, which is comparable with that of standard diclofenac (59.34% inhibition). The ethanol extract (400?mg/kg) and petroleum ether fraction (400?mg/kg) also showed promising central analgesic activity having 74.15 and 82.15% (p?<?0.001) elongation of reaction time, respectively, at 90?min after administration of sample which is also similar to that obtained by morphine (85.84% elongation). In antidiarrhoeal activity screening, ethanol extract (200 and 400?mg/kg) showed significant inhibition of defecation by 53.57 and 60.71%, respectively (p?<?0.001) compared with that of loperamide (71.42%).

Discussion and conclusion The findings of the studies demonstrated antinociceptive and antidiarrhoeal activities of M. zapota leaves which could be the therapeutic option against pain and diarrhoeal disease.