The pharmacology of arachidonic acid-induced rat paw edema

Design, synthesis, and evaluation of benzhydrylpiperazine-based novel dual COX-2/5-LOX inhibitors with anti-inflammatory and anti-cancer activity

Piperazine derivatives were screened using the ChEMBL database, paving the way for the design, synthesis, and evaluation of a novel series of dual COX-2/5-LOX inhibitors and identifying their role in mitigating cancer cell proliferation. Compound 9d with 4-Cl substitution at the terminal phenyl ring showed promising inhibition of COX-2 (IC50 = 0.25 ± 0.03 μM) and 5-LOX (IC50 = 7.87 ± 0.33 μM), outperforming the standards celecoxib (IC50 = 0.36 ± 0.023 μM) and zileuton (IC50 = 14.29 ± 0.173 μM), respectively. The two most active derivatives 9d and 9g indicated a significant anti-inflammatory response in a paw edema model by inhibiting PGE2, IL-6, and TNF-α and an increase in IL-10 concentrations. Interestingly, 9d effectively reduced pain by 55.78%, closely comparable to the 59.09% exhibited by the standard indomethacin, and was also devoid of GI, liver, kidney, and cardiac toxicity. Furthermore, 9d demonstrated anti-cancer potential against in vitro A549, COLO-205, and MIA-PA-CA-2 human cancer cell lines and an in vivo Drosophila cancer model. The pharmacokinetic investigations revealed that 9d has good oral absorption characteristics.

Antiedematogenic and Analgesic Activities of Abietic Acid in Mice

Exacerbated inflammatory responses to harmful stimuli can lead to significant pain, edema, and other complications that require pharmacological intervention. Abietic acid (AA) is a diterpene found as a significant constituent in pine species, and evidence has identified its biological potential. The present study aimed to evaluate abietic acid's antiedematogenic and anti-inflammatory activity in mice. Swiss mice (Mus musculus) weighing 20-30 g were treated with AA at 50, 100, and 200 mg/kg. The central nervous system (CNS) effects were evaluated using open-field and rotarod assays. The antinociceptive and anti-inflammatory screening was assessed by the acetic acid and formalin tests. The antiedematogenic activity was investigated by measuring paw edema induced by carrageenan, dextran, histamine, arachidonic acid, and prostaglandin, in addition to using a granuloma model. The oral administration of abietic acid (200 mg/Kg) showed no evidence of CNS effects. The compound also exhibited significant antiedematogenic and anti-inflammatory activities in the carrageenan and dextran models, mostly related to the inhibition of myeloperoxidase (MOP) activity and histamine action and, to a lesser extent, the inhibition of eicosanoid-dependent pathways. In the granuloma model, abietic acid's effect was less expressive than in the acute models investigated in this study. In conclusion, abietic acid has analgesic and antiedematogenic activities related to anti-inflammatory mechanisms.

Gaafar AR, Nafidi HA, Bourhia M. Mechanistic Evaluation of Antiarthritic Effects of Citronellol in CFA-Induced Arthritic Rats

Rheumatoid arthritis (RA) is an autoimmune disease characterized by systemic inflammation, joint tissue damage, pain, and synovitis. It leads to deformity of joints, disability, and even premature death. Markers of inflammation are highly expressed in synovium fluid and serum of arthritic patients and play an important role in the pathophysiology of RA. These transcription factors promote the fabrication of type I interferons and inflammatory cytokines. In RA, degradation of synovial cartilage and bone results from stimulation of proinflammatory cytokines. Citronellol (Ct), a monoterpene alcohol, is found in citrus fruits and essential oils of many aromatic plants. It possesses numerous pharmacological properties such as antioxidant activity and potential antinociceptive and anti-inflammatory effects. Keeping in view the significant anti-inflammatory role of Ct, a trial of 28 days was conducted. Ct was administered orally at three different doses (25, 50, and 100) mg/kg in Freund's adjuvant-induced arthritic rats, and the results were compared with piroxicam, chosen as the standard drug. The antiarthritic activity of the compound was evaluated through measurements of arthritic scoring and plethysmometry before and after treatment. The blood biochemical and hematological parameters and histopathological analyses were performed. Additionally, qPCR was conducted to analyze the mRNA expression levels of TNF-α, IL-1β, NF-κB, MMP3, IL-6, and IL-4 in the blood. ELISA was performed to evaluate the levels of PGE2. The results demonstrated that Ct showed significant results at all doses, but the highest dose proved to be most significant in terms of decreasing arthritic scoring and paw edema, indicating the antiarthritic potential of Ct. Furthermore, the compound was found to downregulate all the proinflammatory cytokines (TNF-α, IL-1β, NF-κB, MMP3, and IL-6) and upregulate the anti-inflammatory cytokine (IL-4). The levels of PGE2 were also reduced which further supported the antiarthritic effects of Ct and validated it as a potential antiarthritic candidate.

Anti-inflammatory effects of Pikad Tri-phol-sa-mut-than remedy, consisting of dried fruits of Aegle marmelos (L.) Corrêa, Coriandrum sativum L., and Morinda citrifolia L

ETHNOPHARMACOLOGICAL RELEVANCE

Inflammation has been known to possess some essential roles in many diseases, especially those with chronic or severe conditions. Pikad Tri-phol-sa-mut-than, a Thai traditional herbal remedy, has long been used to treat gastrointestinal sicknesses, fever, and severe illness caused by the deformities of Tridosha. In particular, this recipe has also been applied for inflammation-related conditions including gout and rheumatoid arthritis. The Pikad Tri-phol-sa-mut-than recipe consists of dried fruits of three herbs including Aegle marmelos (L.) Corrêa, Morinda citrifolia L., and Coriandrum sativum L. Each of these plant components of Pikad Tri-phol-sa-mut-than exhibited anti-inflammatory activities. However, anti-inflammatory effect of Pikad Tri-phol-sa-mut-than remedy has not been reported.

AIM OF THE STUDY

The objective of this study was to elucidate the anti-inflammatory activities of Pikad Tri-phol-sa-mut-than extract (TS) against acute and chronic inflammation in rats.

MATERIALS AND METHODS

To study the effects of TS on acute inflammation, ethyl phenylpropiolate (EPP)-induced ear edema, carrageenan- and arachidonic acid (AA)-induced hind paw edema models were carried out. In addition, cotton pellet-induced granuloma formation was performed to specify the inhibitory effects of TS on chronic inflammation.

RESULTS

The topical application of TS significantly inhibited EPP-induced ear edema in rats. In the carrageenan- and AA-induced paw edema models, the oral administration of TS significantly reduced paw volumes, compared to those of the control groups. In addition, the 7-day oral treatment of TS demonstrated a significant suppressive effect on cotton pellet-induced granuloma formation.

CONCLUSIONS

The current study revealed that TS possesses anti-inflammatory activities against acute and chronic inflammation. Our studies support the use of TS in traditional medicine, and the development of TS as a novel natural product for treating diseases associated with inflammation.

Novel 5,6-diphenyl-1,2,4-triazine-3-thiol derivatives as dual COX-2/5-LOX inhibitors devoid of cardiotoxicity

A novel series of 5,6-diphenyl-1,2,4-triazine-3-thiol derivatives were designed, synthesized, and screened for their inhibitory potential against COX-2 and 5-LOX enzymes. The compounds from the series have shown moderate to excellent inhibitory potential against both targets. Compound 6k showed the inhibitions against COX-2 (IC₅₀ = 0.33 ± 0.02 μM) and 5-LOX inhibition (IC₅₀ = 4.90 ± 0.22 μM) which was better than the standard celecoxib (IC₅₀ = 1.81 ± 0.13 μM) for COX-2 and zileuton (IC₅₀ = 15.04 ± 0.18 μM) for 5-LOX respectively. Further investigation on the selected derivative 6k in rat paw edema models revealed significant anti-inflammatory efficacy. Compound 6k has also shown negligible ulcerogenic liability as compared to indomethacin. Moreover, in vivo biochemical analysis also established the compound's antioxidant properties. Compounds 6c and 6k were also observed to be devoid of cardiotoxicity post-myocardial infarction in rats. The molecular docking and dynamics simulation studies of the most active derivative 6k affirmed their consentient binding interactions with COX-2 specific ravine and cleft of 5-LOX.

Anti-Inflammatory and Physicochemical Characterization of the Croton Rhamnifolioides Essential Oil Inclusion Complex in β-Cyclodextrin

Croton rhamnifolioides is used in popular medicine for the treatment of inflammatory diseases. The objective of this study was to characterize and evaluate the anti-inflammatory effect of C. rhamnifolioides essential oil complexed in β-cyclodextrin (COEFC). The physicochemical characterization of the complexes was performed using different physical methods. The anti-inflammatory activity was evaluated in vivo by ear edema, paw edema, cotton pellet-induced granuloma, and vascular permeability by Evans blue extravasation. The mechanism of action was validated by molecular docking of the major constituent into the cyclooxygenase-2 (COX-2 enzyme). All doses of the COEFC reduced acute paw edema induced by carrageenan and dextran, as well as vascular permeability. Our results suggest the lowest effective dose of all samples inhibited the response induced by histamine or arachidonic acid as well as the granuloma formation. The complexation process showed that the pharmacological effects were maintained, however, showing similar results using much lower doses. The results demonstrated an involvement of the inhibition of pathways dependent on eicosanoids and histamine. Complexation of β-cyclodextrin/Essential oil (β-CD/EO) may present an important tool in the study of new compounds for the development of anti-inflammatory drugs.

Antinociceptive Activities of the Methanolic Extract of the Stem Bark of Boswellia dalzielii Hutch. (Burseraceae) in Rats Are NO/cGMP/ATP-Sensitive-K+ Channel Activation Dependent

Boswellia dalzielii (B. dalzielii) is traditionally used in the treatment of rheumatism, pain, and inflammation. The present investigation evaluates the property and possible mechanism of action of the methanolic extract of B. dalzielii (BDME) on inflammatory and neuropathic pain models. Effects of BDME (250 and 500 mg/kg), orally administered, were verified in mechanical hypernociception induced by LPS or PGE₂. Mechanical hyperalgesia, cold allodynia, and heat hyperalgesia were used in vincristine-induced neuropathic pain. NW-nitro-L-arginine methyl ester (inhibitor of nitric oxide synthase), glibenclamide (ATP-sensitive potassium channel blocker), methylene blue (cGMP blocker), or naloxone (opioid antagonist receptor) has been used to evaluate the therapeutic effects of BDME on PGE₂-induced hyperalgesia. Chemical profile of BDME was determined by using HPLC-XESI-PDA/MS. BDME showed significant antinociceptive effects in inflammatory pain caused by LPS and PGE₂. The extract also significantly inhibited neuropathic pain induced by vincristine. The antinociceptive property of BDME in PGE₂ model was significantly blocked by L-NAME, glibenclamide, methylene blue, or naloxone. The present work reveals the antinociceptive activities of BDME both in inflammatory and in neuropathic models of pain. This plant extract may be acting firstly by binding to opioid receptors and secondly by activating the NO/cGMP/ATP-sensitive-K⁺ channel pathway.

The anti-inflammatory effects of Yunnan Baiyao are involved in regulation of the phospholipase A2/arachidonic acid metabolites pathways in acute inflammation rat model

The traditional Chinese medicine Yunnan Baiyao (YNB) has been reported to possess anti-inflammatory properties, however its mechanism of action remains unclear. It was previously reported that YNB ameliorated depression of arachidonic acid (AA) levels in a rat model of collagen-induced arthritis. In the current study, the capacity of YNB to ameliorate inflammation was compared in carrageenan-induced and AA-induced acute inflammation of the rat paw with celecoxib and mizolastine, respectively (n=24 per group). The capacity of YNB to affect the phospholipase A2 (PLA2)/AA pathway (using reverse transcription-quantitative polymerase chain reaction) and release of inflammatory lipid mediators (by ELISA) were investigated. Celecoxib ameliorated carrageenan-induced paw edema, and mizolastine ameliorated AA-induced rat paw edema. YNB alleviated paw edema and inhibited inflammatory cell infiltration in the two models. YNB inhibited production of 5-LOX AA metabolite leukotriene B4 (LTB4), and suppressed expression of 5-LOX, cytosolic PLA2 (cPLA2), 5-LOX-activating protein, and LTB4 receptor mRNA in the AA-induced inflammation model (P<0.05). YNB Inhibited the production of the COX-2 AA metabolite prostaglandin E2 (PGE2) and suppressed expression of COX-2, cPLA2, PGE2 mRNA in the carrageenan-induced inflammation mode (P<0.05). Taken together, the data suggest that modulation of COX and LOX pathways in AA metabolism represent a novel anti-inflammatory mechanism of YNB.

Naphthoquinones of Sinningia reitzii and Anti-inflammatory/Antinociceptive Activities of 8-Hydroxydehydrodunnione

Chemical investigation of the tubers of Sinningia reitzii led to the isolation of five new naphthoquinones, 8-hydroxydehydrodunnione (1), 7-hydroxydehydrodunnione (2), 5-hydroxy-6,7-dimethoxy-α-dunnione (3), 5-hydroxy-6,7-dimethoxydunniol (4), and 8-hydroxy-7-methoxy-2-O-methylstreptocarpone (5). Three known naphthoquinones, 7-hydroxy-α-dunnione, 8-hydroxydunnione, and 6,8-dihydroxy-7-methoxy-2-O-methyldunniol, were also identified. When tested for anti-inflammatory activity in a mouse model, compound 1 (50-500 pg/paw) reduced the edema induced by carrageenan in a dose-dependent fashion. The highest dose showed a similar inhibition to that observed for the positive control dexamethasone. At lower doses (5-10 pg/paw), 1 also dose dependently reduced the mechanical hyperalgesia induced by carrageenan. Compound 1 (15 pg/paw) abolished the mechanical hyperalgesia induced by prostaglandin E₂ and dopamine, but not that induced by dibutyryl cyclic AMP. Dipyrone (320 μg/paw) completely abolished the hyperalgesia induced by these algogens. Additionally, compound 1 did not alter heat-induced nociception. These results suggest that this new naphthoquinone exhibits important anti-inflammatory and antinociceptive activities, which is dissimilar to that of most known analgesics.

Design, synthesis, and biological evaluation of some novel indolizine derivatives as dual cyclooxygenase and lipoxygenase inhibitor for anti-inflammatory activity

Some novel indolizine derivatives were synthesized by bioisosteric modification of imidazo[1,2-a]pyridine for anti-inflammatory activity. The physicochemical characterization and structure of compounds were elucidated by state of the art spectroscopic technique. Induced fit docking was performed for initial screening to elucidate the interactions with corresponding amino acids of cyclooxygenase (COX-1, COX-2) and lipoxygenase (LOX) enzymes. The target compounds 53-60 were then evaluated against in vivo carrageenan and arachidonic acid induced rat paw edema models for anti-inflammatory activity. Amongst all the synthesized derivatives, compound 56 showed the significant anti-inflammatory activity in both rat paw edema models with very less ulcerogenic liability in comparison to standard diclofenac, celecoxib, and zileuton. The compounds 56 was further assessed to observe in vitro enzyme inhibition assay on both cyclooxygenase and lipoxygenase enzyme where it showed a preferential and selective non-competitive enzyme inhibition towards the COX-2 (IC₅₀=14.91μM, Ki=0.72µM) over COX-1 (IC₅₀>50μM) and a significant non-competitive inhibition of soybean lipoxygenase enzyme (IC₅₀=13.09μM, Ki=0.92µM). Thus, in silico, in vivo, and in vitro findings suggested that the synthesized indolizine compound 56 has a dual COX-2 and LOX inhibition characteristic and parallel in vivo anti-inflammatory activity in comparison to the standard drugs.

Anti-inflammatory and antiedematogenic activity of the Ocimum basilicum essential oil and its main compound estragole: In vivo mouse models

The genus Ocimum are used in cooking, however, their essential oils are utilized in traditional medicine as aromatherapy. The present study was carried out to investigate the chemical composition and systemic anti-inflammatory activity of the Ocimum basilicum essential oil (EOOB) and its major component estragole, as well as its possible mechanisms of action. The Ocimum basilicum essential oil was obtained by hydrodistillation and analyzed by GC-MS. The anti-inflammatory action was verified using acute and chronic in vivo tests as paw edema, peritonitis, and vascular permeability and granulomatous inflammation model. The anti-inflammatory mechanism of action was analyzed by the participation of histamine and arachidonic acid pathways. The chemical profile analysis identified fourteen components present in the essential oil, within them: estragole (60.96%). The in vivo test results show that treatment with EOOB (100 and 50 mg/kg) and estragole (60 and 30 mg/kg) significantly reduced paw edema induced by carrageenan and dextran. The smallest doses of EOOB (50 mg/kg) and estragole (30 mg/kg) showed efficacy in the reduction of paw edema induced by histamine and arachidonic acid, vascular permeability inhibition and leukocyte emigration in the peritoneal fluid. Theses doses were capable of reducing the chronic inflammatory process. The results observed between the EOOB and estragole demonstrate efficacy in anti-inflammatory activity, however, the essential oil is more efficacious in the acute and chronic anti-inflammatory action. This study confirms the therapeutic potential of this plant and reinforces the validity of its use in popular medicine.

Influence of pro-algesic foods on chronic pain conditions

This paper examines current knowledge about putative "pro-algesic" dietary components, and discusses whether limiting the intake of these substances can help improve chronic pain. Although there is a common impression that numerous food components, natural and synthetic, can cause or worsen pain symptoms, very few of these substances have been investigated. This article focuses on four substances, monosodium glutamate, aspartame, arachidonic acid, and caffeine, where research shows that overconsumption may induce or worsen pain. For each substance, the mechanism whereby it may act to induce pain is examined, and any clinical trials examining the effectiveness of reducing the intake of the substance discussed. While all four substances are associated with pain, decreased consumption of them does not consistently reduce pain.

A possible anti-inflammatory mechanism of ethyl acetate extracts of Teucrium stocksianum Bioss

Background

Teucrium stocksianum (T. stocksianum) is one of the important members of the genus Teucrium which contains numerous biologically active compounds. Traditionally, it is used for the treatment of fever, pain, as expectorant and blood purifier. Researchers are trying to discover plants origin, novel and safe remedies for the management of various ailments. The present study was aimed to determine the possible anti-inflammatory mechanism of ethyl acetate extract of T. stocksianum.

Methods

Preliminary, the ethanolic extract and sub-fractions were screened for anti-inflammatory potential at doses of 100, 200 and 300 mg/kg (i.p) body weight, using carrageenan induced paw edema test in mice. In-order to determine the possible mechanism of anti-inflammatory effect, the ethyl acetate fraction was ascertained with different phlogistic agents like histamine, bradykinin, prostaglandins E₂ and arachedonic acid via paw edema test in mice.

Results

The ethanolic extract and sub-fractions of T. stocksianum displayed marked to moderate anti-inflammatory activity in a carrageenan induced paw edema test in mice. Among the sub-fractions, ethyl acetate fraction (EAF) demonstrated excellent (66 %) anti-inflammatory action at the highest tested dose (300 mg/kg) that reached to the maximum value at 3^rd hour after carrageenan injection and remained significant (***P < 0.001) till 5^th hour of test sample administration. EAF revealed moderate effect against the paw edema induced by histamine (31.048 %) while non-significant results (18.148 %) were observed against the edema induced by bradykinin. The extract demonstrated significant (66.23-73.076 %) anti-inflammatory potential against the edematogenic effect of prostaglandin E₂. Moreover, the extract also significantly inhibited (51.33 %) the paw edema induced by arachedonic acid.

Conclusion

Our results suggest that the EAF has dual action and produced the anti-inflammatory effect by blocking both pathways of arachedonic acid metabolites (cyclooxygenase and lipoxygenase). Thus validating the traditional use of T. stocksianum and could provide a source of novel, effective and safe drug for the treatment of inflammation.

Synthesis, characterization, evaluation and molecular dynamics studies of 5, 6-diphenyl-1,2,4-triazin-3(2H)-one derivatives bearing 5-substituted 1,3,4-oxadiazole as potential anti-inflammatory and analgesic agents

A series of triazin-3(2H)-one derivatives bearing 1,3,4-oxadiazole (4a-4o) were synthesized, characterized and evaluated for anti-inflammatory and analgesic activities. Preliminary in vitro anti-inflammatory activity was assessed using an albumin denaturation assay. The promising compounds were further evaluated in acute, sub-chronic and chronic animal models of inflammation. Derivatives 4d, 4e, 4g, 4j and 4l exhibited significant anti-inflammatory activity with reduced ulcerogenic, hepatotoxic and renotoxic liabilities compared to standard indomethacin. These potential derivatives were also evaluated for in vivo analgesic activity using a writhing model and the formalin-induced paw licking response in mice. Compounds 4d, 4e and 4g exhibited comparable analgesic activity, whereas 4j and 4l yielded moderate effects. The specificity of compounds 4d, 4e, 4g, 4j, and 4l to inhibit (cyclooxygenase-1) COX-1 and (cyclooxygenase-2) COX-2 isozymes and their kinetics were also determined via an in vitro COX inhibition assay. In silico docking studies were performed using a molecular dynamics simulation of the most active compound 4d (COX-2 IC50: 3.07 μM) at the COX-2 active site. The outcome of this exercise helped to verify the consensual interaction of these compounds with the enzyme.

Investigation of anti-inflammatory, antinociceptive and antipyretic activities of Stahlianthus involucratus rhizome ethanol extract

ETHNOPHARMACOLOGICAL RELEVANCE

Stahlianthus involucratus (Zingiberaceae) has long been used in traditional medicine to treat inflammation, pain, and fever. However, no pharmacological study of this plant has been reported to confirm these activities. The aim of this study was to investigate the anti-inflammatory, antinociceptive and antipyretic activities of Stahlianthus involucratus rhizome ethanol extract (SiE) in animal models.

MATERIALS AND METHODS

Anti-inflammatory activity of SiE was investigated in rats using ethyl phenylpropiolate (EPP)-induced ear edema, carrageenan- and arachidonic acid (AA)-induced hind paw edema, and cotton pellet-induced granuloma formation models. Acetic acid-induced writhing response in mice and tail-flick test in rats as well as yeast-induced hyperthermia in rats were used to investigate the antinociceptive and antipyretic activities, respectively.

RESULTS

SiE significantly inhibited EPP-induced ear edema, carrageenan- and AA-induced hind paw edema. Its inhibitory effect in carrageenan-induced hind paw edema seemed to be in a dose-dependent manner. In cotton pellet-induced granuloma formation, SiE showed suppressive effects on granuloma formation but not on body weight gain and dry thymus weight. It could normalize serum alkaline phosphatase activity to nearly normal level. SiE also possessed a significant inhibitory effect, which seemed to be dose-dependent, on acetic acid-induced writhing response, whereas only at the highest dose of SiE could significantly increase test reaction time at all time-points in tail-flick test. However, no antipyretic activity was observed.

CONCLUSIONS

These results suggest that SiE possesses anti-inflammatory and antinociceptive, but not antipyretic, activities. This study therefore rationalizes the traditional use of SiE for the treatment of inflammation and pain.

Evaluation of anti-inflammatory, analgesic, and antipyretic activities of the ethanol extract from Murdannia loriformis (Hassk.) Rolla Rao et Kammathy

Introduction:Murdannia loriformis (hassk) Rolla Roa et Kammathy, family Commelinaceae, is used by Chinese practitioners as a remedy for cancer in an early stage, and also for treating other diseases including colds, throat infections, pneumonia, diabetes mellitus, flu and inflammation. Although anticancer as well as other pharmacological effects of M. loriformis have been reported, its anti-inflammatory and other activities related to inflammation are still limited.

Methods: The anti-inflammatory activity was evaluated using carrageenan- and arachidonic acid-induced paw edema in rats, and cotton pellet-induced granuloma formation in rats. The analgesic and antipyretic activities were determined by formalin test in mice and yeast-induced hyperthermia in rats, respectively.

Results: The ethanol extract of the aerial part of M. loriformis exhibited anti-inflammatory activity on the rat paw edema induced by carrageenan and arachidonic acid. It also showed an inhibitory effect on the granuloma and the transudative formation of the rat implanted with cotton pellets as well as lowered the elevated serum alkaline phosphatase activity to normal level. It exerted potent analgesic effect on both the early and late phase of formalin test as well as the antipyretic effect on yeast-induced hyperthermic rats. The oral single high dose of the extract of 5,000 mg/Kg did not produce death or any abnormalities or changes of the internal organs of rats during 14 days of the observed period.

Conclusion: The results obtained from this study support the use of the plant in traditional medicine for inflammatory ailments.

Antinociceptive and anti-inflammatory activities of Bridelia retusa methanolic fruit extract in experimental animals

Antinociceptive and anti-inflammatory potentials of methanolic extract of Bridelia retusa fruit (BRME) were evaluated against different animal models in rodents. Antinociceptive effects of BRME were assessed in mice using the acetic acid-induced writhing and formalin test. Anti-inflammatory effects of BRME in three different doses, namely, 100, 200, and 400 mg/kg, were evaluated by utilizing different animal models representing various changes associated with inflammation, namely, carrageenan-induced paw oedema, histamine and serotonin-induced paw oedema, arachidonic acid-induced paw oedema, formalin-induced paw oedema, TPA-induced ear oedema, acetic acid-induced vascular permeability, total WBC count in paw fluid, and myeloperoxidase assay. Also BRME was phytochemically evaluated using chromatographic method. The BRME did not exhibit any signs of toxicity up to a dose of 2000 mg/kg. The extract showed statistical significant inhibition of induced nociception and inflammation in dose dependent manner. The higher dose of extract significantly inhibited pain and inflammation against control (P < 0.001). HPLC results revealed the presence of gallic acid and ellagic acid as phytoconstituents in BRME and it was proven as anti-inflammatory agents. The present study scientifically demonstrated the antinociceptive and anti-inflammatory potential of fruit of B. retusa methanolic extract. These effects may be attributed to the presence of polyphenolic phytoconstituents in the extract.

Anti-inflammatory and antioxidant activities of Costus afer Ker Gawl. hexane leaf fraction in arthritic rat models

ETHNOPHARMACOLOGICAL RELEVANCE

Costus afer Ker Gawl is an indigenous tropical African medicinal plant used as therapy in the treatment of inflammatory ailments such as rheumatoid arthritis. This study was designed to evaluate the anti-inflammatory and antioxidant activities of the hexane fraction of C. afer leaves (CAHLF).

MATERIALS AND METHODS

The anti-inflammatory effect of varying doses of CAHLF on carrageenan, arachidonic acid, and formaldehyde induced arthritis in male albino rats׳ models were investigated in order to study the acute inflammatory phase. Complete Freund׳s Adjuvant (CFA)-induced arthritis model was used to study the chronic inflammatory phase. Two known anti-inflammatory drugs, Diclofenac sodium (non-steroidal anti-inflammatory drug [NSAID]) and prednisolone (glucocorticoid [steroidal drug]) were used as standards for comparison. Various biochemical indices viz. superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), reduced glutathione (GSH) and malondialdehyde (MDA), aspartate amino transferase (AST), alanine amino transferase (ALT), alkaline phosphatase (ALP), total bilirubin (TB), total protein (TP), globulin and albumin levels were assayed using spectrophotometric methods.

RESULTS

Control animals in which arthritis have been induced using carrageenan, arachidonic acid, formaldehyde or CFA showed significant increases (P<0.05) in paw edema when compared with normal animals. Treatment of the arthritis induced rats with CAHLF significantly (P<0.05) suppressed the edema. in vivo antioxidant study showed that CAHLF treated animals had a significantly (P<0.05) elevated GSH level, SOD, CAT and GST activities while MDA levels were significantly (P<0.05) reduced in the plasma, liver, kidney and brain. CAHLF treated rats had a significantly (P<0.05) reduced plasma AST, ALT and ALP. Plasma TP, globulin, TB levels were reduced while albumin levels were elevated in CAHLF treated animals.

CONCLUSIONS

CAHLF possesses substantial anti-inflammatory and antioxidant activities against inflammatory diseases especially arthritis. It could be considered as a choice candidate in pharmaceutical anti-inflammatory drug development.

Evaluation of anti-inflammatory and antinociceptive activity of Triphala recipe

The anti-inflammatory and antinociceptive activities of Triphala recipe were studied in animal models. Triphala recipe (4 mg/ear) significantly exhibited an inhibitory effect on the ear edema formation induced by ethyl phenylpropiolate-induced, but not on the arachidonic acid-induced ear edema in rats. Furthermore, Triphala recipe at the doses of 300, 600 and 1,200 mg/kg significantly reduced carrageenan-induced hind paw edema. Next, the anti-inflammatory action in chronic inflammation was measured using the cotton pellet-induced granuloma formation assay in rats. Triphala recipe (1,200 mg/kg) reduced neither transudative weight nor granuloma formation. It also did not affect on body weight gain and thymus weight indicating that Triphala recipe does not have a steroid-like effect. In antinociceptive study, Triphala recipe (300, 600, 1,200 mg/kg), elicited significant inhibitory effect on both phases, especially in late phase, of the formalin test in mice suggesting that the antinociceptive action of Triphala recipe may be via both peripheral and at least partly centrally acting.

Antiinflammatory, analgesic and antioxidant activities of Cyathula prostrata (Linn.) Blume (Amaranthaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Cyathula prostrata (Linn) Blume (Amaranthaceae) is an annual herb widely used traditionally in the treatment of various inflammatory and pain related health disorders in Nigeria. The aim of this study is to evaluate the anti-inflammatory, analgesic and antioxidant activities of the methanolic extract of Cyathula prostrata (Linn) Blume.

MATERIALS AND METHODS

The anti-inflammatory (phorbol 12-myristate 13-acetate (PMA)-induced reactive oxygen species (ROS), lipopolysaccharide (LPS) induced nitric oxide production in U937 macrophages, LPS-induced COX-2 expression, carrageenan-induced rat paw oedema, arachidonic acid-induced ear oedema and xylene-induced ear oedema), analgesic (acetic acid-induced writhing and hot plate tests) and antioxidant activities (DPPH [1,1-diphenyl-2-picrylhydrazyl] and lipid peroxidation assays) activities of the plant extract were investigated.

RESULTS

The methanolic extract of Cyathula prostrata did not show inhibitory activity in the in vitro PMA-induced reactive oxygen species, LPS-induced nitric oxide production and LPS-induced COX-2 expression assays. In the in vivo anti-inflammatory assays, the extract (50, 100 and 200mg/kg) showed a significant (P<0.05) dose-dependent inhibition in the carrageenan, arachidonic acid and xylene-induced tests. Cyathula prostrata produced a significant (P<0.05, 0.001) dose-dependent inhibition in the acetic acid and hot plate analgesic tests respectively. The plant extract did not exhibit any antioxidant activity in the DPPH and lipid peroxidation assays.

CONCLUSION

The results suggest that the methanolic extract of Cyathula prostrata possesses anti-inflammatory and analgesic activities and this authenticates the use of the plant in the traditional treatment of ailments associated with inflammation and pain.

Inhibition of LPS-Induced iNOS, COX-2 and Inflammatory Mediator Expression by Paeonol through the MAPKs Inactivation in RAW 264.7 Cells

We evaluated the in vivo anti-inflammatory and analgesic activities of orally administered paeonol in mice, and also investigated the anti-inflammatory activity of paeonol in a cell line. Paeonol significantly reduced the edema induced by arachidonic acid in rats. The analgesic effects were assayed using 2 different models, i.e., by acetic acid-induced writhing response and by formalin induced licking and biting time. Moreover, we examined the effects of paeonol on the release of inflammatory mediators such as NO , PGE2 and IL-6. Our results demonstrated that paeonol inhibited LPS induced expression of NO , PGE2 and IL-6. Paeonol prevented LPS induced iNOS, COX-2 and ERK activation. Therefore, paeonol appears to have potential as a treatment for inflammatory disease and analgesic.

Antioxidant, antinociceptive, and anti-inflammatory properties of the ethanolic extract of Combretum duarteanum in rodents

The antioxidant, antinociceptive, and anti-inflammatory activities of the ethanolic extract from leaves of Combretum duarteanum (EEC) were assessed in rodents through in vitro tests. The antioxidant activity was investigated by using thiobarbituric acid reactive species (TBARS), hydroxyl radical-scavenging, and scavenging activity of nitric oxide assays. The antinociceptive activity was investigated by using acetic acid-induced writhing, formalin, and hot-plate tests in mice. The anti-inflammatory activity was assessed in rats by using the carrageenan-induced hind-paw edema test and arachidonic acid-induced paw edema test. EEC possesses a strong antioxidant potential according to the TBARS, nitric oxide, and hydroxyl radical-scavenging assays; it also presented scavenger activity in all in vitro tests. After intraperitoneal injection, EEC (100, 200, and 400 mg/kg) significantly reduced the number of writhes (38.1%, 90.6%, and 97.8%, respectively) in a writhing test and the number of paw licks during phase 1 (30.5% and 69.5%, higher doses) and phase 2 (38.1%, 90.6%, and 97.8%, all doses) of a formalin test when compared with the control group. Naloxone (1.5 mg/kg, intraperitoneally) antagonized the antinociceptive action of EEC (400 mg/kg), and this finding suggests participation of the opioid system. Administration of 200 and 400 mg/kg (intraperitoneally) of EEC exhibited an anti-inflammatory activity in the carrageenin test, which was based on interference with prostaglandin synthesis. This finding was confirmed by the arachidonic acid test. Together, these results indicate that properties of EEC might be further explored in the search for newer tools to treat painful inflammatory conditions, including those related to pro-oxidant states.

Studies on anti-inflammatory and analgesic activities of betel nut in rodents

ETHNOPHARMACOLOGICAL RELEVANCE

Areca catechu, commonly known as betel nut, is very famous for its medicinal use in multiple disorders. It is also popular as a remedy against inflammatory disorders in the Unani (Greco-Arab) system of medicine.

OBJECTIVE OF THE STUDY

This study was aimed at investigating the anti-inflammatory and analgesic activities of the crude extract of Areca catechu and its respective fractions.

MATERIALS AND METHODS

Paw edema, formalin-induced nociception and acetic acid-induced writhing assays were carried out in vivo. Free radical scavenging activity of the plant extract was performed in vitro.

RESULTS

Preliminary experiments using a single dose (100 mg/kg) of Areca catechu and its respective fractions demonstrated an anti-inflammatory effect on carrageenan-induced edema in mice and rats, the aqueous fraction being distinctly more effective. When studied on prostaglandin E₂ (PGE₂), arachidonic acid, histamine, or serotonin (5HT)-induced edema in rats, Areca catechu and its aqueous fraction markedly repressed only the PGE₂ and arachidonic acid-induced inflammation. When studied for analgesic activity, the crude extract and its aqueous fraction produced a dose-dependent (10-100 mg/kg) inhibitory effect on formalin-induced nociception in mice and acetic acid-induced writhing in rats, similar to aspirin. In DPPH assay, Areca catechu and its aqueous fraction exhibited free radical scavenging activity with respective IC(50) values of 5.34 μg/ml (4.93-5.78, CI; 95%, n=5) and 7.28 μg/ml (6.04-7.95, n=4), like that of rutin with IC(50) value of 4.75 μg/ml (3.89-5.42, n=4).

CONCLUSION

These results indicate the anti-inflammatory and analgesic effects of Areca catechu and provide a rationale for its medicinal use in inflammatory disorders.

Anti-inflammatory, analgesic, and antipyretic activities of virgin coconut oil

This study investigated some pharmacological properties of virgin coconut oil (VCO), the natural pure oil from coconut [Cocos nucifera Linn (Palmae)] milk, which was prepared without using chemical or high-heat treatment. The anti-inflammatory, analgesic, and antipyretic effects of VCO were assessed. In acute inflammatory models, VCO showed moderate anti-inflammatory effects on ethyl phenylpropiolate-induced ear edema in rats, and carrageenin- and arachidonic acid-induced paw edema. VCO exhibited an inhibitory effect on chronic inflammation by reducing the transudative weight, granuloma formation, and serum alkaline phosphatase activity. VCO also showed a moderate analgesic effect on the acetic acid-induced writhing response as well as an antipyretic effect in yeast-induced hyperthermia. The results obtained suggest anti-inflammatory, analgesic, and antipyretic properties of VCO.

Response of rice advance line PB-95 to potassium application in saline-sodic soil

A field experiment was conducted to evaluate the response of rice crop to potassium fertilization in saline-sodic soil during 2005. Soil samples were collected before transplanting of rice crop and analysed for physical and chemical properties of the soil. In this experiment five rates of K2O (0, 25, 50, 75 and 100 kg ha(-1)) were applied in the presence of basal doses of N and P2O5 i.e., 110 and 90 kg ha(-1), respectively. Whole of P, K and 1/2 of N were applied at the time of rice transplanting. Twelve and halfkg ha(-1) ZnSO4 was also applied 15 days after rice transplanting. The remaining half of N was applied 30 days after rice transplanting. The system of layout was Randomized Complete Block Design with four replications. The net plot size was 6x4 m. Fertilizer sources of NPK were urea, TSP and SOP, respectively. Rice salt tolerant line PB-95 was used as test crops. The data of growth parameters and yield was recorded and samples of paddy and straw were collected treatment-wise and analysed for N, P and K contents. Soil samples after harvesting the crop were also collected, processed and analysed for the changes in the extractable soil K. The results showed that increasing rates of potassium fertilizer increased the number of tillers m(-2), plant height (cm), 1000-paddy weight and paddy as well as straw yield significantly. Maximum paddy (3.24 t ha(-1)) and straw (3.92 t ha(-1)) yields were obtained in T5 (100 kg K2O ha(-1)) which was at par with T4 (75 kg K2O ha(-1)). With increasing rates of potassium fertilizer, concentration of potassium in paddy and straw increased significantly. After harvesting the crop, the extractable potassium contents of soil increased from that of the original soil. It was concluded from the results that there was an increase of 30.65% in paddy over control by applying potassium (100 kg K2O ha(-1)) in saline-sodic soil.

Anti-inflammatory and anti-nociceptive activities of the stem bark extracts from Allanblackia monticola STANER L.C. (Guttiferae)

THE AIM OF THIS STUDY

was to assess the anti-inflammatory and mechanism of action of Allanblackia monticola (Guttiferae). The anti-inflammatory activity "in vivo" of the methylene chloride/methanol extract, methanol and methylene chloride fractions of stem barks of Allanblackia monticola, administered orally at doses of 37.5; 75; 150 and 300 mg/kg, was evaluated on carrageenan-induced oedema in rats to determine the most active fraction. Indomethacin, inhibitor of cyclo-oxygenase was used as reference drug. The effects of the most active fraction were then examined on the rat paw oedema caused by histamine, serotonin, arachidonic acid and dextran followed by its ulcerogenic effect. The results showed that the methylene chloride fraction of Allanblackia monticola was more effective on the oedema caused by the carrageenan. The anti-nociceptive activity of the methylene chloride fraction was assessed using the acetic acid-induced abdominal constriction model, formalin test and hot plate test. At 150 mg/kg, Allanblackia monticola caused maximum inhibitions of inflammation induced by carrageenan (83.33%), by histamine (42.10%), by dextran (40.29%) and by arachidonic acid (64.28%). Allanblackia monticola (75-300 mg/kg) did not cause significant modification of the oedema induced by serotonin. Concerning the anti-nociceptive properties of the plant, the methylene chloride fraction (75-300 mg/kg) caused a dose-dependent inhibition on abdominal contractions induced by acetic acid (32.34-77.37%) and significantly inhibited the inflammatory pain caused by formalin (40.71-64.78%). Allanblackia monticola did not increase the latency time in the hot plate test. Like indomethacin (10mg/kg), the fraction at the dose of 150 mg/kg caused ulceration of the gastric mucous membrane in treated rats. These results show that Allanblackia monticola has an anti-inflammatory and analgesic activities with gastric ulcerative side effects.

Effects of acetylsalicylic acid on germination, growth and chlorophyll amounts of cucumber (Cucumis sativus L.) seeds

Germination activities, various growth parameters (primary root length, hypocotyl length, primary leaf length, plant length and increase in fresh weight) and chlorophyll (a+b) amounts of cucumber seeds exposed to 0, 10(-5), 10(-4), 10(-3) and 0.5x 10(-2) M aqueous solutions of acetylsalicylic acid (ASA) for 48 h were established. While 0.5x 10(-2) M ASA significantly prevented germination activity of the seeds, other concentrations did not produce any effect, either positive or negative. Meanwhile, 0.5x 10(-2) M ASA inhibited radicle growth of the germinated seeds, while 10(-5) M ASA increased radicle growth. Other concentrations of ASA did not affect radicle growth. The following findings were obtained from the one-week seedlings exposed to ASA for 48 h: 0.5x10(-2) M ASA prevented growth (lengthening) of root, hypocotyl, leaf and plant and increased chlorophyll (a+b) amount with an increase in fresh weight. Contrary to 0.5x 10(-2) M ASA application, these features of the seedlings (except for the leaf length) were encouraged by 10(-5) M ASA. 10(-3)) M ASA only prevented root growth and reduced chlorophyll (a+b) amount. Other concentrations of ASA did not bring about any positive or negative effect on the features studied.

Anti-inflammatory, analgesic and antipyretic activities of the extract of gamboge from Garcinia hanburyi Hook f

In Thai folklore medicine, gamboge, the yellow gum-resin secreted from Garcinia hanburyi, is used for infected wound, pain and edema The ethyl acetate extract from Garcinia hanburyi (GH5763) was assessed for anti-inflammatory, analgesic and antipyretic activities using experimental animal models. It was found that GH5763 possessed inhibitory activity on acute phase of inflammation as seen in ethyl phenylpropiolate-induced ear edema and carrageenin-induced hind paw edema in rats. However, GH5763 did not elicit any inhibitory effect on arachidonic acid-induced hind paw edema. In subchronic inflammatory model, GH5763 provoked a significant reduction of both transudative and proliferative phase when tested on cotton pellet-induced granuloma model. GH5763 also reduced the alkaline phosphatase activity in serum of rats in this animal model. In the analgesic test, GH5763 elicited inhibitory activity on acetic acid-induced writhing response and on both the early and the late phase of formalin test. Moreover, GH5763 also possessed an excellent antipyretic effect when tested in yeast-induced hyperthermic rats. It is postulated that the anti-inflammatory, analgesic and antipyretic activities of GH5763 are caused by the inhibition of the prostaglandin biosynthesis.

Analgesic, anti-inflammatory and venotonic effects of Cissus quadrangularis Linn

Cissus quadrangularis, a medicinal plant indigenous to Asia and Africa, is used for many ailments, especially for the treatment of hemorrhoid. The effects associated with hemorrhoid, i.e. analgesic and anti-inflammatory activities as well as the venotonic effect of the methanol extract of C. quadrangularis (CQ) were assessed in comparison with reference drugs. In the analgesic test, CQ provoked a significant reduction of the number of writhes in acetic acid-induced writhing response in mice. CQ also significantly reduced the licking time in both phases of the formalin test. The results suggest peripheral and central analgesic activity of CQ. In acute phase of inflammation CQ elicited the inhibitory effect on the edema formation of the rats' ear induced by ethyl phenylpropiolate as well as on the formation of the paw edema in rats induced by both carrageenin and arachidonic acid. It is likely that CQ is a dual inhibitor of arachidonic acid metabolism. In addition, CQ exerted venotonic effect on isolated human umbilical vein similarly to the mixture of bioflavonoids, i.e. 90% diosmin and 10% hesperidin. The results obtained confirmed the traditional use of C. quadrangularis for the treatment of pain and inflammation associated with hemorrhoid as well as reducing the size of hemorrhoids.

Anti-inflammatory activity of Bacopa monniera in rodents

The ethanol extract of Bacopa monniera (Scrophulariaceae) exhibited marked anti-inflammatory activity against carrageenan-induced paw edema in mice and rats, an acute inflammatory model. To assess the possible mechanism of anti-inflammatory action against carrageenan, the ethanol extract was treated with chemical mediators (histamine, serotonin, bradykinin, prostaglandin E(2) and arachidonic acid)-induced edema in rats. The extract selectively inhibited prostaglandin E(2)-induced inflammation. Thus, it may be inferred that B. monniera possesses significant anti-inflammatory activity that may well be relevant for its effectiveness in the healing of various inflammatory conditions in traditional medicine.

Anti-inflammatory and analgesic activity of Peperomia pellucida (L.) HBK (Piperaceae)

An aqueous extract of the aerial part of Peperomia pellucida (L.) HBK (Piperaceae) was tested for anti-inflammatory (paw edema induced by carrageenin and arachidonic acid) and analgesic activity (abdominal writhes and hot plate) in rats and mice, respectively. Oral administration of 200 and 400 mg/kg of the aqueous extract exhibited an anti-inflammatory activity in the carrageenin test, which was based on interference with prostaglandin synthesis, as confirmed by the arachidonic acid test. In the abdominal writhing test induced by acetic acid, 400 mg/kg of the plant extract had the highest analgesic activity, whereas in the hot-plate test the best dose was 100 mg/kg. The LD(50) showed that Peperomia pellucida (5000 mg/kg) presented low toxicity.

Anti-inflammatory activity of tea (Camellia sinensis) root extract

Pharmacological studies were carried out with methanol-water (1:1) extract of dried tea (Camellia sinensis) root extract (TRE). TRE was found to possess anti-inflammatory, analgesic and antipyretic activities at 1/10th of its LD50 dose of 100 mg/kg i.p. It was found that TRE inhibited the arachidonic acid-induced paw oedema in rats which indicated that TRE produced the anti-inflammatory activity by inhibiting both the cyclooxygenase and lypooxygenase pathways of arachidonic acid metabolism. TRE also enhanced peritoneal cell count and the number of macrophages in normal mice. It is plausible that the saponins present in TRE may be responsible for these activities of TRE.

Anti-inflammatory and analgesic activities of Mallotus spodocarpus Airy shaw

The chloroform extract from the roots of Mallotus spodocarpus was investigated for anti-inflammatory and analgesic activities in animal models. In acute inflammatory models, the extract significantly inhibited ethyl phenylpropiolate-induced ear edema and carrageenin- and arachidonic acid-induced hind paw edema in rats. In the chronic inflammatory model using the cotton pellet-induced granuloma in rats, the extract exhibited inhibitory activity on the formation of granuloma. The extract also elicited pronounced inhibitory effect on acetic acid-induced writhing response in mice in the analgesic test. The results obtained suggest marked anti-inflammatory and analgesic activity of the extract.

Anti-inflammatory and antipyretic properties of Clerodendrum petasites S. Moore

The methanol extract from Clerodendrum petasites S. Moore (CP extract) was assessed for anti-inflammatory and antipyretic activities on the experimental animal models. It was found that CP extract possessed moderate inhibitory activity on acute phase of inflammation in a dose-related manner as seen in ethyl phenylpropiolate-induced ear edema (ED(50)=2.34 mg/ear) as well as carrageenin-induced hind paw edema (ED(30)=420.41 mg/kg) in rats. However, CP extract did not elicit any inhibitory effect on arachidonic acid-induced hind paw edema in rats. In subchronic inflammatory model, CP extract provoked a significant reduction of transudation but had no effect on proliferative phase when tested in cotton pellet-induced granuloma model. CP extract also reduced the alkaline phosphatase activity in serum of rats in this animal model. Moreover, CP extract possessed an excellent antipyretic effect when tested in yeast-induced hyperthermic rats. It is postulated that the anti-inflammatory and antipyretic effects of CP extract are caused by the inhibition of the prostaglandin synthesis. Anyhow, CP extract did not possess any analgesic activity in acetic acid-induced writhing response in mice. The results obtained show that C. petasites has beneficial properties since it possesses potent antipyretic and moderate anti-inflammatory activities without ulcerogenic effect.

Antioxidant activity of the methanol fraction of Pluchea indica root extract

Studies were carried out to evaluate the influence of the methanol fraction of Pluchea indica Less root extract (PIRE), the dual inhibitors (BW 755C and phenidone) and vitamin on both in vivo and in vitro free radical-scavenging activities, CCl(4)-induced lipid peroxidation and the metabolism of arachidonic acid by lipoxygenase. PIRE produced significant antiinflammatory activity against glucose oxidase-induced paw oedema (in vivo), inhibited hydroxyl radical and superoxide generation, lysis of erythrocytes induced by hydrogen peroxide, CCl(4)-induced lipid peroxidation and also dioxygenase activity of lipoxygenase (both in the presence and absence of hydrogen peroxide). Significantly higher free radical-scavenging activity was observed with BW 755C and phenidone compared with PIRE. However, both BW 755C and phenidone stimulated hydroxyl radical generation compared with the observed inhibitory effects of PIRE and vitamin E.

Antinociceptive and antiedematogenic effects of the aqueous extract of Hyptis pectinata leaves in experimental animals

The aqueous leaf extract of Hyptis pectinata (L.) Poit (Lamiaceae), popularly known in Brazil as "sambaicatá" or "canudinho", was tested for its antinociceptive effects using the abdominal writhing, hot plate and formalin test models, and for its aniedematogenic effects using the carrageenin and arachidonic acid-induced rat paw edema. The aqueous extract of Hyptis pectinata administered orally at doses of 100, 200 and 400 mg/kg had a significant antinociceptive effect in the test of acetic acid-induced abdominal writhing, with 43, 51 and 54% reduction of writhes, respectively, compared to the control. An increase in hot-plate latency of 47 and 37.5% was also observed in animals receiving doses of 200 and 400 mg/kg, p.o. when placed on a hot plate. In the formalin test, doses of 200 and 400 mg/kg, p.o. had no significant effect during the first phase of the test (0-5 min), while the dose of 200 mg/kg, p.o. reduced the nociceptive effect by 70% during the second phase (20-25 min). At the dose of 600 mg/kg, p.o., the aqueous extract inhibited carrageenin-induced rat paw edema by 34.1%, and the dose of 300 mg/kg administered intraperitoneally inhibited the rat paw edema induced by subplantar injection of arachidonic acid by 32.8%. These results suggest that the aqueous extract from the Hyptis pectinata leaves produces antiedematogenic and antinociceptive effects. The antinocipetion observed with the hot-plate test probably involves the participation of the opioid system.

Anti-inflammatory, analgesic activity and acute toxicity of Sida cordifolia L. (Malva-branca)

Sida cordifolia L. (Malvaceae) is used in folk medicine for the treatment of inflammation of the oral mucosa, blenorrhea, asthmatic bronchitis and nasal congestion. The anti-inflammatory, analgesic effects and acute toxicity of an aqueous extract of S. cordifolia were evaluated in animal models. The extract was prepared using leaves collected before the flowering period. The aqueous extract (AE) showed a significant inhibition of carrageenin-induced rat paw edema at a dose of 400 mg/kg administered orally, but did not block the edema induced by arachidonic acid. The AE also increased the latency period for mice in the hot plate test, and inhibited the number of writhes produced by acetic acid at the oral dose of 400 mg/kg. The aqueous extract of S. cordifolia showed low acute toxicity in mice.

Antiinflammatory activity of Anthurium cerrocampanense Croat in rats and mice

Aqueous (AE), ethanol (EE) and dichloromethane (DE) extracts from the whole plant of Anthurium cerrocampanense Croat, endemic to Panama, were assayed for antiinflammatory activity by carrageenan-induced rat paw edema and croton oil-induced mouse ear edema tests. The extracts were administered i.p. and topically, respectively. The best antiinflammatory activity in the carrageenan-induced rat paw edema test, was shown by DE (31% inhibition), which did not show any irritant effect in the peritoneal examination 4 h after administration of the extracts. Furthermore, the highest activity in the croton oil-induced mouse ear edema test was also exhibited by DE (93% inhibition). Since DE was the most effective of the extracts in both tests, it's activity was assessed in various inflammation models in rats. At 100 mg/kg, DE markedly inhibited inflammation produced by dextran (66.6% inhibition) and decreased weakly the edema induced by zymosan A, carrageenan and C16-platelet activation factor (C16-PAF) (33.2, 31.6 and 23.8%, respectively). At 50 mg/kg, DE only significantly reduced the swelling caused by dextran (36.2%). No effect was observed at the same doses in arachidonic acid-induced edema. A clear dose-related antiinflammatory activity of DE was seen in the croton oil-induced mouse ear edema test, and ED50 calculated was found to be 25.5 microg/ear. which was much lower than ED50 obtained for indomethacin (56.1 microg/ear).

Heterotheca inuloides: anti-inflammatory and analgesic effect

Heterotheca inuloides Cass. (Asteraceae) is used in the traditional medicine of Mexico. The aqueous extract obtained from the flowers of H. inuloides was assessed for anti-inflammatory activity by carrageenan-induced edema test. At 100 mg/kg, i.p, it produced 29% inhibition of inflammation. Ethyl ether (HI-1), butanol (HI-2) and aqueous fraction (HI-3) were obtained from the aqueous extract. The biological assay, by carrageenan-induced edema test, gave the following values (% inhibition): HI-1, 19.9; HI-2, 58.0 and HI-3, 30.0. HI-2 was significantly more effective than HI-1 and HI-3. The dose-effect curve of HI-2 was obtained and the calculated ED50 was 29.7 (22.5-39.2) mg/kg. The peritoneal examination after the treatment with HI-2 showed that the anti-inflammatory action of H. inuloides was not due to an irritating effect at the injection site. At 50-100 mg/kg, i.p., HI-2 inhibited inflammation induced by dextran (38.9-68.1% inhibition) and arachidonic acid (0-33.9%). No effect was observed at the same doses for zymosan or C16-paf-induced edema. In addition, HI-2 reduced abdominal constrictions in mice following injection of acetic acid: at 50-100 mg/kg, it gave 73.8-78.2% inhibition. The ulcerogenic assay showed that ulcer indices after HI-2 i.p. treatment were 0.5 +/- 0.5 at 50 mg/kg and 1.2 +/- 0.4 at 100 mg/kg. The results showed related anti-inflammatory activity and the analgesic effect of HI-2.

Studies on the possible mechanism of the gastric mucosal protection by Calotropis procera--involvement of 5-lipoxygenase pathway

The role of chloroform fraction of Calotropis procera root extract on different experimental ulcer models in rats was investigated. The extract demonstrated significant anti-ulcer activity against aspirin, indomethacin, ethanol, indomethacin + ethanol, or stress-induced ulcerations. Significant inhibition of gastric secretory volume and total acidity in pylorus ligated rats were observed to occur with the extract. It was also observed that the root extract significantly inhibited arachidonic acid metabolism induced by soyabean lipoxygenase. The results suggest that the anti-ulcer activity of the extract might be attributable to the inhibition of 5-lipoxygenase (5-LO).

Anti-inflammatory action of Pluchea sagittalis: involvement of an antioxidant mechanism

Pluchea sagittalis, (Lam.) Cabr., a popular medicinal herb grown in South America, was studied for anti-inflammatory and antioxidant activities. The anti-edema action of P. sagittalis aqueous extract was assayed in different models of inflammation: 1) the mouse ear edema test induced by arachidonic acid and croton oil; 2) the rat hind-paw edema test produced by several inflammatory inductors: carrageenan, dextran, zymosan, platelet-activating factor (PAF) and arachidonic acid; 3) a subacute model based on the rat carrageenan air-pouch granuloma test. Blood leukocyte free radical production was measured by flow cytometry with 2',7'-dichlorofluorescin diacetate (DCFH-DA) in vivo, in rats with induced air-pouch granuloma, and in a model in vitro. stimulating leukocytes with hydrogen peroxide. The aqueous extract of P. sagittalis showed a marked anti-inflammatory effect in both ear edema tests, dextran and carrageenan hind-paw edemas and carrageenan air-pouch model. It also had a potent antioxidant activity in blood leukocytes, both in vivo and in vitro. Our results correlate the reduction of free radical production with the anti-inflammatory effect of this plant.

Antiinflammatory effect of petroleum ether extract of leaves of Litchi chinensis Gaertn. (Sapindaceae)

Pharmacological studies were conducted with the petroleum ether extract of leaves of the plant Litchi chinensis Gaertn. (Sapindaceae) on experimental animals. The extract was found to possess antiinflammatory, analgesic and antipyretic activity. Acute toxicity studies revealed that the extract, up to a dose of 1 g/kg intraperitoneally, was nontoxic. The extract did not inhibit arachidonic acid-induced paw inflammation thus indicating that it may inhibit the cyclooxygenase pathway of arachidonic acid metabolism. The extract also enhanced peritoneal cell exudate along with macrophage significantly.

Evaluation of anti-inflammatory potential of fixed oil of Ocimum sanctum (Holybasil) and its possible mechanism of action

The fixed oil of Ocimum sanctum (Labiatae) was found to possess significant anti-inflammatory activity against carrageenan- and different other mediator-induced paw edema in rats. Significant inhibitory effect was also observed in castor oil-induced diarrhoea in rats. It also inhibited arachidonic acid and leukotriene-induced paw edema. The results of anti-inflammatory activity of Ocimum sanctum support the dual inhibition of arachidonate metabolism as indicated by its activity in inflammation models that are insensitive to selective cyclooxygenase inhibitors. On the basis of the findings it may be inferred that Ocimum sanctum may be a useful anti-inflammatory agent which blocks both the pathways, i.e. cyclooxygenase and lipoxygenase, or arachidonic acid metabolism.