Carrageenan-induced Inflammation In Rats Research Articles

Evaluation of hematoprotective, hepatoprotective, and anti-inflammatory potentials of chia seed (Salvia hispanica L.) extract in rats

This study was conducted to evaluate the effects of chia seed extract on CCl4-induced hepatotoxicity, hematological profile, and carrageenan-induced inflammation in rats. Water-ethanol-acetone extract of chia seeds at the doses of 200 and 400 mg/kg body weight/day were applied to evaluate the comparative protective roles. Hematological profile and serum biochemical parameters were measured to evaluate the hematoprotective, and hepatoprotective effects of chia seed extract. Paw thickness and motility level were assessed at 0, 1, 3, 5, and 7 h after sub-planter injection of carrageenan to evaluate the anti-inflammatory potential. Tissue histopathology was performed in both cases. Chia seed extract reduced the elevated level of serum AST and ALT significantly in a dose-dependent manner following intra-peritoneal injection of CCl4. Histopathological study of the liver tissue exhibited acute impairment of the hepatocytes and liver parenchyma following CCl4 exposure, which was markedly regenerated by the chia seed extract treatment. Protective effects of the extracts were also evidenced by the RBC count, Hb (%), PCV (%), ESR, and neutrophil count. Chia seed extract was found to inhibit the carrageenan-induced paw edema and increase motility level in a dose-oriented fashion. Histological examination of the paw tissue revealed severe inflammation characterized by massive infiltration of inflammatory cells in the carrageenan group, which was significantly reduced by chia seed extract treatment. The higher dose of chia seed extract showed significant increases in bodyweight gain and feed efficiency ratio but decrease in visceral fat deposition. These results suggest that chia seeds possess potentials for hematoprotective, hepatoprotective, and anti-inflammatory activities.

Anti-inflammatory potential of Penicillium brefeldianum endophytic fungus supported with phytochemical profiling

Various factors contribute to the development of the acute inflammation process, like the pro-inflammatory cytokines, certain enzymes as well as oxidative stress mediators. The anti-inflammatory potential of the endophytic fungus Penicillium brefeldianum was explored in carrageenan-induced inflammation in rats. After isolation of the fungus from Acalypha hispida leaves, it was identified by 18S rRNA gene sequencing. Then, its phytochemical profile was elucidated using LC–ESI–MS/MS technique. There was a remarkable decrease in the edema weight in the endophytic fungi-treated group (200 mg/kg). Also, this group had few inflammatory cells and thickened epidermis with underlying moderate collagenosis when stained with haematoxylin and eosin. Besides, immunostaining with monoclonal antibodies of cyclooxygenase-2 and tumor necrosis factor alpha showed a decrease in the positive immune cells in the endophytic fungi treated group (200 mg/kg) in relation to the positive control. Interestingly, the levels of the inflammatory as well as oxidative stress markers, including prostaglandin E2, nitric oxide, and malondialdehyde, which are hallmarks of the inflammatory process, considerably diminished (p < 0.05) in this group. qRT-PCR was utilised to elucidate the impact of the endophytic fungi treatment on the expression of interleukins (IL-1β and IL-6) genes, which decreased in comparison with the positive control group. Consequently, we can deduce that P. brefeldianum endophytic fungus has a promising anti-inflammatory potential and should be extensively studied on a broader range in the near future.Graphical

Reduning Injection prevents carrageenan-induced inflammation in rats by serum and urine metabolomics analysis

ObjectiveTo elucidate the anti-inflammatory mechanism of Reduning Injection (RDN) by analyzing the potential biomarkers and metabolic pathways of the carrageenan-induced inflammatory model from the overall metabolic level. MethodsRat inflammatory model was established by carrageenan. UPLC-Q-TOF/MS was used to detect and analyze changes of endogenous metabolites in the serum and urine of carrageenan-induced inflammatory rats. Combined with multivariate analysis and databases analysis, inflammatory-related potential biomarkers were screened and identified to analyze possible metabolic pathways. The reliability and biological significance of these biomarkers was verified by metabolic network analysis and correlation analysis with pharmacodynamic indicators. ResultsA total of 16 potential biomarkers were screened and identified by multivariate analysis and metabolite databases, among which 13 species could be adjusted by RDN. The metabolism pathway analysis revealed that histidine metabolism, sphingolipid metabolism, and tyrosine metabolism were greatly disturbed. Their biomarkers involved urocanic acid, sphingosine, and norepinephrine, all of which showed a callback trend after RDN treatment. The three biomarkers had a certain correlation with some known inflammatory-related small molecules (histamine, arachidonic acid, Leukotriene B4, and PGE2) and pharmacodynamic indicators (IL-6, IL-1β, PGE2 and TNF-α), which indicated that the selected biomarkers had certain reliability and biological significance. ConclusionRDN has a good regulation of the metabolic disorder of endogenous components in carrageenan-induced inflammatory rats. And its anti-inflammatory mechanism is mainly related to the regulation of amino acid and lipid metabolism. This research method is conducive to the interpretation of the overall pharmacological mechanism of Chinese medicine.

The anti-inflammatory properties of the methanolic extract of Cucumis melo Linn. against prostate enlargement in Wistar rats

In different parts of the world, Cucumis melo Linn. (C melo) is used for its medicinal properties.The present study examined the effects of a methanolic extract of C melo Linn. (F1 hybrid, MECM) on benign prostatic hyperplasia in adult male Wistar rats and evaluated its anti-inflammatory activity in vivo.MECM treatment reduced prostate weight mildly. Histopathological studies showed that the extract produced a strong protective effect against the development of BPH by testosterone. The MECM also showed protection from testosterone-induced benign prostatic hyperplasia (BPH). MECM was tested against carrageenan-induced inflammation in rats' paws to determine its anti-inflammatory activity. It was shown that MECM had a pronounced effect on the inflammatory response in the late phase, i.e., one hour after carrageenan injection. Prostaglandins and nitric oxide are primarily responsible for this phase indicating that MECM can modify the production and release of prostaglandin and nitric oxide. A novel formulation containing C melo may be able to treat the conditions mentioned above.

Marine sponges Sarcotragus foetidus, Xestospongia carbonaria and Spongia obscura constituents ameliorate IL-1 β and IL-6 in lipopolysaccharide-induced RAW 264.7 macrophages and carrageenan-induced oedema in rats.

Marine sponges are prolific producers of an array of diverse chemical structures containing compounds with multiple biological activities. In this study, whole methanol extracts and fractionated compounds from three marine sponges namely Xestospongia carbonaria, Sarcotragus foetidus and Spongia obscura were thoroughly investigated for their antibacterial, antifungal, antioxidant and anti-inflammatory activities. Methanol extracts and fractionated compounds were characterised using high performance liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. Extracts were checked for cytotoxicity in RAW macrophages by MTT assay, before using them for the treatment study. Enzyme linked immunosorbent assay kits were used to check the effects on inflammatory mediator's levels (PGE2, COX-2, IL-6, IL-1β, TNF-α) in vitro. The results demonstrated good anti-inflammatory activity of all the three marine sponges; X. carbonaria, S. foetidus and S. obscura suppressed the levels of anti-inflammatory cytokines in vitro. Reverse transcriptase-polymerase chain reaction confirmed the inhibition of IL-1β and IL-6 genes expression by the isolates of X. carbonaria and S. foetidus, while reducing cytokine levels in lipopolysaccharide-induced inflammation in vitro as well as in carrageenan-induced inflammation in rats. Two semi pure compounds isolated from X. carbonaria and S. foetidus also confirmed suppression of IL-1β and IL-6 genes expression in RAW macrophages.

Evaluation of Juglans regia L., root for wound healing via antioxidant, antimicrobial and anti-inflammatory activity

The burden of the management of problematic skin wounds characterized by a compromised skin barrier is growing rapidly. There is an urgent requirement for efficient mechanism-based treatments and more efficacious drug delivery systems. The present study was aimed to examine the wound healing potential of Juglans regia L. root (JR) in rats by incision and excision wound methods via the anti-inflammatory, antioxidant and antimicrobial activities. We have used tensile strength and biochemical parameters for studying the wound healing properties of JR by incision wound methodology. The anti-inflammatory effect was assessed by the measurement of paw edema in carrageenan-induced inflammation in rats. The wound contraction area, antioxidant status, and antimicrobial studies were exhausted excision wound methodology. There was a significant decrease in percent inhibition of paw edema (0.63 ± 0.03 to 0.33 ± 0.02 after 24 h) with an increase in JR concentration. Tensile strength and hydroxyproline level of different concentrations (1, 2.5, 5, and 10% w/w) of JR ointment treated groups were found significantly (P <0.001) comparable to the reference group. Moreover, JR showed significant antimicrobial and antioxidant properties, by its ability to increase antioxidant and antimicrobial levels. In conclusion, the overall results obtained in this study clarify that JR inhibits paw edema and accelerates cutaneous wound healing.

Evaluation of anti-inflammatory, antimicrobial and wound healing activity of Morus nigra

The present study was aimed to judge wound healing and the anti-inflammatory potential of Morus nigra leaves (MNL) in rats by incision and excision wound methods. Anti-inflammatory effects were assessed by measurement of paw oedema in carrageenan-induced inflammation in rats. The tensile strength and biochemical parameters were used for studying the wound healing properties of MNL by incision wound methodology. The wound contraction area, antioxidant status, and antimicrobial studies were exhausted excision wound methodology. Tensile strength and hydroxyproline level of different concentrations (% w/w) of MNL ointment treated groups were found significantly (P < .01) comparable to the reference group. There was a significant decreased in percent inhibition of paw oedema with an increase in MNL concentration. Moreover, MNL showed significant antimicrobial and antioxidant properties, by its ability to increase antioxidant levels (29.97 ± 1.31 mg/50 mg tissue of SOD, 25.17 ± 0.91 mmol/50 mg tissue of CAT and 31.71 ± 1.21 mmol/50 mg tissue of GSH) and antimicrobial levels (16.0 ± 0.50 μg/disc for Bacillus subtilis; 16.1 ± 0.28 μg/disc for Staphylococcus aureus; 25.8 ± 0.50 μg/disc for Escherichia coli; 26.1 ± 0.28 μg/disc for Proteus vulgaris; 18.0 ± 0.50 μg/disc for Candida albicans and 17.3 ± 0.50 μg/disc for Candida glaborata). The results obtained in the present study clarify that MNL inhibits paw oedema and accelerates cutaneous wound healing.

Anti-Inflammatory Concentrate Enriched with Substituted Oligofucans Derived from Brown Seaweed Turbinaria conoides (J. Agardh) Kützing and Its Safety Assessment on Wistar Rats

ABSTRACTAqueous extract of the seaweed Turbinaria conoides was purified to obtain an oligofucan-enriched seaweed concentrate (OESC). Oligofucans isolated were characterized as two types with (→1)-fucose-(2,3-diSO3−)-(1→4)-fucose-(2-SO3−)-(1→3)-fucose-(2,3-diSO3−)-(1→4)-fucose-(2-SO3−, 3-OAc)-(4→) and (→1)-fucose-(3-SO3−)-(1→4)-fucose-(2-SO3−)-(1→4)-fucose-(3-SO3−)-(1→4)-fucose-(2-SO3−)-(4→) motifs. A 90-day accelerated shelf-life study (50°C) showed that OESC maintained its antioxidant properties (free radical scavenging, reducing, lipid peroxidation inhibition, and chelating activities) even after 30 days. In vitro COX-2 and 5-LOX inhibitory properties of OESC (67.2 and 95.2%, respectively) showed no significant variation even at the 30th day. OESC significantly mitigated the carrageenan-induced inflammation in rats at 0–2 h (59.7–70.3% inhibition), which were greater compared to the synthetic NSAID aspirin. The safety of OESC has been assessed by acute (14 days) and subchronic (90 days) oral toxicity studies, which showed no toxicity-related significant changes in renal or hepatic function, hematological indices, and serum biochemical parameters in the OESC-treated Wistar rats. No histopathological alterations were observed in the vital organs of rats treated with OESC. LD50 and sub-chronic no-observed-adverse-effect level (NOAEL) for this concentrate were found to be > 5,000 and 2,000 mg/kg BW, respectively. Hence, oligofucan-enriched seaweed concentrate is safe to consume without any adverse effects in the body.

Vasoactive intestinal peptide dampens formyl-peptide-induced ROS production and inflammation by targeting a MAPK-p47phox phosphorylation pathway in monocytes.

Reactive oxygen species (ROS) produced by the phagocyte NADPH oxidase (NOX2) are required for microbial clearance; however, when produced in excess they exacerbate inflammatory response and injure surrounding tissues. NOX2 is a multicomponent enzyme composed of membrane-associated cytochrome b588 and cytosolic components p47phox, p67phox, p40phox, and rac1/2. We investigated whether vasoactive intestinal peptide (VIP), an endogenous immune-modulatory peptide, could affect ROS production by NOX2 in primary human phagocytes. VIP did not modulate basal ROS production by phagocytes, but it inhibited monocyte and not neutrophil ROS production in response to the bacterial peptide N-formyl-methionyl-leucyl-phenylalanine (fMLF). The action of VIP was essentially mediated by high-affinity G-protein coupled receptors VPAC1 as its specific agonist, [ALA11,22,28]VIP, mimicked VIP-inhibitory effect, whereas the specific VPAC1 antagonist, PG97-269, blunted VIP action. Further, we showed that VIP inhibited fMLF-induced phosphorylation of ERK1/2 (extracellular signal-regulated kinase 1/2), p38MAPK (p38 mitogen-activated protein kinase) pathways, and phosphorylation of p47phox on Ser345 residue. Also, VIP exerted an anti-inflammatory effect in a model of carrageenan-induced inflammation in rats. We thus found that VIP exerts anti-inflammatory effects by inhibiting the "MAPK-p47phox phosphorylation-NOX2 activation" axis. These data suggest that VIP acts as a natural anti-inflammatory agent of the mucosal system and its analogs could be novel anti-inflammatory molecules.

Preliminary investigation for wound healing and anti-inflammatory effects of Bambusa vulgaris leaves in rats

BackgroundBambusa vulgaris (Family: Poaceae) used in Ayurveda for paralytic complaints, inflammatory disorders and externally to skin disorders. It has various medicinal uses with good nutritional composition and a rich source of vitamins, proteins, amino acid, beta-carotene and phenolic compounds. ObjectiveThe present study was aimed to evaluate wound healing and anti-inflammatory potential of ethanol extract of B. vulgaris leaves in rats. Materials and methodsThe B. vulgaris leaves were evaluated for wound healing on incision and excision wound methods. Anti-inflammatory effect was evaluated by measurement of paw edema in carrageenan-induced inflammation in rats. Ethyl acetate (BVL-A) and aqueous (BVL-B) fractions from the ethanol extract of leaves were screened for wound healing effects by measuring tensile strength and biochemical parameters in incision wound method. The wound contraction area, antioxidant status and histopathological studies were done in excision wound method. ResultsTensile strength and hydroxyproline level of 5% w/w ointment of BVL-A and BVL-B treated groups were found significantly (P < 0.01) higher and comparable to the reference group. The histopathological study showed the proliferation of collagen, fibrous tissue, and capillaries with epidermal covering at the margin of the wound. The percent inhibition of paw edema was significantly decrease by increasing concentration of BVL-A and BVL-B fractions. In addition, it was found that B. vulgaris possesses antioxidant properties, by its ability to increase antioxidants level. ConclusionsThe results obtained in the present study were indicated that ethyl acetate fraction of B. vulgaris leaves inhibits paw edema and accelerates cutaneous wound healing.

Dolichos biflorus exhibits anti-inflammatory and antioxidant properties in an acute inflammatory model

Dolichos biflorus (Muthira) is a branched, suberect, and downing herb, native to most parts of India, and found at altitudes of up to 1000 m, whose seeds can be cooked and eaten. Nutrition plays a key role in building immunity and preventing noncommunicable diseases to a certain extent. The purpose of this study was to evaluate the anti-inflammatory and antioxidant effects of 70% methanolic extract of seeds of D. biflorus (DME) in carrageenan-induced inflammation. DME exhibited maximum percentage of oedema inhibition at a dose of 50 mg/kg at the 3rd hour of carrageenan induction. The effect was higher than that of the standard drug Voveran. The activities of cyclooxygenase, lipoxygenase, nitric oxide synthase, myeloperoxidase, and malondialdehyde showed significant (p < 0.05) reduction whereas the activities of antioxidant enzymes, vitamins C, and reduced glutathione level were increased significantly (p < 0.05) on treatment with DME. Also levels of the acute phase protein, ceruloplasmin, were brought to their normal range in DME-treated rats. Phytochemical analysis showed that the extract contains alkaloids, flavonoids, carbohydrates, proteins, and tannins, which may contribute to its anti-inflammatory and antioxidant activity. Thus the results demonstrate the potential beneficiary effect of DME on carrageenan-induced inflammation in rats.

Disruption of 5-HT2A Receptor-PDZ Protein Interactions Alleviates Mechanical Hypersensitivity in Carrageenan-Induced Inflammation in Rats

Despite common pathophysiological mechanisms, inflammatory and neuropathic pain do not respond equally to the analgesic effect of antidepressants, except for selective serotonin reuptake inhibitors (SSRIs), which show a limited efficacy in both conditions. We previously demonstrated that an interfering peptide (TAT-2ASCV) disrupting the interaction between 5-HT2A receptors and its associated PDZ proteins (e.g. PSD-95) reveals a 5-HT2A receptor-mediated anti-hyperalgesic effect and enhances the efficacy of fluoxetine (a SSRI) in diabetic neuropathic pain conditions in rats. Here, we have examined whether the same strategy would be useful to treat inflammatory pain. Sub-chronic inflammatory pain was induced by injecting λ-carrageenan (100 µl, 2%) into the left hind paw of the rat. Mechanical hyperalgesia was assessed after acute treatment with TAT-2ASCV or/and fluoxetine (SSRI) 2.5 h after λ-carrageenan injection. Possible changes in the level of 5-HT2A receptors and its associated PDZ protein PSD-95 upon inflammation induction were quantified by Western blotting in dorsal horn spinal cord. Administration of TAT-2ASCV peptide (100 ng/rat, intrathecally) but not fluoxetine (10 mg/kg, intraperitoneally) relieves mechanical hyperalgesia (paw pressure test) in inflamed rats. This anti-hyperalgesic effect involves spinal 5-HT2A receptors and GABAergic interneurons as it is abolished by a 5-HT2A antagonist (M100907, 150 ng/rat, intrathecally) and a GABAA antagonist, (bicuculline, 3 µg/rat, intrathecally). We also found a decreased expression of 5-HT2A receptors in the dorsal spinal cord of inflamed animals which could not be rescued by TAT-2ASCV injection, while the amount of PSD-95 was not affected by inflammatory pain. Finally, the coadministration of fluoxetine does not further enhance the anti-hyperalgesic effect of TAT-2ASCV peptide. This study reveals a role of the interactions between 5-HT2A receptors and PDZ proteins in the pathophysiological pathways of inflammatory pain and opens new perspectives in its control thanks to molecules disrupting 5-HT2A receptor/PDZ protein interactions.

Anti-inflammatory effects of medicinal plants mixture used by Bedouin people in Saudi Arabia

Abstract Due to toxic and adverse side effects of synthetic drugs, traditional herbal medicine has the potential as a source of new bioactive molecules. That is why we investigated this research, searching new anti-inflammatory drugs from plants growing around us. The anti-inflammatory effect of the mixture of different plants used in traditional medicine (Alkanna tinctoria, Rubia tinctorum and Artemisia herba alba) were studied using carrageenan-induced paw edema (oil mixture extract 100 mg/kg and 200 mg/kg). These material reduces carrageenan-induced inflammation in rats and shows inhibition after 4 h especially at a concentration 200 mg/ kg. Oil mixture extract were investigated by capillary GC and GC-MS in combination with retention indices revealed the presence of about 17 compounds: artemisol, epiglobulol and α-bisabolol are the main constituents as well as volatile oil and other triterpenes: taraxasterol, stigmasterol, ursan-12-ene, olean-12-ene, betulin, germincol, lupeol acetate and lupeol. Other heterocyclic compounds: moropholine and piperidinol were also identified

Evaluation of anti-inflammatory potential of Atropa acuminata in carrageenan induced inflammation in rats

The present study was envisaged to assess the rationality for the use of traditionally in vogue herb Atropa acuminata as an anti-inflammatory agent. The drug, that is, A. acuminata when tested against carrageenan induced paw oedema showed significant anti-inflammatory activity at the dose of 1 g/kg body weight. The effects were analyzed by following the evaluation of various biochemical parameters including succinate dehydrogenase (SDH), gamma-glutamyl transpeptidase (GGT), lipid peroxidation (LPO), nitric oxide (NO), superoxide dismutase (SOD), glutathione, xanthine oxidase (XO), catalase and reduced glutathione peroxidase (GPx) were measured and the results suggested that the extracts possess significant anti-inflammatory activity, and with regard to certain parameters, the extracts performed fairly well than the allopathic drug, Diclofenac. Key words: Atropa acuminate, anti-inflammatory lipid peroxidation activity, carrageenan

Inhibitory effect of ginsenoside-Rd on carrageenan-induced inflammation in rats

A previous study reported that ginsenoside-Rd reduced the production of tumor necrosis factor-α by inhibiting nuclear factor-κB in lipopolysaccharide-activated N9 microglia in vitro. The aim of the present study was to confirm the anti-inflammatory effects and mechanisms of ginsenoside-Rd in animal experiments involving acute inflammation. The results indicated that ginsenoside-Rd at doses ranging from 12.5 to 50mg/kg i.m. significantly inhibited the swelling of hind paws in rats for 1-6h after the carrageenan injection. The levels of proinflammatory cytokines and proinflammatory mediators were markedly reduced by ginsenoside-Rd. Ginsenoside-Rd, when administered intramuscularly at 12.5, 25, and 50mg/kg doses, showed signicant inhibition of carrageenan-induced production of interleukin-1β (6.91%, 45.75%, and 55.18%, respectively), tumor necrosis factor-α (37.99%, 56.39%, and 47.38%, respectively), prostaglandin E(2) (22.92%, 30.12%, and 36.36%, respectively), and nitric oxide (28.27%, 44.53%, and 53.42%, respectively). In addition, ginsenoside-Rd (12.5, 25, and 50mg/kg i.m.) effectively decreased the levels of nuclear factor-κB (6.77%, 20.28%, and 41.03%, respectively) and phosphorylation of IκBα (13.23%, 26.92%, and 41.80%, respectively) in the carrageenan-inflamed paw tissues. These results suggest that ginsenoside-Rd has significant anti-inflammatory effects in vivo, which might be due to its blocking of the nuclear factor-κB signaling pathway. Thus, it may be possible to develop ginsenoside-Rd as a useful agent for inflammatory diseases.

Antipyretic, anti-inflammatory and analgesic properties of nilavembu kudineer choornam: a classical preparation used in the treatment of chikungunya fever

Objective To investigate the efficacy of ethanolic extract of nilavembu kudineer choornam (EENKC) in inflammation, pain and fever using animal models to support its actions. Methods Acute toxicity study of EENKC was performed in mice to fix the effective dose. The antipyretic, anti-inflammatory and analgesic activity of EENKC was evaluated in brewer's yeast induced pyrexia in rats, carrageenan-induced inflammation in rats and acetic-acid induced writhing in mice model. Results Acute toxicity revealed that EENKC didn't show death and toxic signs up to 2 000 mg/kg. In brewer's yeast induced pyrexia and carrageenan-induced inflammation EENKC at the doses of 200 and 400 mg/kg inhibited fever and inflammation significantly (P<0.01 and <0.05) compared to control animals. In mice, the number of writhing induced by acetic-acid was significantly (P<0.01) reduced after treatment with both the dose of EENKC than control animals. EENKC 200 mg/kg inhibits inflammation higher level in carrageenan-induced paw edema, but there is no significant difference when compared to indomethacin 10 mg/kg. Conclusions The present findings revealed that EENKC possesses antipyretic, anti-inflammatory and analgesic activity which supports nilavembu kudineer choornam efficacy in chikungunya fever.

Effect of oleanolic acid on complement in adjuvant- and carrageenan-induced inflammation in rats.

The present work was aimed at evaluating the influence of oleanolic acid on complement-related inflammation. In adjuvant-induced arthritis and carrageenan-induced paw oedema in rats, oleanolic acid was found to possess significant anti-inflammatory and complement-inhibitory activities. The intraperitoneal injection of oleanolic acid (60 mg kg-1, twice a day), before and after Freund's Complete Adjuvant challenge and thereafter repeated for several days, significantly reduced foot-pad thickness of experimental animal models and simultaneously reduced complement activity. Oleanolic acid also produced marked reduction in complement levels and inflammatory effects on carrageenan-induced paw oedema in rats when injected intraperitoneally (60 mg kg-1, twice a day).

Effect of pre-existing inflammation on carrageenan-induced paw oedema in rats.

Twenty-four hours after injection of carrageenan into one hind paw, injection of the same amount into the contralateral paw produced a significantly attenuated inflammatory response. However, when the second injection was given 7 days later, the inflammation induced in the contralateral paw was comparable with the initial response to carrageenan. A time-course study of carrageenan-induced inflammation in rats showed that significant oedema persisted 24 h after carrageenan administration and complete recovery was achieved in 7 days. The attenuated inflammatory response in the contralateral paw after 24 h was antagonized by bilateral adrenalectomy and chemical sympathectomy induced by 6-hydroxydopamine. Carrageenan-induced paw oedema was also significantly less in rats with subacute inflammation induced by the croton oil granuloma pouch technique. This attenuated response was antagonized by pretreatment of the rats with metyrapone, an inhibitor of adrenocorticoid synthesis, and by 6-hydroxydopamine. It is likely that the pre-existing acute or subacute inflammation attenuates the inflammatory response of carrageenan, by acting as a stressor, inducing activation of the sympatho-adrenal system.

Anti-Inflammatory Activity of the Marine Cyanobacterium Trichodesmium Erythraeum against Carrageenan-Induced Paw Oedema in Wistar Albino Rats

Inflammatory diseases, including rheumatic, diseases are a major cause of morbidity of the working force throughout the world. Inflammation is a tissue reaction to infection. The effects are redness (erythema), swelling (oedema) and pain, to the area that can result in loss of function. Cyanobacteria are photosynthetic prokaryotic organisms which are potentially useful in pharmaceuticals, industrial chemicals, and restriction enzymes. Trichodesmium species are non-heterocystous cyanobacteria, commonly found in tropical and subtropical oligotrophic oceans. They occur in filaments of 20–200 cells which often congregate to form larger colonies called blooms that can be seen and often form dense blooms covering vast areas in sub-tropical regions. The present study tested the anti-inflammatory effect of the marine cyanobacterium, Trichodesmium erythraeum in carrageenan-induced inflammation in rats. The aqueous extract showed anti-inflammatory activity at a high dosage (500 mg/kg) and this effect was on par with the commercial drug, indomethacin. The inhibition of inflammation volume was 57.5±5.5 % and 47.5±4.7% respectively, at higher and lower dosages, in 30 minutes of treatment. The control group without any treatment exhibited an increase in the paw volume. This is the first report on the anti-inflammatory effect of marine-derived Trichodesmium erythraeum.

Antagonism of 5-HT2A receptors inhibits the expression of pronociceptive mediator and enhances endogenous opioid mechanism in carrageenan-induced inflammation in rats

We have recently reported that treatment with the 5-HT2A receptor antagonist ketanserin in the inflamed paw raises the nociceptive threshold above normal level (hypoalgesia) and this response is naloxone-reversible. The present study aimed to investigate neurochemical changes at the site of inflammation and in dorsal root ganglia (DRG) and the spinal cord following the blockade of 5-HT2A receptors. Intraplantar injection of ketanserin (20μg) inhibited carrageenan-induced increase in CGRP immunoreactivity-positive neurons in DRG. On the other hand, administration of ketanserin (20μg) and 5-HT (10μg), but not vehicle, enhanced and inhibited recruitment of β-endorphin-expressing immune cells, respectively, in subcutaneous loci of inflamed hindpaw. Moreover, the treatment with ketanserin increased the number of endomorphine-containing cells in the inflamed paw and μ-opioid receptor-expressing neurons in DRG at L4–5 but reduced the expression of endomorphine in superficial layers of the lumbar spinal cord. The present study provided evidence at the cellular level showing that the blockade of 5-HT2A receptors inhibited inflammation-associated increase in pronociceptive mediator, and that the pronociceptive property of 5-HT is mediated by the suppression of inflammation-activated opioid mechanism. Therefore, targeting the 5-HT2A receptors in the site of inflammation may be a promising approach to inhibit inflammatory pain.