Antinociceptive and anti‐inflammatory properties of 7‐hydroxycoumarin in experimental animal models: potential therapeutic for the control of inflammatory chronic pain

Objectives In the present study we investigated the antinociceptive, anti‐inflammatory and antipyretic effects of 7‐hydroxycoumarin (7‐HC) in animal models. Methods The effects of oral 7‐HC were tested against acetic acid‐induced writhing, formalin test, tail flick test, complete Freund's adjuvant (CFA)‐induced hypernociception, carrageenan‐induced paw oedema, lipopolysaccharide‐induced fever and the rota rod test. Key findings 7‐HC (3–60 mg/kg) produced a dose‐related antinociception against acetic acid‐induced writhing in mice and in the formalin test. In contrast, treatment with 7‐HC did not prevent thermal nociception in the tail flick test. A single treatment with 7‐HC, 60 mg/kg, produced a long‐lasting antinociceptive effect against CFA‐induced hypernociception, a chronic inflammatory pain stimulus. Notably, at 60 mg/kg per day over 4 days the administration of 7‐HC produced a continuous antinociceptive effect against CFA‐induced hypernociception. 7‐HC (30–120 mg/kg) produced anti‐inflammatory and antipyretic effects against carrageenan‐induced inflammation and lipopolysaccharide‐induced fever, respectively. Moreover, 7‐HC was found to be safe with respect to ulcer induction. In the rota rod test, 7‐HC‐treated mice did not show any motor performance alterations. Conclusions The prolonged antinociceptive and anti‐inflammatory effects of 7‐HC, in association with its low ulcerogenic activity, indicate that this molecule might be a good candidate for development of new drugs for the control of chronic inflammatory pain and fever.     

Beneficial Pharmacological Effects of Levosimendan on Antioxidant Status of Acute Inflammation Induced in Paw of Rat: Involvement in Inflammatory Mediators

Levosimendan (LEVO) is a new calcium sensitizer with positive inotropic and vasodilating properties that represents a new pharmacological class of inotropic drugs that stimulate elevated cardiac output. The purpose of this study was to examine anti‐inflammatory effect and antioxidant activity of LEVO in a carrageenan (CAR)‐induced inflammatory paw oedema rat model. The CAR‐induced rat groups received LEVO 1, 2 and 3 mg/kg by intraperitonally and indomethacin (IND) 25 mg/kg by oral gavage. LEVO inhibited CAR‐induced paw oedema and suppressed the production of TNF‐α, IL‐1 and IL‐6 at doses of 2 and 3 mg/kg. In contrast to CAR‐injected paws, 2 and 3 mg/kg doses of LEVO and IND increased superoxide dismutase (SOD) activity and also both doses of LEVO, and IND decreased the 8‐isoprostaglandin F2α (8‐ISO) level. A 2 mg/kg dose of LEVO produced 39%, 46%, 61% and 64.7% anti‐inflammatory effects (p < 0.0001) for the 1st, 2nd, 3rd and 4th hours, respectively. Other results of our current study have shown that SOD and glutathione for CAR‐injected groups were lower, and 8‐ISO level was higher than those for the healthy rat group. LEVO may be provided as a pharmacological agent in the prevention or treatment of diseases in which acute or chronic inflammation occurs based on a pathogenic factor.     

Antiinflammatory Effects of Moringa oleifera Root Extract

A crude methanol extract of the root of the plant Moringa oleifera Lam. was screened for anti inflammatory effect using the rat paw edema and the rat 6-day air pouch inflammatory models. Following oral administration, the extract inhibited carrageenan-induced rat paw edema in a dose-dependent manner, with 50% inhibitory concentration - IC 50 (dose producing 50% inhibition) of 660 mg/kg. On the 6-day air pouch acute inflammation induced with carrageenan, the extract was much more potent, with IC 50 values of 302.0 mg/kg and 315.5 mg/kg, for the inhibition of cellular accumulation and fluid exudation, respectively. Maximum inhibition obtained with 600 mg/kg were 83.8% and 80.0%, respectively. When delayed (chronic) inflammation was induced in the 6-day air pouch model using Freund’s complete adjuvant, the extract was still effective though less than in acute inflammation. In contrast, a moderate dose of indomethacin (5 mg/kg) inhibited the acute, but not the delayed form of air pouch inflammation. Acute toxicity tests in mice suggest very low toxicity. These results suggest that the root of Moringa oleifera contains anti inflammatory principle(s) that may be useful in the treatment of both the acute and chronic inflammatory conditions.     

Simvastatin and Indomethacin Have Similar Anti‐Inflammatory Activity in a Rat Model of Acute Local Inflammation

Abstract: Statins, such as simvastatin, lower circulating cholesterol levels and are widely prescribed for the treatment of hypercholesterolaemia. Several studies have shown unexpected effects of statins on inflammation. We studied the anti‐inflammatory effect of simvastatin using a standard model of an acute local inflammation, the carrageenan‐induced footpad oedema. Experimental groups (n = 6–8) were given simvastatin in a dose range 5–30 mg/kg, indomethacin 1–8 mg/kg and methylcellulose (control) per os. Footpad volume was measured with a plethysmograph and compared with the pre‐injection volume of the same paw. Swelling (in microlitres) was then calculated, and in drug‐treated animals, per cent inhibition was derived through comparison with the control group. Histopathological examination of the skin biopsies was performed to examine severity of paw skin lesions and to confirm the simvastatin‐induced inhibition of acute inflammation. Both simvastatin and indomethacin administered orally, 1 hr before carrageenan injection, significantly reduced the extent of footpad oedema. Indomethacin dose‐dependently blocked the swelling; the maximal effect was obtained with 8 mg/kg by 48.3% (P < 0.05). Simvastatin produced a comparable anti‐inflammatory activity at a dose of 5 mg/kg (32%), while 10 and 30 mg/kg caused a 47.6% and 51.7% reduction, respectively, with the maximal effect observed at 20 mg/kg by 57.2% (P < 0.05). The comparison of the ED₅₀ of these agents on molar basis showed equipotent anti‐inflammatory activity. Histopathological examination of the footpad skin biopsies revealed that simvastatin, dose‐dependently and comparablly to indomethacin, reduced polymorphonuclear leucocyte infiltration. These data support the hypothesis that simvastatin has an acute anti‐inflammatory activity.     

高乌甲素对炎症性疼痛的镇痛作用

目的　研究高乌甲素对急、慢性炎症的镇痛作用。方法　采用大鼠甲醛溶液致炎 ,鹿角菜胶致炎及佐剂性关节炎三种炎症性疼痛模型进行实验。结果　高乌甲素 8、1 6mg/kg灌胃对急性 (甲醛溶液 ,鹿角菜胶致炎 )及慢性 (佐剂性关节炎 )的炎症性疼痛有明显镇痛作用 ,峰值在给药后 0 5～ 1h ,持续 2h以上。结论　高乌甲素对急、慢性炎症性疼痛具有显著镇痛作用     

Anti‐inflammatory and antinociceptive effects of tilifodiolide,isolated from Salvia tiliifolia Vahl (Lamiaceae)

Salvia tiliifolia Vahl (Lamiaceae) is used for the empirical treatment of pain and inflammation. The diterpenoid tilifodiolide (TFD) was isolated from Salvia tiliifolia. The in vitro anti‐inflammatory effects of TFD (0.1–200 µM) were assessed using murine macrophages stimulated with LPS and estimating the levels of pro‐inflammatory mediators for 48 h. The in vivo anti‐inflammatory activity of TFD was assessed using the carrageenan‐induced paw edema test for 6 h. The antinociceptive effects of TFD were evaluated using the formalin test and the acetic acid induced‐writhing test. The effects of TFD on locomotor activity were assessed using the open field test and the rotarod test. TFD inhibited the production of TNF‐α (IC₅₀ = 5.66 µM) and IL‐6 (IC₅₀ = 1.21 µM) in macrophages. TFD (200 mg/kg) showed anti‐inflammatory effects with similar activity compared to 10 mg/kg indomethacin. The administration of TFD induced antinociception in the phase 1 (ED₅₀ = 48.2 mg/kg) and the phase 2 (ED₅₀ = 28.9 mg/kg) of the formalin test. In the acetic acid assay, TFD showed antinociceptive effects (ED₅₀ = 32.3 mg/kg) with similar potency compared to naproxen (ED₅₀ = 36.2 mg/kg). In the presence of different inhibitors in the acetic acid assay, only the co‐administration of TFD and naloxone reverted the antinociceptive activity shown by TFD alone. TFD did not affect locomotor activity in mice. TFD exerts in vitro and in vivo anti‐inflammatory activity and in vivo antinociceptive effects.     

Suppressive effects of propolis in rat adjuvant arthritis

The effects of ethanolic extract (EEP) of propolis on chronic inflammation were evaluated using rat adjuvant arthritis. In the chronic inflammatory animal model, the arthritis index was suppressed by EEP treatments (50 mg/kg/day and 100 mg/kg/day, p.o.). Moreover, physical weakness, induced by the chronic disease state, was dose-dependently improved in the EEP-treated groups. Its analgesic effect, assessed using the tail-flick test, was comparable to prednisolone (2.5 mg/kg/day, p.o.) and acetyl salicylic acid (100 mg/kg/day, p.o.). In carrageenan rat hind paw edema, which was conducted to test the effects of subfractions of EEP, the petroleum ether sub-fraction (100 mg/kg, p.o.) showed an inhibitory effect on the paw edema whereas EEP (200 mg/kg, p.o.) showed a significant anti-inflammatory effect at 3 and 4 hrs after carrageenan injection. From these results, we conclude that the ethanolic extract of propolis had a profound anti-inflammatory effects on both chronic and acute inflammations.     

Enhancement of anti-inflammatory and antinociceptive actions of red ginseng extract by fermentation

Objectives This work aimed to compare some pharmacological properties of red ginseng extract (RG) and fermented red ginseng extract (FRG). Methods Antinociceptive activity was analysed using the acetic acid‐induced abdominal constriction response. Anti‐inflammatory activity was evaluated using acetic acid‐induced vascular permeability and carrageenan‐induced inflammation in the air pouch, and analysed through the measurement of nitrite content in the lipopolysaccharide (LPS)‐stimulated macrophage cells. Anti‐angiogenic activity was determined using the chick chorioallantoic membrane assay. Key findings In‐vivo anti‐inflammatory activity of FRG was stronger than that of RG in two animal models, vascular permeability and air‐pouch models. In the vascular permeability model, the doses of RG and FRG required for half‐maximal inhibition (IC50) were 181 and 59 mg/kg, respectively. FRG exhibited significantly stronger antinociceptive activity than RG. In the acetic acid‐induced abdominal constriction response, the IC50 values of RG and FRG were 153 and 27 mg/kg, respectively. Although both RG and FRG were able to suppress production of nitric oxide in the LPS‐stimulated RAW264.7 macrophage cells, the suppressive activity of FRG appeared to be stronger than that of RG. However, RG and FRG showed similar anti‐angiogenic activity. Conclusions FRG possesses enhanced anti‐inflammatory and antinociceptive activity but similar anti‐angiogenic activity than RG.     

Agmatine Reverses Sub‐chronic Stress induced Nod‐like Receptor Protein 3 (NLRP3) Activation and Cytokine Response in Rats

The activation of Nod‐like receptor protein 3 (NLRP3) has lately been implicated in stress and depression as an initiator mechanism required for the production of interleukin (IL)‐1β and IL‐18. Agmatine, an endogenous polyamine widely distributed in mammalian brain, is a novel neurotransmitter/neuromodulator, with antistress, anxiolytic and antidepressant‐like effects. In this study, we examined the effect of exogenously administered agmatine on NLRP3 inflammasome pathway/cytokine responses in rats exposed to restraint stress for 7 days. The rats were divided into three groups: stress, stress+agmatine (40 mg/kg; i.p.) and control groups. Agmatine significantly down‐regulated the gene expressions of all stress‐induced NLRP3 inflammasome components (NLRP3, NF‐κB, PYCARD, caspase‐1, IL‐1β and IL‐18) in the hippocampus and prefrontal cortex (PFC) and reduced pro‐inflammatory cytokine levels not only in both brain regions, but also in serum. Stress‐reduced levels of IL‐4 and IL‐10, two major anti‐inflammatory cytokines, were restored back to normal by agmatine treatment in the PFC. The findings of the present study suggest that stress‐activated NLRP3 inflammasome and cytokine responses are reversed by an acute administration of agmatine. Whether antidepressant‐like effect of agmatine can somehow, at least partially, be mediated by the inhibition of NLRP3 inflammasome cascade and relevant inflammatory responses requires further studies in animal models of depression.     

The antiinflammatory potential of phenolic compounds from <Emphasis Type="Italic">Emblica officinalis</Emphasis> L. in rat

Antiinflammatory effects of phenolic compounds from Emblica officinalis were evaluated in carrageenan and cotton pellet induced acute and chronic inflammatory animal model. Fractions of E. officinalis containing free (FPEO) and bounded (BPEO) phenolic compounds were assessed by HPLC technique. The free and bound phenolic compounds were studied for their acute and chronic antiinflammatory activity at dose level of 20 and 40 mg/kg. The carrageenan induced acute inflammation was assessed by measuring rat paw volume at different time of intervals. Further, cotton pellet induced chronic inflammation was assessed by granulomatous tissue mass estimation along with the estimation of tissue biomarker changes (i.e. lipid peroxidation, reduced glutathione, myeloperoxidase and plasma extravasation). The results indicated that in both acute and chronic inflammation, FPEO and BPEO show reduction in the inflammation, but significant effects was observed only at high doses of both fractions which was comparable to diclofenac treated group. In conclusion, phenolic compounds of E. officinalis may serve as potential herbal candidate for amelioration of acute and chronic inflammation due to their modulatory action of free radicals.     

Effect of FK506 (tacrolimus) in animal models of inflammation

Inflammation is the response of living tissue to damage. Cytokines play an important role in inflammatory processes. FK506 (tacrolimus), an immunosuppressant, is known to reduce the activation of microglia in vitro and affect the expression of various cytokines like interleukin-1, interleukin-6 and tumor necrosis factor. With this background the present study was designed to explore the effect of FK506 in animal models of acute inflammation and experimental pleurisy. Acute inflammation in rats was induced by intraplantar injection of carrageenan (1%, w/v). Experimental pleurisy was induced in rats by intrapleural injection of carrageenan (2%, w/v). Pretreatment with FK506 (0.5–3 mg/kg p.o.) significantly and dose-dependently reduced carrageenan-induced increase in paw volume, as well as carrageenan-induced inflammatory nociception. FK506 (1 and 3 mg/kg p.o.) inhibits exudate formation and migration of polymorhonuclear leukocytes and monocytes in carrageenan-induced experimental pleurisy. The myeloperoxidase enzyme level was significantly increased in carrageenan-treated animals, which was significantly reversed by FK506 treatment. The results of the present study suggest the potential anti-inflammatory properties of FK506 against carrageenan-induced acute inflammation and experimental pleurisy.     

Tracking anti‐fibrotic pathways of nilotinib and imatinib in experimentally induced liver fibrosis: An insight

The tyrosine kinase inhibitors imatinib and nilotinib have been suggested to have promising antifibrotic activity in experimental models of liver fibrosis. The aim of the present study was to investigate new pathways underlying this beneficial effect. Hepatic injury was induced in male Wistar rats by intraperitoneal injection of CCl₄ for 12 weeks. During the last 8 weeks of treatment, rats were also injected daily intraperitoneally with 20 mg/kg imatinib or 20, 10 or 5 mg/kg nilotinib. At the end of treatment, effects on fibrosis were assessed by measuring serum fibrotic markers and profibrogenic cytokines, as well as by histopathological examination. Possible anti‐inflammatory effects were estimated by measuring levels of inflammatory cytokines in liver tissue. Liver expression of α‐smooth muscle actin, transforming growth factor (TGF)‐β1 antibodies and platelet‐derived growth factor receptor β (PDGFRβ) was evaluated by immunohistochemical staining techniques. Nilotinib (5 and 10 mg/kg) significantly (P < 0.05) decreased all serum fibrotic markers measured, but 20 mg/kg of either nilotinib or imatinib had limited effects. At all doses tested, nilotinib significantly (P < 0.05) decreased the CCl₄‐induced increases in tissue inflammatory cytokines. Furthermore, 5 and 10 mg/kg nilotinib significantly decreased TGF‐β1 levels and tissue expression of its antibody, as well expression of PDGFRβ. In conclusion, low doses (5 and 10 but not 20 mg/kg) of nilotinib, rather than imatinib, can control hepatic fibrosis by regulating levels of proinflammatory cytokines, primarily interleukin (IL)‐1 and IL‐6. Nilotinib also controls the signalling pathways of profibrogenic cytokines by lowering TGF‐β1 levels and decreasing expression of PDGFRβ.     

Evaluation of the Effect of Hydroalcoholic Extract of Zingiber officinale Rhizomes in Rat Collagen‐induced Arthritis

Abstract: Patients with chronic, painful diseases often seek alternative therapy. The purpose of this study was to investigate the potential of hydroalcoholic extract of Zingiber officinale rhizomes (Z. officinale extract) to ameliorate inflammatory process in rat collagen‐induced arthritis. Our results show that Z. officinale extract in doses higher than 50 mg/kg/day intraperitoneally starting from the dose of booster immunization and for 26 days can ameliorate the clinical scores, disease incidence, joint temperature and swelling, and cartilage destruction, together with reduction of serum levels of interleukin (IL)‐1β, IL‐2, IL‐6, tumour necrosis factor‐α, and anti‐CII antibodies. Moreover, Z. officinale extract at the dose of 200 mg/kg/day was superior to 2 mg/kg/day of indomethacin at most of the measured parameters. These observations might make Z. officinale extract a good alternative to non‐steroidal anti‐inflammatory drugs for patients with rheumatoid arthritis.     

Pharmacological studies on nitro‐naproxen (naproxen‐2‐nitrooxyethylester)

Naproxen‐2‐nitrooxyethylester (S‐(+)‐2‐(6‐methoxy‐2‐naphthyl)propanoic acid‐2‐nitrooxyethylester, LE‐EK06) was synthesized from naproxen and 2‐nitrooxyethylbromide as a novel nitric oxide–releasing derivative of naproxen. Molar equivalents of LE‐EK06 (6.93–27.73 mg/kg, p.o.) to naproxen dose‐dependently exhibited greater antinociceptive activity in comparison to naproxen in a writhing assay. The compound (5.54–22.18 mg/kg, p.o.) showed greater anti‐inflammatory activity at 2 h after as comparable to its effect at 4 h after carrageenan challenge in rats. Further, LE‐EK06 (9.45 mg/kg, p.o.) was more potent in the carrageenan‐evoked hyperalgesia. LE‐EK06 (11.09 mg/kg, p.o.) and naproxen (8.0 mg/kg, p.o.) showed a comparable inhibitory effect on exudate formation and migration of polymorphonuclear leukocytes (PMNs) in a carrageenan‐induced pleurisy test. Further, the compound (11.09 mg/kg, p.o.) significantly reduced myeloperoxidase activity in carrageenan‐treated paw and demonstrated significantly less gastrotoxicity in acute and chronic (21 days) studies. The scanning electron microscopy revealed that LE‐EK06 showed only mild gastric damage (slight disruption of mucus layer) in comparison to naproxen. The present study suggested that naproxen‐2‐nitrooxyethylester (LE‐EK06) represents a novel gastric sparing NSAID. Drug Dev. Res. 61:66–78, 2004. © 2004 Wiley‐Liss, Inc.     

Evaluation of anti‐angiogenic,anti‐inflammatory and antinociceptive activity of coenzyme Q10 in experimental animals

Objectives This work aimed to assess some pharmacological activities of coenzyme Q₁₀ (CoQ₁₀) in animal experimental models. Methods The chick chorioallantoic membrane assay was used to evaluate anti‐angiogenic activity of CoQ₁₀. Anti‐inflammatory activity of CoQ₁₀ was confirmed using two animal models of inflammation. These were the vascular permeability and air pouch models, models of acute and sub‐acute inflammation, respectively. Antinociceptive activity was assessed by the acetic acid‐induced abdominal constriction response. Key findings CoQ₁₀ dose‐dependently displayed inhibition of chick chorioallantoic membrane angiogenesis. In the acetic acid‐induced vascular permeability model in mice, CoQ₁₀ at 50, 100 and 200 mg/kg reduced vascular permeability from 0.74 ± 0.01 (A₅₉₀) to 0.67 ± 0.01 (P < 0.01), 0.46 ± 0.02 (P < 0.01) and 0.30 ± 0.01 (P < 0.01), respectively. In the carrageenan‐induced inflammation in the air pouch, CoQ₁₀ was able to diminish exudate volume, the number of polymorphonulcear leucocytes and nitrite content in the air pouches. CoQ₁₀ at 25, 50 and 100 mg/kg significantly reduced acetic acid‐induced abdominal constriction in mice from 27.0 ± 2.00 (number of abdominal constrictions) to 17.7 ± 0.33 (P < 0.01), 9.3 ± 0.67 (P < 0.01) and 1.3 ± 0.33 (P < 0.01), respectively, suggesting a strong antinociceptive activity. Conclusions CoQ₁₀ possessed considerable anti‐angiogenic, anti‐inflammatory and antinociceptive activity, possibly via down‐regulating the level of nitric oxide, which partly supported its use as a dietary supplement and in combination therapy.     

Anti-inflammatory, analgesic and antipyretic effects of friedelin isolated from Azima tetracantha Lam. in mouse and rat models

Objectives Friedelin was isolated from Azima tetracantha Lam. leaves collected from Kallakurichi, Villuppuram district, Tamil Nadu, India. The anti‐inflammatory, analgesic and antipyretic activities of friedelin have been investigated in Wistar rats and mice. Methods Friedelin was isolated from the hexane extract of leaves of A. tetracantha using column chromatography. The effects of friedelin on inflammation were studied by using carrageenan‐induced hind paw oedema, croton oil‐induced ear oedema, acetic acid‐induced vascular permeability, cotton pellet‐induced granuloma and adjuvant‐induced arthritis. The analgesic effect of friedelin was evaluated using the acetic acid‐induced abdominal constriction response, formalin‐induced paw licking response and the hot‐plate test. The antipyretic effect of friedelin was evaluated using the yeast‐induced hyperthermia test in rats. Key findings In the acute phase of inflammation, maximum inhibitions of 52.5 and 68.7% (P < 0.05) were noted with 40 mg/kg friedelin in carrageenan‐induced paw oedema and croton oil‐induced ear oedema, respectively. Administration of friedelin (40 mg/kg) significantly (P < 0.05) decreased the formation of granuloma tissue induced by cotton pellet at a rate of 36.3%. In the adjuvant‐induced arthritis test friedelin inhibited 54.5% of paw thickness. Friedelin inhibited acetic acid‐induced vascular permeability in mice. Friedelin also produced significant (P < 0.05) analgesic activity in the acetic acid‐induced abdominal constriction response and formalin‐induced paw licking response. In the hot‐plate test, friedelin did not show any significant results when compared with control. Treatment with friedelin showed a significant (P < 0.05) dose‐dependent reduction in pyrexia in rats. Conclusions The results suggested that friedelin possessed potent anti‐inflammatory, analgesic and antipyretic activities.