Effect of Silymarin on Different Acute Inflammation Models and on Leukocyte Migration

In-vivo anti-inflammatory activity of silymarin was tested in different acute inflammation experimental models. In carrageenan-induced paw oedema in rats, silymarin given orally reduced in a dose-dependent manner the food-pad abscesses (ED50 = 62.42 mg kg^?1). In xylene-induced ear mouse inflammation, silymarin applied topically was more effective than administered intraperitoneally, with effects comparable with those of indomethacin. Silymarin also produced a dose-dependent inhibition of leukocyte accumulation in inflammatory exudates following intraperitoneal injection of carrageenan in mice; silymarin significantly reduced the number of neutrophils. Silymarin was unable to inhibit phospholipase A₂ in an in-vitro assay. Besides its known anti-oxidative properties and its ability to act as a radical scavenger, these results suggest that silymarin exerts an important anti-inflammatory action in-vivo by reducing oedema with the effect markedly influenced by the inhibition of neutrophil migration into the inflamed site.     

Anti-inflammatory Activity of Polygonum bistorta,Guaiacum officinale and Hamamelis virginiana in Rats

Abstract— The aqueous ethanolic extracts of Polygonum bistorta L. Polygonaceae, Guaiacum officinale L. Zygophyllaceae and Hamamelis virginiana L. Hamamelidaceae were screened for anti-inflammatory activity. Administered (100 and 200 mg kg^?1, p.o.) before the induction of carrageenan rat paw oedema, extracts of P. bistorta significantly suppressed both the maximal oedema response and the total oedema response (monitored as area under the time course curve). H. virginiana was inactive and G. officinale was only active at 200 mg kg^?1. At 200 mg kg^?1 administered before the induction of adjuvant arthritis, P. bistorta significantly inhibited both the acute and chronic phases of the adjuvant-induced rat paw swelling, while G. officinale and H. virginiana were only active against the chronic phase. Further studies on P. bistorta (100–800 mg kg^?1) revealed a dose-dependent inhibition of the carrageenan-induced rat paw oedema over the dose range 100–400 mg kg^?1, the E50 value being approximately 158·5 mg kg^?1. The extract (200 mg kg^?1), administered after the onset of the inflammatory responses reversed the course of both the carrageenan- and adjuvant- induced rat paw swelling. The results confirm that the extracts of P. bistorta, G. officinale and H. virginiana contain anti-inflammatory substances.     

Inhibition of Rat Acute Inflammatory Paw Oedema by Dihemiphthalate of Glycyrrhetinic Acid Derivatives: Comparison with Glycyrrhetinic Acid

Abstract— The anti-inflammatory profile of dihemiphthalate compounds of glycyrrhetinic acid derivatives in acute rat paw oedema induced by various vasoactive agents was compared with the parent compound. Three dihemiphthalate compounds (the di-sodium salt of 18 β-olean-12-ene-3β,30-diol di-O-hemiphthalate, 18β-olean-9(11),12-dione-3β,30-diol di-O-hemiphthalate and olean-11,13(18)-diene-3β,30-diol di-O-hemiphthalate), significantly inhibited development of carrageenan-induced rat paw oedema during the first 3 h (ED50 70, 90, and 108 mg kg^?1 respectively, p.o.), while glycyrrhetinic acid (ED50, 200 mg kg^?1) showed a significant inhibition of paw oedema 3 h after carrageenan treatment. The dihemiphthalate compounds also suppressed mouse paw oedema induced by histamine, bradykinin, and PAF acether at doses of less than 100 mg kg^?1. However, these compounds failed to inhibit 5-HT-induced mouse paw oedema. Glycyrrhetinic acid had little effect on mouse paw inflammation induced by the above irritants. The three compounds at 10^?7-10^?4 m , inhibited histamine-induced contraction of guinea-pig isolated ileum. However, concentration-response curves to 5-HT and bradykinin were not affected by the same compounds. These results suggest that the dihemiphthalate compounds modulate vascular permeability caused by endogenous vasoactive agents as one of the anti-inflammatory mechanisms. This action is quite different from that of glycyrrhetinic acid.     

Effect of Fepradinol on Rat Hind Paw Oedema Induced by Several Inflammatory Agents

Abstract— Fepradinol is an effective non-steroidal anti-inflammatory agent. The effect on rat paw oedema induced by various phlogistic agents was investigated. The inhibitory effect of fepradinol (25 mg kg^?1, p.o.) on dextran-induced oedema was nearly equal to that of cyproheptadine (10 mg kg^?1, p.o.). On oedema induced by platelet-activating factor only fepradinol (25 mg kg^?1, p.o.) and phenidone (100 mg kg^?1, p.o.) clearly inhibited the inflammatory process. Both the above induced oedemas are thought to be unrelated to prostaglandins in the rat system and therefore, the anti-inflammatory activity against them is not shared by selective cyclo-oxygenase inhibitors. Fepradinol (25 mg kg^?1, p.o.) displayed an inhibitory effect on the early and late stage of kaolin- and nystatin-induced oedemas in contrast with indomethacin (10 mg kg^?1, p.o.) and piroxicam (10 mg kg^?1, p.o.) which only inhibited the late stage. The results obtained in this study confirm that fepradinol is a potent anti-inflammatory agent and indicate that its mechanism of action is different from that of other anti-inflammatory compounds.     

Pharmacological Evaluation of the Anti-inflammatory Activity of a Citrus Bioflavonoid,Hesperidin, and the Isoflavonoids,Duartin and Claussequinone,in Rats and Mice

Abstract— Pretreatment of rats with hesperidin (50 and 100 mg kg^?1, s.c .) reduced the paw oedema induced by carrageenan by 47 and 63%, respectively, within 5 h. The effect was equivalent to that produced by indomethacin (10 mg kg^?1, p.o .), although unrelated to the administered dose, particularly at high doses. At 100 mg kg^?1 hesperidin decreased the rat paw oedema induced by dextran by 33%, without influencing the histamine-induced paw oedema. Hesperidin also inhibited pleurisy induced by carrageenan, reducing the volume of exudate and the number of migrating leucocytes by 48 and 34%, respectively, of control values. Equal doses of duartin and claussequinone were ineffective in all the above tests. Pretreatment of mice with hesperidin (100 mg kg^?1, s.c .) reduced acetic acid-induced abdominal constriction by 50%, but did not affect the tail flick response. Hyperthermia induced by yeast in rats was slightly reduced by hesperidin. No lesions of the gastric mucosae were detected in rats pretreated with hesperidin. The results indicate that hesperidin obtained from citrus cultures may present a potential therapeutical use as a mild antiinflammatory agent, being also useful as a precursor of new flavonoids endowed with such activity.     

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

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

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

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

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

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

Evaluation of Some Pharmacological Activities of ethanol extracts of seeds, pericarp and leaves of Eugenia Jamolana in Rats

The present study investigated the effect of ethanol extracts of seeds, pericarp and leaves of Eugenia Jamolana (E. Jamolana) on inflammation, gastric ulcer, anti-oxidants and hepatoprotective in rats. The acute inflammation was induced by intra-plantar injection of carrageenan (100 μl of 1 %) in the rat hind paw. Gastric ulcer was evoked by indomethacin (25 mg/kg) oral administration. Liver damage was induced by given CCL₄ (2.5 ml/kg) orally. The median lethal (LD₅₀) of the ethanol extract of both seeds and pericarp were determined and revealed that the investigated extracts of seeds and pericarp were non toxic up to 5g/kg. The anti-inflammatory results showed that the oral administration of ethanol extract of E. Jamolana seeds (250,500 mg/kg) showed significant inhibition of oedema formation in dose-dependent manner by −27.86, −41.23, −44.73, −51.78 % and by −63.16, −37.77, −47.04, −55.36 % at 1, 2, 3 and 4 h at 1, 2, 3 and 4 h, respectively. While the pericarp given at dose (500 mg/kg) exhibited significant inhibition of the oedema formation by −34.64, −21,8, 19.23 and −33.47 % at 1, 2, 3 and 4 h, respectively post carrageenan injection as compared with saline control group. E. Jamolana leaves fraction 1 given orally at dose of 25 mg/kg, induced non significant change on oedema, while the oedema response was significantly inhibited by −25.14, −33.4, −20.57 and −26.46 % at 1, 2, 3 and 4 h, respectively in group of rats that received leaves fraction 2 at the same dose. Rats were given leaves fraction 3 extract showed inhibition of oedema formation by −4.48 % at 1^st h post- carrageenan injection, while at 2^nd, 3^rd and 4^th h showed non significant change on oedema formation. The acute gastric mucosal lesions was significantly reduced by given ethanol extract of E. Jamolana seeds, pericarp (250, 500 mg/kg) and leaves fractions 1, 2 and 3 (25 mg/kg) respectively in dose dependent manner, as compared with indomethacin treated group (control group). All tested extracts showed significant reduction in elevated serum ALT, AST and ALP levels as compared with CCl ₄ treated group. The ethanol extract of E. Jamolana seeds, pericarp and leaves fractions 1, 2, 3 showed significant elevation of blood GSH level and significant reduction in elevated plasma lipid peroxides (MDA) as compared with CCl₄ treated group. In conclusion we can see that the ethanol extracts of E. Jamolana of seeds, pericarp and leaves fractions showed anti-inflammatory, anti-ulcer, hepatoprotective and anti-oxidants activity. Received 15 June 2008; accepted 11 November 2008     

Natural Products: Anti-hyperalgesic Effect of an Ethanolic Extract of Propolis in Mice and Rats

Propolis, or bee glue, which contains a complex mixture of secondary metabolites, has long been used in many countries for the management of several diseases. The purpose of this study was to evaluate, by means of several pharmacological models, the anti-hyperalgesic effect of propolis collected in the south of Brazil. The abdominal constrictions induced in mice by intraperitoneal injection of acetic acid (0.6%), kaolin (50 mg kg^?1) or zymosan (40 mg kg^?1) were inhibited to different extents by an extract of propolis (1–60 mg kg^?1) administered intraperitoneally 30 min earlier; mean ID50 (concentrations resulting in 50% inhibition) values were 2.7, 10.8 and 10.7 mg kg^?1, respectively, and maximum inhibition was 58 ± 5, 57 ± 10 and 51 ± 5%, respectively. Given orally (25–200 mg kg^?1, 1 h previously) propolis also inhibited the abdominal constrictions induced by acetic acid (maximum inhibition 43 ±5%). When injected intraperitoneally (3–60 mg kg^?1, 30 min previously), propolis attenuated both the neurogenic (first phase) and inflammatory (second phase) pain responses and paw oedema caused by intraplantar injection of formalin (2.5%); maximum inhibition was 32 ±5, 43 ±6 and 19 ±2%, respectively. Oral administration of propolis (25–200 mg kg^?1, 1 h previously) inhibited both phases and reduced the oedema formation associated with the second phase of the formalin test (maximum inhibition 22±5, 33 ±6 and 26±3%) and extract of propolis (3–30 mg kg^?1 i.p. or 25–100 mg kg^?1 p.o., respectively 30 min and 1 h previously) significantly inhibited capsaicin-induced pain with maximum inhibition of 39±8 and 41 ±8%, respectively. When assessed in the Randall–Sellito test of pain, the extract of propolis (3–30 mg kg^?1, i.p., 30 min previously) significantly reversed the hyperalgesia induced by intraplantar injection of bradykinin (3 nmol per paw) in rats (P < 0.01). In contrast with morphine the extract of propolis (. 100 mg kg^?1, 30 min previously) was ineffective when assessed in the tail-flick and hot-plate thermal assays. Naloxone (5 mg kg^?1 i.p.) reversed (P < 0.01) the effect of morphine (5 mg kg^?1 s.c.) by 70 and 94% respectively in the first and second phases of the formalin test, but did not interfere with the analgesic effect of propolis (10 mg kg^?1 i.p., 30 min previously). These results show that ethanolic extract of propolis, given systemically, has significant anti-hyperalgesic action when assessed in chemical, but not thermal, models of nociception in mice and rats. Its analgesic action seems to be unrelated to release or activation of the opioid system.     

A Study of the Anti-pyretic Effect of Quinine,an Alkaloid Effective Against Cerebral Malaria,on Fever Induced by Bacterial Endotoxin and Yeast in Rats

The effect of quinine on fever induced by lipopolysaccharide and brewer's yeast has been investigated in rats. Oral administration of 50 or 100 mg kg^?1 quinine, doses which had no effect on normothermic rats, significantly reduced lipopolysaccharide- (50 μg kg^?1, i.m.) and yeast- (2 g kg^?1) induced fever in rats. Pentoxifylline (100 mg kg^?1), a tumour necrosis factor antagonist also attenuated the febrile response induced by lipopolysaccharide, but not that by yeast, in a manner similar to quinine. Piroxicam (5 mg kg^?1), a cyclooxygenase inhibitor suppressed both types of fever with a longer duration of action. In addition to its anti-pyretic effect, quinine had a significant anti-inflammatory effect in the carrageenan model of acute inflammation in the hind-paw of rats. The results indicate the anti-inflammatory and anti-pyretic potential of quinine which might be important in addition to its anti-plasmodial action in the therapy of cerebral malaria.     

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

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

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

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

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

Prostaglandins and the anti-inflammatory activity of a human plasma fraction in carrageenan-induced paw oedema in the rat

A fraction prepared from normal human plasma inhibits the swelling of the acute carrageenan-induced paw oedema in the rat. Treatment of the animals with prostaglandin E₁, arachidonic acid or with substances which either block the formation of prostaglandins or antagonize their action showed that these mediators are concerned in the development of the paw oedema. The anti-inflammatory effect of the plasma fraction in the carrageenan reaction does not involve a specific interference with the prostaglandin system. The plasma fraction is not an inhibitor of the action of SRS-A on the guinea-pig ileum.     

Histamine, 5-hydroxytryptamine, kinins and the anti-inflammatory activity of human plasma fraction in carrageenan-induced paw oedema in the rat

In the carrageenan-induced paw oedema reaction in the rat, the swelling and accumulation of [¹³¹I]albumin showed a similar time course over 4 h. Both aspects of the oedema were inhibited by a fraction prepared from human plasma. Treatment of the animals with substances which either deplete the levels or antagonize the actions of either histamine, 5-hydroxytryptamine or kinins showed that these mediators are concerned in the development of rat paw oedema after the injection of either carrageenan or yeast but not with the anti-inflammatory action of the plasma fraction.     

Sympathomimetic Effects of Scoparia dulcis L. and Catecholamines Isolated from Plant Extracts

The herb Scoparia dulcis L. is used in Brazilian folk medicine to treat bronchitis, gastric disorders, haemorrhoids, insect bites and skin wounds, and in oriental medicine to treat hypertension. A previous study has shown that extracts of S. dulcis have analgesic and anti-inflammatory properties; in this work the sympathomimetic activity of an ethanolic extract of Scoparia dulcis L. has been investigated in rodent preparations in-vivo and in-vitro. Administration of the extract (0.5-2 mg kg^?1, i.v.) to anaesthetized rats produced dose-related hypertension blocked by the α-adrenoceptor antagonist prazosin (1 mg kg^?1). Partition of the extract in chloroform-water yielded an aqueous phase 20 times more potent than the extract; this produced hypertension in either reserpine-treated or pithed rats. In untreated and reserpine-treated rats the same fraction (1–3 × 10³ μg mL^?1) produced concentration-dependent contractions of the vas deferens musculature parallel to those obtained with noradrenaline (10^?8-10^?4 m ). Prazosin (10^?7 m ) reduced the maximum contractile effect of the aqueous fraction, and shifted the concentration-response curves for noradrenaline to the right. The aqueous fraction (25 and 50 μg mL^?1) increased the inotropism of electrically driven left atria of rats, the effect being blocked by propranolol (0.4 μg mL^?1). In preparations of guinea-pig tracheal rings the aqueous fraction (1–3 × 10³ μg mL^?1) relaxed the muscle contraction induced by histamine (10^?4 m ) in proportion to the concentration. The effect was antagonized competitively by propranolol (1.5 μm ). High-performance liquid-chromatographic analysis of the aqueous fraction revealed the presence of both noradrenaline and adrenaline in the plant extract. The results indicated that both catecholamines may account for the hypertensive and inotropic effects obtained after parenteral administration of S. dulcis extracts. This sympathomimetic activity is, however, unrelated to the previously reported analgesic and anti-inflammatory properties of the plant extract, but may explain its effectiveness upon topical application in the healing of mucosal and skin wounds.     

Anti-inflammatory and antinociceptive activities of Homalium letestui

Abstract

Context. Homalium letestui Pellegr (Flacourtiaceae) is used in various decoctions traditionally by the Ibibios of the Niger Delta of Nigeria to treat stomach ulcer, malaria and other inflammatory diseases, as well as an aphrodisiac.

Objective: To investigate the anti-inflammatory and antinociceptive activities of the stem extract of the plant.

Materials and methods: The ethanol stem extract (500, 750, 1000?mg/kg, i.p.) of H. letestui was investigated for anti-inflammatory activity using carrageenan, egg albumin-induced and xylene-induced ear edema models and analgesic activity using acetic acid-induced writhing, formalin-induced paw licking and thermal-induced pain models. The ethanol extract was administered to the animals orally, 30?min to 1?h depending on the model, before induction of inflammation/pain. The LD₅₀ was also determined. GC–MS analysis of dichloromethane fraction was carried out.

Results: The extract caused a significant (p?<?0.05–0.001) reduction of inflammation induced by carrageenan (8.3–70.0%), egg albumin (10.0–71.42%) and xylene (39.39–84.84%). The extract also reduced significantly (p?<?0.05–0.001) pain induced by acetic acid (44.22–73.65%), formalin (55.89–79.21%) and hot plate (93.0–214.5%). The LD₅₀ was determined to be 4.38?±?35.72?g/kg.

Discussion and conclusion: The results of this study suggest that the ethanol stem extract of H. letestui possesses anti-inflammatory and analgesic properties which may in part be mediated through the chemical constituents of the plant as revealed by the GC–MS.     

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

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

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

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

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

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

Natural Products: Anti-inflammatory Activity in Rats and Mice of Phenolic Acids Isolated from Scrophularia frutescens

Different species of the Scrophularia genus (Scrophulariaceae) have been reported to have bacteriostatic and anti-inflammatory properties. In previous studies the anti-inflammatory and antibacterial activity of different extracts from Scrophularia frutescens were investigated and p-coumaric, caffeic, ferulic gentisic, protocatechuic, syringic and isovanillic acids were isolated and identified. In this work the anti-inflammatory activity of these compounds, administered orally, has been studied against carrageenan-induced rat paw oedema and, administered topically, against tetradecanoylphorbol acetate (TPA)-induced mouse ear oedema. The compounds' myeloperoxidase activity in inflamed ear was also investigated. Some of the phenolic acids were remarkably active in the TPA test (protocatechuic 71.59% inhibition, P < 0.001; syringic 74.43%, P < 0.001; ferulic 71.02% P < 0.001) and all significantly inhibited mouse ear oedema. They were only moderately active, or were without activity, in the carrageenan test. These results imply that the phenolic acids assayed are more effective topically than as oral anti-inflammatory agents and that their action is markedly influenced by the inhibition of neutrophil migration into inflamed tissue. This study has also enabled us to make some observations on the possible relationship between the chemical structure and antiinflammatory activity of the compounds assayed.     

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

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

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

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

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

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

Anti-inflammatory activity of aqueous leaf extract of Chromolaena odorata

The anti-inflammatory activity of the aqueous extract of Chromolaena odorata was investigated in rats using the carrageenan-induced oedema, cotton pellet granuloma and formalin-induced oedema methods. The extract was administered orally at doses of 25, 50, 100 and 200 mg/kg. In the carrageenan method the paw oedema was significantly reduced by all the doses of the extract administered, with the 200 mg/kg dose producing the highest oedema inhibition (80.5%). In the cotton pellet method, granuloma weight was significantly reduced from 14 ± 0.1 to 9.0 ± 0.1 mg, while in the formaldehyde induced arthritis the extract inhibited the oedema during the 10-day period. In conclusion, this study has established the anti-inflammatory activity of C. odorata and, thus, justifies the traditional uses of the plant in the treatment of wounds and inflammation.     

Antioxidant and anti-inflammatory activities of Aerva pseudotomentosa leaves

Context: Aerva pseudotomentosa Blatt. &; Hallb. (Amaranthaceae), commonly called ‘Bui’, is a medicinal plant of the arid region. It is used for the treatment of inflammatory disorders, such as rheumatic pain, and healing of wounds, which are associated with oxidative stress.

Objective: The present study evaluated the antioxidant potential of Aerva pseudotomentosa leaves by in vitro models and its anti-inflammatory effect in rats.

Material and methods: The aqueous extract (APAE) was analyzed by HPTLC and HPLC. The antioxidant effect of APAE was evaluated by various in vitro methods [DPPH (1, 1-diphenyl-2-picryl-hydrazil) and hydrogen peroxide free radical scavenging, reducing power, and anti-lipid peroxidation assays]. Anti-inflammatory effect was studied in carrageenan and formalin-induced paw oedema models in rats. APAE (200 and 400?mg/kg) and standard drug, indomethacin (10?mg/kg), were administered orally 1?h before carrageenan/formalin administration and inflammation was noted up to 5?h.

Results: HPLC analysis of APAE revealed the presence of rutin. APAE showed significant scavenging effect on DPPH (IC₅₀ 49.37?μg/mL) and peroxide (IC₅₀ 288.2?μg/mL) radicals. The extract exhibited reducing potential and inhibition of lipid peroxidation. APAE treatment significantly attenuated mean increase in paw volume and exhibited inhibition of paw oedema in both in vivo models with inhibition of 45.11% and 49.42%, respectively at 5?h.

Discussion and conclusion: APAE exhibited in vitro antioxidant and anti-inflammatory activities. Anti-inflammatory effect of APAE may be attributed to its antioxidant potential, due to the presence of rutin and other phenolics. This study substantiates folk use of leaves in inflammatory disorders.     

The actions of cimetidine hydrochloride and mepyramine maleate in rat adjuvant arthritis

Adjuvant arthritis in rats was induced by a single subcutaneous injection of Freund adjuvant into a hind paw. The injected paws' mean volume increased continuously by 80±26% after 6 h (acute local response). The injected paw displayed a biphasic response peaking at day 1–2 decreasing to day 5, then increased to day 14 by 123% while the contralateral non-injected paw showed little increase until day 10 and increased by 42% at day 14. The lateral diameter of both knee-joints also increased biphasically, peaking at day 4, decreasing to day 6, then increasing to day 14 (early and late systemic phase). Mepyramine maleate, 1 mg·kg^?1 (i.p.) daily, suppressed only the early systemic phase by 50%. Daily cimetidine hydrochloride, 1 mg·kg^?1·day^?1, almost completely abolished the inflammatory response in the knee joints up to day 12, while at day 14 the supression was 71%. The increase in mean paw volume was also suppressed by orally administered cimetidine. Intraperitoneal doses of cimetidine (3.5 μmol·kg^?1) totally suppressed paw oedema produced by subplantar injection of histamine (1.8 mM) but had no action on equiactive dose of the specific H₁-agonist, 2-pyridylethylamine. Mepyramine at 3.5 μmol·kg^?1 or greater produced no more than 50% suppression of the histamine response. A component of both adjuvant and histamine-induced responses thus appears to be histamine H₂-receptor mediated.