Estrogenic activity of Sage (Salvia officinalis L.) aerial parts and its isolated ferulic acid in immature ovariectomized female rats.

ETNOPHARMACOLOGICAL RELEVANCE: Common sage (Salvia officinalis L., Lamiaceae), a medicinal plant of Mediterranean origin, has been traditionally applied in cases of excessive sweating, and in menopausal complaints, including hot flushes. AIM OF THE STUDY: This study aims to study the possible estrogenic effect of the aerial parts of S. officinalis ethanolic extract in immature ovariectomized female rats. MATERIALS AND METHODS: The ethanolic extract was subjected to qualitative and quantitative HPLC analysis and phytochemical isolation. The estrogenic activity of S. officinalis ethanolic extract at oral doses of 50, 100 and 200 mg/kg b.wt. and its isolated ferulic acid at a dose of 50 mg/kg b.wt. for a week, was assessed on ovariectomized immature Wistar rats. The experiment was confirmed by luteinizing hormone (LH) and follicle stimulating hormone (FSH) serum levels determination, a histopathological examination and a histomorphometrical study. RESULTS: HPLC/PDA analysis revealed fourteen phenolic compounds the major constituents were methyl rosmarinate (24.86 mg/100 g) and ferulic acid (6.06 mg/100 g) together with five flavonoids where the major constituents were rutin, naringenin and quercetin. Two compounds were isolated from the polar fraction and identified as methyl rosmarinate (1) and ferulic acid (2). Oral administration of sage ethanolic extract and ferulic acid revealed a significant increase in the uterine weight compared to ovariectomized control rats. Moreover, S. officinalis and ferulic acid showed different phases of estrus cycle denoting estrogenic activity, and significantly decreased the serum levels of FSH and LH. CONCLUSION: From these results it could be concluded that S. officinalis ethanolic extract and its content of ferulic acid could be useful as a safe natural source for estrogenic activity, supporting its traditional use to improve postmenopausal symptoms.

New Apigenin Glycoside, Polyphenolic Constituents, Anti-inflammatory and Hepatoprotective Activities of Gaillardia grandiflora and Gaillardia pulchella Aerial Parts.

BACKGROUND: Gaillardia grandiflora Hort. ex Van Houte and Gaillardia pulchella Foug are flowering plants widely cultivated in Egypt for their ornamental value. Previous reports demonstrated that sesquiterpene derivatives represent the major compounds in both species. Moreover, only few flavones were identified from genus Gaillardia and few studies on the cytotoxicity of G. pulchella were found. AIM OF THE STUDY: Investigation of the phenolic constituents of the aerial parts of both species and evaluation of their anti-inflammatory and hepatoprotective activities. MATERIALS AND METHODS: The 80% aqueous methanol extracts (AME) were prepared for both plants and evaluated for their biological activities. Phytochemical investigation of both extracts resulted in isolation of twelve compounds, which have been identified on the basis of ultraviolet, 1D and 2D nuclear magnetic resonance spectroscopy and negative ESI-MS. RESULTS: The new 8-hydroxyapigenin 6-O-ß-D-apiofuranosyl-(1'''→6'')-C-ß-D-4C1-glucopyranoside was isolated from G. grandiflora for the first time in nature, along with schaftoside, luteolin 6-C-ß-D-4C1-glucopyranoside 8-methyl ether, apigenin 6-C-ß-D-4C1-glucopyranoside 8-methyl ether, isoorientin, isovitexin, 6-methoxyluteolin and hispidulin, as well as vicenin-2, vitexin, luteolin and apigenin, which were isolated from G. pulchella together with 6-methoxyluteolin. Furthermore, the AME of both species were found to be nontoxic to mice and exhibited significant anti-inflammatory and hepatoprotective activities in dose dependent manner. CONCLUSION: Current results shed light on the phenolic constituents of G. grandiflora and G. pulchella aerial parts and the safety of the AME of both species, in addition to their significant anti-inflammatory and hepatoprotective activities. Both plant species may be promising candidates for natural anti-inflammatory and hepatoprotective drugs. SUMMARY: Phytochemical investigation of Gaillardia grandiflora and Gaillardia pulchella 80% aqueous methanol extracts of the aerial parts led to the isolation of twelve compoundsThe new compound 8-hydroxyapigenin 6-O-ß-D-apiofuranosyl-(1''''→6'')-C-ß-D-4C1-glucopyranoside was isolated from G. grandiflora for the first time in natureSchaftoside, luteolin 6-C-ß-D-4C1-glucopyranoside 8-methyl ether, apigenin 6-C-ß-D-4C1-glucopyranoside 8-methyl ether, isoorientin, isovitexin, 6-methoxyluteolin and hispidulin were isolated from G. grandifloraVicenin-2, vitexin, luteolin, apigenin and 6-methoxyluteolin were isolated from G. pulchellaThe extracts of both species were nontoxic to mice up to 5 g/kg body weightBoth extracts exhibited significant anti-inflammatory and hepatoprotective activities in dose dependent manner Abbreviations used: ALP: Alkaline phosphatase; ALT: Alanine aminotransferase; AME: The 80% aqueous methanol extract of G. grandiflora or G. pulchella aerial parts; AST: Aspartate aminotransferase; br d: Broad doublet; Comp-PC: Comparative paper chromatography; d: Doublet; 2D-PC: Two-dimensional paper chromatography; DMSO-d6: Deuterated dimethyl sulfoxide; G.: Gaillardia; GPx: Glutathione peroxidase; GRd: Glutathione reductase; GSH: glutathione; GST: Glutathione-S-transferase; J: Nuclear spin-spin coupling constant; m: Multiplet; [M-H]-: Molecular ion peak; MDA: Malondialdehyde; m/z: Mass/charge ratio; NO: Nitric oxide; p: Probability; PC: Paper chromatography; Rf: Retention flow; rpm: Rotation per minute; s: Singlet; SDE: The ethanol extract of Scoparia dulcis; SE: Standard error; SOD: Superoxide dismutase; TMS: Tetramethylsilane; λmax: Maximum fluorescence emission wavelength.

EVESOR, a model-based, multiparameter, Phase I trial to optimize the benefit/toxicity ratio of everolimus and sorafenib.

AIM: This novel multiparameter Phase I study aimed to optimize doses/dosing schedules of everolimus and sorafenib drug combination, based on modeling/simulation (NCT01932177). PATIENTS & METHODS: About 26 patients with solid tumors were treated in four different dosing schedules. Everolimus once daily + sorafenib twice daily were given continuously in arms A and B, and intermittently in arms C (alternating every other week) and D (everolimus continuous and sorafenib 3 days on/4 days off). RESULTS: Continuous schedules exhibited higher toxicity risks than intermittent schedules (64.1 vs 35.9%; p < 0.0001), and trends for lower disease control rates (80 vs 100%). No significant pharmacokinetic interaction was identified. CONCLUSION: Feasibility of EVESOR trial is demonstrated. Intermittent schedules might provide better tolerance and efficacy than continuous schedules.

Effect of a topical copper indomethacin gel on inflammatory parameters in a rat model of osteoarthritis.

OBJECTIVE: We aimed to investigate the effect of topical application of a Copper indomethacin (Cu-Indo) gel preparation on monosodium iodoacetate (MIA) induced arthritis of the knee joint of rats and to test our hypothesis that copper complex of indomethacin could be a more potent anti-inflammatory agent than its parent compound. METHODS: After induction of osteoarthritis by the intracapsular injection of 50 µL with 40 mg/mL MIA, we compared the anti-inflammatory efficacy and safety of a topical application of 1% indomethacin gel in a dose of 1 g/kg of the gel (equivalent to 10 mg/kg of the active substance) daily for 3 weeks versus three decremental dose levels of Cu-Indo gel: an equivalent dose, half the dose, and 25% of the dose of indomethacin. Anti-inflammatory efficacy was assessed in all treated groups by measurement of serum inflammatory cytokines: interleukin 6, interleukin 8, and tumor necrosis factor alpha; and by the weekly assessment of knee joint swelling. Joint mobility and motor coordination were also assessed once weekly by the accelerating rotarod apparatus; histopathological examination of affected joints was also performed. Safety of topical application of Cu-Indo (0.25, 0.5, and 1 g/kg) for up to 3 months to rats' skin was determined by the estimation of a complete blood count, liver and kidney functions, and histopathologic examination for target tissues. RESULTS: Cu-Indo gel at lower doses was superior to or at least as effective as its parent substance, indomethacin, in most of the studied parameters of inflammation. The lowest tested dose of Cu-Indo, corresponding to 25% of the parent substance indomethacin, exhibited the highest efficacy in reducing the elevated serum-tested interleukins and in increasing the time of duration on the rotarod test, whereas its effect on reduction of edema and tumor necrosis factor alpha was comparable to that of the others. After 3 months of daily application, there were no notable changes in studied safety parameters with the lowest Cu-Indo dose, but the group treated with the higher dose showed a small but statistically significant increase in serum-unconjugated bilirubin and a slight decrease in hemoglobin levels, red blood cells, and platelet count, with normal indices denoting a slight hemolytic effect at the highest dose. CONCLUSION: Cu-Indo gel has potent anti-inflammatory activity against joint inflammation in the MIA-treated rat model of osteoarthritis at doses of 0.25, 0.5, and 1 g/kg. The lowest studied dose was better on both safety and efficacy parameters.

Anti-depressant effect of hesperidin in diabetic rats.

This study aimed to investigate the anti-depressant effect of hesperidin (Hsp) in streptozotocin (STZ)-induced diabetic rats. Additionally, the effect of Hsp on hyperglycaemia, oxidative stress, inflammation, brain-derived neurotrophic factor (BDNF), and brain monoamines in diabetic rats was also assessed. The Wistar rats in the experimental groups were rendered hyperglycaemic with a single dose of STZ (52.5 mg·(kg body mass)(-1), by intraperitoneal injection). The normal group received the vehicle only. Hyperglycaemic rats were treated with Hsp (25.0, 50.0, or 100.0 mg·(kg body mass)(-1)·day(-1), per oral) and fluoxetine (Flu) (5.0 mg·(kg body mass)(-1)·day(-1), per oral) 48 h after the STZ injection, for 21 consecutive days. The normal and STZ control groups received the vehicle (distilled water). Behavioral and biochemical parameters were then assessed. When Hsp was administered to the STZ-treated rats, this reversed the STZ-induced increase in immobility duration in the forced swimming test (FST) and attenuated hyperglycaemia, decreased malondialdehyde (MDA), increased reduced glutathione (GSH) decreased interleukin-6 (IL-6), and increased BDNF levels in the brain. Treatment with Hsp attenuated STZ-induced neurochemical alterations, as indicated by increased levels of monoamines in the brain, namely, norepinephrine (NE), dopamine (DA), and serotonin (5-hydroxytryptamine; 5-HT). All of these effects of Hsp were similar to those observed with the established anti-depressant Flu. This study shows that Hsp exerted anti-depressant effect in diabetic rats, which may have been partly mediated by its amelioration of hyperglycaemia as well as its anti-oxidant and anti-inflammatory activities, the enhancement of neurogenesis, and changes in the levels of monoamines in the brain.

Tissue distribution and efficacy of gold nanorods coupled with laser induced photoplasmonic therapy in ehrlich carcinoma solid tumor model.

Gold nanorods (GNR) within tumor microregions are characterized by their ability to absorb near IR light and emit heat in what is called photoplasmonic effect. Yet, the efficacy of nanoparticles is limited due to intratumoral tissue distribution reasons. In addition, distribution of GNRs to normal tissue might result in non specific toxicity. In the current study, we are assessing the intratumoral and tissue distribution of PEGylated GNRs on the top of its antitumor characteristics when given intravenously or intratumoral to solid tumor bearing mice and coupled with laser photoplasmonic sessions. PEGylated GNRs with a longitudinal size of less than 100 nm were prepared with aspect ratio of 4.6 showing strong surface plasmon absorption at wavelength 800 nm. Pharmacokinetics of GNR after single I.V. administration (0.1 mg/kg) showed very short systemic circulating time (less than 3 h). On the other hand, tissue distribution of I.V. GNR (0.1 mg/kg) to normal animals showed preferential deposition in spleen tissue. Repeated administration of I.V. GNR resulted in preferential accumulation in both liver and spleen tissues. In addition, I.V. administration of GNR to Ehrlich carcinoma tumor bearing mice resulted in similar tissue distribution; tumor accumulation and anti-tumor effect compared to intratumoral administration. In conclusion, the concentration of GNR achieved within tumors microregions after I.V. administration was comparable to I.T. administration and sufficient to elicit tumoral growth arrest when coupled with laser-aided photoplasmonic treatment.

Antihypercholesterolaemic effect of ginger rhizome (Zingiber officinale) in rats.

INTRODUCTION: Many herbal medicinal products have potential hypocholesterolaemic activity and encouraging safety profiles. However, only a limited amount of clinical research exists to support their efficacy. AIM OF THE WORK: The present study was designed to evaluate the antihypercholesterolaemic effects of aqueous ginger (Zingiber officinale) infusion in hypercholesterolaemic rat models. METHODS: 48 rats were used throughout the experiment, which were divided into six groups, eight animals each as follows: normal control group (normal rats which fed with standard diet). After induction of hypercholesterolaemia by feeding rats with high cholesterol diet, the remaining rats were divided into five groups: group 1, hypercholesterolaemic control group (hypercholesterolaemic rats group); groups 2, 3 and 4, rats were given aqueous infusion of ginger (100, 200 and 400 mg/kg, respectively) orally; and group 5, rats were given atorvastatin (0.18 mg/kg) orally as a reference antihypercholesterolaemic drug. The blood was obtained from all groups of rats after being lightly anaesthetized with ether and the following lipid profile [serum total cholesterol (TC), HDL-cholesterol (HDL-C), LDL-C and triglyceride levels] was measured at zero time and 2 and 4 weeks after ginger and atorvastatin treatment, and the risk ratio (TC/HDL-cholesterol) was assessed. RESULTS: The results revealed that the hypercholesterolaemic rats treated with aqueous ginger infusion in the three doses used after 2 and 4 weeks of treatment induce significant decrease in all lipid profile parameters which were measured and improved the risk ratio.

Polyphenolic profile and bioactivity study of Oenothera speciosa Nutt. aerial parts.

Two new flavonol glycosides, myricetin 4'-O-alpha-L-rhamnopyranoside (1) and quercetin 3'-O-alpha-L-rhamnopyranoside (2), together with a novel biflavonol compound, speciin (3), as well as eleven phenolic metabolites, namely myricitrin (4), europetin 3-O-alpha-L-(1)C(4)-rhamnopyranoside (5), quercitrin (6), hyperin (7), rhamnetin 3-O-beta-galacto-pyranoside (8), caffeic acid (9), caffeic acid methyl ester (10), chlorogenic acid (11), chlorogenic acid methyl ester (12), gallic acid (13) and gallic acid methyl ester (14), were identified from the 80 % methanol extract of the aerial parts (leaves and stems) of Oenothera speciosa Nutt. (Onagraceae). In addition myricetin (15), quercetin (16) and ellagic acid (17) were identified from the chloroform extract. The structures were established depending on their chemical and physical analyses (UV, HR-ESIMS, 1D and 2D NMR). It was found that 80 % aqueous methanol extract of O. speciosa is non-toxic to mice up to 5 g kg(-1)b wt. The investigated extract exhibited significant antihyperglycaemic and anti-inflammatory activities in a dose dependant manner. Also, the 80 % methanol extract, myricitrin(4) and hyperin(7) showed potent antioxidant activity in vitro using 1,1-diphenyl 2-picryl hydrazyl (DPPH) radical assay.

Synthesis and pharmacological evaluation of 2-substituted benzo[b]thiophenes as anti-inflammatory and analgesic agents.

An efficient method for trapping isocyanate 4, generated from the Curtius rearrangement, with ethyl alcohol to afford the carbamate 5 is reported. 5-Nitrobenzo[b]thiophene-2-carboxylic acid 1 is converted to the corresponding hydrazide 2 by the reaction with hydrazine hydrate and then to the azide 3 with nitrous acid, followed by thermal rearrangement, cooling, and trapping in one pot reaction. The carbamate 5 is treated with hydrazine hydrate to afford the desired, Zileuton analogue, 4-(5-nitrobenzo[b]thiophene-2-yl)semicarbazide 6. Also the reactivity of hydrazide 2 towards some carboxyaldehydes and phenylisothiocyanate afforded the corresponding carbohydrazides 7, 8 and phenylthiosemicarbazide 9, respectively. Compounds 9, 2 and 6, respectively, were more potent as anti-inflammatory and anti-nociceptive agents.

Comparative evaluation of the protective effect of selenium and garlic against liver and kidney damage induced by mercury chloride in the rats.

The present study was designed to compare the protective effect of selenium and garlic against liver and kidney damage induced by (ip) injection of 0.5 mg/kg mercury chloride (HgCl(2)) in rats. Thirty-six Sprague-Dawley rats were used in the present experiment and divided into six groups: one group was orally given (1 ml) saline and served as a control group; two groups of rats were given either selenium (0.1 mg/kg) or garlic (63 mg/kg) alone, once daily an oral dose for 30 successive days; other two groups of rats were given either selenium or garlic alone, once daily a dose for 15 successive days prior to HgCl(2) injection and on the next 15 successive days simultaneously with HgCl(2) injection; and the last group of rats was injected ip with HgCl(2) for 15 days and at the end of the experiment (which lasted 30 days), blood samples for the biochemical analysis were obtained from all rats after being lightly anesthetized with ether, and specimens of kidney and liver were removed and prepared for histochemical study. Computer image analysis was applied to liver and kidney tissues to evaluate the DNA density and DNA ploidy pattern in different groups. The results revealed that the rats injected with HgCl(2) showed a significant increase in levels of blood urea nitrogen (BUN), serum creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST) by 29.3%, 62.5%, 29.46% and 30.61%, respectively, while alkaline phosphatase (ALP) showed a significant decrease by 22.6% as compared with saline control group. Rats that were given selenium in combination with the HgCl(2) injection showed a significant decrease in BUN, Serum creatinine, ALT and AST levels, while ALP was significantly increased as compared with HgCl(2) group. Also rats that were given garlic in combination with HgCl(2) injection showed a significant decrease in BUN, Serum creatinine, ALT and AST levels, although serum ALP level showed an increase as compared to HgCl(2) group. Rats that had been orally administered selenium or garlic alone did not show any significant changes in the serum level of BUN, Serum creatinine, ALT and AST but there was a significant decrease in ALP level as compared with saline control group. The cytometric results revealed that injection of HgCl(2) induced an increase in the DNA density in kidney tissues with an increase in aneuploid cells and decrease in diploid cells. However, DNA density decreased in liver tissues with mild decrease in diploid cells and little percentage of aneuploid cells. We can conclude that oral administration of either selenium or garlic produces a significant protection against liver and kidney damage induced by the HgCl(2) injection, but garlic appears to be more protective.

Antinociceptive and anti-inflammatory steroidal saponins from Dracaena ombet.

Two new steroidal saponins, namely (25R)-5beta-spirostan-3-beta-ol 3-O-beta-D-galactopyranosyl-(1'''-->4'')-O-beta-D-galactopyranosyl-(1''-->3')-O-beta-D-glucopyranoside (2), and (25R)-5beta-spirostan-3-beta-ol 3-O-beta-D-galactopyranosyl-(1'''-->4'')-O-beta-D-glucopyranosyl-(1''-->3')-O-beta-D-glucopyranoside (3), together with six known constituents, have been isolated from the leaves of Dracaena ombet Kotschy & Peyr. (Dracaenaceae). The structures of the two saponins were established by chemical and physicochemical analyses, including FAB- and HR-ESI-MS and 2D NMR. The fraction rich in saponins showed significant analgesic and anti-inflammatory activities (at a high dose of 30 mg/kg b.w.) and non-significant antiulcer activities at the same doses.

Synthesis and biological evaluation of new 3-substituted indole derivatives as potential anti-inflammatory and analgesic agents.

Treatment of 3-cyanoacetyl indole 1 with the diazonium salts of 3-phenyl-5-aminopyrazole and 2-aminobenzimidazole afforded the corresponding hydrazones 4 and 5. 3-Cyanoacetyl indole reacted with phenylisothiocyanate to give the corresponding thioacetanilide derivative 7. Treatment of 7 with hydrazonoyl chlorides afforded the corresponding 1,3,4-thiadiazole derivatives 8a-f and 9. Also, the thioacetanilide reacted with alpha-haloketones to afford thiophene derivatives 10a,b (tenidap analogues), or thiazolidin-4-one derivative 11. The newly synthesized compounds were found to possess potential anti-inflammatory and analgesic activities.

Effect of pentoxifylline on hepatic injury caused in the rat by the administration of carbon tetrachloride or acetaminophen.

The effect of pentoxifylline (PTX) on acute liver injury caused by CCl4 or acetaminophen was studied in the rat. PTX was given twice daily (18, 36 or 72 mg/kg), intraperitoneally (ip) for 5 days prior to CCl4 or acetaminophen. In addition, the effect of PTX administered simultaneously with CCl4 or acetaminophen was evaluated. Rats were killed 72 h or 48 h after CCl4 or acetaminophen administration, respectively. The administration of PTX at 72 mg/kg, conferred significant protection against the hepatotoxic actions of CCl4, reducing serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels to 31%, 59.2% and 63%, respectively. Histological examination showed a decrease in centrilobular necrotic areas in rats pretreated with PTX. Histochemical investigation revealed a decrease in glycogen and protein contents caused by CCl4 and these were prevented by PTX pretreatment. When administered with CCl4, PTX did not reduce CCl4-induced hepatic injury. In contrast, hepatic injury induced by acetaminophen was prevented by prior or co-treatment with PTX. Accordingly, with 72 mg/kg of PTX, the elevation of AST, ALT and ALP levels was lower by 45%, 80.6%, 54.3% for the former and by 32.4%, 77.2%, 52.4% for the latter, respectively. Stained sections were subjected to morphometric evaluation using computerized image analyzer. Quantitative analysis of the acetaminophen area of damage showed a reduction by 34.8, 65.5 and 89.2% by 18, 36 or 72 mg/kg for PTX, respectively. Rats treated with PTX revealed more or less normal hepatocyte architecture as well as marked improvement in protein and glycogen content. The study demonstrates that prior but not co-toxicant administration of PTX in a model of CCl4-induced liver injury results in less liver damage. In contrast, PTX is equally protective, when given either as a pretreatment or with acetaminophen exposure.

Effect of cysteamine on bile secretion in the rat.

The effect of cysteamine, a specific somatostatin depletor, on biliary secretion was studied in urethane-anesthetized rats. Different groups of rats received ip cysteamine at 25, 100 or 340 mg/kg just before bile collection commenced. Other groups of rats were pretreated with cysteamine (340 mg/kg ip) at 4 or 24 h prior to bile duct cannulation and bile collection. Bile secretions were collected at 30-min intervals for 4 h after bile duct cannulation. Total proteins, cholesterol, total lipids, glucose and several hepatic enzymes were assessed in bile. Results indicated that basal bile secretion was only slightly reduced and tended to decrease after drug administration (13% decrease after 340 mg/kg). Cysteamine induced dose-dependent decrease in protein secretion, and the maximum effect was reached at a dose of 340 mg/kg. The effect of cysteamine on protein secretion was prolonged, since it was still observed 24 h after the treatment with cysteamine. Cholesterol and lipid secretion was inhibited by 52.5 and 42.5%, respectively, by the drug, with the latter effect being evident 24 h after drug administration. In addition, the drug inhibited biliary glucose and aspartate aminotransferase concentrations, but increased that of alkaline phosphatase. The results suggest that acute administration of cysteamine inhibits protein, cholesterol and lipid secretion into bile.

Effect of capsaicin on bile secretion in the rat.

Capsaicin is a popular food ingredient. This study aimed to determine if capsaicin can affect bile flow and bile protein secretion, and the extent to which capsaicin can reach bile in the rat. The effect of capsaicin was studied in anesthetized rats equipped with cannulas inserted into the common bile duct. Capsaicin was administered by intragastric, intraduodenal (4-400 microg/ml; 10-1,000 microg/kg), intravenous (10 microg/kg) routes or applied on the serosal surface of the duodenum at 4 microg/ml. The administration of capsaicin decreased bile flow in comparison to the corresponding basal values, the maximum effect being reached at a concentration of 400 microg/ml of intragastric capsaicin (30.2%; p < 0.01), and 40 microg/ml (30.8%; p < 0.01) of intraduodenal capsaicin, 75 min after drug administration. Meanwhile, a decrease of 24.7 and 40% was observed 60 min after serosal and intravenous capsaicin administration, respectively. Biliary protein secretion was also reduced following capsaicin administration. High-performance liquid chromatography (HPLC) analysis showed that capsaicin was readily excreted into bile, peak levels were reached 75 or 60 min following its intragastric or intraduodenal administration, respectively (range 100-248 and 144-698.6 ng/ml after intragastric or intraduodenal capsaicin at 4-400 microg/ml, respectively). Capsaicin concentrations of 86 and 75 ng/ml could be detected in bile 15 min after intravenous administration or serosal application of the agent, respectively. Results suggest that capsaicin is readily absorbed after its intragastric or intraduodenal administration and goes through hepatobiliary excretion. Results also indicate that administration of capsaicin reduces bile flow and biliary proteins in the rat.

Studies on the glycemic and lipidemic effect of monopril and losartan in normal and diabetic rats.

The effects of the angiotensin-converting enzyme (ACE) inhibitor monopril and the angiotensin II receptor blocker losartan on serum glucose, protein levels and some serum lipid components were compared in normal and diabetic rats receiving oral antidiabetic drugs 'repaglinide or gliclazide'. The two antihypertensive agents, when administered concurrently with oral hypoglycemic agents 'repaglinide or gliclazide' in normal and diabetic rats exerted a significant hypoglycemic effect. Serum protein levels were mainly unaffected by the two antihypertensive drugs. Monopril and losartan exhibit a hypolipidemic effect in normal and diabetic rats when administered in combination with oral hypoglycemic agents 'gliclazide or repaglinide'. Monopril or losartan when used alone exerted insignificant effect in high density lipoprotein (HDL) in normal rats, while in combination with gliclazide or repaglinide caused a significant increase in HDL in normal rats. Concomitantly, monopril or losartan, when administered alone or in combination with repaglinide or gliclazide in diabetic rats exerted a significant increase in serum HDL. On the other hand, all the investigated drugs showed a significant decrease in serum low density lipoprotein (LDL) in normal and diabetic rats.

Evaluation of the anti-inflammatory and anti-nociceptive effects of different antidepressants in the rat.

The present study was designed to compare the anti-inflammatory and anti-nociceptive effects of different classes of antidepressant drugs on the carrageenan paw oedema and tail-electric stimulation assays in the rat. Drugs were intraperitoneally administered 30 min prior to carrageenan or nociceptive testing. The non-selective noradrenaline (NA) and serotonin (5-HT) reuptake inhibitors imipramine, amitriptyline and clomipramine displayed anti-inflammatory activity in the carrageenan model of paw inflammation. The maximal degree of oedema inhibitions seen with these agents were 28.8, 41.5 and 46.8% for 5, 10 and 20 mg kg(-1) amitriptyline, 26.2, 38.2 and 51.4% for 3.75, 7.5 and 15 mg kg(-1) imipramine and 51.2 and 54.1% for 16 and 32 mg kg(-1) clomipramine, respectively. The heterocyclic agent trazodone significantly inhibited paw oedema by 46 and 41% at 1 and 2h after dosing at the highest dose (40 mg kg(-1)) examined. Fluoxetine, a selective 5-HT reuptake inhibitor (SSRI) caused dose-related reduction of paw oedema, with 20.7% inhibition at the dose of 10 mg kg(-1). In contrast, sertraline, another SSRI caused dose-dependent enhancement of paw oedema. All antidepressant drugs in the study showed anti-nociceptive properties in the tail-electric stimulation assay with amitriptyline and trazodone being the most effective in this respect. Taken together, data in the present study confirm anti-inflammatory and anti-nociceptive effect for some antidepressant drugs and indicate that SSRIs differently affects inflammation.

The anti-inflammatory effects of the phosphodiesterase inhibitor pentoxifylline in the rat.

The present study aimed to evaluate the anti-inflammatory effects of pentoxifylline (PTX), a non-specific phosphodiesterase inhibitor in the rat. Acute inflammation was induced by subplantar injection of carrageenan (1%) in the rat hind paw. Results showed that intraperitoneal (i.p.) administration of PTX (36 or 72 mg kg(-1)) 30 min prior to carrageenan reduced the paw oedema response in dose-dependent manner with a maximal effect of 18.9 and 40.1%, respectively, at 2h post-carrageenan (P<0.001 and <0.001 at respective doses). Theophylline given at equimolar doses (29.9 or 45.8 mg kg(-1), i.p.) did not reduce the oedema response. With higher doses of PTX (144-300 mg kg(-1), i.p.) the anti-oedema effect of the drug was more pronounced, but mainly confined to the first 2h following carrageenan injection and decreasing rapidly thereafter. PTX (72 mg kg(-1), i.p.) given 30 min after carrageenan challenge reduced the oedema response by 24.7 and 26.2% at 1 and 2h after dosing (P<0.05 and <0.05, respectively). PTX (36 or 72 mg kg(-1), i.p.) co-administered with indomethacin (5 mg kg(-1), i.p.) 30 min before carrageenan had little modulatory effect on the anti-oedema effect of indomethacin, but the higher dose of PTX (144 mg kg(-1), i.p.) reduced the anti-inflammatory effect of indomethacin by 24% at 4h post-carrageenan. PTX (72 mg kg(-1), i.p.) enhanced the anti-oedema effect of the selective COX-2 inhibitor celecoxib (33 mg kg(-1), i.p.) by 55.1% at 4h post-carrageenan. In contrast, the higher dose of PTX (144 mg kg(-1), i.p.) reduced the anti-oedema effect of celecoxib by 46.8% at 4h post-carrageenan. PTX (36 or 72 mg kg(-1)) enhanced the anti-oedema effect of dexamethasone (0.1 mg kg(-1)) with maximal effect of 76 and 104.8% at 2h post-carrageenan (P<0.01 and <0.01 for respective doses). PTX (0.6 mg per paw) given with carrageenan into the rat hind paw reduced the oedema response with a maximal effect of 33.4% at 1h following carrageenan. PTX (0.6 mg per paw) given in the contralateral hind paw reduced the carrageenan-induced paw oedema for 1h by 32.2%. Thus, PTX, when given at doses comparable to those used in man for treatment of circulatory disorders displayed anti-inflammatory in vivo and enhanced the anti-inflammatory effect of a selective COX-2 inhibitor or dexamethasone. PTX may have therapeutic potential as anti-inflammatory agent either alone or in combination with non-steroidal anti-inflammatory drugs or with steroids. There is also an intriguing possibility for the use of topical preparations for the management of local inflammatory conditions.

Studies on the anti-inflammatory and anti-nociceptive effects of melatonin in the rat.

The present study aimed to evaluate the anti-inflammatory and anti-nociceptive effects of melatonin in the rat. Acute inflammation was induced by sub-plantar injection of carrageenan (1%) in the rat hind paw. The rats received vehicle or drug 30 min before carrageenan administration and were evaluated for paw oedema at 1, 2, 3, and 4 h post-carrageenan. The induced inflammation and the formation of oedema were determined by measurement of the paw thickness. Nociception was tested by determining vocalization following electrical stimulation of the tail. Given intraperitoneally (i.p.) 30 min before carrageenan, melatonin caused significant and a dose-dependent reduction of hind paw swelling induced by carrageenan. At doses of 0.5 and 1 mg kg(-1), melatonin inhibited the carrageenan-induced oedema by 20.5 and 29.6% versus control values at 4 h post-carrageenan, respectively. Melatonin (0.5 and 1 mg kg(-1), i.p.) 30 min beforehand displayed anti-nociceptive effect in the electric stimulation of the rat tail test, increasing nociceptive thresholds to electrically-induced pain at 4 h post-treatment by 29.6 and 39.5%, respectively. Melatonin given simultaneously with the non-selective COX-1 and COX-2 inhibitor indomethacin (5 mg kg(-1), i.p.) 30 min prior to carrageenan, enhanced the anti-inflammatory effect of the latter in the carrageenan-induced paw oedema model by 23%. Melatonin (0.5 mg kg(-1), i.p.) increased the anti-nociceptive effect of indomethacin (5 mg kg(-1), i.p.). Meanwhile, the anti-inflammatory and anti-nociceptive effect of the highly selective COX-2 inhibitor rofecoxib (2.25 mg kg(-1), i.p.) was only slightly increased by melatonin administration at 0.5 mg kg(-1). Melatonin enhanced the anti-inflammatory effect of cysteamine (300 mg kg(-1), s.c.) in the carrageenan-induced paw oedema. Melatonin (20 and 40 microg per paw) given prior to carrageenan into the rat hind paw was devoid of anti-inflammatory effect. These results indicate that melatonin possesses anti-inflammatory and anti-nociceptive properties in the rat and enhance those of indomethacin. This effect is likely to be centrally mediated.