Hepatoprotective,antinociceptive and antioxidant activities of cimetidine,ranitidine and famotidine as histamine H2 receptor antagonists

The antioxidant, antinociceptive and hepatoprotective effects of H₂ receptor blockers were examined with different experimental models. Antioxidant activities were determined by employing various in vitro assay systems such as 1,1‐diphenyl‐2‐picryl hydrazyl (DPPH) radical‐scavenging activity assays, reducing power determination assays, nitric oxide‐scavenging activity assays and hydrogen peroxide‐scavenging activity assays. Antinociceptive effects were determined using the hot plate test in mice. The hepatoprotective effects of cimetidine, ranitidine and famotidine against hepatotoxicity induced by carbon tetrachloride (CCl₄) were determined by measuring the levels of serum enzymes alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) activities in mice. We found that the IC₅₀ values of cimetidine, ranitidine and famotidine on DPPH radical‐scavenging activity were 671 ± 28, 538 ± 21 and 955 ± 43 μg/mL, respectively. Famotidine showed very strong nitric oxide‐scavenging activity. All three compounds showed very weak hydrogen peroxide‐scavenging activity. Moreover, the compounds did not exhibit any reducing power activity until concentrations of 1.6 mg/mL. All compounds also showed a dose‐dependent and marked analgesic activity in mice relative to controls. Pretreatment of mice with cimetidine, ranitidine or famotidine for three consecutive days reduced CCl₄‐induced hepatotoxicity in mice. Treatment with 200 mg/kg ranitidine reduced AST, AST and ALP serum levels, while 200 and 40 mg/kg of cimetidine and famotidine, respectively, reduced AST and ALP serum levels. H₂ blockers exhibited varying levels of antioxidant activities in various assays. Our results indicate that the antioxidant activities of H₂ blockers have an analgesic activity and protective effect on CCl₄‐induced hepatotoxicity in mice. These effects were greater with ranitidine than with the other compounds.     

New pathways driving the experimental hepatoprotective action of tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl) against acute hepatotoxicity

PurposeIn absence of liver protective drugs, a large number of hepatopathies may arise during drug administration. This study was executed to investigate the possible new pathways underlying the hepatoprotective effect of Tempol (4-hydroxy-2,2,6,6- tetramethylpiperidine-1-oxyl), following oral administration of carbon tetrachloride in mice.Methods and resultsThirty albino mice were randomized into 3 equal groups. The duration of study was 28 days. The groups were classified as follows: Group I (healthy control): received saline, in the same volume of CCl₄ dose, daily, orally, for 14 days, then sacrificed. Group II: received CCl₄, as a single oral dose only, of 1 ml/kg body weight, dissolved in olive oil (1:1 v/v), the animals of this group were sacrificed 14 days after CCl₄ single dose intoxication. Group III (protective Tempol treated): received a single dose of Tempol, 20 mg/kg, orally, daily for 14 days. Two hours after the last Tempol dose, animals of group III received a single oral dose of CCl₄. Fourteen days later, animals were scarified to collect blood and liver tissues for analysis. Tempol pretreatment significantly captured elevated levels of ALT and AST activities, lipid peroxidation, total bilirubin and increased total thiol and catalase contents. Notably, it significantly reduced the expression of tumor necrosis factor-alpha (TNF-α), Caspase-3 and endoplasmic reticulum (ER) inositol-requiring enzyme 1(IRE1) mRNAs, which is an ER trans membrane sensor that activates the unfolded protein response (UPR) to maintain the ER and cellular function.ConclusionPretreatment with Tempol has potential hepatoprotective effects against acute liver injury, induced by CCl₄, through antioxidant and anti-inflammatory activities.     

Quercetin reverses experimental cirrhosis by immunomodulation of the proinflammatory and profibrotic processes

The ability of quercetin to reverse an established cirrhosis has not yet been investigated. Therefore, the aim of this study was to examine the efficacy of this flavonoid in reversing experimental cirrhosis. Cirrhosis was induced by intraperitoneal administration of TAA (200 mg/kg of body weight) three times per week for 8 weeks or by intraperitoneal petrolatum‐CCl₄ (400 mg/kg of body weight) administration three times per week for 8 weeks. To determine the capacity of quercetin to prevent liver fibrosis, the flavonoid (50 mg/kg of body weight, p.o.) was administered daily to rats during the CCl₄ or TAA treatment. To evaluate the ability of quercetin to reverse the previously induced cirrhosis, we first treated rats with CCl₄ for 8 weeks, as previously described and then the flavonoid was administered for four more weeks. We found that the liver anti‐inflammatory and antinecrotic effects of quercetin are associated with its antioxidant properties, to the ability of the flavonoid to block NF‐κB activation and in consequence to reduce cytokine IL‐1. The ability of quercetin to reverse fibrosis may be associated with the capacity of the flavonoid to decrease TGF‐β levels, hepatic stellate cell activation, and to promote degradation of the ECM by increasing metalloproteinases. The main conclusion is that quercetin, in addition to its liver protective activity against TAA chronic intoxication, is also capable of reversing a well‐stablished cirrhosis by blocking the prooxidant processes and by downregulating the inflammatory and profibrotic responses.     

Hepatoprotective effects of misoprostol and silymarin on carbon tetrachloride-induced hepatic damage in rats

The aim of this study was to investigate the effect of misoprostol, silymarin or the co‐administration of misoprostol + silymarin on the carbon tetrachloride (CCl₄)‐induced hepatic injury in rats. Misoprostol (10, 100, 1000 μg/kg), silymarin (25 mg/kg) or misoprostol (100 μg/kg) + silymarin (25 mg/kg) was given once daily orally simultaneously with CCl₄ and for 15 days thereafter. The results showed that misoprostol (10, 100 or 1000 μg/kg) conferred significant protection against the hepatotoxic actions of CCl₄ in rats, reducing serum alanine aminotransferase (ALT) levels by 24.7%, 42.6% and 49.4%, respectively compared with controls. Misoprostol, given at 100 or 1000 μg/kg, decreased aspartate aminotransferase (AST) by 28 and 43.6% and alkaline phosphatase (ALP) by 19.3% and 53.4% respectively. Meanwhile, silymarin reduced ALT, AST and ALP levels by 62.7%, 66.1% and 65.1% respectively. The co‐administration of misoprostol (100 μg/kg) and silymarin (25 mg/kg) resulted in 61.4%, 66.1% and 57.5% reduction in ALT, AST and ALP levels respectively. Histopathological alterations and depletion of hepatocyte glycogen and DNA content by CCl₄ were markedly reduced after treatment with misoprostol, silymarin or misoprostol + silymarin. Image analysis of liver specimens revealed a marked reduction in liver necrosis; area of damage: 32.4%, 24% and 10.2% after misoprostol (10, 100 or 1000 μg/kg), 7.2% after silymarin and 10.9% after treatment with misoprostol 100 μg/kg + silymarin, compared with CCl₄ control group (46.7%). These results indicate that treatment with misoprostol protects against hepatocellular necrosis induced by CCl₄. This study suggests a potential therapeutic use for misoprostol in liver injury.     

Hepatoprotective and antioxidant potential of Asphodeline lutea (L.) Rchb. roots extract in experimental models in vitro/in vivo

The aim of this study was to investigate the effect of Asphodeline lutea (L.) Rchb. dry root extract (ALE) administered alone and against carbon tetrachloride (CCl₄)-induced liver injury in vitro/in vivo. The dried roots of A. lutea were extracted with 70% ethanol and was characterized with HPLC-UV. Hepatoprotective potential was investigated by in vivo/in vitro assays in Wistar rats as well as antioxidant properties. At concentrations ranging from 10 to 200 μg/mL of ALE significant cytotoxic effects on isolated hepatocytes were found. ALE showed some toxicity in Wistar rats discerned by increased ALT (Alanine transaminase), ALP (Alkaline phosphatase) activities and MDA (malondialdehyde) quantity, decreased GSH (reduced glutathione) levels without affecting the activity of the antioxidant enzymes (GPx (Gluthatione peroxidase), GR (Glutathione reductase) and GST (Glutathione-S-transferase activity)). The antioxidant and hepatoprotective potential of ALE was also observed in vitro/in vivo against CCl₄-induced liver injury, where ALE normalizes all the examined parameters perturbated by CCl₄ administration. In addition, ALE preserved the decreased cytochrome P450 level and EMND (Ethylmorphine-N-Demethylase) activity without affecting AH (Aniline 4-Hydroxylase) activity. ALE is rich in anthraquinones, naphthalenes and caffeic acid. The pro-oxidant effects of ALE could be due to naphthalene and anthraquinone bioactivation pathways involving toxic metabolites.     

Involvement of monoaminergic system in the antidepressant‐like effect of riparin I from Aniba riparia (Nees) Mez (Lauraceae) in mice

In past studies conducted by our group, riparin I (rip I) isolated from the green fruit of Aniba riparia presented antianxiety effects in mice, while its analogs rip II and III showed anxiolytic and antidepressant‐like actions. This time around, we investigated a possible antidepressant activity of rip I using the forced swimming test (FST) and tail suspension test (TST) as predictive tests for antidepressant activity in rodents. In addition, the involvement of the monoaminergic system in this effect was also assessed. rip I was acutely administered by intraperitoneal (i.p.) and oral (p.o) routes to male mice at doses of 25 and 50 mg/kg. Results showed that rip I at both tested doses and administration routes produced a significant decrease in immobility time in FST and TST. The pretreatment of mice with prazosin (1 mg/kg, i.p., an α₁‐adrenoceptor antagonist), yohimbine (1 mg/kg, i.p., an α₂‐adrenoceptor antagonist), SCH23390 (15 μg/kg, i.p., a dopamine D1 receptor antagonist), sulpiride (50 mg/kg, i.p., a dopamine D2 receptor antagonist), p‐chlorophenylalanine (100 mg/kg, an inhibitor of serotonin synthesis) or ritanserin (4 mg/kg, a serotonin 5‐HT2_a/2_c receptor antagonist) blocked the anti‐immobility effects elicited by rip I (50 mg/kg, p.o.) in the FST. Taken together, results indicate that rip I produces significant antidepressant‐like activity in the FST and TST, and this effect seems to be dependent on its interaction with noradrenergic, dopaminergic and serotonergic systems.     

Evaluation of antioxidant and stabilizing lipid peroxidation nature of Solanum xanthocarpum leaves in experimentally diethylnitrosamine induced hepatocellular carcinogenesis

Solanum xanthocarpum Schrad. & Wendl, is a traditional edible leaves as a form of decoction, extracts used as a herbal medicine, and consumed for health promoting profiles. The present investigation was carried out to evaluate antioxidant status and lipid peroxidation level of anticancer activity of Solanum xanthocarpum (SXC) on Diethylnitrosamine (DEN) induced hepato carcinogenesis in male Wistar albino rats. Hepatic cancer was developed on the liver of Wistar rats treated by DEN or vehicle three times a week for 16 weeks. Tumour incidence, tumour volume, tumour burden, lipid peroxidation, antioxidant, liver marker enzymes and histopathological changes were assessed in DEN alone and in DEN + SXC leaves extract treated rats. Hundred percent tumour incidences with an imbalance in carcinogen metabolizing enzymes and cellular redox status were observed in rats treated with DEN alone. Oral administration of SXC aqueous leaves extract treatment at a dose of 150 mg/kg b.w. to DEN treated rats were prevented tumour incidence and restored the elevated activities of liver marker enzymes and antioxidant status to near normal with decreased lipid peroxide levels. The biochemical consistent with histopathological observations suggesting marked hepatoprotective effect of the leaves extract in a dose dependent manner. These results clearly suggest that SXC aqueous leaves extract treatment prevents liver damage, lipid peroxidation, protects the antioxidant defense system and anti-carcinogenic potential in DEN induced hepatic carcinogenesis.     

藤梨根拮抗四氯化碳致急性肝损伤作用活性部位的初步筛选

目的:通过建立四氯化碳(CCl4)致急性肝损伤小鼠模型,测定其血清中谷丙转氨酶(ALT)的含量,对藤梨根不同提取部位抑制ALT升高的作用比较,筛选出具有拮抗肝损伤作用的提取部位。方法:取藤梨根原药材,经过乙醇提取、乙酸乙酯萃取,得乙酸乙酯提取部位;过聚酰胺柱洗脱,得不同提取部位,分为X部位、Y部位、Z部位;小鼠预防性给药2 d,以CCl4橄榄油混合物(1%)2 mL/kg腹腔注射造就小鼠化学性肝损伤模型,第3天给药后摘眼球取血,测血清中ALT活力。结果:乙酸乙酯部位、X部位、Y部位均具有拮抗CCl4致急性肝损伤小鼠血清ALT升高的作用,其中X部位在一定剂量范围内具有量效关系。结论:含有黄酮类化合物的藤梨根提取X部位,具有拮抗CCl4致急性肝损伤的作用,且在一定剂量范围内具有量效关系。     

Antioxidant properties of flavonoid derivatives and their hepatoprotective effects on CCl4 induced acute liver injury in mice

Excessive accumulation of free radicals in the body can cause liver damage, aging, cancer, stroke, and myocardial infarction. Anastatin B, a skeletal flavonoid, was reported to have antioxidant and hepatoprotective effects. Anastatin B derivatives, compound 1 and 2, were synthesized by our group previously. In this study, their antioxidant activity and hepatoprotective mechanism were studied using chemical evaluation methods, a cellular model of hydrogen peroxide (H₂O₂)-induced oxidative damage, and a mouse model of carbon tetrachloride (CCl₄)-induced liver injury. Results from the chemical evaluation suggested that both compounds had good antioxidant power and radical scavenging ability in vitro. MTT assay showed that both compounds had cytoprotective activity in H₂O₂-treated PC12 cells. Moreover, their hepatoprotective activities evaluated using a mouse model of CCl₄-induced liver injury that compared with the model group, pretreatment with compound 1 and 2 significantly decreased alanine transaminase (ALT), aspartate transaminase (AST), lactate dehydrogenase (LDH), and malondialdehyde (MDA) levels; reduced the liver tissue damage; and increased glutathione content. However, compound 2 was a more effective hepatoprotectant than compound 1 was. Finally, the amount of TNF-α and cytochrome P450 2E1 (CYP2E1) were significantly downregulated in compound 1 and 2 pretreatment groups. Collectively, our findings demonstrate that both compounds have potential antioxidant activity and hepatoprotective effect in vitro and in vivo. Further chemo-biological study and investigation of the compounds'' enzymatic targets are ongoing.

Excessive accumulation of free radicals in the body can cause liver damage, aging, cancer, stroke, and myocardial infarction.     

Comparative study of the efficacy of liposomal amphotericin B and amphotericin B deoxycholate against six species of Zygomycetes in a murine lethal infection model

The objective of this study was to investigate the efficacy of liposomal amphotericin B (L-AMB) at a clinical dose (3 mg/kg) against six species (5 genera) of Zygomycetes in a murine lethal infection model, and to compare findings with those for deoxycholate amphotericin B (D-AMB). The correlation between in-vitro activity and in-vivo efficacy of L-AMB was also investigated. Cyclophosphamide-treated mice were inoculated intravenously with conidial suspensions. Four hours or 1 day after inoculation, a single dose of L-AMB or D-AMB was administered intravenously. The number of mice that survived for 14 days was recorded. L-AMB at a dose of at least ≥1 mg/kg significantly prolonged the survival time of infected mice compared with the control group. The ED₅₀ of L-AMB was nearly equivalent to that of D-AMB, except for the treatment initiated on day 1 in the Rhizopus oryzae model. At the maximum tolerated dose (MTD) of each agent, survival percentages with L-AMB (10 mg/kg) were equal to or higher than those with D-AMB (1 mg/kg). The ED₅₀ of L-AMB decreased as the MIC against the infecting strain decreased. In conclusion, L-AMB was effective at a clinical dosage, and at the MTD the efficacy of L-AMB was equal or superior to that of D-AMB in a murine model of disseminated zygomycosis. The in-vivo activity of L-AMB was correlated with its in-vitro activity.     

Therapeutic effects of metabotropic glutamate receptor 5 positive allosteric modulator CDPPB on phencyclidine‐induced cognitive deficits in mice

This study was undertaken to examine the effects of CDPPB (3‐cyano‐N‐(1,3‐diphenyl‐1H‐pyrazol‐5‐yl)benzamide), a positive allosteric modulator (PAM) of metabotropic glutamate receptor 5 (mGlu₅), on cognitive deficits in mice after repeated administration of the N‐methyl‐D‐aspartate (NMDA) receptor antagonist phencyclidine (PCP). In the novel object recognition test, PCP (10 mg/kg/day for 10 days)‐induced cognitive deficits in mice were not improved by a single administration of CDPPB (10 mg/kg/day). However, PCP (10 mg/kg/day for 10 days)‐induced cognitive deficits in mice were significantly improved by subsequent subchronic (14 days) administration of CDPPB (10 mg/kg/day), but not of CDPPB (1.0 mg/kg/day). This study suggests that PCP‐induced cognitive deficits in mice are improved by subsequent subchronic administration of CDPPB. Therefore, mGlu₅ PAMs would be potential therapeutic drugs for cognitive deficits in schizophrenia.     

Synergistic interaction of gabapentin with tiagabine in the formalin test in mice: An isobolographic analysis

The aim of this study was to determine the analgesic effect of gabapentin and tiagabine – two antiepileptic drugs, administered alone and in combination at the fixed-ratio of 1:1, in two phases of the formalin test in mice. Log-probit analysis was used to evaluate dose–response effects and calculate the ED₅₀ values for gabapentin, tiagabine, and their combination at the fixed-ratio of 1:1 in the phases I and II of the formalin test in mice. The types of interactions between both antiepileptic drugs were characterized using the isobolographic analysis.Results indicated that gabapentin and tiagabine produced the antinociceptive effect in both phases of the formalin test. The ED₅₀ values for gabapentin and tiagabine, administered singly, in the phase I of the formalin test were 29.59 and 2 mg/kg, whereas in the phase II of the formalin test were 8.22 and 0.50 mg/kg, respectively. With isobolography, the ED_50 mix values at the fixed-ratio combination of 1:1 were 7.30 mg/kg (phase I) and 0.48 mg/kg (phase II), indicating both additive and supra-additive (synergistic) interactions between gabapentin and tiagabine in the formalin test in mice.In conclusion, the combination of gabapentin with tiagabine at the fixed-ratio of 1:1 exerted additive interaction in the phase I and synergistic interaction in the phase II of the formalin test in mice. If the results from this study could be extrapolated to clinical settings, the combination of tiagabine with gabapentin might be beneficial in the pain relief in humans.     

Influence of arachidonyl‐2′‐chloroethylamide,a selective cannabinoid CB1 receptor agonist,on the anticonvulsant and acute side‐effect potentials of clobazam,lacosamide, and pregabalin in the maximal electroshock‐induced seizure model and chimney test in mice

The influence of arachidonyl‐2′‐chloroethylamide (ACEA – a selective cannabinoid CB₁ receptor agonist) on the anticonvulsant potency and acute adverse‐effect potentials of clobazam, lacosamide, and pregabalin was determined in the maximal electroshock‐induced seizure model and chimney test in mice. ACEA (2.5 mg/kg, i.p.) significantly enhanced the anticonvulsant potency of pregabalin in the mouse maximal electroshock‐induced seizure model by decreasing the median effective dose (ED₅₀) of pregabalin from 125.39 to 78.06 mg/kg (P < 0.05). In contrast, ACEA (2.5 mg/kg) had no significant impact on the anticonvulsant potency of clobazam and lacosamide in the mouse maximal electroshock‐induced seizure model. On the other hand, ACEA (2.5 mg/kg) did not affect acute adverse effects of clobazam, lacosamide or pregabalin, and the median toxic doses (TD₅₀) for the studied anti‐epileptic drugs in combination with ACEA did not differ from the TD₅₀ values as determined for the drugs administered alone in the chimney test. In conclusion, ACEA ameliorates the pharmacological profile of pregabalin, when considering both the anticonvulsant and the acute adverse effects of the drug in preclinical study on animals. The combination of pregabalin with ACEA can be of pivotal importance for patients with epilepsy as a potentially advantageous combination if the results from this study translate into clinical settings.     

Eugenol reduces acute pain in mice by modulating the glutamatergic and tumor necrosis factor alpha (TNF‐α) pathways

Eugenol is utilized together with zinc oxide in odontological clinical for the cementation of temporary prostheses and the temporary restoration of teeth and cavities. This work explored the antinociceptive effects of the eugenol in different models of acute pain in mice and investigated its possible modulation of the inhibitory (opioid) and excitatory (glutamatergic and pro‐inflammatory cytokines) pathways of nociceptive signaling. The administration of eugenol (3–300 mg/kg, p.o., 60 min or i.p., 30 min) inhibited 82 ± 10% and 90 ± 6% of the acetic acid‐induced nociception, with ID₅₀ values of 51.3 and 50.2 mg/kg, respectively. In the glutamate test, eugenol (0.3–100 mg/kg, i.p.) reduced the response behavior by 62 ± 5% with an ID₅₀ of 5.6 mg/kg. In addition, the antinociceptive effect of eugenol (10 mg/kg, i.p.) in the glutamate test was prevented by the i.p. treatment for mice with naloxone. The pretreatment of mice with eugenol (10 mg/kg, i.p.) was able to inhibit the nociception induced by the intrathecal (i.t.) injection of glutamate (37 ± 9%), kainic (acid kainite) (41 ± 12%), α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA) (55 ± 5%), and substance P (SP) (39 ± 8%). Furthermore, eugenol (10 mg/kg, i.p.) also inhibited biting induced by tumor necrosis factor alpha (TNF‐α, 65 ± 8%). These results extend our current knowledge of eugenol and confirm that it promotes significant antinociception against different mouse models of acute pain. The mechanism of action appears to involve the modulation of the opioid system and glutamatergic receptors (i.e., kainate and AMPA), and the inhibition of TNF‐α. Thus, eugenol could represent an important compound in the treatment for acute pain.     

Branched chain amino acids supplementation modulates TGF‐β1/Smad signaling pathway and interleukins in CCl4‐induced liver fibrosis

The alterations and low levels of circulating branched chain amino acids (BCAAs), leucine, isoleucine, and valine, are associated with liver diseases. The study was designed to evaluate hepatoprotective effect of BCAAs on CCl₄‐induced liver fibrosis and to investigate the molecular mechanisms underlying these effects in rats. In all, 30 male rats were divided into three groups. Control group (n = 10) and CCl₄ group (n = 10), where rats were injected with CCl₄ (1 mL/kg of 0.5 : 1 v/v injected i.p. twice weekly for 12 weeks). In CCl₄ + BCAAs group (n = 10), rats were injected with similar doses of CCl₄ and supplemented with a mixture of 600 mg/kg BCAAs (2 : 1 : 1.2 leucine : isoleucine : valine) by oral gavage, three times/week for 12 weeks. Liver fibrosis was assessed by measuring total bilirubin, total protein, alanine aminotransferase, and aspartate aminotransferase, hydroxyproline content, and serum IL‐6 and IL‐10. Histopathologic studies and α‐smooth muscle actin (α‐SMA) were detected immunohistochemically in liver. Serum insulin level, blood glucose, liver malodialdehyde concentration (MDA), glutathione peroxidase, and superoxide dismutase (SOD) activities were quantified. TGF‐β1, Smad3, and Smad7 gene expressions were estimated by qRT‐PCR. BCAAs suppressed liver fibrosis induced by CCl₄ treatment. BCAAs modulated liver indices and downregulated TGF‐β1, Smad3, and Smad7 expressions in hepatocytes. BCAAs enhanced liver antioxidant enzyme activities (P < 0.001), reduced serum levels of TGF‐β1, IL‐6, and IL‐10 compared to CCL₄ group and ameliorated histopathologic changes in rat liver. BCAAs may have a protective role against liver fibrosis via antioxidant and anti‐inflammatory mechanisms.     

Chrysin,a flavonoid attenuates histological changes of hyperammonemic rats: A dose dependent study

Chrysin (5,7-dihydroxyflavone) is a major component of some traditional medicinal herbs present in honey, propolis and many plant extracts. The study was aimed to illuminate the effect of chrysin in the pathogenesis of ammonium chloride (NH₄Cl) induced hyperammonemic rat model in a dose dependent manner. Rats were injected with NH₄Cl (100 mg/kg b.w.) by intraperitonially (i.p) thrice a week for 8 consecutive weeks for the induction of experimental hyperammonemia. Hyperammonemic rats were treated with chrysin by orally at a dose of 25, 50 & 100 mg/kg b.w. respectively. Protective effect of chrysin against hyperammonemia was evaluated by performing biochemical estimations and morphopathological investigations of hematoxylin and eosin stained sections of liver, brain and kidney tissues. Supplementation of chrysin reinstated the levels of blood ammonia, plasma urea, uric acid, total bilirubin, creatinine, brain glutamate, glutamine, nitric oxide (NO) and the activities of Na⁺/K⁺-ATPase, and liver marker enzymes. On the other hand increased level of plasma urea was observed in chrysin treated rats as compared with hyperammonemic rats. Chrysin administration caused distortion of hepatic, brain and kidney architecture as shown by histological examination. Chrysin at a dose (100 mg/kg b.w.) showed an utmost decline in the level of all biochemical estimations. Both biochemical and morphological studies clearly revealed that chrysin protects against cell injury induced by ammonia intoxication in a dose-response manner with respect to endogenous antioxidants and hypoammonemic effects.     

Antidepressant‐like effect of bis‐eugenol in the mice forced swimming test: evidence for the involvement of the monoaminergic system

Dehydrodieugenol, known as bis‐eugenol, is a eugenol ortho dimer, and both compounds were able to exhibit anti‐inflammatory and antioxidant activities in previous studies. Furthermore, eugenol showed antidepressant‐like effect; however, the biological actions of bis‐eugenol on experimental models for screening antidepressant activity are still unknown. The present study investigated a possible antidepressant‐like activity of bis‐eugenol in the forced swimming test (FST) and tail suspension test (TST) in mice and the involvement in the monoaminergic system in this effect. In addition, a neurochemical analysis on brain monoamines of mice acutely treated with bis‐eugenol was also conducted. Bis‐eugenol decreased the immobility time in the FST and TST without accompanying changes in ambulation in the open field test at 10 mg/kg, i.p.. Nevertheless, it induced ambulation at 25 and 50 mg/kg doses. The anti‐immobility effect of bis‐eugenol (10 and 50 mg/kg, i.p.) was prevented by pretreatment of mice with p‐chlorophenylalanine (PCPA, 100 mg/kg, i.p., an inhibitor of serotonin synthesis, for four consecutive days), yohimbine (1 mg/kg, i.p., an α2‐adrenoceptor antagonist), SCH23390 (15 μg/kg, s.c., a dopamine D1 receptor antagonist) and sulpiride (50 mg/kg, i.p., a dopamine D2 receptor antagonist). Monoamines analysis using high‐performance liquid chromatograph revealed significant increase in the 5‐HT, NE and DA levels in brain striatum. The present study indicates that bis‐eugenol possesses antidepressant‐like activity in FST and TST by altering dopaminergic, serotonergic and noradrenergic systems function.     

Exenatide suppresses 1,2-dimethylhydrazine-induced colon cancer in diabetic mice: Effect on tumor angiogenesis and cell proliferation

Colon cancer is the third leading cause of cancer mortality worldwide, which results from interactions of different factors. It is frequently a pathological consequence of persistent inflammation. Diabetes affects several cancers and is positively correlated with the incidence of colon cancer. This study aimed to study the effect of exenatide in ameliorating inflammation, angiogenesis and cell proliferation in 1,2-dimethyl hydrazine (DMH) induced colorectal carcinoma in diabetic mice. Mice were randomly allocated into six groups, 8 mice each. Group 1: vehicle control group. Group 2: diabetic control group. Group 3: DMH control group: diabetic mice treated with DMH (20 mg/kg/week, s.c.) for 15 week. Group 4: DMH-cisplatin group: mice received cisplatin (4 mg/kg/week, i.p.). Groups 5 & 6: DMH-exenatide (10 and 20 μg/kg) group: mice received exenatide (10 or 20 μg/kg/day, s.c.), respectively. The present results highlighted an increase in angiogenic markers and cell proliferation in the DMH-diabetic group in comparison with the control group with greater expression of endothelial marker (CD₃₄) and Ki-67 in colon tissue. Monotherapy with cisplatin or exenatide (10 and 20 μg/kg) downregulated these markers to different extents. The current results provided evidence that exenatide represents a promising chemopreventive effect against DMH-induced colon carcinogenesis in diabetic mice, at least in part, attributed to its anti-angiogenic and anti-proliferative mechanisms.     

鬼针草抗小鼠急性肝损伤有效部位的筛选

目的对鬼针草抗小鼠急性肝损伤的有效部位进行筛选,并初步探讨其对肝脏的保护作用。方法采用四氯化碳(CC l4)小鼠急性肝损伤模型,测定肝脏指数、肝功能酶、肝匀浆丙二醛(MDA)含量、过氧化物歧化酶(SOD)活性,并光镜下观察肝脏病理变化。结果与正常组相比,CCl4模型对照组肝脏指数、血清ALT、AST活性和肝组织MDA含量显著升高(P<0.01),肝脏SOD活性显著降低(P<0.01),肝脏出现不同程度的变性及坏死,肝小叶及肝细胞消失,肝脏病理学分级与正常组有显著差异(P<0.01)。鬼针草黄酮类组分可使肝损伤小鼠的肝脏指数、ALT、AST和MDA显著降低,并升高SOD活性。病理检查显示鬼针草能明显减轻CC l4引起的肝脏结构损害,其中尤以黄酮类组分疗效最佳(P<0.01)。结论鬼针草黄酮类组分有显著的抗肝损伤作用,可能是鬼针草保肝作用的主要有效部位。     

Efficiency of combined methotrexate/chloroquine therapy in adjuvant-induced arthritis

The present study evaluates the effects of methotrexate (MTX) and chloroquine (CQ), and of combined MTX + CQ treatment, on the inflammatory response and on plasma and liver phosphatase and transaminase activities, employing an adjuvant-induced arthritis model in rats. Arthritis was induced by the intradermal injection of a suspension of Mycobacterium tuberculosis in mineral oil into the plantar surface of the hind paws. Development of the inflammatory response was assessed over a 21-day period. Animal groups received either: (i) MTX, administered i.p., weekly, in 0.15, 1.5, 3, 6 or 12 mg/kg doses; (ii) CQ, given intragastrically, in daily 25 or 50 mg/kg doses; or (iii) MTX + CQ, administered in two combinations (MTX1.5 mg/kg + CQ50 mg/kg, or MTX6 mg/kg + CQ50 mg/kg). At the end of the experimental period, the animals were anesthetized and killed, blood and liver samples were collected and prepared for measurement of acid and alkaline phosphatase (AP, ALP), and aspartate (AST) and alanine aminotransferase (ALT) activities. MTX at 6 and 12 mg/kg reduced the inflammatory response while CQ had no effect. MTX6 mg/kg + CQ50 mg/kg reduced the inflammatory response similar to MTX12 mg/kg, without affecting the bone marrow. Plasma AP and liver ALP activities were very elevated in the arthritic rats. While MTX treatment partially reduced both plasma AP and liver ALP activities at all doses used in the arthritic rats, CQ treatment reduced plasma AP, but increased liver AP activity. MTX + CQ treatment decreased plasma AP and liver ALP activities in the arthritic rats to control values. Plasma and liver AST activities were unaltered in the arthritic rats, and were unaffected by treatment. However, plasma and liver ALT activities were significantly reduced in the arthritic rats. While MTX or CQ treatment did not alter plasma transaminase activity in the arthritic rats, after MTX + CQ treatment, plasma ALT activity returned to normal values. In conclusion, the present data suggest that MTX + CQ treatment provides more effective anti-inflammatory protection against adjuvant-induced arthritis than does MTX alone, reverting the alterations in enzyme activities induced by this inflammatory disease in rats.