Enduring effects of tacrine on cocaine-reinforced behavior: Analysis by conditioned-place preference, temporal separation from drug reward, and reinstatement.

Previous work by our laboratory has shown that tacrine can produce long-lasting reductions in cocaine-reinforced behavior, when administered to rats as daily intravenous infusions over four days. Tacrine causes dose-related liver toxicity in different species, and its manufacture for human use was recently discontinued. This study was conducted to further characterize its actions on cocaine reward. Cocaine-experienced animals that had no contact with drug over one week resumed self-administration at levels similar to their initial baseline. When tacrine was administered over four days which were preceded and followed by washout periods to allow elimination of cocaine and tacrine respectively, subsequent cocaine self-administration was attenuated by more than one-half. Tacrine administered at 10 mg/kg-day as a chronic infusion by osmotic pump did not modify cocaine-induced increases in locomotor activity or conditioned-place preference. In rats that exhibited persistent attenuation of cocaine-self-administration after receiving tacrine, cocaine-induced reinstatement was also attenuated. No changes in plasma measures of renal or hepatic function were observed in rats receiving tacrine. In conclusion, pretreatment with tacrine can decrease cocaine-motivated behavior measured by self-administration or reinstatement, but not conditioned-place preference. Reductions in cocaine self-administration following pretreatment with tacrine do not require direct interaction with cocaine and are not secondary to either liver or kidney toxicity.

Triptolide inhibits colon cancer cell proliferation and induces cleavage and translocation of 14-3-3 epsilon.

Triptolide is a diterpenoid triepoxide derived from the traditional Chinese medical herb Tripterygium wilfordii. In the present study, we demonstrated that this phytochemical attenuated colon cancer growth in vitro and in vivo. Using a proteomic approach, we found that 14-3-3 epsilon, a cell cycle- and apoptosis-related protein, was altered in colon cancer cells treated with triptolide. In this regard, triptolide induced cleavage and perinuclear translocation of 14-3-3 epsilon. Taken together, our findings suggest that triptolide may merit investigation as a potential therapeutic agent for colon cancer, and its anticancer action may be associated with alteration of 14-3-3 epsilon.

Reversible and persistent decreases in cocaine self-administration after cholinesterase inhibition: different effects of donepezil and rivastigmine.

We recently observed that pretreatment with the cholinesterase inhibitor, tacrine can produce long-lasting reductions in cocaine-reinforced behavior, described as persistent attenuation. In addition to inhibiting both acetylcholinesterase (AChE) and butyrylcholinesterase, tacrine can potentiate actions of dopamine. This study was carried out to evaluate the effects of donepezil (which selectively inhibits AChE) and rivastigmine (which inhibits both AChE and butyrylcholinesterase) on cocaine self-administration. High self-administration rats self-administered different doses of cocaine under a fixed ratio-5 schedule. Over a 4-day period, vehicle, donepezil, or rivastigmine was infused as animals were maintained in home cages (21 h per day), with signs of cholinergic stimulation (fasciculation, vacuous jaw movements, yawning, and diarrhea) scored by a blinded observer. Both compounds dose-dependently decreased cocaine self-administration, but differed in the potency and temporal pattern of their effects. Self-administration of low-dose cocaine was decreased to a greater degree by rivastigmine than donepezil (50% effective doses of 2.33 and 6.21 mg/kg/day, respectively), but this early effect did not continue beyond sessions immediately after treatment with rivastigmine. Group means for cocaine self-administration were decreased at some time points occurring between 1 and 3 days after the treatment with 10 mg/kg/day of donepezil (late effects), with decreases of more than 80% observed in some individual rats that persisted for 1 week or longer. Early, but not late, effects were correlated with signs of cholinergic stimulation. In summary, pretreatment with donepezil, but not rivastigmine produced persistent reductions in cocaine-reinforced behavior, which were not associated with signs of cholinergic stimulation.

Antioxidant and Antiapoptotic Polyphenols from Green Tea Extract Ameliorate CCl4-Induced Acute Liver Injury in Mice.

OBJECTIVE: To investigate the phenolic composition, antioxidant properties, and hepatoprotective mechanisms of polyphenols from green tea extract (GTP) in carbon tetrachloride (CCl4)-induced acute liver injury mouse model. METHODS: High-performance liquid chromatography was used to analyze the chemical composition of the extract. Antioxidant activity of GTP was assessed by O2∙-, OH∙, DPPH∙, and ferric-reducing antioxidant power (FRAP) assay in vitro. Sixty Kunming mice were divided into 6 groups including control, model, low-, medium-, and high-doses GTP (200, 400, 800 mg/kg) and vitamin E (250 mg/kg) groups, 10 in each group. GTP and vitamin E were administered at a level of abovementioned doses twice per day for 7 days prior to exposure to a single injection of CCl4. Hepatoprotective effects of GTP were evaluated in a CCl4-induced mouse model of acute liver injury, using commercial enzyme linked immunosorbent assay kits, histopathological observation, terminal deoxynucleotidyl transferase-mediated dUTPNick-end labeling (TUNEL) assay and Western blot. RESULTS: GTP contained 98.56 µg gallic acid equivalents per milligram extract total polyphenols, including epicatechingallate, epigallocatechin gallate, epicatechin, and epigallocatechin. Compared with the model group, low-, medium-, or high doses GTP significantly decreased serum levels of alanine aminotransferase and aspartate transaminase (P<0.01). Histopathological observation confirmed that pretreatment of GTP prevented swelling and necrosis in CCl4-exposed hepatocytes. Hepatoprotective effects of low-, medium-, and high-dose GTP were associated with eliminating free radicals and improving superoxide dismutase, catalase, and glutathione peroxidase activity in the liver. Additionally, low-, medium-, and high-dose GTP decreased cell apoptosis in the CCl4-exposed liver (P<0.01). Phosphorylated nuclear factor kappa-B (NF-κB), p53, Bcl-2 associated x protein/B-cell lymphoma/leukemia-2 gene, cytochrome C, and cleaved caspase-3 levels were downregulated compared with the model group (P<0.01). CONCLUSION: GTP achieves hepatoprotective effects by improving hepatic antioxidant status and preventing cell apoptosis through caspase-3-dependent signaling pathways.

Dose-related effects of the acetylcholinesterase inhibitor tacrine on cocaine and food self-administration in rats.

RATIONALE: Acetylcholine (ACh) is involved in brain reward and learning functions and contributes to opiate- and psychostimulant-motivated behaviors. Tacrine is a centrally acting, reversible cholinesterase inhibitor that also inhibits monoamine oxidase (MAO) and blocks reuptake of dopamine (DA) and serotonin. OBJECTIVES: To determine the effects of pretreatment with tacrine on self-administration of cocaine and nondrug reinforcers. MATERIALS AND METHODS: Male Wistar rats were trained to self-administer cocaine under a fixed-ratio-5 (FR-5) schedule during 2-h multiple-component sessions in which 0.1, 0.2, and 0.4 mg/kg per injection of cocaine were each available for 40 min. Other animals self-administered 45 mg food pellets under FR-30 or 20% Ensure (liquid food) under FR-5 in amounts of 30, 60, or 120 microl. Vehicle or tacrine was administered as single intravenous doses 20 min before self-administration of cocaine, food pellets, or liquid food. RESULTS: Although pretreatment with 0.032 mg/kg of tacrine increased self-administration of food pellets, pretreatment with higher doses of tacrine attenuated self-administration of cocaine, food pellets, or liquid food. Tacrine's ED50 value for attenuating self-administration of 0.1 mg/kg per injection of cocaine was more than sixfold lower than values for attenuating liquid food- or food pellet-reinforced behavior. However, ED50 values for attenuating self-administration of higher doses of cocaine were similar to those observed for 30 or 60 microl of liquid food. CONCLUSIONS: Tacrine can selectively attenuate self-administration of low-dose cocaine, but its effects on higher doses of cocaine are similar to its ability to decrease self-administration of nondrug reinforcers.

Selective breeding for intravenous drug self-administration in rats: a pilot study.

Although the role of genetic factors in the response to drugs of abuse has been emphasized, no earlier studies have applied selective breeding to intravenous drug self-administration. Here we report the effects of six generations of selective breeding for rat lines with low or high levels of intravenous drug self-administration (LS and HS lines, respectively). Rats from the outbred founder population and the first selected generation were evaluated for intravenous self-administration of either morphine or cocaine. All subsequent generations were assessed for self-administration of cocaine, using a multifactorial score based on how rapidly self-administration behavior was acquired, levels of self-administration during acquisition, and the response to different doses of cocaine. All changes in cocaine self-administration that occurred in generations three through six were consistent with effects of selection, with most measures differing in sixth-generation LS and HS animals. Sixth-generation HS rats self-administered approximately five times more injections of low-dose cocaine than LS animals under fixed-ratio-5 (a schedule in which an injection is delivered after five lever presses). These findings support a role of genetic factors in influencing cocaine-reinforced behavior. Establishment of the LS and HS lines will allow future studies to evaluate the role of specific genetic factors that underlie these differences and may contribute to substance abuse disorders in humans.

Protective effects of medical ozone combined with traditional Chinese medicine against chemically-induced hepatic injury in dogs.

AIM: To investigate the protective effect of medical ozone (O(3)) combined with Traditional Chinese Medicine (TCM) Yigan Fuzheng Paidu Capsules (YC) against carbon tetrachloride (CCl(4))-induced hepatic injury in dogs. METHODS: Thirty healthy dogs were divided randomly into five groups (n = 6 in each group), namely control, oleanolic acid tablet (OAT), O(3), YC and O(3) + YC, given either no particular pre-treatment, oral OAT, medical ozone rectal insulfflation every other day, oral YC, or oral YC plus medical ozone rectal insulfflation every other day, respectively, for 30 consecutive days. After pre-treatment, acute hepatic injury was induced in all dogs with a single-dose intraperitoneal injection of CCl(4). General condition and survival time were recorded. The biochemical and hematological indexes of alanine aminotransferase (ALT), aspartate aminotransferase/alanine aminotransferase (AST/ALT), serum total bilirubin (TBIL), prothrombin time (PT), blood ammonia (AMMO), and blood urea nitrogen (BUN) were measured after CCl(4) injection. Hepatic pathological changes were also observed. RESULTS: Compared to the other four groups, the changes of group O(3) + YC dogs' general conditions (motoricity, mental state, eating, urination and defecation) could be better controlled. In group O(3) + YC the survival rates were higher (P < 0.05 vs group control). AST/ALT values were kept within a normal level in group O(3) + YC. Hepatic histopathology showed that hepatic injury in group O(3) + YC was less serious than those in the other four groups. CONCLUSION: Medical ozone combined with TCM YC could exert a protective effect on acute liver injury induced by CCl(4).

SHYCD induces APE1/Ref-1 subcellular localization to regulate the p53-apoptosis signaling pathway in the prevention and treatment of acute on chronic liver failure.

Background & Aims: San huang yin chi decoction(SHYCD) is derived from the yin chen hao decoction, a well-known and canonical Chinese medicine formula from the "Treatise on Febrile Diseases". Over the past decade, SHYCD has been used to treat and prevent the liver cirrhosis and liver failure. In the present study, we investigated the effects of SHYCD for acute on chronic liver failure(ACLF) and explored its potential mechanism. an ACLF rat model, which induced by carbon tetrachloride (CCl4) combined with D-galactosamine (D-GalN) and lipopolysaccharide(LPS), was used and confirmed by B-ultrasound analysis. Rats were randomly divided into control group, model group, SHYCD-H group, SHYCD-M group, SHYCD-L group, AGNHW group. Compared with the ACLF model group, High, medium, and low doses of SHYCD reduced ALT, AST, TBIL, NH3, IL-1ß, IL-6, and TNFα expression levels in the serum, Shorten PT and INR time,and increased Fbg content in the whole blood, increased survival rate of the rats, improved liver pathological changes. APE1 / Ref-1 was mainly expressed in the nucleus, but the nucleus and cytoplasm were co-expressed after hepatocyte injury. SHYCD significantly downregulated APE1/Ref-1 expression in the cytoplasm. Increased APE1/Ref-1, Bcl-2, reduced p53, caspase-3, Bax, and Cyt-c in the total protein. Base on the results, we conclused that High, medium, and low doses of SHYCD could be applied in prevention and treatment of ACLF, and dose-dependent. The possible mechanism is to promote the APE1 / Ref-1 from the cytoplasm to the nuclear transfer, regulation of p53 apoptosis signal pathway prevention and treatment of ACLF.

[Protective effect of Sanhuangyinchi Fang drug serum on hydrogen peroxide-induced DNA oxidative damage in LO2 cells].

OBJECTIVE: To study the protective effect of Sanhuangyinchi Fang drug serum (SF) against hydrogen peroxide-mediated DNA oxidative damage in LO2 cells. METHODS: The LO2 cells were randomly divided into the control group, H(2)O(2) group, SF groups (5%, 10%, and 15%) and vitE group. The morphological features of the treated LO2 cells were observed under inverted microscope. The viability of the treated cells was assessed with CCK-8 method, and the activity of SOD, CAT and GSH-PX were detected biochemically. Reactive oxygen species (ROS) levels, the content of 8-OHdG, and DNA damage of the cells were evaluated by flow cytometry, ELISA, and Comet assay, respectively. RESULTS: Compared with H(2)O(2) group, the cells in SF groups (10% and 15%) and vitE group showed higher cell survival rate (P<0.05) and higher SOD, CAT, GSH-PX (P<0.05) and ROS scavenging activities (P<0.01) with markedly decreases the content of 8-OHdG (P<0.01) and reduced tailing ratio, tail length, tail moment and Olive tail moment (P<0.05). CONCLUSION: SF drug serum, especially at the concentration of 15%, can protect LO2 cells from H(2)O(2)-mediated DNA oxidative damage.

[Expressions of hTERT, p53, c-erbB-2 and Bcl-2 in colonic adenocarcinoma mouse models with liver metastases: effects of classical traditional Chinese medicine prescriptions for promoting circulation and removing blood stasis].

OBJECTIVE: To observe the effects of classical traditional Chinese medicine prescriptions that function to promote blood circulation and removing blood stasis on the metastatic behavior of malignant tumors, and explore the possible mechanisms of such effects. METHODS: BALB/c mouse models of colonic adenocarcinoma with liver metastases were established by intrasplenic injection of colonic adenocarcinoma cells (CT26) to receive treatment with the three representative classical circulation-promoting and blood stasis-removing prescriptions of traditional Chinese medicine, namely Guizhifuling pills, Didang Tang and Danshenyin, respectively. The expressions of human telomerase reverse transcriptase (hTERT), p53, c-erbB-2 and Bcl-2 were detected in the mouse models with different treatments and in normal control mice. RESULTS: Tumor metastases of various degrees were observed in the mice after inoculation of the tumor cells. The expressions of hTERT, p53, c-erbB-2 and Bcl-2 in the models receiving treatment with either Didang Tang or Guizhifuling pills differed significantly from those of the untreated model group (P<0.05), whereas between Danshenyin group and the model group, only the expression of hTERT showed significant difference. CONCLUSION: Didang Tang and Guizhifuling pills can reduce the expressions of hTERT, p53, c- erbB-2 and Bcl-2, while Danshenyin can only reduce the expression of hTERT without similar effects on the other 3 oncogenes. Such inhibitory effects of the prescriptions on hTERT and the oncogenes might explain their actions to inhibit malignant tumor metastasis, which can be related to performance of the prescriptions in promoting circulation by removing blood stasis.

[Sanhuangyinchi decoction pretreatment ameliorates acute hepatic failure in rats by suppressing antioxidant stress and caspase-3 expression].

OBJECTIVE: To observe the effects of Sanhuangyinchi decoction (SHYCD) pretreatment on acute hepatic failure (AHF) induced by D-galactosamine and lipopolysaccharide (LPS) in rats and explore the possible mechanisms involving antioxidant stress and cell apoptosis-related protein expression. METHODS: Forty-eight SD rats were randomized equally into control group, AHF model group, high-, medium- and low-dose SHYCD groups, and Bicyclol group. Five days after administration of the corresponding drugs, the rats were challenged with peritoneal D-galactosamine (700 mg/kg) plus LPS (10 ug/kg) injections to induce AHF acute hepatic failure except for those in the control group. At 48 h after the injections, blood samples were collected from the rats to detect the levels of ALT, AST, TBIL, PT, INR and FIB, and pathological changes and superoxide dismutase (SOD) and malondialdehyde (MDA) contents in the liver were examined; immunohistochemistry and western blotting were used to detect caspase-3 protein expression in the liver. RESULTS: The levels of ALT, AST, TBIL, TP and INR in the 3 SHYCD groups and Bicyclol group significantly decreased (P<0.05) while FIB significantly increased in comparison with those in the model group. SHYCD obviously ameliorated the pathological changes, enhanced SOD activity (P<0.05), and decreased MDA levels (P<0.05) and caspase-3 expression (P<0.05) in the liver tissue. SHYCD at the medium dose produced similar effects to Bicyclol (P>0.05) and showed better effects at the high dose than Bicyclol (P<0.05). CONCLUSION: SHYCD pretreatment can dose-dependently ameliorate AHF in rats possibly by suppressing antioxidant stress and caspase-3 expression to decrease hepatic cell apoptosis.

[Effect of Sanhuangyinchi decoction on liver damage and caspase-3 in rats with acute hepatic failure].

OBJECTIVE: To investigate effect of Sanhuangyinchi decoction (SHYCD) on liver damage and the pro-apoptotic factor caspase-3 in rats with acute hepatic failure. METHODS: SD rats were randomly divided into blank control group, model group, Angongniuhuang group (AGNH) and SHYCD group. Acute hepatic failure was induced in the rats by intraperitoneal injections of D-GaLN and LPS, and the death rate, ALT, TBIL, PT and caspase-3 activity was observed or tested. RESULTS: At 36 h after the injections, the death rate of the rats was 74.29% (26/35) in the model group, 31.43% (11/35) in AGNH group and 28.57%(10/35) in SHYCD group. The death rate, ALT, TBIL, PT and caspase-3 activity in AGNH and SHYCD groups were significantly lower than those in the model group (P<0.01). SHYCD showed stronger effect than AGNH in depressing TBIL and the activity of caspase-3 (P<0.05). CONCLUSION: SHYCD can improve the liver function and inhibit the activity of caspase-3 in rats, which can be the possible mechanism for its therapeutic effect against acute hepatic failure.

Long-lasting decreases in cocaine-reinforced behavior following treatment with the cholinesterase inhibitor tacrine in rats selectively bred for drug self-administration.

Tacrine is a centrally acting, reversible cholinesterase inhibitor that increases synaptic levels of acetylcholine (ACh) and can potentiate the actions of dopamine (DA). The present study was conducted to evaluate effects of tacrine on cocaine-reinforced responding in a rat line selectively bred for high levels of drug self-administration (the HS line). HS rats self-administered different doses of cocaine under a fixed-ratio-5 (FR-5) schedule. Over a four-day period, vehicle or tacrine (1.0, 3.2, or 10 mg/kg-day) was infused when animals were maintained in home cages (21 h per day). Tacrine dose-dependently decreased cocaine self-administration. Actions of tacrine differed for self-administration that was initiated within 20 min of pretreatment (described as early sessions), and for self-administration that occurred between one and three days after administration of tacrine was discontinued (late sessions). Tacrine's potency for attenuating self-administration during late sessions was greater for cocaine- relative to food-reinforcement in HS rats, and for HS relative to outbred rats. In a subset of tacrine-treated HS rats, cocaine self-administration was persistently attenuated by more than 80% from pretreatment baseline levels over a one-week period during which no further tacrine was administered. In summary, pretreatment with tacrine can produce a long-lasting attenuation of cocaine-reinforced responding.

[Protective effect of Yigan Fuzheng Paidu capsules combined with ozone on CCl4-induced acute hepatic injury in dogs].

OBJECTIVE: To investigate the protective effect of Yigan Fuzheng Paidu Capsules (YC) combined with medical ozone against hepatic injury in dogs induced by hepatotoxic drug. METHODS: Twenty-four dogs were randomized equally into 4 groups (n=6), namely the model group, oleanolic acid tablet (OAT) group, YC group and YC+O(3) group, given either no particular treatment, oral OAT at 10 mg/day, oral YC at 0.2 g/day, or YC at 0.2 g/day plus 150 ml medical ozone transrectal insufflation every other day, respectively, for totally 30 consecutive days. Acute hepatic injury was induced after the treatment in the dogs with a sing-dose intraperitoneal injection of 0.9 ml/kg CCl(4) and peanut oil mixture (1:1, W/W). The general condition, survival time, alanine aminotransferase (ALT), aspartate aminotransferase/alanine aminotransferase (AST/ALT), serum total bilirubin (TBIL), prothrombin time (PT), blood ammonia (AMMO), and blood urea nitrogen (BUN) were recorded or measured. The hepatic pathological changes were observed upon death or on day 15 following CCl(4) injection. RESULTS: Compared with the other 3 treatment protocols, YC plus O(3) showed favorable effects on the activity, mental state, diet, urination and defecation of the dogs, which had significantly higher survival rate and higher levels of ALT, TBIL, PT, and AMMO than the model and OAT groups (P<0.05). AST/ALT remained normal in YC+O(3) group, which had also milder hepatic injury than the other 3 groups. CONCLUSIONS: YC combined with medical ozone may decrease transaminase and blood ammonia levels, relieve jaundice, prolong the survival time of dogs with CCl(4)-induced hepatic injury.