Assessment of acute, sub-acute, chronic and genotoxicity of polyherbal formulation DCD-684 in mice.

Digas colic drops (DCD-684) a polyherbal formulation containing Carum carvi, Foeniculum vulgare, Mentha arvensis, Mentha piperita and Zingiber officinale is widely used in Pakistan against gastrointestinal ailments including infantile colic. The DCD-684 (0.03-3ml/kg.bw) administered orally in acute (7-days) and sub-acute toxicity (14-days) tests, displayed neither mortality nor toxicological changes in physical, behavioral, biochemical and histopathological parameters. In chronic study (90-days), DCD-684 (0.3-12ml/kg.bw) also revealed no changes. However, at 18 and 36 ml/kg.bw, liver demonstrated mild inflammation correlating with raised aspartate transaminase (AST), alkaline phosphatase (ALP) and alpha fetoprotein (AFP) levels. Increased levels of urea and inflamed renal parenchyma indicated mild nephro-toxicity with high alanine aminotransferase (ALT) at 36ml/kg.bw. The LD50 of DCD-684 in mice was 27.5 ml/kg.bw. In hepatocytes at 36ml/kg.bw, elevated mRNA expression of pro-inflammatory chemokines and cytokines were evident. DCD-684 neither damaged DNA nor induced cytotoxicity in micronucleus assay. In conclusion, polyherbal DCD-684 caused neither hepatic, renal, genotoxicity nor any undesirable effect in mice. Higher doses administered for 90 days showed mild toxic effects with no sign of necrosis, fibrosis or genotoxicity. Thus, in mice DCD-684 demonstrated a wide margin of safety to be used for the relief of infantile colic.

Assessment of intestinal peristalsis in vitro.

The protocol detailed in this unit is designed to assess intestinal peristaltic motility in the isolated small intestine in vitro and to measure the effects of drugs able to interfere with gut propulsive activity. The procedure is based on Trendelenburg's classic technique, described at the beginning of the 20th century in the isolated guinea pig ileum and, later on, extended to other intestinal preparations from the same animal and other animal species. This unit illustrates the basic procedures for setting up the intestinal preparation, recording peristalsis under near-physiologic conditions, and testing the pharmaco-toxicological effects of drugs and pollutants on the contractile behavior of the gut wall. The protocol allows evaluating the action of drugs affecting sensory and/or motor neurons of the enteric nervous system and how these neurons control the development of the motor program of the gut wall. This model can be exploited to investigate novel compounds undergoing preclinical development and both inhibitors and stimulants of gastrointestinal peristaltic activity, as well as environmental or alimentary pollutants, like xenobiotics and naturally-occurring toxins, endowed with noxious activity with regard to digestive functions.

Genotoxicity assessment of Pyungwi-san (PWS), a traditional herbal prescription.

ETHNOPHARMACOLOGICAL RELEVANCE: Pyungwi-san (PWS, Heii-san in Japanese) is a mixture of six herbs and is traditionally used in Northeast Asia (especially Korea and Japan) for the treatment of gastrointestinal disorder, such as dyspepsia and inappetance induced by gastric dilatation and gastrointestinal catarrh. AIM OF THE STUDY: Although PWS is a widely used herbal prescription in Korea and Japan, little information is available in the literature on the safety and toxicity of PWS. As part of a safety evaluation of PWS, the present study evaluated the potential genotoxicity of PWS using a standard battery of test. MATERIALS AND METHODS: We prepared PWS using a water extraction method and simultaneously extracted three compounds from PWS using high performance liquid chromatography. The PWS extract that was obtained was assayed for genotoxicity using the standard three tests recommended by the Korea Food and Drug Administration. These tests included the bacterial reverse mutation test (Ames test), the chromosomal aberration test using China hamster lung cells, and the micronucleus test using ICR mice. RESULTS: The Ames test showed that the PWS extract did not induce an increase in the number of revertant colonies compared with vehicle control at any dose in all of tester strains. In the micronucleus test, no significant increase was observed in micronucleated polychromatic erythrocytes (MNPCEs) at any dose of PWS extract compared with vehicle control. Conversely, chromosomal aberration test showed that the PWS extract at a dosage of 4500 µg/mL induced an increase in the number of chromosomal aberrations in the 6 h group with metabolic activation compared with the vehicle control. CONCLUSION: PWS extract exhibits genotoxicity, based on the results of the chromosomal aberration test. Thus, further detailed experiments will be needed to identify the ingredient responsible for inducing this genotoxicity and to determine its mechanism.

Economic analysis of alvimopan in North American Phase III efficacy trials.

PURPOSE: The economic effect of the use of alvimopan in four randomized, double-blind, placebo-controlled, Phase III, North American efficacy trials was analyzed. METHODS: Patients were eligible for the study if they were 18 years or older, were undergoing laparotomy for partial small or large bowel resection with primary anastomosis, and were scheduled for postoperative pain management with opioid-based i.v. patient-controlled analgesia. Patients analyzed in the North American Phase III trials received placebo or alvimopan 12 mg orally before surgery. Doses were administered twice daily beginning the day after surgery until hospital discharge or for a maximum of 15 doses. RESULTS: Compared with placebo, alvimopan was associated with a significantly shorter mean time to gastrointestinal (GI) recovery and a significantly shorter mean time to a written discharge order. Alvimopan was also associated with a mean hospital length of stay (LOS) of one full day less than placebo. The mean cost of alvimopan based on a mean of 8.9 12-mg doses was $558.00; the alvimopan cost at the upper limit of allowed dosing was $937.50. Combining the alvimopan and hospital costs for each patient, total costs for the alvimopan group were estimated to be lower than for the placebo group. CONCLUSION: In a post hoc analysis, alvimopan was associated with significantly faster upper and lower GI recovery after bowel resection and a mean LOS reduction of one day compared with placebo. The mean estimated hospital cost was $879-$977 less for patients who received alvimopan compared with placebo. The base-case and sensitivity analyses suggest that, on average, the use of alvimopan compared with placebo may have a cost-saving effect in the hospital setting.

Tacrolimus for Crohn's disease.

(1) Tacrolimus (FK-506) is an immunosuppressant that is being investigated for use in patients with Crohn's disease, mainly in those with refractory illness and fistulizing patterns of the disease. (2) Evidence from a small, randomized controlled trial indicates that, compared with placebo, tacrolimus is associated with higher rates of improvement and similar rates of remission in those with fistulizing patterns of disease. (3) Nephrotoxicity, which has been reported with the use of tacrolimus in clinical trials, seems to improve with dose reduction, but may be associated with irreversible histologic changes. (4) More studies are needed to determine the optimal dose and duration of therapy, and whether the drug is beneficial to patients with non-fistulizing patterns of Crohn's disease.

Pharmacokinetic/pharmacodynamic assessment of the effects of E4031, cisapride, terfenadine and terodiline on monophasic action potential duration in dog.

1. Torsades de pointes (TDP) is a potentially fatal ventricular tachycardia associated with increases in QT interval and monophasic action potential duration (MAPD). TDP is a side-effect that has led to withdrawal of several drugs from the market (e.g. terfenadine and terodiline). 2. The potential of compounds to cause TDP was evaluated by monitoring their effects on MAPD in dog. Four compounds known to increase QT interval and cause TDP were investigated: terfenadine, terodiline, cisapride and E4031. On the basis that only free drug in the systemic circulation will elicit a pharmacological response target, free concentrations in plasma were selected to mimic the free drug exposures in man. Infusion regimens were designed that rapidly achieved and maintained target-free concentrations of these drugs in plasma and data on the relationship between free concentration and changes in MAPD were obtained for these compounds. 3. These data indicate that the free ED50 in plasma for terfenadine (1.9 nM), terodiline (76 nM), cisapride (11 nM) and E4031 (1.9 nM) closely correlate with the free concentration in man causing QT effects. For compounds that have shown TDP in the clinic (terfenadine, terodiline, cisapride) there is little differentiation between the dog ED50 and the efficacious free plasma concentrations in man (< 10-fold) reflecting their limited safety margins. These data underline the need to maximize the therapeutic ratio with respect to TDP in potential development candidates and the importance of using free drug concentrations in pharmacokinetic/pharmacodynamic studies.