Biliary excretion and pharmacokinetics of several fluoroquinolones after intravenous injection in rabbits.

The aim of this study was to measure the concentrations of enrofloxacin (ERFX) and other fluoroquinolones; orbifloxacin (OBFX), marbofloxacin (MBFX), and ofloxacin (OFLX) in the plasma and bile of rabbits after a single intravenous (IV) injection. Twenty male rabbits were divided into four groups and given each drug by IV injection into the ear vein at a dose of 5.0 mg/kg BW. The concentration of ERFX, ciprofloxacin (CPFX), OBFX, MBFX and OFLX in plasma and bile were determined by HPLC. CPFX, metabolite of ERFX, was also measured by HPLC in plasma and bile of rabbits receiving ERFX. Several pharmacokinetic parameters in plasma were calculated and biliary clearance (CLbile) was calculated from extent of biliary excretion and accumulation of AUC of each drug. After IV injection, elimination half-life (t1/2ß) was 4.13, 3.68, 6.60, 5.14 hr; volume of distribution at a steady state (Vdss) was 1.24, 0.503, 0.771, 1.02 L/kg; and total body clearance (CLtot) was 1.05, 0.418, 0.271, 0.453 L/kg/hr, respectively. The values for CLbile for ERFX, OBFX, MBFX, and OFLX were 0.0048, 0.0050, 0.0057, and 0.0094 L/kg/hr, respectively. These values represent 0.48%, 1.2%, 2.1%, and 2.3% of the total body clearance (CLtot) of each drug, respectively. The biliary clearance of CPFX was also measured and found to be 0.0199 L/kg/hr with ERFX administration. The results showed that ERFX, OBFX, MBFX, and OFLX were not excreted into the bile to a significant extent, making them safe drugs to use in rabbits.

Oral pharmacokinetics of sulfadiazine and sulfamonomethoxine in female Holstein milking cows.

The efficacy of orally administered drugs in cattle is thought to be slow because of the anatomical and physiological features of their forestomach. Thus, parenteral routes are mainly preferred to administer drugs. However, the effect of some drugs with unique physicochemical properties was promptly obtained even after oral administration in clinically ill cattle. Therefore, the present study aimed to investigate pharmacokinetically the usefulness of the oral route in cattle by comparing the oral pharmacokinetic properties of two sulfonamides with different physicochemical properties. Sulfadiazine (SDZ) and sulfamonomethoxine (SMM) were administered by intravenous and oral route to four female Holstein cows with a 4-weeks washout period. Blood samples were collected over time, and SDZ and SMM concentrations in plasma were analyzed by HPLC. Data obtained from the same animal after intravenous and oral administration were simultaneously analyzed with the one compartment model, and kinetic parameters were calculated. The Tmax (mean ± SD) of SMM (2.75 ± 0.96 hr) was significantly achieved earlier than that of SDZ (5.00 ± 1.15 hr). Further, the mean absorption time of SMM (5.24 ± 0.69 hr) was significantly shorter than that of SDZ (5.92 ± 1.11 hr). Also, the half-life of absorption of SMM (3.91 ± 0.51 hr) was significantly shorter than that of SDZ (4.51 ± 0.82 hr). These data suggest that the absorption rates of highly unionized drugs (such as SMM) from the forestomach of cattle may be markedly higher than less unionized ones (such as SDZ).

Effect of dapagliflozin alone and in combination with insulin in a rat model of type 1 diabetes.

Dapagliflozin is a selective sodium-glucose cotransporter 2 (SGLT2) inhibitor; it reduces glucose reabsorption via the kidney and increases the glucose excretion in urine. This inhibitor functions through a unique insulin-independent mechanism, and is therefore a potential new approach for the treatment of hyperglycemia in patients with diabetes. In this study, we evaluated the effectiveness of the SGLT2 inhibitor, dapagliflozin, by using a rat model of type 1 diabetes. Type 1 diabetes was induced by a single intraperitoneal injection of 60 mg/kg streptozotocin (STZ). The STZ-induced rats showed marked hyperglycemia and other metabolic abnormalities. We clarified the hypoglycemic effect of the combination treatment of dapagliflozin with a low dose of insulin compared with dapagliflozin alone and insulin alone in 3-week and 8-week studies. Our results showed that dapagliflozin in combination with a low dose of insulin significantly lowered hyperglycemia, hypercholesterolemia, and hypertriglyceridemia. Furthermore, the antioxidant status and body weight were improved. In contrast, treatment with dapagliflozin alone did not improve the blood glucose levels, lipid profile, antioxidant status, or body weight. These findings suggested that in type 1 diabetes, dapagliflozin was effective in combination with a low dose of insulin; however, the administration of dapagliflozin alone did not achieve a significant effect.

Effects of several organophosphates on hepatic cytochrome P450 activities in rats.

Four commonly used organophosphates (fenitrothion, dichlorvos, chlorpyrifos, and trichlorfon) were orally administered to male Sprague-Dawley rats for five days in order to explore their effects on the activities of liver cytochrome P450 (CYP). In addition, Michaelis-Menten kinetics of the metabolic reactions catalyzed by liver CYPs were analyzed following the addition of these compounds to the assay system to examine their potential inhibitory effects on liver CYPs activities. These reactions included ethoxyresorufin O-deethylation, midazolam 4-hydroxylation, tolbutamide hydroxylation, and bufuralol 1'-hydroxylation for CYP1A, 3A, 2C, and 2D activities, respectively. Total CYP content was also examined after oral administration of each organophosphate. Results revealed that oral giving of fenitrothion inhibited significantly CYP1A and 3A activities while elevated activity of CYP2C. Fenitrothion is a potent inhibitor for CYP1A and 2C with Ki values of 0.42 and 36.1 µM, respectively but had a weak inhibitory effect on CYP2D and 3A with Ki values of 290 and 226 µM, respectively. Chlorpyrifos is a potent inhibitor of CYP1A with Ki 0.24 µM and moderately inhibited CYP2C or 3A with Ki values of 84.8 and 77.7 µM, respectively. On the other hand, dichlorvos and trichlorfon caused extremely low or negligible inhibition of different CYP activities. From these results, it is concluded that both fenitrothion and chlorpyrifos may increase the toxicity of chemicals in environmental living organisms through their potent inhibitory effects on these CYP activities, but dichlorvos and trichlorfon may not.

Effects of leucovorin (folinic acid) in the methotrexate-treated rat brain.

Folinic acid (FA) is generally administered to patients with CNS tumors in order to treat severe neurological disorders caused by methotrexate (MTX); therefore, we herein examined the effects of the co-administration of FA on MTX concentrations in the rat brain and cerebrospinal fluid (CSF) as well as the pharmacokinetics of MTX. MTX was intravenously or intrathecally administered to rats with or without FA. MTX concentrations were assessed by HPLC. No significant differences were observed in pharmacokinetic parameters, including kel, Vd, AUC, Cltot and t1/2, between the FA-treated and non-treated groups. MTX concentrations were not significantly different in the brain or CSF 6 hr after the intrathecal administration of MTX. However, compare to intravenous administration of MTX, intravenous administration of both FA and MTX significantly decreased MTX concentrations in the brains and CSF. These results suggest that FA inhibits the influx of MTX into the brain and CSF, possibly by competing with folate carriers, but has no effect on its efflux from these regions. Therefore, FA may be administered to CNS tumor patients receiving intrathecal MTX therapy in order to treat the adverse effects of MTX without affecting its concentrations in the brain and CSF.

Effect of interleukin-1ß on occludin mRNA expression in the duodenal and colonic mucosa of dogs with inflammatory bowel disease.

BACKGROUND: Mucosal imbalance of interleukin (IL)-1ß and IL-1 receptor antagonist (Ra) has been reported in the duodenal mucosa of dogs with inflammatory bowel disease (IBD). However, the imbalance in the colonic mucosa and its role in duodenitis and colitis in IBD of dogs remain unclear. OBJECTIVES: To measure the expression of IL-1ß and IL-1Ra proteins in the colonic mucosa of dogs with IBD, and to determine the effect of IL-1ß on expression of occludin (ocln) mRNA, a tight junction component, in the duodenal and colonic mucosa of dogs with IBD. ANIMALS: Twelve dogs with IBD and 6 healthy dogs. METHODS: IL-1ß and IL-1 Ra proteins in the colonic mucosa were quantified by ELISA in 7 of the 12 dogs with IBD. Expression of ocln mRNA in the duodenal and colonic mucosa was examined in the 12 dogs by real-time PCR. RESULTS: The ratio of IL-1ß to IL-1Ra in the colonic mucosa was significantly higher in dogs with IBD than in healthy dogs. The ex vivo experiment determined that IL-1ß suppressed expression of ocln mRNA in the colonic mucosa, but not in the duodenal mucosa, of healthy dogs. Expression of ocln mRNA in the colonic mucosa, but not in the duodenal mucosa, was significantly lower in dogs with IBD than in healthy dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: A relative increase in IL-1ß may attenuate ocln expression, leading to intestinal barrier dysfunction and promotion of intestinal inflammation in the colonic mucosa, but not in the duodenal mucosa, of dogs with IBD.

Influence of glucocorticoids on time-of-day-dependent variations in IgE-, histamine-, and platelet-activating factor-mediated systemic anaphylaxis in different mouse strains.

A time-of-day-dependent variation in IgE-mediated passive systemic anaphylaxis was previously reported in ICR mice. In the present study, we investigated time-of-day-dependent variations in IgE-, histamine-, and platelet-activating factor (PAF)-mediated systemic anaphylaxis in C57BL/6, BALB/c, and NC/Nga mice at 9:00 h and 21:00 h, and evaluated the potential influence of glucocorticoids (GCs) on these variations. We found significant time-of-day-dependent variations in IgE-mediated systemic anaphylaxis in C57BL/6 mice, and in histamine- and PAF-mediated systemic anaphylaxis in BALB/c mice. Significant daily variations in IgE-, histamine-, and PAF-mediated systemic anaphylaxis were not observed in NC/Nga mice. Pretreatment with dexamethasone and adrenalectomy abolished the daily variations in IgE-mediated systemic anaphylaxis in C57BL/6 mice and in PAF-mediated systemic anaphylaxis in BALB/c mice, suggesting that GCs from adrenal glands are pivotal in regulating these variations. In contrast, pretreatment with dexamethasone and adrenalectomy did not abolish the daily variation in histamine-mediated systemic anaphylaxis in BALB/c mice, suggesting that GC-independent and adrenal gland-independent mechanisms are important for the variation. The present study demonstrated that time-of-day-dependent variations in systemic anaphylaxis differed among inbred mouse strains and with anaphylaxis-inducing substances. Thus, mouse strains, time of experiment, and anaphylaxis-inducing substances used must be considered to obtain appropriate experimental results.

Effectiveness of the liver micronucleus assay using juvenile mice.

This study investigated the effectiveness of the liver micronucleus (MN) assay using juvenile mice. Therefore, we analyzed various hepatic cytochrome P450 (CYP)- mediated activities of ethoxyresorufin O-deethylation, pentoxyresorufin O-dealkylation, tolbutamide hydroxylation, bufuralol 1'-hydroxylation, aniline hydroxylation and midazolam 4-hydroxylation by CYP1A, CYP2B, CYP2C, CYP2D, CYP2E and CYP3A, respectively, in non-treated male ICR mice aged between 3 and 8 weeks. The enzyme efficiency levels in 3- and 4-week-old mice were approximately similar to or higher than those in 8-week-old mice, except for CYP1A and CYP2E in 3- and 4-week-old mice, respectively. Since these results suggest that juvenile mice have sufficient activities for most CYP enzymes, we also conducted a liver MN assay using diethylnitrosamine (DEN), a rodent hepatocarcinogen, on male ICR mice aged between 3 and 6 weeks. A peripheral blood (PB) MN assay was performed simultaneously in 4-week-old mice. Assays incorporating DEN produced positive results in 3- and 4-week-old mice and showed a dose-dependent increase in the micronucleated hepatocyte frequencies at 4 weeks. Both the liver MN assay in 5- and 6-week-old mice and the PB MN assay had negative results when using DEN. These results suggest that 3- and 4-week-old mice have micronuclei-inducing potential in the liver to detect genotoxic compounds using the liver MN assay.

Expression of epithelial cell-derived cytokine genes in the duodenal and colonic mucosae of dogs with chronic enteropathy.

It remains unclear whether epithelial cell-derived cytokines, including interleukin (IL)-25, IL-33 and thymic stromal lymphopoietin (TSLP), contribute to development of canine chronic enteropathy (CE), which includes antibiotic-responsive enteropathy (ARE), food-responsive enteropathy (FRE) and inflammatory bowel disease (IBD). In the present study, we examined mRNA expression of il-25, il-33 and tslp in the duodenal and colonic mucosae of dogs with ARE, FRE and IBD. Real-time PCR analysis revealed that mRNA expression of il-33 was significantly lower in the duodenum in dogs with FRE than in healthy dogs. The results suggest that epithelial cell-derived cytokines may not be an inducer of Th2-type immunity in the gut of dogs with CE, and decreased expression of IL-33 may be involved in induction of FRE. Further studies are required to clarify roles of epithelial cell-derived cytokines, especially IL-33, in the pathogenesis of canine CE.

CAN a P-gp modulator assist in the control of methotrexate concentrations in the rat brain? -inhibitory effects of rhodamine 123, a specific substrate for P-gp, on methotrexate excretion from the rat brain and its optimal route of administration.

Although methotrexate (MTX) is mainly transported by reduced folate carrier, P-gp and MRP1 may also be involved in its transport. In our previous study, a potent P-gp and MRP1 modulator, Cyclosporine A, potentiated MTX concentration in rat brain. Since it is important for MTX therapy for brain tumor to clarify which transporter is dominant, we herein determined whether the specific P-gp substrate, rhodamine123 (Rho123), potentiates the transport and retention of MTX in the brain. Rho123 was injected intravenously or intrathecally into rats immediately after injection of MTX. 6 or 12 hr after the MTX injection, brains were isolated just after the sampling of cerebrospinal fluid (CSF). Blood was also collected intermittently. MTX concentrations were determined in plasma, CSF and the brain using high-performance liquid chromatography with UV detection. When MTX was intravenously injected, Rho123 didn't affect MTX concentrations in the brain. However, Rho123 resulted in significantly higher MTX concentrations in the brain at 12 hr after injection when MTX was intrathecally injected. It is suggested that Rho123 inhibits the excretion of MTX from the brain, but does not potentiate its distribution from the blood into the brain. This reveals that P-gp can be one of the major transporters of MTX in rat brain. Therefore, treatments with P-gp modulators may contribute to intrathecal MTX therapy for brain tumor. Since plasma concentration-time curves of MTX were not affected by Rho123, treatments with P-gp modulators may not potentiate the adverse effects of MTX.

Characterization of platelet-activating factor-induced cutaneous edema and erythema in dogs.

OBJECTIVE To characterize platelet-activating factor (PAF)-induced edema and erythema in the skin of dogs and compare those reactions with histamine-induced cutaneous reactions. ANIMALS 6 healthy Beagles. PROCEDURES Experiments were performed at ≥ 2-week intervals. Each dog received ID injections (5 µg/site) of PAF C16, PAF C18, lyso-PAF, and histamine. Edema (mean diameter) and erythema scores (none, mild, moderate, or severe) were assessed 30 minutes after the injections. Dogs received ID injections of PAF and histamine each with various concentrations of WEB 2086 (PAF receptor antagonist) or underwent ID testing with PAF and histamine before and 3 hours after oral administration of cetirizine hydrochloride or prednisolone (at 2 doses each). RESULTS ID injections of PAF C16 and PAF C18, but not lyso-PAF, induced comparable levels of edema and erythema. The PAF-induced edema and erythema peaked at 30 minutes and lasted for 6 hours after the injection; histamine-induced edema and erythema peaked at 30 minutes and lasted for 3 hours after the injection. Edema sizes and erythema scores were significantly smaller and lower, respectively, for PAF than for histamine. The WEB 2086 inhibited PAF-induced but not histamine-induced edema and erythema. Cetirizine slightly, but significantly, repressed PAF-induced edema and erythema as well as histamine-induced cutaneous reactions. Prednisolone suppressed both PAF-induced and histamine-induced edema and erythema. CONCLUSIONS AND CLINICAL RELEVANCE In canine skin, the duration of PAF-induced inflammation was longer than that of histamine-induced inflammation. The PAF- and histamine-induced cutaneous reactions were effectively suppressed by oral administration of prednisolone. The importance of PAF in dogs with anaphylaxis and allergic disorders warrants further investigation.

Influence of glucocorticoids on a time-of-day-dependent variation in intradermal reactivity to histamine in dogs.

The objectives of this study were to determine daily variation in intradermal reactivity to histamine in dogs and to evaluate a potential influence of glucocorticoids on reactivity. Wheal sizes formed after intradermal injections of histamine were measured every 6 h during a single 24 h period in six healthy dogs. To determine whether glucocorticoids were implicated in daily variation, intradermal reactivity to histamine was evaluated at 9:00 h and at 21:00 h during a single day in dogs that received oral prednisolone (a synthetic glucocorticoid) or oral trilostane (an inhibitor of endogenous glucocorticoid synthesis). Finally, the time required for the histamine reaction to diminish after an intravenous injection of hydrocortisone was also assessed. A significant time-of-day-dependent variation in intradermal reactivity to histamine was detected in dogs, with a larger wheal size observed at 9:00 h than at 21:00 h. Administration of prednisolone or trilostane disrupted this variation. Intradermal reactivity to histamine was significantly reduced 6 h after an intravenous injection of hydrocortisone. These results suggest that glucocorticoid secretion from the adrenal glands could be involved in the regulation of daily variation in histamine-mediated reactions in dogs.

Rapid absorption of diclofenac and acetaminophen after their oral administration to cattle.

The oral pharmacokinetics of diclofenac (DF) were evaluated in cattle by analyzing plasma concentration-time data after its intravenous and oral administration in order to propose the oral administration of DF as effective route to avoid long withdraw period. DF was intravenously and orally administered at 1 mg/kg to cattle using a crossover design with a 4-week washout period. Plasma concentrations of DF were determined by a HPLC analysis. The mean absorption time (MAT) and absorption half-life (t1/2ka) were 1.61 ± 0.61 and 1.51 ± 0.38 hr, respectively, and bioavailability was nearly 100%. The oral pharmacokinetics of acetaminophen (AAP) were also evaluated in cattle. Plasma concentrations of AAP were determined by a HPLC analysis. MAT and t1/2ka were 2.85 ± 0.93 and 1.53 ± 0.28 hr, respectively, and bioavailability was approximately 70%. In conclusion, the results of the present study indicate that DF and AAP are rapidly absorbed from the forestomach of cattle. Therefore, the appropriate efficacies of these drugs may be achieved via their oral administration, even in cattle.

Oral absorption profiles of sulfonamides in Shiba goats: a comparison among sulfadimidine, sulfadiazine and sulfanilamide.

The oral pharmacokinetics of three sulfonamides, sulfadimidine (pKa 7.5), sulfadiazine (pKa 6.5) and sulfanilamide (pKa 10.5), with different rates of unionization in rumen juice, were compared in Shiba goats to clarify the relationship between drug absorption profiles after their oral administration as well as their degree of unionization in the rumen. Sulfonamides were administered either into the left jugular vein or orally to five male goats at doses of 10 mg/kg body weight, using a crossover design with at least a 3-week washout period. The Tmax of sulfadimidine, sulfadiazine and sulfanilamide reached 2.0 ± 1.2, 6.0 ± 0.0, and 7.8 ± 1.6 hr, respectively, after their oral administration, and this was followed by their slow elimination due to a slow rate of drug absorption from the gastrointestinal tract. The MAT and t1/2ka of sulfadiazine (13.2 ± 2.0 and 10.9 ± 1.08 hr) were significantly longer than those of sulfanilamide (9.09 ± 1.67 and 7.46 ± 1.70 hr) and sulfadimidine (7.52 ± 0.85 and 5.17 ± 0.66 hr). These results suggest that the absorption rates of highly unionized drugs (such as sulfanilamide and sulfadimidine) from the forestomach of goats may be markedly higher than less unionized ones (such as sulfadiazine). The mean oral bioavailability of sulfadiazine was high (83.9 ± 17.0%), whereas those of sulfadimidine and sulfanilamide were low (44.9 ± 16.4% and 49.2 ± 2.11%, respectively).

Possible drug-drug interaction in dogs and cats resulted from alteration in drug metabolism: A mini review.

Pharmacokinetic drug-drug interactions (in particular at metabolism) may result in fatal adverse effects in some cases. This basic information, therefore, is needed for drug therapy even in veterinary medicine, as multidrug therapy is not rare in canines and felines. The aim of this review was focused on possible drug-drug interactions in dogs and cats. The interaction includes enzyme induction by phenobarbital, enzyme inhibition by ketoconazole and fluoroquinolones, and down-regulation of enzymes by dexamethasone. A final conclusion based upon the available literatures and author's experience is given at the end of the review.

Oral pharmacokinetics of acetaminophen to evaluate gastric emptying profiles of Shiba goats.

The pharmacokinetics of acetaminophen was investigated following oral dosing to Shiba goats in order to evaluate the properties of gastric emptying. Acetaminophen was intravenously and orally administered at 30 mg/kg body weight to goats using a crossover design with a 3-week washout period. The stability of acetaminophen in rumen juice was also assessed. Acetaminophen concentrations were measured by HPLC. Since acetaminophen was stable in rumen juice for 24 hr, the extremely low bioavailability (16%) was attributed to its hepatic extensive first-pass effect. The mean absorption time and absorption half-life were unexpectedly short (4.93 and 3.35 hr, respectively), indicating its marked absorption from the forestomach, which may have been due to its smaller molecular weight. Therefore, acetaminophen was considered to be unsuitable for evaluating gastric emptying in Shiba goats.

Effect of cyclosporin on distribution of methotrexate into the brain of rats.

The effect of the antitumor drug, methotrexate (MTX), which is applied to brain tumors, is restricted by the blood-brain barrier (BBB), which is composed of P-glycoprotein (P-gp) and multidrug resistance associated protein (MRP). We, therefore, studied if a potent P-gp and MRP modulator, cyclosporin A (CysA), can modulate the MTX concentration in the rat brain. If it can, which route is more effective, intravenous or intrathecal? We intravenously or intrathecally administered MTX to rats with or without CysA. After 6 hr, brains and cerebrospinal fluid (CSF) were sampled, and their MTX concentrations were compared. Each MTX concentration was determined by high-performance liquid chromatography with UV detection. CysA had no significant affect on the MTX concentration in the brain or CSF when MTX was intravenously injected. In contrast, when MTX was intrathecally administered, CysA had a larger effect on the MTX concentration in the brain than in the CSF. This indicates CysA potentiated the brain MTX concentration when MTX was intrathecally administered. It is suggested that CysA did not potentiate the distribution of MTX from blood into the brain, but instead potentiated the distribution of MTX from CSF into the brain. Since chemicals in CSF generally diffuse into the brain easily, CysA probably inhibited the excretion of MTX from the brain. This could be caused by inhibition of P-gp or MRP at the BBB. Therefore, CysA can be a useful tool to achieve an appropriate MTX concentration in brain.

Oral pharmacokinetics of the acidic drugs, diclofenac and sulfamonomethoxine in male Shiba goats.

In the present study, we examined the oral pharmacokinetics of the acidic drugs, diclofenac (DF) and sulfamonomethoxine (SMM), which have different physicochemical properties, in Shiba goats. DF and SMM were intravenously and orally administered to 5 male goats using a crossover design. The T(max) of DF and SMM were reached 1.5 and 5.6 hr after they have been orally administered, respectively, and this was followed by their slow elimination. The elimination of both drugs was markedly faster after being intravenously rather than orally administered, which indicated flip-flop phenomena after the oral administration. The mean absorption times (MATs) of DF and SMM were 6 and 15 hr, respectively. This slow absorption may have been due to slow gastric emptying in goats. The large difference observed in MATs between DF and SMM may have been because DF, which is more lipophilic than SMM, was partly absorbed from the forestomach. Therefore, these results suggest that the absorption of highly lipophilic drugs from the forestomach may be markedly high in Shiba goats. In case of drugs whose elimination is quite fast, their efficacies may appear from the early stage after oral administration even in ruminants, because elimination rate is the determinant factor of T(max) in flip-flop phenomena. Such drugs may be used orally even in ruminants.

Isolation of volatiles from Nigella sativa seeds using microwave-assisted extraction: effect of whole extracts on canine and murine CYP1A.

The volatile components of Nigella sativa seeds were isolated using microwave-assisted extraction (MAE) and identified using gas chromatography. Further investigations were carried out to demonstrate the effects of whole extracts on canine (dog) and murine (rat) cytochrome P450 1A (CYP1A). The optimal extraction conditions of MAE were as follows: 25 mL of water, medium level of microwave oven power and 10 min of extraction time. A total of 32 compounds were identified under the conditions using GC-FID and GC-MS. Thymoquinone (38.23%), p-cymene (28.61%), 4-isopropyl-9-methoxy-1-methyl-1-cyclohexene (5.74%), longifolene (5.33%), α-thujene (3.88) and carvacol (2.31%) were the main compounds emitted from N. sativa seeds. Various extracts including pure compounds, essential oil, nonpolar partition, relatively high-polar/nonpolar partition, and polar partition extracts effectively inhibited the reaction of ethoxyresorufin O-de-ethylation, which is specified for CYP1A activity both in dog and rat. This in vitro data should be heeded as a signal of possible in vivo interactions. The use of human liver preparations would considerably strengthen the practical impact of the data generated from this study.

Receptor binding activities of Chlorella on cysteinyl leukotriene CysLT, glutamate AMPA, ion channels, purinergic P 2Y, tachykinin NK2 receptors and adenosine transporter.

A Chlorella powder was tested in a total of 129 in vitro receptor binding assay systems. The results showed a potent inhibition of this powder on cysteinyl leukotriene CysLT2, and glutamate AMPA in a dose-concentration manner with IC(50) mean +/- SEM values of 20 +/- 4.5 microg/mL and 44 +/- 14 microg/mL, respectively. Other moderate and weak activities reflected in competitive binding experiments were seen versus adenosine transporter; calcium channel L-type, benzothiazepine; gabapentin; kainate, NMDA-glycine; inositol trisphosphate IP(3); cysteinyl CysLT(1), LTB(4); purinergic P(2Y); tachykinin NK(2); serotonin 5-HT(2B) and prostanoid, thromboxane A(2). Together, the results suggest that the various inhibitory effects of Chlorella powder in these receptor binding assays could reflect its actions in modulating Ca(2+)-dependent signal related targets and might be relevant to the mechanisms of its biological effects. These results reveal important potential biochemical activities that might be exploited for the prevention or treatment of several pathologies. From these results, the possible therapeutic usage of the product is discussed.