| HPABA(2-(2-hydroxypropanamido)benzoic acid)is a secondary metabolite of a marine fungus Penicillium chrysogenum.Initial investigations demonstrate that HPABA possesses remarkable response against acetic acid induced abdominal constriction and xylene induced ear edema in mice at a dose of 100 mg/kg,but it exhibits no ulcerogenic effect like aspirin,hence HPABA is likely to be a promising non-steroidal anti-inflammatory drug with good bioactivities and little side effect.In this paper,further anti-inflammatory activities and mechanism of HPABA were studied,and its pharmacokinetics,tissue distribution,metabolism,excretion and plasma protein binding rate were evaluated.The aim of this research was to provide guidance for designing dosage form and clinical use of HPABA.Anti-inflammatory activities and mechanism The effects of HPABA against acute and chronic inflammations were evaluated by carrageenan induced hind paw edema and tampon-induced granuloma in rats.HPABA could remarkably inhibit the formation of arrageenan induced hind paw edema and tampon-induced granuloma at doses of 25,50 and 100 mg·kg-1 and exhibit better anti-inflammatory effect than aspirin at the same dosage.Results indicated that HPABA showed good activities for acute and chronic inflammations,and its anti-inflammatory mechanism is synthetically,including nitric oxide(NO),malondialdehyde(MDA)and PGE2 suppression and increase in the activities of superoxide dismutase(SOD).Moreover,HPABA showed no gastroenteric stimulatory after given at doses of 25,50 and 100 mg·kg-1 for seven consecutive day.Pharmacokinetics A rapid,sensitive and high throughput UHPLC-MS/MS method was established and validated to assay the concentration of HPABA in rat plasma,and the method was successfully applied to the pharmacokinetic study of HPABA in rats.Following intravenous administration of HPABA at a dose of 12.5 mg·kg-1 and intragastric administration of HPABA at doses of 25,50 and 100 mg·kg-1 to male rats,the pharmacokinetic behaviors of HPABA were fit for two-compartment model.Cmax were 59.53±7.84,12.96±4.17,26.71±3.33 and 53.92±13.55 ?g·mL-1;AUC0-t were 17.15±2.55,25.02±6.82,40.56±17.18 and 90.00±26.27 ?g·mL-1·h;AUC0-? were 17.16±2.56,25.13±6.81,40.63±17.21 and 90.11±26.20?g·mL-1·h;t1/2 were 0.59±0.22,1.52±0.31,1.87±0.47 and 2.28±0.72 h;CL were 0.74±0.09,1.05±0.25,1.36±0.39 and 1.22±0.49 L·h-1·kg-1.The pharmacokinetic parameters obtained were then compared and analysed,dose-dependent linear relationships for HPABA were found in the range of 25?100 mg·kg-1 and the absolute bioavailabilities were 73.0%,59.1%and 65.6%at doses of 25,50 and 100 mg·kg-1,which indicated HPABA possessed relative higher oral bioavailability.Following intragastric administration of HPABA at a dose of 50 mg·kg-1 to famale rats,the pharmacokinetic behaviors of HPABA were fit for two-compartment model.Cmax were 35.80±6.09 ?g·mL-1,AUC0-t were 63.48±18.24 ?g·mL-1-h,AUC0-? were 63.50±18.23 ?g·mL-1·h,t1/2 were 2.48±0.74 h,CL were 0.83±0.20 L·h-1·kg-1.The pharmacokinetic parameters of male and female rats obtained were then compared and analysed,similar absorption rate were found,but the elimination rate of female rat were remarkably slower than male rat.Tissue distribution A rapid,sensitive and high throughput UHPLC-MS/MS method was developed for quantifying HPABA in rat tissues.The tissue distribution of HPABA in male rats was investigated.After oral administration of HPABA(50 mg·kg-1),the drug was fast and extensively distributed.The highest levels of HPABA in most tissues were observed at 0.25 h after administration.The levels of HPABA in tissues were almost eliminated in 4 h,which indicated HPABA was rapidly distributed and eliminated,and little accumulated.The drug concentration levels of HPABA in intestine,stomach,kidney,liver and lung were higher than other tissues.HPABA can be detected in the brain,indicating that it could cross the blood-brain barrier.The drug concentration level was relative low in testis,but relative high in ovary.The drug concentration in female rat tissues was relative higher than male rat tissues,but no envident distribution sex difference was found.Excretion A rapid,sensitive and high throughput UHPLC-MS/MS method was established to determine the concentration of HPABA in rat urine,feces and bile.The excretion of HPABA in rats was investigated.After intragastric administration of HPABA at a dose of 50 mg·kg-1,the cumulative amounts of HPABA excreted in the urine(0?48 h)of male and female rats were 3089.3±76.2 ?g and 2418.3±178.2 ?g,the urinary excretion amounted to 28.1%and 22.0%of the dosage,respectively;the cumulative amounts of HPABA excreted in the feces(0?48 h)of male and female rats were 2377.3±228.0 ?g and 2031.8±255.8 ?g,the fecal excretion amounted to 21.6%and 18.5%of the dosage,respectively;the cumulative amounts of HPABA excreted in the bile(0?24 h)of male and female rats were 500.8±40.6 ?g and 393.4±22.2 ?g,the biliary excretion amounted to 4.6%and 3.6%of the dosage,respectively;the summation of urinary,fecal and biliary excretion amounted to 54%and 44%of the dosage in male and female rats.Renal excretion was the main excretion pathway for HPABA.Results indicated envident excretion sex difference in male and female rats,and relative faster excretion rate and larger excretion amount were found in male rat.Metabolism An ultra high performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry(UHPLC-FT-ICR-MS)method was developed to investigate the plasma,urine,feces and bile metabolism of HPABA following intragastric administration of HPABA at a dose of 100 mg·kg-1.Besides the parent drug,a total of 13 metabolites(3 phase I and 10 phase ? metabolites)were detected and tentatively identified.The phase I biotransformation pathways of HPABA included decarboxylation,hydroxylation and dehydrogenation,and metabolic pathways involved in phase ? metabolism contained glucuronidation,glycine conjugation and N-acetyl conjugation.Hydroxylation metabolite,glucuronidation metabolites and glycine conjugation of hydrolysis product could be found in all biological matrices.No envident metabolism sex difference was found between male and female rats.Plasma protein binding rate The plasma protein binding rate of HPABA was determined by equilibrium dialysis method at concentrations of 3.0,10 and 30 ?g·mL-1 in rat and human plasma.Results demonstrated there were evident species differences in plasma protein binding rate between rat and human,and significant concentration-dependent in the same specie,with the increasement of drug concentration,the plasma protein binding rate decreased.The plasma protein binding rate of HPABA to human was more than 85%.Results indicated HPABA belonged to high plasma protein binding rate drug,the concentration of HPABA should be paid more attention in case of side effects when HPABA was administrated with other high plasma protein binding rate drugs. |
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