Phenylboronic Acid and Amino Bifunctional Modified Adsorbent for Quickly Separating Phenolic Acids from Crude Extract of Clerodendranthus spicatus and Evaluation of Their Antioxidant and Hypoglycemic Activities.

A novel phenylboronic acid and amino bifunctional modified silica gel (SiO2-NH2-FPBA) was prepared, which was 30-80 µm, had a pore size of 8.69 nm, a specific surface area of 206.89 m2/g, was stable at low temperature, and contained 0.4793 mmol/g of the phenylboronic acid group and 1.6377 mmol/g of the amino group. It was used to develop a rapid separation method for phenolic acids. The results showed that it could adsorb 93.64 mg/g caffeic acid, 89.35 mg/g protocatechuic acid and 79.66 mg/g gallic acid. The adsorption process was consistent with the pseudo-second-order model (R2 > 0.99), and fitted the Langmuir isotherm model well (R2 > 0.99). CH3COOH could effectively desorb phenolic acids (>90%) and did not destroy their structures. When SiO2-NH2-FPBA was added to crude extract of Clerodendranthus spicatus, 93.24% of the phenolic acids could be captured, and twenty-two kinds of phenolic acids were identified by Q Exactive HF LC-MS. Furthermore, the isolated phenolic acids from Clerodendranthus spicatus possessed great DPPH, ABTS, and hydroxyl radicals scavenging activities and ferric reducing power. They also demonstrated effective inhibition of α-amylase and α-glucosidase activities (IC50 = 110.63 ± 3.67 µg/mL and 64.76 ± 0.30 µg/mL, respectively). The findings indicate that SiO2-NH2-FPBA has significant potential in practical applications of separating active constituents from natural resources.

A Multifunctional Nano-Delivery System Against Rheumatoid Arthritis by Combined Phototherapy, Hypoxia-Activated Chemotherapy, and RNA Interference.

Purpose: Effective therapy for rheumatoid arthritis (RA) keeps a challenge due to the complex pathogenesis of RA. It is not enough to completely inhibit the process of RA with any single therapy method. The purpose of the research is to compensate for the insufficiency of monotherapy using multiple treatment regimens with different mechanisms. Material and Methods: In this study, we developed a new method to synthesize mesoporous silica nanoparticles hybridized with photosensitizer PCPDTBT (HNs). Branched polyethyleneimine-folic acid (PEI-FA) could be coated on the surface of HNs through electrostatic interactions. It simultaneously blocked the hypoxia-activated prodrug tirapazamine loaded into the mesopores and binded with Mcl-1 siRNA (siMcl-1) that interfered with the expression of the anti-apoptotic protein Mcl-1. Released from the co-delivery nanoparticles (PFHNs/TM) Tirapazamine and siMcl-1 upon exposure to acidic conditions of endosomes/lysosomes in activated macrophages. Under NIR irradiation, photothermal therapy and photodynamic therapy derived from PCPDTBT, hypoxia-activated chemotherapy derived from tirapazamine, and RNAi derived from siMcl-1 were used for the combined treatment for RA by killing activated macrophages. PEI-FA-coated PFHNs/TM exhibited activated macrophage-targeting characteristics, thereby enhancing the in vitro and in vivo NIR-induced combined treatment of RA. Results: The prepared PFHNs/TM have high blood compatibility (far below 5% of hemolysis) and ideal in vitro phototherapy effect while controlling the TPZ release and binding siMcl-1. We prove that PEI-FA-coated PFHNs/TM not only protect the bound siRNA but also are selectively uptaked by activated macrophages through FA receptor-ligand-mediated endocytosis, and effectively silence the target anti-apoptotic protein by siMcl-1 transfection. In vivo, PFHNs/TM have also been revealed to be selectively enriched at the inflammatory site of RA, exhibiting NIR-induced anti-RA efficacy. Conclusion: Overall, these FA-functionalized, pH-responsive PFHNs/TM represent a promising platform for the co-delivery of chemical drugs and nucleic acids for the treatment of RA cooperating with NIR-induced phototherapy.

Preparation of boronic acid and carboxyl-modified molecularly imprinted polymer and application in a novel chromatography mediated hollow fiber membrane to selectively extract glucose from cellulose hydrolysis.

A novel boronic acid and carboxyl-modified glucose molecularly imprinted polymer were prepared through suspension polymerization, which is based on 1.0 mmol glucose as a template, 1.2 mmol methacrylamidophenylboronic acid, and 6.8 mmol methacrylic acids as monomers, 19 mmol ethyleneglycol dimethacrylate, and 1 mmol methylene-bis-acrylamide as crosslinkers. The prepared glucose-molecularly imprinted polymer had a particle size of 25-70 µm, and was thermally stable below 215°C, with a specific surface area of 174.82 m2/ g and average pore size of 9.48 nm. The best selectivity between glucose and fructose was 2.71 and the maximum adsorption capacity of glucose- molecularly imprinted polymer was up to 236.32 mg/ g which was consistent with the Langmuir adsorption model. The similar adsorption abilities in six successive runs and the good desorption rate (99.4%) verified glucose-molecularly imprinted polymer could be reused. It was successfully used for extracting glucose from cellulose hydrolysis. The adsorption amount of glucose was 2.61 mg/mL and selectivity between glucose and xylose reached 4.12. A newly established chromatography (glucose-molecularly imprinted polymer) mediated hollow fiber membrane method in time separated pure glucose from cellulose hydrolysates on a large scale, and purified glucose solution with a concentration of 3.84 mg/mL was obtained, which offered a feasible way for the industrial production of glucose from cellulose hydrolysates.

Folate receptor-targeting semiconducting polymer dots hybrid mesoporous silica nanoparticles against rheumatoid arthritis through synergistic photothermal therapy, photodynamic therapy, and chemotherapy.

With ideal optical properties, semiconducting polymer quantum dots (SPs) have become a research focus in recent years; a considerable number of studies have been devoted to the application of SPs in non-invasive and biosafety phototherapy with near-infrared (NIR) lasers. Nevertheless, the relatively poor stability of SPs in vitro and in vivo remains problematic. PCPDTBT was chosen to synthesize photothermal therapy (PTT) and photodynamic therapy (PDT) dual-model SPs, considering its low band gap and desirable absorption in the NIR window. For the first time, cetrimonium bromide was used as a stabilizer to guarantee the in vitro stability of SPs, and as a template to prepare SP hybrid mesoporous silica nanoparticles (SMs) to achieve long-term stability in vivo. The mesoporous structure of SMs was used as a reservoir for the hypoxia-activated prodrug Tirapazamine (TPZ). SMs were decorated with polyethylene glycol-folic acid (SMPFs) to specifically target activated macrophages in rheumatoid arthritis (RA). Upon an 808 nm NIR irradiation, the SMPFs generate intracellular hyperthermia and excessive singlet oxygen. Local hypoxia caused by molecular oxygen consumption simultaneously activates the cytotoxicity of TPZ, which effectively kills activated macrophages and inhibits the progression of arthritis. This triple PTT-PDT-chemo synergistic treatment suggests that SMPFs realize the in vivo application of SPs and may be a potential nano-vehicle for RA therapy with negligible side-toxicity.

Self-Assembled pH-Sensitive Polymeric Nanoparticles for the Inflammation-Targeted Delivery of Cu/Zn-Superoxide Dismutase.

The use of superoxide dismutase (SOD) is currently limited by its short half-life, rapid plasma clearance rate, and instability. We synthesized a small library of biofriendly amphiphilic polymers that comprise methoxy poly(ethylene glycol)-poly(cyclohexane-1,4-diyl acetone dimethyleneketal) (mPEG-PCADK) and mPEG-poly((cyclohexane86.7%, 1,5-pentanediol13.3%)-1,4-diyl acetone dimethylene ketal) (PK3) for the targeted delivery of SOD. The novel polymers could self-assemble into micellar nanoparticles with favorable hydrolysis kinetics, biocompatibility, long circulation time, and inflammation-targeting effects. These materials generated a better pH-response curve and exhibited better hydrolytic kinetic behavior than PCADK and PK3. The polymers showed good biocompatibility with protein drugs and did not induce an acidic microenvironment during degradation in contrast to materials such as PEG-block-poly(lactic-co-glycolic acid) (PLGA) and PLGA. The SOD that contained reverse micelles based on mPEG2000-PCADK exhibited good circulation and inflammation-targeting properties. Pharmacodynamic results indicated exceptional antioxidant and anti-inflammatory activities in a rat adjuvant-induced arthritis model and a rat peritonitis model. These results suggest that these copolymers are ideal protein carriers for targeting inflammation treatment.

Folate receptor-targeting mesoporous silica-coated gold nanorod nanoparticles for the synergistic photothermal therapy and chemotherapy of rheumatoid arthritis.

The synergy of photothermal therapy (PTT) and chemotherapy is widely regarded as an effective treatment for complex diseases, such as cancer and inflammation. In this paper, we report the synthesis of a nanoscaled drug delivery system, which was composed of a gold nanorod (GNR) as the photothermal agent and a mesoporous silica shell as the methotrexate (MTX) reservoir, named FAGMs. Due to folate modification on the surface, FAGMs targeted specifically activated macrophages in rheumatoid arthritis (RA). Under 808 nm laser irradiation, FAGMs could kill macrophages by reaching sufficient local hyperthermia with excellent efficiency in the photothermal conversion of GNRs. Meanwhile, internal heating caused hydrogen bond fracture; thus, MTX released rapidly from FAGMs for localized synergistic PTT and chemotherapy. The FAGMs had a mean particle size of about 180 nm and a zeta potential of 14.36 mV. The release rate of MTX from FAGMs in vitro increased markedly under 808 nm laser irradiation. In a cellular uptake study, stronger fluorescence signals were observed in activated macrophages when treated with FAGMs, suggesting that folic acid molecules enabled the enhancement of endocytosis into activated macrophages. In rats with adjuvant-induced arthritis, synergistic treatment excellently inhibited the progression of RA. These results demonstrated that FAGMs could be promising for the treatment of RA.

Delivery of siRNA using folate receptor-targeted pH-sensitive polymeric nanoparticles for rheumatoid arthritis therapy.

Systemic delivery of siRNA to target tissues is difficult to achieve owing to its limited cellular uptake and poor serum stability. Herein, polymeric nanoparticles were developed for systemic administration of siRNA to inflamed tissues. The polymeric nanoparticles were composed of PK3 as a pH-sensitive polymer, folate-polyethyleneglycol-poly(lactide-co-glycolide) as a targeting ligand, and a DOTAP/siRNA core. The polymeric nanoparticles had a mean particle size of 142.6 ±â€¯0.61 nm and a zeta potential of 3.6 ±â€¯0.43 mV. In vitro studies indicated pH-dependent siRNA release from polymeric nanoparticles, with accelerated release at pH 5.0. Cellular uptake was efficient and gene silencing was confirmed by Western blot. In vivo, polymeric nanoparticles were shown to have inflammation-targeting activity and potent therapeutic effects in an adjuvant-induced arthritis rat model. These results suggest that pH-sensitive and folate receptor-targeted nanoparticles are a promising drug carrier for siRNA delivery for rheumatoid arthritis.

Hyaluronic Acid Coated Acid-Sensitive Nanoparticles for Targeted Therapy of Adjuvant-Induced Arthritis in Rats.

Activated macrophages play a vital role in rheumatoid arthritis (RA) pathophysiology. CD44 is an overexpressed receptor on activated macrophages that is a potential target site for RA treatment. In this study, we prepared hyaluronic acid (HA) coated acid-sensitive polymeric nanoparticles (HAPNPs) composed of egg phosphatidylcholine, polyethylenimine, and poly (cyclohexane-1,4-diyl acetone dimethylene ketal) (PCADK) loaded with dexamethasone (Dex) for the treatment of RA. PCADK was used to form polymeric cores because of its acid-sensitivity. The HAPNPs were about 150 nm in size and had a zeta potential of -2.84 mV. The release rate of Dex from HAPNPs/Dex in vitro increased markedly when the pH decreased from 7.4 to 4.5, indicating that the HAPNPs were pH-sensitive. In a cellular uptake study, stronger fluorescence signals were observed in activated macrophages treated with HAPNPs, suggesting that HAPNPs could be effective nanodevices target to activated macrophages. In rats with adjuvant-induced arthritis, HAPNPs could inhibited the progression of RA. Taken together, these results suggest that the HAPNPs could be useful in RA therapy.

Dual-functional lipid polymeric hybrid pH-responsive nanoparticles decorated with cell penetrating peptide and folate for therapy against rheumatoid arthritis.

Methotrexate (MTX), as a disease modifying antirheumatic drug (DMARD), was first line drug to treat rheumatoid arthritis. However, the severe side effect during long term and high dosage usage limit its application. The aim of this study was to develop dual-functional lipid polymeric hybrid pH-responsive nanoparticles to deliver MTX to inflamed joints selectively. The designed MTX loaded stearic acid-octa-arginine and folic acid decorated poly lactic-co-glycolic acid (PLGA) -PK3-based lipid polymeric hybrid nanoparticles (Sta-R8-FA-PPLPNs/MTX) were composed of PK3, Folate-PEG-PLGA, egg PC, and Sta-R8. The nanoparticles exhibited smooth spherical morphology and particle size of 100-150 nm. The in vitro release study indicated that MTX was released faster in phosphate buffered solution (PBS) of pH 5.0 than that in PBS of pH 7.4 from Sta-R8-FA-PPLPNs/MTX. The cellular uptake study revealed that Sta-R8-FA-PPLPNs/MTX were internalized through folate receptor mediated endocytosis into activated macrophages. Therapeutic effects on adjuvant-induced arthritis (AIA) rats further confirm that Sta-R8-FA-PPLPNs/MTX could be promising against rheumatoid arthritis.

Trastuzumab- and Fab' fragment-modified curcumin PEG-PLGA nanoparticles: preparation and evaluation in vitro and in vivo.

INTRODUCTION: Nanoparticles (NPs) modified with bio-ligands represent a promising strategy for active targeted drug delivery to tumour. However, many targeted ligands, such as trastuzumab (TMAB), have high molecular weight, limiting their application for targeting. In this study, we prepared Fab' (antigen-binding fragments cut from TMAB)-modified NPs (Fab'-NPs) with curcumin (Cur) as a model drug for more effective targeting of human epidermal growth factor receptor 2 (HER2/ErbB2/Neu), which is overexpressed on breast cancer cells. MATERIAL AND METHODS: The release kinetics was conducted by dialysis bags. The ability to kill HER2-overexpressing BT-474 cells of Fab'-Cur-NPs compared with TMAB-Cur-NPs was conducted by cytotoxicity experiments. Qualitative and quantitative cell uptake studies using coumarin-6 (fluorescent probe)-loaded NPs were performed by fluorescence microscopy and flow cytometry. Pharmacokinetics and biodistribution experiments in vivo were assessed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: The release kinetics showed that both Fab'-Cur-NPs and TMAB-Cur-NPs provided continuous, slow release of curcumin for 72 h, with no significant difference. In vitro cytotoxicity experiments showed that Fab'-Cur-NPs manifested prominent ability to kill HER2-overexpressing BT-474 cells compared with TMAB-Cur-NPs. Qualitative and quantitative cell uptake studies indicated that the accumulation of Fab'-NPs was greater than that of TMAB-NPs in BT-474 (HER2+) cells; However, there was no significant difference in MDA-MB-231 (HER2-) cells. Pharmacokinetics and biodistribution experiments in vivo demonstrated that the half-life (t1/2) and area under the blood concentration-time curve (AUC0-t) of Fab'-Cur-NPs increased 5.30-fold and 1.76-fold relative to those of TMAB-Cur-NPs, respectively. Furthermore, the tumor accumulation of Fab'-Cur-NPs was higher than that of TMAB-Cur-NPs. CONCLUSION: Fab' fragment has greater capacity than the intact antibody to achieve tumor targeting through NP-based delivery.

Multifunctional folate receptor-targeting and pH-responsive nanocarriers loaded with methotrexate for treatment of rheumatoid arthritis.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by progressive cartilage and bone destruction. Activated macrophages that overexpress folic acid (FA) receptors play an important role in RA, due to their abundance in inflamed synovial membrane and joints. In an effort to deliver drugs to the inflamed tissues, multifunctional FA receptor-targeting and pH-responsive nanocarriers were developed. They were composed of lipids, polyethylene glycol (PEG)-poly(lactic-co-glycolic acid) (PLGA) forming a hydrophilic shell, FA around the hydrophilic shell as a targeting ligand, and poly(cyclohexane-1,4-diylacetone dimethylene ketal) (PCADK) and PLGA as a hydrophobic core. PCADK also acts as a pH-responsive material. Methotrexate (Mtx) was encapsulated in the nanoparticles, which exhibited pH-responsive release in vitro. Cellular uptake and cytotoxicity experiments revealed that FA-PEG-PLGA/PCADK-lipid nanoparticles loaded with Mtx (FA-PPLNPs) exhibited superior cellular uptake and higher cytotoxicity to activated macrophages than PPLNPs/Mtx. The therapeutic effect of FA-PPLNPs/Mtx in RA was confirmed in an adjuvant-induced arthritis rat model. These results suggest that the multifunctional folate receptor-targeting and pH-responsive nanocarriers are promising for the treatment of RA.

Development of a capillary electrophoresis method for analyzing adenosine deaminase and purine nucleoside phosphorylase and its application in inhibitor screening.

A novel capillary electrophoresis (CE) method was developed for simultaneous analysis of adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) in red blood cells (RBCs). The developed method considered and took advantage of the natural conversion from the ADA product, inosine to hypoxanthine. The transformation ratio was introduced for ADA and PNP analysis to obtain more reliable results. After optimizing the enzymatic incubation and electrophoresis separation conditions, the determined activities of ADA and PNP in 12 human RBCs were 0.237-0.833 U/ml and 9.013-10.453 U/ml packed cells, respectively. The analysis of ADA in mice RBCs indicated that there was an apparent activity difference between healthy and hepatoma mice. In addition, the proposed method was also successfully applied in the inhibitor screening from nine traditional Chinese medicines, and data showed that ADA activities were strongly inhibited by Rhizoma Chuanxiong and Angelica sinensis. The inhibition effect of Angelica sinensis on ADA is first reported here and could also inhibit PNP activity.

Parenteral thermo-sensitive organogel for schizophrenia therapy, in vitro and in vivo evaluation.

Novel biodegradable in situ forming organogel, obtained via the self-assembly of long chain fatty acid in pharmaceutical oil, was prepared and characterized. Different from traditional organogels, the use of organic solvent was avoided in this gel system, in consideration of its tissue irritation. Four kinds of fatty acids were employed as organogelators, which could successfully gel with injectable soybean oil. The gelation procedure was thermo-reversible. Phase transition temperature and time were depended on carbon chain length and concentration of gelators. Optimized formulations containing drug were then injected subcutaneously in rats for pharmacokinetic study. Results showed the steady drug release for one week with the well-controlled burst, which fitted well with the drug release mechanism of both drug diffusion and frame erosion. In vivo imaging of the organogel with fluorescence in live animals suggested that the organogel matrix was gradually absorbed and completely up-taken in nine days. Histopathological analysis of the surrounding tissues was carried out and revealed an overall good biocompatibility property of the implants over drug release period. This research demonstrates that this thermo-sensitive in situ forming organogel system represents a potentially promising platform for sustained drug delivery.

Enhancement of γ-aminobutyric acid production in recombinant Corynebacterium glutamicum by co-expressing two glutamate decarboxylase genes from Lactobacillus brevis.

γ-Aminobutyric acid (GABA), a non-protein amino acid, is a bioactive component in the food, feed and pharmaceutical fields. To establish an effective single-step production system for GABA, a recombinant Corynebacterium glutamicum strain co-expressing two glutamate decarboxylase (GAD) genes (gadB1 and gadB2) derived from Lactobacillus brevis Lb85 was constructed. Compared with the GABA production of the gadB1 or gadB2 single-expressing strains, GABA production by the gadB1-gadB2 co-expressing strain increased more than twofold. By optimising urea supplementation, the total production of L-glutamate and GABA increased from 22.57 ± 1.24 to 30.18 ± 1.33 g L⁻¹, and GABA production increased from 4.02 ± 0.95 to 18.66 ± 2.11 g L⁻¹ after 84-h cultivation. Under optimal urea supplementation, L-glutamate continued to be consumed, GABA continued to accumulate after 36 h of fermentation, and the pH level fluctuated. GABA production increased to a maximum level of 27.13 ± 0.54 g L⁻¹ after 120-h flask cultivation and 26.32 g L⁻¹ after 60-h fed-batch fermentation. The conversion ratio of L-glutamate to GABA reached 0.60-0.74 mol mol⁻¹. By co-expressing gadB1 and gadB2 and optimising the urea addition method, C. glutamicum was genetically improved for de novo biosynthesis of GABA from its own accumulated L-glutamate.

Effects of formulation parameters on encapsulation efficiency and release behavior of risperidone poly(D,L-lactide-co-glycolide) microsphere.

A 4-week sustained release risperidone biodegradable poly(D,L-lactide-co-glycolide) (PLGA) microsphere for the therapy of schizophrenia, the effects of formulation parameters on encapsulation efficiency and release behavior were studied. The risperidone PLGA microspheres were prepared by O/W solvent evaporation method and characterized by HPLC, SEM, laser particle size analysis, GC and HPLC-MS. The results indicated that the morphology of the risperidone PLGA microspheres presented a spherical shape with smooth surface, the particle size was distributed from 32 to 92 microm and the drug encapsulation efficiency was influenced by homogeneous rotation speed, intrinsic viscosity, carboxylic terminal group, the polymer concentration in the oil phase and the molecular weight of the polymer. These changes were also reflected in drug release. When the Mw of the polymers increased from ca. 28000 to ca. 90000, the initial burst release of risperidone PLGA microspheres decreased from 13 to 0.8% and the sustained-release could be extended to 4 weeks. Pharmacokinetic study on beagle dogs showed that the 4-week sustained release profile of the risperidone loaded microspheres prepared with 75253A was verified. The PLGA 75253A and 75255A show the potential as excipients for the monthly sustained release risperidone PLGA microspheres due to higher encapsulation efficiency and almost zero-order release kinetics of release profile.

Poly(lactic-co-glycolic acid) microspheres for the controlled release of huperzine A: in vitro and in vivo studies and the application in the treatment of the impaired memory of mice.

Huperzine A loaded poly(D,L-lactic-co-glycolic acid) (PLGA) microspheres were prepared by an oil/water (o/w) solvent evaporation technique. With a decrease of the ratio of o/w from 1 : 100 to 1 : 50, the encapsulation efficiency was reduced about 4%. Increasing the PVA concentration from 0.5 to 2% reduced the percentage encapsulation efficiency of huperzine A from 60.7 to 47.4% and the particle size of microspheres from 84.2 to 26.2 microm. The addition of stearic acid improved the encapsulation efficiency, but also accelerated the in vitro release of hupezine A from microspheres. After i.m. administration of huperzine A loaded microspheres in mice, huperzine A was sustained released from the PLGA microspheres up to 12 d with a low initial burst. Passive avoidance test of mice showed that the microspheres formulation offered an improved therapeutic efficiency in the treatment of the impaired memory of the mice superior to injection gastric (i.g.) administration of huperzine A suspension at the same dose, whose therapeutic efficiency was similar as that of a 50% reduced dose of the microspheres formulation.

[Analysis of detecting methods of digoxin blood drug level].

Digoxin plays a part in healing of congestive heart failure in clinic. Its therapeutic dose is very approximate to toxic dose and even they overlap each other sometimes. There are many influencing factors on blood drug level of digoxin. Pharmacodynamics and pharmacokinetics varies with different individuality. It is indispensable to detecting blood drug level in order to treat disease and prevent intoxication. Integrating with the detecting-methods of blood drug level of digoxin home and broad, characteristic of many methods are summarized from sensitivity, linearity range, cross-reaction and precision. These methods include radio immunoassay, enzyme immunoassay, chemiluminescence immunoassay, fluorescence immunoassay and HPLC-MS-MS. These methods are popular for their specialized ascendancy. The cost of radio immunoassay is low. Enzyme immunoassay has good specificity. Sensitivity and stability of chemiluminescence immunoassay is very excellent. Fluorescence polarization immunoassay is sensitive and convenient. HPLC-MS-MS has high resolution and good specificity. One of the development tendencies is to combine two or more methods in detecting the blood drug level of digoxin which contribute to these methods integrated use.

Pharmacokinetics of huperzine A in dogs following single intravenous and oral administrations.

The pharmacokinetics of huperzine A in dogs after single intravenous and oral administrations was investigated. Concentrations of huperzine A were determined by a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Pharmacokinetic parameters were calculated by non-compartmental methods. After single intravenous administration, the Cmax, T1/2, AUC0-t, AUC0-infinity, CL, Vd and Vss were 5.55 +/- 1.61 microg/L, 5.02 +/- 0.31 h, 16.04 +/- 5.24, 16.49 +/- 5.29 microgh/L, 0.66 +/- 0.19 L/h/kg, 4.76 +/- 1.46, and 3.93 +/- 1.54 L/kg, respectively. After single oral administration, the Cmax, Tmax, T1/2, AUC0-t, AUC0-infinity and oral bioavailability were 2.60 +/- 0.60 microg/L, 1.25 +/- 0.50 h, 5.71 +/- 2.25 h, 12.90 +/- 3.19, 13.78 +/- 3.24 microgh/L, and 94.4 +/- 36.5%, respectively. In conclusion, huperzine A had a rapid and nearly complete oral absorption and was extensively distributed into tissues after drug administration in dogs.