Oridonin Research Articles

Identification of metabolites of oridonin in rats with a single run on UPLC-Triple-TOF-MS/MS system based on multiple mass defect filter data acquisition and multiple data processing techniques.

Oridonin (ORI) is an active natural ent-kaurane diterpenoid ingredient originating from well-known traditional Chinese herb medicine and is expected to be pursued as a new anticancer agent. In the present study, a novel and efficient approach was developed for in vivo screening and identification of ORI metabolites using ultra high performance liquid chromatography coupled with hybrid triple quadrupole time-of-flight mass spectrometry (UPLC-Triple-TOF-MS/MS). This analytical strategy was as follows: an effective on-line data acquisition method multiple mass defect filter (MMDF) combined with dynamic background subtraction (DBS), was developed to trace all of potential metabolites of ORI. The MMDF and DBS method could trigger an information dependent acquisition scan, which could give the information of low-level metabolites masked by background noise and endogenous components in complex matrix. Moreover, the sensitive and specific multiple data-mining techniques including extracted ion chromatography, mass defect filtering, product ion filtering and neutral loss filtering were employed to identify the metabolites of ORI. Then, structures for the metabolites were successfully assigned based on accurate masses, the mass fragmentation of ORI and metabolic knowledge. Finally, an important parameter Clog P was used to estimate the retention time of isomers. Based on the proposed strategy, 16 phase I and 2 phase II metabolites were detected in rats after oral administration of ORI. The main biotransformation route of ORI was identified as reduction, oxidation, dehydroxylation and glucuronic acid conjugation. This is the first study of ORI metabolism in vivo. This study not only proposed a practical strategy for rapidly screening and identifying metabolites, but also provided useful information for further study of the pharmacology and mechanism of ORI in vivo. At the same time this methodology can be widely applied for the structural characterization of the metabolites of other ent-kaurane diterpenoid.

Oridonin inhibits the proliferation of human osteosarcoma cells by suppressing Wnt/β-catenin signaling.

It has been reported that oridonin (ORI) can inhibit proliferation and induce apoptosis in various types of cancer cell lines. However, the exact mechanism for this function remains unclear. In this study, we investigated the proliferation inhibitory effect of ORI on human osteosarcoma (OS) 143B cells and dissected the possible molecular mechanism(s) underlying this effect. We demonstrated that ORI can inhibit proliferation, induce apoptosis and arrest the cell cycle in 143B cells. Using luciferase reporter assay, we found that the Wnt/β-catenin signaling was inhibited in 143B cells by ORI. Accordingly, the total protein levels and nuclear translocation of β-catenin were reduced by ORI treatment. ORI increased glycogen synthase kinase 3β (GSK3β) activity and upregulated Dickkopf-1 (Dkk-1) expression. We found that Dkk-1 overexpression or β-catenin knockdown can potentiate the proliferation inhibitory effect of ORI in 143B cells, while β-catenin overexpression attenuated this effect. Using the xenograft tumor model of human OS, we demonstrated that ORI effectively inhibited the growth of tumors. Histological examination showed that ORI inhibited cancer cell proliferation, decreased the expression of PNCA and β-catenin. Our findings suggest that ORI can inhibit 143B OS cell proliferation by downregulating Wnt/β-catenin signal transduction, which may be mediated by upregulating the Dkk-1 expression and/or enhancing the function of GSK3β. Therefore, ORI can be potentially used as an effective adjuvant agent for the clinical management of OS.

Galactosylated bovine serum albumin nanoparticles for parenteral delivery of oridonin: tissue distribution and pharmacokinetic studies

Bovine serum albumin (BSA) nanoparticle is a promising drug carrier system. Oridonin (ORI)-loaded galactosylated BSA nanoparticle (ORI-GB-NP) was prepared for liver targeting delivery of ORI. This work was designed to investigate the in vitro release, in vivo pharmacokinetics and tissue distribution of ORI-GB-NP. ORI-GB-NP was prepared by the desolvation method. The particle size of ORI-GB-NP was 172.0 ± 8.3 nm with narrow size distribution. The in vitro release of ORI-GB-NP exhibited biphasic drug release pattern with an initial burst release and consequently sustained release. Pharmacokinetic analysis displayed that ORI-GB-NP and ORI-loaded BSA nanoparticle (ORI-BSA-NP) could enhance the drug plasma level and prolong the circulation time in contrast with ORI solution. Meanwhile, compared with ORI-BSA-NP, ORI-GB-NP could deliver more ORI to liver and simultaneously reduce the toxicity of ORI to heart, lung and kidney. In conclusion, ORI-GB-NP could be a promising drug delivery system for liver cancer therapy.

Oridonin Loaded Solid Lipid Nanoparticles Enhanced Antitumor Activity in MCF‐7 Cells

Oridonin (ORI), a famous diterpenoid from Chinese herbal medicine, has drawn rising attention for its remarkable apoptosis and autophagy‐inducing activity in human cancer therapy, while clinical application of ORI is limited by its strong hydrophobicity and rapid plasma clearance. The purpose of this study was to evaluate whether the antitumor activity of ORI could be enhanced by loading into solid lipid nanoparticles (SLNs). ORI‐loaded SLNs were prepared by hot high pressure homogenization with narrow size distribution and good entrapment efficacy. MTT assay indicated that ORI‐loaded SLNs enhanced the inhibition of proliferation against several human cancer cell lines including breast cancer MCF‐7 cells, hepatocellular carcinoma HepG 2 cells, and lung carcinoma A549 cells compared with free ORI, while no significant enhancement of toxicity to human mammary epithelial MCF‐10A cells was shown. Meanwhile, flow cytometric analysis demonstrated that ORI‐SLNs induced more significant cell cycle arrest at S and decreased cell cycle arrest at G1/G0 phase in MCF‐7 cells than bulk ORI solution. Hoechst 33342 staining and Annexin V/PI assay indicated that apoptotic rates of cells treated with ORI‐loaded SLNs were higher compared with free ORI. In summary, our data indicated that SLNs may be a potential carrier for enhancing the antitumor effect of hydrophobic drug ORI.

Synthesis, characterization, in vitro and in vivo evaluation of PEGylated oridonin conjugates

Oridonin (ORI), a diterpenoid compound with promising antitumor activity, was proved to possess potent antileukemia efficacies in vitro and in vivo recently. However, the development and application of ORI was limited by its poor solubility and rapid plasma clearance. The purpose of this study was to solve these problems. PEGylated oridonin linked with succinic acid (SA) as spacer moiety (PEG-SA-ORI conjugate) was synthesized. mPEG amines with four specifications of molecular weight (MW) were utilized. All polymeric conjugates showed satisfactory aqueous solubility and in vitro studies implied that the drug solubility and release features of conjugates were relevant to PEGs. The drug solubility increased more when the MW of PEG was lower, while more significant sustained-release effect was shown with higher PEG MW. Moreover, the release behaviors of conjugates showed a pH-sensitive property. In vivo pharmacokinetic studies demonstrated that the elimination half-life was prolonged in comparison with ORI solution. PEGylation could be a promising method to obtain better efficacy in the field of drug delivery system.

In vitro and in vivo studies of galactose-modified liver-targeting liposomes

Oridonin (ORI) is a bioactive diterpenoid compound extracted from the well known Chinese traditional medicine Rabdosia rubescens. The aim of this study was to prepare ORI loaded liposomes surface-modified with galactose (NOH-ORI-LP) and evaluate their characteristics compared with ORI loaded liposomes (ORI-LP) and ORI solution in vitro and in vivo. The NOH-ORI-LP was prepared by ethanol injection method. The NOH-ORI-LP was characterized by their morphology, particle size, zeta potential and encapsulation efficiency. The concentration of ORI in plasma and tissues at different sampling time points were determined. The liver concentration-time curves of NOH-ORI-LP in mice were determined, and the pharmacokinetic parameters were calculated and compared by statistical analysis. Our data revealed that NOH-ORI-LP has a particle size of about (173 ± 12) nm. The particles exhibit a negative electrical charge (−31.5 ± 1.6 mV), and possess high encapsulation efficiency (94.1 ± 1.2%). There were significantly different parameters of k10 and area under the plasma concentration-time curve (AUC0−t) between liposomes and solution. The mean residence time (MRT0−t) in plasma of NOH-ORI-LP was 5.56 times longer than that of solution. Compared with solution, NOH-ORI-LP delivered about 4.28 times higher ORI into liver. Thus, an optimum intravenous galactose-modified liposome formulation for ORI could be developed as an alternative to the commercial ORI preparations.

In vivo studies on the oridonin-loaded nanostructured lipid carriers

Oridonin (ORI)-loaded Nanostructured lipid carriers (NLC) were prepared by emulsion–evaporation and low temperature–solidification technique, and evaluated for morphological observation, particle size, zeta potential and in vitro drug release. Next, the characteristics of biodistribution and pharmacokinetics in vivo were examined. The average particle size of resultant NLC was 245.2 nm and the zeta potential was found to be -38.77 mV. The in vivo characteristics of ORI-loaded NLC were studied after intravenous administration using Kunming strain mice as experimental animals. An ORI control solution was studied parallelly. In tested organs, the distribution of ORI-loaded NLC to liver was higher than that of free drug. ORI-loaded NLC showed higher AUC (area under tissue concentration–time curve) values and circulated in the blood stream for a longer time compared with ORI solution. These results support the potential applications of NLC for the delivery of ORI.

Biodegradable Self-Assembled MPEG-PCL Micelles for Hydrophobic Oridonin Delivery <I>In Vitro</I>

The great potential of oridonin (ORI) for clinical application in cancer therapy is greatly limited due to its poor water-solubility. The purpose of this study was to increase the water solubility of oridonin using monomethoxy poly(ethylene glycol)-poly(epsilon-caprolactone) (MPEG-PCL) as drug carrier. The ORI-loaded MPEG-PCL micelles were prepared by thin film hydration method. The obtained ORI-micelles could be lyophilized into powder form, which could be re-dissolved in water to form homogeneous solution. This study showed that ORI was successfully incorporated in the core-shell structure of MPEG-PCL micelles and maintained its anticancer activity. The average particle size was 25.55 +/- 0.10 nm and the mean zeta potential was -4.71 +/- 0.05 mV. The actual drug loading and encapsulation efficiency were 7.99 +/- 0.03% and 99.51 +/- 0.34%, respectively. ORI could be released from MPEG-PCL micelles in a sustained manner in vitro. The permeation profiles of ORI from ORI-micelles and ORI water saturated solution through excised mouse skin demonstrated that ORI-micelles showed much better transdermal penetration performance than ORI water saturated solution. The prepared ORI-micelles have great potential for both direct intravascular administration and being further developed as a transdermal drug delivery system in cancer chemotherapy.

In vitro and in vivo evaluation of oridonin-loaded long circulating nanostructured lipid carriers

The purpose of this study was to develop poly(ethylene glycol)-coated nanostructured lipid carriers (PEG-NLC) for parenteral delivery of oridonin (ORI) to prolong drug circulation time in blood. Oridonin-loaded PEG-NLC (ORI-PEG-NLC) consisting of PEG2000-stearate, glycerol monostearate and medium chain triglycerides were prepared by emulsion-evaporation and low temperature-solidification technique. Oridonin-loaded NLC (ORI-NLC) were also prepared as control. ORI-PEG-NLC were observed by transmission election microscope and the morphology was in rotiform shape. The mean particle size of ORI-PEG-NLC was 329.2nm and entrapment efficacy was 71.18%. The results of differential scanning calorimetry and X-ray diffraction revealed a low-crystalline structure of ORI and verified the incorporation of ORI into the nanoparticles. In vitro drug release of ORI-PEG-NLC exhibited biphasic drug release patterns with burst release initially and prolonged release afterwards. Pharmacokinetic analysis showed that the mean residence time of ORI-PEG-NLC was prolonged and AUC (area under tissue concentration–time curve) value was also improved compared with ORI-NLC and ORI solution. In conclusion, ORI-PEG-NLC could be a potential carrier to get prolonged retention time of oridonin in blood.

RGD-modified poly(D,L-lactic acid) nanoparticles enhance tumor targeting of oridonin

ObjectiveThe purpose of this study was to develop an active targeting strategy to improve the therapeutic antitumor efficacy of oridonin (ORI), the main active ingredient in the medicinal herb Rabdosia rubescens.MethodsA modified spontaneous emulsification solvent diffusion method was used to prepare the ORI-loaded atactic poly(D,L-lactic acid) nanoparticles (ORI-PLA-NPs). Surface cross-linking with the peptide Arg-Gly-Asp (RGD) further modified the ORI-PLA-NPs, generating ORI-PLA-RGD-NPs. The NPs were characterized and release experiments were performed in vitro. The pharmacokinetics, tissue distribution, and antitumor activity of the NPs were studied in mice bearing hepatocarcinoma 22 (H22)-derived tumors.ResultsThe ORI-PLA-NPs and ORI-PLA-RGD-NPs were smooth, sphere-like, and relatively uniform in size. The RGD surface modification slightly increased the mean particle size (95.8 nm for ORI-PLA-NPs versus 105.2 nm for ORI-PLA-RGD-NPs) and considerably altered the surface electrical property (−10.19 mV for ORI-PLA-NPs versus −21.95 mV for ORI-PLA-RGD-NPs), but it had no obvious influence on ORI loading (8.23% ± 0.35% for ORI-PLA-NPs versus 8.02% ± 0.38% for ORI-PLA-RGD-NPs), entrapment efficiency (28.86% ± 0.93% for ORI-PLA-NPs versus 28.24% ± 0.81% for ORI-PLA-RGD-NPs), or the release of ORI. The pharmacokinetic properties of free ORI were improved by encapsulation in NPs, as shown by increased area under the concentration-time curve (11.89 ± 0.35 μg·mL−1 · h for ORI solution versus 22.03 ± 0.01 μg · mL−1 · h for ORI-PLA-RGD-NPs) and prolonged mean retention time (2.03 ± 0.09 hours for ORI solution versus 8.68 ± 0.66 hours for ORI-PLA-RGD-NPs). In the tissue distribution study, more ORI targeted tumor tissue in the mice treated with ORI-PLA-RGD-NPs than with ORI-PLA-NPs or ORI solution. Consistent with these observations, ORI-PLA-RGD-NPs showed greater antitumor efficacy than ORI-PLA-RGD-NPs or ORI solution, as reflected by the decreased tumor growth and the prolonged survival time of mice bearing H22 tumors.ConclusionThe tumor-targeting efficiency and subsequent antitumor efficacy of ORI is increased by incorporation into ORI-PLA-RGD-NPs.

Oridonin Up-regulates Expression of P21 and Induces Autophagy and Apoptosis in Human Prostate Cancer Cells

Background: Oridonin (ORI) could inhibit the proliferation and induce apoptosis in various cancer cell lines. However, the mechanism is not fully understood.Methods: Human prostate cancer (HPC) cells were cultured in vitro and cell viability was detected by the CCK-8 assay. The ultrastructure changes were observed under transmission electron microscope (TEM). Chemical staining with acridine orange (AO), MDC or DAPI was used to detect acidic vesicular organelles (AVOs) and alternation of DNA. Expression of LC3 and P21 was detected by Western Blot. Apoptotic rates and cell cycle arrest were detected by FACS.Results: Our study demonstrated that after ORI treatment, the proliferations of human prostate cancer (HPC) cell lines PC-3 and LNCaP were inhibited in a concentration and time-dependent manner. ORI induced cell cycle arrest at the G2/M phase. A large number of autophagosomes with double-membrane structure and acidic vesicular organelles (AVOs) were detected in the cytoplasm of HPC cells treated with ORI for 24 hours. ORI resulted in the conversion of LC3-I to LC3-II and recruitment of LC3-II to the autophagosomal membranes. Autophagy inhibitor 3-methyladenine (3-MA) reduced AVOs formation and inhibited LC3-I to LC3-II conversion. At 48 h, DNA fragmentation, chromatin condensation and disappearance of surface microvilli were detected in ORI-treated cells. ORI induced a significant increase in the number of apoptotic cells (PC-3: 5.4% to 27.0%, LNCaP: 5.3% to 31.0%). Promoting autophagy by nutrient starvation increased cell viability, while inhibition of autophagy by 3-MA promoted cell death. The expression of P21 was increased by ORI, which could be completely reversed by the inhibition of autophagy.Conclusions: Our findings indicated that autophagy occurred before the onset of apoptosis and protected cancer cells in ORI-treated HPC cells. P21 was involved in ORI-induced autophagy and apoptosis. Our results provide an experimental basis for understand the anti-tumor mechanism of ORI as treatment for prostate cancer.

Study on the Autophagy of Prostate Cancer PC‐3 Cells Induced by Oridonin

To investigate the mechanism of oridonin (ORI)-induced autophagy in prostate cancer PC-3 cells, PC-3 cells cultured in vitro were treated with ORI, and the inhibitory ratio of ORI on PC-3 cells was assayed by 3-4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide. The ultrastructural changes of the cells were observed under light microscope, scanning electron microscope (SEM), and transmission electron microscope (TEM). Acridine orange (AO) staining was used to observe the acidic vesicular organelles (AVOs). The level of autophagy-related proteins, MAP1-LC3, was detected by Western Blot, and RT-PCR was used to detect the level of mRNA of beclin 1. After ORI treatment, the proliferation of PC-3 cells was inhibited significantly in a concentration and time-dependent manner. SEM examination revealed cellular shrinkage and disappearance of surface microvilli in ORI-treated cells. Under TEM examination, the nuclei exhibited chromatin condensation and the appearance of a large number of autophagosomes with double-membrane structure in cytoplasm. AO staining showed the existence of AVOs. The expression of LC3 and the mRNA level of beclin 1 was increased by ORI. Furthermore, autophagy inhibitor 3-methyladenine reversed the increase of beclin 1 mRNA. The growth of PC-3 cells was inhibited, and autophagy was induced by ORI, indicating ORI may have a potential antitumor effect.

Study on pharmacokinetics of oridonin in mice

To develop a HPLC method for the determination of plasma concentration of oridonin (ORI) and study the pharmacokinetics of ORI in mice. Blood was sampled from mice which were injected ORI by 10 mg x kg(-1) at different time intervals, and the concentration of ORI was determined by HPLC. The pharmacokinetic parameters were accessed by 3P97. The calibration curve was linear (r = 0.998 7) within the range of 0.202-20.0 mg x L(-1) for ORI in plasma. The average recoveries were more than 93%. The within-day and between-day precisions were no more than 9%. After i.v. oridonin in mice, the plasma concentration-time course fitted well to two-compartment model. The pharmacokinetic equation was C = 16.192 5e(-0.554 6t) + 5.475 7e(-0.016 3t). The pharmacokinetic parameters were below: t1/2alpha 1.249 9 min, t1/2beta 42.638 4 min, K21 0.152 3 min(-1), K12 0.359 3 min(-1), K10 0.0592 min(-1), AUC 366.035 0 microg x min x mL(-1), CL 0.0273 L x min(-1) x kg(-1), V(c)0.461 5 L x kg(-1). The method can be used to determine the concentration and to investigate the pharmacokinetics of ORI in mice. ORI was absorbed and distributed very fast in mice. The effect of ORI was rapid. The elimination was the main process.

Galactose-Decorated pH-Responsive Nanogels for Hepatoma-Targeted Delivery of Oridonin

Nanogels based on the polymers of galactosylated chitosan-graft-poly (N-isopropylacrylamide) (Gal-CS-g-PNIPAm) were used as carriers of oridonin (ORI) for tumor targeting. Three ORI-loaded nanogels with various degrees of galactose substitution were prepared, and their characteristics were evaluated. The release behavior of ORI from these nanogels was pH-dependent, and the release could be accelerated under mildly acidic conditions. The cytotoxicity of ORI-loaded nanogels was pH-sensitive. ORI-loaded nanogels exhibited a higher antitumor activity than drug-loaded nanogels without galactosylation, and the anticancer activity increased in relation to increases in the number of galactose moieties of the nanogels in HepG2 cells. In contrast, the cytotoxicity of ORI-loaded nanogels against MCF-7 cells decreased compared with that of drug-loaded nanogels without galactosylation. Results demonstrated that these nanogels could enhance the uptake of ORI into HepG2 cells via asialoglycoprotein receptor-mediated endocytosis. These galactose-decorated pH-responsive nanogels were well-suited for targeted drug delivery to liver cancer cells.

Chitosan- g-poly( N-isopropylacrylamide) based nanogels for tumor extracellular targeting

The principle objective of this research was to develop and characterize pH-responsive and biocompatible nanogels as a tumor-targeting drug delivery system. The nanogels were self-assembled from chitosan-based copolymers, chitosan- graft-poly( N-isopropylacrylamide) (CS- g-PNIPAm). The copolymers were synthesized via free radical copolymerization and characterized for their chemical structure by FT-IR and 1H NMR. These copolymers could be efficiently loaded with oridonin (ORI) and the characteristics of ORI-loaded nanogels were evaluated. Drug release researches indicated that the ORI-loaded nanogels displayed pH-dependent release behaviors. Based on MTT assay and cellular morphological analysis, the anti-tumor activity of ORI-loaded nanogels was higher at pH 6.5 than at pH 7.4. In conclusion, the obtained nanogels appeared to be of great promise in tumor extracellular pH targeting for ORI.

Growth inhibition and induction of apoptosis in MCF-7 breast cancer cells by oridonin nanosuspension

The mechanism for anti-tumor activity of oridonin (ORI) nanosuspension, prepared by the high pressure homogenization method, was studied using MCF-7 human breast carcinoma cells in vitro. MTT assay, observation of morphologic changes, flow cytometric analysis, and western blot analysis indicated that ORI nanosuspension could significantly intensify the in vitro anti-tumor activity to MCF-7 cells, as compared with ORI solution. Furthermore, ORI nanosuspension induced G2/M stage proliferation arrest and apoptosis in MCF-7 cells depending on its concentration. In addition, western blot analysis indicated that the pro-caspase-3 protein was not cleaved into the activated form and the expression of anti-apoptotic Bcl-2 protein decreased, on the contrary, the expression of pro-apoptotic Bax protein increased in a dose-dependent manner in ORI nanosuspension-treated cells. These observations indicated that the anti-tumor activity of ORI nanosuspension was intensified by cell-cycle arrest and apoptosis induction.

Autophagy of prostate cancer PC-3 cells under the induction of oridonin

To investigate the mechanism of oridonin (ORI)-induced autophagy in prostate cancer PC-3 cells. The PC-3 cells cultured in vitro were treated with ORI. The inhibitory ratio of oridonin In PC-3 cells was assayed by MTT. The ultrastructural cellular changes were observed under light microscope, scanning electron microscope (SEM) and transmission electron microscope (TEM). AO staining was used to observe the acidic vesicular organelles (AVOs). The level of MAP1-LC3 was detected by Western blot and reverse transcriptase polymerase chain reaction (RT-PCR) used to detect the level of mRNA of beclin 1. After oridonin treatment, the proliferation of PC-3 cells was inhibited significantly in a concentration and time-dependent manner. The SEM examination revealed cellular shrinkage and the disappearance of surface microvilli after ORI treatment. And on the TEM examination, the nuclei exhibited chromatin condensation and the appearance of a large number of autophagosome with double-membrane structure in cytoplasm. AO staining showed the existence of AVOs. Simultaneously, the expressions of autophagy-related proteins, MAP-LC3 and the mRNA level of beclin 1 were elevated by ORI. The autophagy inhibitor 3-MA reversed the elevation of beclin 1 mRNA. The growth of PC-3 cells is inhibited. And cellular is induced by oridonin with a potential anti-tumor effect.

In vitro and in vivo antitumor activity of oridonin nanosuspension

The aim of the present study was to evaluate the antitumor activity of an oridonin (ORI) nanosuspension relative to ORI solution both in vitro and in vivo. ORI nanosuspension with a particle size of 897.2 ± 14.2 nm was prepared by the high pressure homogenization method (HPH). MTT assay showed that ORI nanosuspension could significantly enhance the in vitro cytotoxicity against K562 cells compared to the ORI solution, the IC 50 value at 36 h was reduced from 12.85 μmol/L for ORI solution to 8.11 μmol/L for ORI nanosuspension. Flow cytometric analysis demonstrated that the ORI nanosuspension also induced a higher apoptotic rate in K562 cells compared to ORI solution. In vivo studies in a mouse model of sarcoma-180 solid tumors demonstrated significantly greater inhibition of tumor growth following treatment with ORI nanosuspension than ORI solution at the same dosage. The mice injected with ORI nanosuspension showed a higher reduction in tumor volume and tumor weight at the dose of 20 mg/kg compared to the ORI solution ( P < 0.01), with the tumor inhibition rate increased from 42.49% for ORI solution to 60.23% for the ORI nanosuspension. Taken together, these results suggest that the delivery of ORI in nanosuspension is a promising approach for the treatment of the tumor.

An HPLC method for determination of oridonin in rabbits using isopsoralen as an internal standard and its application to pharmacokinetic studies for oridonin-loaded nanoparticles

A simple and sensitive HPLC method has been developed and validated for the determination of oridonin (ORI) in rabbit plasma. A simple liquid–liquid extraction (LLE) method was applied to extract ORI and the internal standard (IS), isopsoralen, from rabbit plasma. Chromatographic separation of ORI and the IS was achieved with a Kromasil C18 5-μm column (250 mm × 4.6 mm) using methanol–water (50:50, v/v) as mobile phase at a flow rate of 1 mL/min. The ultraviolet (UV) detection wavelength was set at 241 nm. The lower limit of quantification (LLOQ) was 0.02 μg/mL. The calibration curves were linear over a concentration range of 0.02–10 μg/mL. The assay accuracy and precision were within the range of 95.1–113.5% and 5.4–8.6%, respectively. This HPLC method was applied successfully to the pharmacokinetic study of ORI-loaded poly(caprolactone)-poly(ethylene oxide)-poly(caprolactone) copolymer nanoparticles (ORI-PCL-PEO-PCL-NP) in rabbits, given as a single intravenous injection at the dose equivalent to 2 mg of ORI/kg, and the pharmacokinetic parameters for ORI were compared with a single intravenous injection of a ORI solution at the same dose.

Preparation and Characterization of an Oridonin Nanosuspension for Solubility and Dissolution Velocity Enhancement

This study describes the preparation of an oridonin (ORI) nanosuspension by high-pressure homogenization (HPH). The aim was to obtain a stable nanosuspension with an increased drug saturation solubility and dissolution velocity. The homogenization procedure was optimized in regard to particle size and long-term stability. The characteristics of the oridonin nanosuspension, such as particle size, size distribution, shape, and zeta potential, were evaluated following the water removal. The solubility and dissolution experiments were performed to verify the obvious improvement of the dissolution behavior compared with commercial ORI. Finally, crystalline state evaluation before and following the formulation was performed through differential scanning calorimetry (DSC) and powder X-ray (PXRD).