Effect of allyl isothiocyanate on oxidative stress in COPD via the AhR / CYP1A1 and Nrf2 / NQO1 pathways and the underlying mechanism.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is currently the third leading cause of death globally. Oxidative stress affects various molecular mechanisms and is the main driving factor of COPD. Ally isothiocyanate (AITC) is an effective component of Semen Sinapis Albae, which has favorable effects for the treatment of COPD, but its mechanism has not been fully elucidated. PURPOSE: This study aimed to elucidate the antioxidant effect of AITC on COPD and its molecular mechanism, and preliminarily determine the role of AhR in the progression of COPD. STUDY DESIGN: The COPD rat model was established by smoking combined with intratracheal instillation of lipopolysaccharide. Different doses of AITC, positive control drug acetylcysteine, AhR inhibitor alpha-naphthoflavone, and agonist beta-naphthoflavone were administered by gavage. Human bronchial epithelial cells induced by cigarette smoke extract (CSE) were used in an in vitro model to explore the molecular mechanisms of AITC. METHODS: The effects of AITC on lung function and oxidative stress in rats were evaluated in vivo using the respiratory function test, white blood cell count, enzyme-linked immunosorbent assay, and histological staining. The changes in protein expression in the lung tissue were detected by immunohistochemistry and Western blotting. RT-PCR, western blotting, and immunofluorescence were used to explore the molecular mechanisms of AITC. Enzyme-linked immunosorbent assay, reactive oxygen species probing, and flow cytometry were used to determine the antioxidant effect of AITC. RESULTS: AITC can improve the lung function of rats with COPD, restore lung tissue structure, improve oxidative stress, reduce inflammation, and inhibit lung cell apoptosis. AITC reversed the upregulation of AhR and CYP1A1 and the down-regulation of Nrf2 and NQO1 in the lung tissues of rats with COPD. CSE stimulation can increase the expressions of AhR and CYP1A1 and decrease the expressions of Nrf2 and NQO1 in 16HBE cells, leading to severe oxidative stress and inflammatory response and, ultimately, apoptosis. AITC inhibited AhR and CYP1A1 expressions, induced Nrf2 and NQO1 expressions, promoted Nrf2 nuclear translocation, and improved CSE-induced toxicological effects. CONCLUSION: AITC may improve lung oxidative stress by inhibiting the AhR / CYP1A1 and activating the Nrf2 / NQO1 pathways, thereby delaying the pathological progression of COPD.

Effects of allyl isothiocyanate on the expression, function, and its mechanism of ABCA1 and ABCG1 in pulmonary of COPD rats.

BACKGROUND AND AIMS: Allyl isothiocyanate(AITC) has been shown to play an important role in the improved symptoms of chronic obstructive pulmonary disease(COPD) and the inhibition of inflammation, but the role in COPD lipid metabolism disorder and the molecular mechanism remains unclear. We aimed to explore whether and how AITC affects COPD by regulating lipid metabolism and inflammatory response. METHODS: The COPD rat model was established by cigarette smoke exposure. Cigarette smoke extract stimulated 16HBE cells to induce a cell model. The effect of AITC treatment was detected by lung function test, H&E staining, Oil red O staining, immunohistochemistry, ELISA, CCK-8, HPLC, fluorescence efflux test, siRNA, RT-PCR, and Western blotting. Biological analysis was performed to analyze the results. Graphpad Prism 8.0 software was used for statistical analysis. RESULTS: AITC can improve lung function and pathological injury in COPD rats. The levels of IL-1 ß and TNF- α in the AITC treatment group were significantly lower than those in the model group(P < 0.05), and the lipid metabolism was also improved (P < 0.05). AITC reverses CSE-induced down-regulation of LXR α, ABCA1, and ABCG1 expression and function in a time-and concentration-dependent manner (P < 0.05). AITC regulates the cholesterol metabolism disorder induced by CSE in NR8383 cells and attenuates macrophage inflammation (P < 0.05). In addition, after silencing LXR α with siRNA, the effect of AITC was also inhibited. CONCLUSION: These results suggest that AITC improves COPD by promoting RCT process and reducing inflammatory response via activating LXR pathways.

[Comparative study on serum transitional components of Huatan Jiangqi Capsules in rats under pathological and physiological status].

The differences of transitional components and metabolic processes of Huatan Jiangqi Capsules(HTJQ) in rats under normal physiological and pathological conditions of COPD were analyzed by UPLC-Q-TOF-MS. The rat COPD model was established by passive smoking and intratracheal instillation of lipopolysaccharide. After the normal and COPD model rats were douched with HTJQ, the blood was collected from hepatic portal vein and the drug-containing serum samples were prepared by methanol precipitation of protein. Then, 10 batches of drug-containing serum samples of HTJQ were prepared and analyzed by UPLC serum fingerprint to evaluate the quality and stability of drug-containing serum samples. UPLC-Q-TOF-MS was used to collect the mass spectrometric information of the transitional components. Twenty-eight transitional components of HTJQ in normal rats and 25 transitional components of HTJQ in COPD model rats were identified by UPLC-Q-TOF-MS. Under pathological and physiological conditions, there were not only the same transitional components in rat serum, but also corresponding differences. Further studies showed that there were also differences in the metabolic process of transitional components between the two conditions. In normal rats, most of the metabolic types of transitional components were phase I reactions. In COPD model rats, phase Ⅰ reactions decreased and phase Ⅱ reactions increased correspondingly. With UPLC-Q-TOF-MS technology, the differences of transitional components and the metabolism process of HTJQ in rats under normal physiological and pathological conditions were analyzed. The results showed that types of transitional components and the activity of some metabolic enzymes would be changed in COPD pathological state, which would affect the metabolic process of bioactive components in vivo. It laid a foundation for further elucidating the metabolic process and pharmacodynamic substance basis of HTJQ.

Allyl isothiocyanate upregulates MRP1 expression through Notch1 signaling in human bronchial epithelial cells.

Multidrug resistance associated protein-1 (MRP1) and Notch signaling are closely related and both play a critical role in chronic obstructive pulmonary disease (COPD) establishment and progression. The aim of our work was to test whether Notch1 is involved in allyl isothiocyanate (AITC) induced MRP1 expression. We used cigarette smoke extract (CSE) to simulate the smoking microenvironment in vitro. The results demonstrated that CSE led to apoptosis as well as reduced the expression of Notch1, Hes1, and MRP1, while AITC significantly reversed this downregulation. Transfected with Notch1 siRNA downregulated MRP1 expression and activity, aggravated the suppression effect by CSE, and abolished the AITC-induced Notch1, Hes1, and MRP1 expression. Validation of the correlation between Notch1 and MRP1 was implemented by gel-shift assays (electrophoretic mobility shift assay). The result revealed an interaction between a specific promoter region of MRP1 and the intracellular domain of Notch1. In conclusion, Notch1 signaling positively regulated MRP1 in 16HBE cells and AITC induced MRP1 expression and function may be attributed to Notch1 signaling. These findings show that Notch1 and MRP1 might have a potential protective effect in the COPD process and become a new therapeutic target for COPD or other lung diseases. It also provides a theoretical basis for the therapeutic effects of AITC.

(-)-Epigallocatechin-3-gallate encapsulated realgar nanoparticles exhibit enhanced anticancer therapeutic efficacy against acute promyelocytic leukemia.

Realgar and (-)-Epigallocatechin-3-gallate (EGCG) are natural medicines that inhibit cancer cell growth, resulting in inhibition of formation and development of tumors. The anticancer effects of realgar and EGCG were greatly improved following formulation as nanoparticles. EGCG has received increased attention as a drug carrier. The aim of this study was to prepare a new nanomedicine, (EGCG-RNPs), in which encapsulated nano-realgar. EGCG-RNPs were prepared by coprecipitation and characterized by transmission electron microscopy (TEM), differential scanning calorimetry (DSC), particle size and zeta potential, X-ray diffraction, Fourier transform infrared spectroscopy (FTIR) and in vitro release. Furthermore, we evaluated the antiproliferative effects of EGCG-RNPs on HL-60 cells in vitro, antitumor effect by intratumoral injection of EGCG-RNPs into solid tumors derived from APL HL-60 cells in vivo. Possible mechanisms were evaluated using uptake and efflux experiments in HL-60 cells. The results showed that the average particle size and zeta potentials of EGCG-RNPs was 200.3 ± 1.23 nm and -46.8 ± 1.31 mV. Controlled release of EGCG-RNPs was sustained and continued up to 72 h in vitro. Compared with nano-realgar and EGCG + RNPs (EGCG and nano-realgar physical mixing), EGCG-RNPs significantly inhibited growth of HL-60 cells. In a solid tumor model, EGCG-RNPs decreased tumor volumes, with an inhibitory rate of 60.18% at a dose of 70 mg · kg-1. The mechanisms of antitumor improvement may correlate with the increased uptake of realgar and prolonged the retention time of realgar in HL-60 cells due to EGCG as a carrier. EGCG-RNPs could enhance anticancer therapeutic efficacy for acute promyelocytic leukemia.

Aminated ß-cyclodextrin-grafted Fe3O4-loaded gambogic acid magnetic nanoparticles: preparation, characterization, and biological evaluation.

Based on aminated ß-cyclodextrin (6-NH2-ß-CD)-grafted Fe3O4 and gambogic acid (GA) clathrate complexes, a nanoparticle delivery system was developed with the aim to achieve low irritation, strong targeting, and high bioavailability of a gambogic acid magnetic nanopreparation. 6-NH2-ß-CD grafted onto Fe3O4 MNPs was demonstrated by high-resolution transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, zeta potential, and magnetic measurements. The average particle size of the Fe3O4@NH2-ß-CD MNPs was 147.4 ± 0.28 nm and the PDI was 0.072 ± 0.013. The encapsulation efficiency, drug loading, zeta potential, and magnetic saturation values of the Fe3O4@NH2-ß-CD MNPs were 85.71 ± 3.47%, 4.63 ± 0.04%, -29.3 ± 0.42 mV, and 46.68 emu g-1, respectively. Compared with free GA, the in vitro release profile of GA from Fe3O4@NH2-ß-CD MNPs was characterized by two phases: an initial fast release and a delayed-release phase. The Fe3O4@NH2-ß-CD MNPs displayed continuously increased cytotoxicity against HL-60 and HepG2 cell lines in 24 h, whereas the carrier Fe3O4@NH2-ß-CD MNPs showed almost no cytotoxicity, indicating that the release of GA from the nanoparticles had a sustained profile and Fe3O4@NH2-ß-CD MNPs as a tumor tissue-targeted drug delivery system have great potential. Besides, blood vessel irritation tests suggested that the vascular irritation could be reduced by the use of Fe3O4@NH2-ß-CD MNPs encapsulation for GA. The t 1/2 and the AUC of the Fe3O4@NH2-ß-CD@GA MNPs were found to be higher than those for the GA solution by approximately 2.71-fold and 2.42-fold in a pharmacokinetic study, respectively. The better biocompatibility and the combined properties of specific targeting and complexation ability with hydrophobic drugs make the Fe3O4@NH2-ß-CD MNPs an exciting prospect for the targeted delivery of GA.

Preparation and Characterization of Folate Targeting Magnetic Nanomedicine Loaded with Gambogenic Acid.

To engineer multifunctional nanomedicines for simultaneous imaging and therapy of cancer cells, we have prepared Gambogenic acid (GNA) loaded folic acid (FA) armed MNPs (FA-GNA-MNPs) to target the folate receptor (FR) positive cancer cells. The FA-GNA-MNPs have been prepared by a facile method, which have been further characterized by SEM, TEM, IR and UV-vis spectra. And the cytotoxicity of FA-GNA-MNPs to HeLa and A549 cells was assessed using the MTT assay. The FA-GNA-MNPs (with loading efficiency of 4.35%) showed sustained liberation of GNA molecules (with 73.46% release in 96 h). The mean particle diameter (MD) of FA-GNA-MNPs and the polydispersity index (PDI) are 254.3 nm and 0.139, respectively. The cytotoxicity of free GNA and FA-GNA-MNPs toward HeLa cells showed that FA-GNA-MNPs was more cytotoxic than GNA. Based on these findings, it suggests that FA-GNA-MNPs would be as a novel multifunctional nanomedicine/theranostic for concurrent targeting, imaging and therapy of the FR-positive cancer cells.

[Preparation Technique of Tetraploid of Dioscorea zingiberensis Synthetic Seed Based on Embryogenic Callus].

OBJECTIVE: To provide technical support for industrialization promotion of tetraploid of Dioscorea zingiberensis, the manufacturing method for synthetic seeds of tetraploid of Dioscorea zingiberensis was established and the correlated influential factors were studied. METHODS: By taking embryogenic calluses of tetraploid of Dioscorea zingiberensis as propagation materials, the influential factors such as components of artificial endosperm, seed coats,storage conditions and germination materials on germination and seedling of the synthetic seeds were evaluated. RESULTS: When 4% alginate +2% CaCl2 + 2% chitosan was served as seed coat materials, and 1/2 MS +0. 2 mg/L BA +0. 5 mg/L NAA + 0. 1 mg/L penicillin + 0. 3% carhendazim powder + 0. 2% sodium benzoate + 1. 0% sucrose + 0. 5% activated carbon + 1. 0% tapioca starch was served as endosperm, the synthetic seeds had high germination rate and seedling rate. After storing at 4 °C for 20 d, the germination rate and seedling rate of synthetic seeds was 76. 7% and 71. 7%, respectively. CONCLUSION: Manufacturing technology of synthetic seeds of tetraploid of Dioscorea zingiberensis with embryogenic calluses as propagation materials has production prospects.

[Roles of the cross talk between MAP kinases and Keap1-Nrf2-ARE signaling pathways in chronic obstructive pulmonary disease].

Chronic obstructive pulmonary disease (COPD), a common preventable and treatable disease, is characterized by airflow limitation that is usually progressive and associated with an enhanced chronic inflammatory response in the airways. Its main pathological manifestations include airway inflammation, mucus hypersecretion, oxidative stress and apoptotic epithelial cells. Recent research suggests that MAP kinases and Keap1-Nrf2-ARE signaling pathway are involved in the pathological process of inflammation and oxidative stress. This review explores the potential role of the cross talk of these signaling pathways in airway inflammation, mucus hypersecretion, oxidative stress and apoptotic epithelial cells. To clarify the roles of cross talk between MAP kinases and Keap1-Nrf2-ARE signaling pathway, we also focus on the drugs related to that in the treatment of COPD, and it provides ideas for more drug research in the treatment of COPD.

The application of biotechnology in medicinal plants breeding research in China.

Breeding is not only an important area of medicinal plants research but also the foundation for the superior varieties acquirement of medicinal plants. The rise of modern biotechnology provides good opportunities and new means for medicinal plants breeding research in China. Biotechnology shows its technical advantages and new development prospects in breeding of new medicinal plants varieties with high and stable yield, good quality, as well as stress-resistance. In this paper, we describe recent advances, problems, and development prospects about the application of modern biotechnology in medicinal plants breeding research in China.

Crystal structure of 4-methyl-2-oxo-2H-chromen-7-yl ferrocene-carboxyl-ate.

The title mol-ecule, [Fe(C5H5)(C16H11O4)], consists of a ferrocenyl moiety and a 4-methyl-coumarin group linked through an ester unit to one of the cyclo-penta-dienyl (Cp) rings. The two Cp rings are virually parallel, with an angle between the two least-squares planes of 0.74 (16)°. The distances between the Fe(II) atom and the centroids of the two Cp rings are 1.639 (2) and 1.652 (2) Å. The conformation of the ferrocenyl moiety is slightly away from eclipsed. The dihedral angle between the coumarin ring system and the ferrocenyl ester moiety is 69.17 (19)°. π-π stacking inter-actions involving the benzene rings of neighbouring coumarin moieties, with centroid-centroid distances of 3.739 (2) Å, consolidate the crystal packing.

[Genetic stability study on autotetraploid plant of Dioscorea zingiberensis].

OBJECTIVE: To study the genetic stability of autotetraploid plant of Dioscorea zingiberensis. METHODS: The chromosome of root-tip was determined by photomicroscope, and the agronomic characters were observed in the period of stable growth. The protein content was determined and the experiment of protein polyacrylamide gel electrophoresis was carried out. Furthemore, the diosgenin content was determined and compared. RESULTS: The chromosome number of autotetraploid plantlet was 2n = 4x = 40. The agronomic characters showed typical autotetraploid characteristics. The contents of diosgenin and protein of autotetraploid were higher than that of the diploid. The protein electrophoresis bands of all the lines were similar. CONCLUSION: The experiment confirmed that the autotetraploid plant of Dioscorea zingiberensis, which was artificially induced, had good genetic stability. It lays the foundation for the polyploid breeding to develop superior varieties of Dioscorea zingiberensis.

[Influence of huatanjiangqi prescription on multidrug resistance-associated protein 1 in human bronchial epithelial cells].

OBJECTIVE: To investigate the effect of Huatanjiangqi prescription (Sinapis Semen, Perillae Fructus, Cynanchi Stauntonii Rhizoma et Radix, Inulae Herba, Angelicae Sinensis Radix, Honey-fried Ephedrae Herba) on multidrug resistance-associated protein 1 (MRP1) in human bronchial epithelial cells. METHODS: The human bronchial epithelial cells line 16HBE140- was used to analyze the in vitro effect of Huatanjiangqi prescription on MRP1 transport. 5-CFDA was used as a model MRP1 substrate and was measured with flow cytometry. The mRNA expression of MRP1 was detected by real-time PCR. RESULTS: Huatanjiangqi prescription could promote the proliferation of human bronchial epithelial cells 16HBE140- in a certain range of concentration; Compared with the control group (5-CFDA), low, medium and high concentration (100, 1 000, 2 000 microg/mL) of Huatanjiangqi prescription on MRP1 function were increased by 22.59%, 47.14% and 68.36%, respectively; Huatanjiangqi prescription could concentration-dependently induce the expression of MRP1 mRNA, medium and high concentration could induce a significant difference. CONCLUSION: Huatanjiangqi prescription can improve MRP1 efflux function and mRNA levels in a concetration-dependent manner.

Germplasm preservation in vitro of Polygonum multiflorum Thunb.

BACKGROUND: The root of Polygonum multiflorum Thunb. is a common traditional Chinese medicine. In recent years, the wild resources of P. multiflorum have been seriously broken, and the cultivated varieties have been degrading. The germplasm resources of P. multiflorum need protection and preservation. So far, no in vitro germplasm preservation of P. multiflorum has been reported. OBJECTIVE: To explore a method for the in vitro germplasm preservation of P. multiflorum. MATERIALS AND METHODS: A large number of buds from seed explants were induced by tissue culture. The single buds were used as experimental materials to study the effects of plant growth regulator, temperature, and osmotic pressure on the preservation time, growth recovery, and genetic stability. RESULTS: When the buds were inoculated onto Murashige and Skoog (MS) basal media containing 4% w/v sucrose, 2% w/v mannitol, and 1% w/v sorbitol, supplemented with paclobutrazol (PP333) 1.0 mg/l, abscisic acid (ABA) 5.0 mg/l, and daminozide (B9) 30.0 mg/l in an illuminated chamber under a 16 h photoperiod of 1500 lx light intensity at 15°C for 10 months, the survival rate was over 70% with good growth recovery and genetic stability. CONCLUSION: The results of this study can be used for medium-term in vitro germplasm preservation of P. multiflorum, and meeting actual needs of research and production.

Ultra-high-performance liquid chromatography tandem mass spectrometry method for the determination of gambogenic acid in dog plasma and its application to a pharmacokinetic study.

A highly sensitive and rapid ultra-high-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of gambogenic acid in dog plasma. Gambogic acid was used as an internal standard (IS). After a simple liquid-liquid extraction by ethyl acetate, the analyte and internal standard were separated on an Acquity BEH C18 (100 × 2.1 mm, 1.7 µm; Waters ) column at a flow rate of 0.2 mL/min, using 0.1% formic acid-methanol (10:90, v/v) as mobile phase. Electrospray ionization source was applied and operated in the positive ion mode. Multiple reaction monitoring mode with the transitions m/z 631.3 → 507.3 and m/z 629.1 → 573.2 was used to quantify gambogenic acid and the internal standard, respectively. The calibration curves were linear in the range of 5-1000 ng/mL, with a coefficient of determination (r) of 0.999 and good calculated accuracy and precision. The low limit of quantification was 5 ng/mL. The intra-and inter-day precisions (relative standard deviations) were <15%. The methodology recoveries were more than 66.63%. This validated method was successfully applied to a pharmacokinetic study after intravenous injection administration of gambogenic acid in dogs at a dose of 1 mg/kg.

Allyl isothiocyanate increases MRP1 function and expression in a human bronchial epithelial cell line.

Multidrug resistance-associated protein 1 (MRP1), a member of the ATP-binding cassette (ABC) superfamily of transporters, plays an important role in normal lung physiology by protecting cells against oxidative stress and toxic xenobiotics. The present study investigates the effects of allyl isothiocyanate (AITC) on MRP1 mRNA and MRP1 protein expression and transporter activity in the immortalised human bronchial epithelial cell line 16HBE14o-. MRP1 mRNA and MRP1 protein expression in 16HBE14o- cells that were treated with allyl isothiocyanate were analysed by real-time PCR assay and Western blotting. The transport of carboxyfluorescein, a known MRP1 substrate, was measured by functional flow cytometry to evaluate MRP1 activity. Treatment with AITC at concentrations of 5-40 µM increased MRP1 protein levels in a concentration-dependent manner. AITC treatments at concentrations of 1-40 µM caused concentration-dependent increases in MRP1 mRNA levels that were up to seven times greater than the levels found in control cells. Finally, AITC treatment at concentrations of 5-40 µM significantly increased MRP1-dependent efflux in 16HBE14o- cells. These results suggest that AITC can increase the expression and activity of MRP1 in 16HBE14o- cells in a concentration-dependent manner. The upregulation of MRP1 activity and expression by AITC could produce therapeutic effects in the treatment of lung disease.

[Study on inducing embryogenic callus of Dioscorea zingiberensis by orthogonal design].

OBJECTIVE: To select the suitable medium to induce embryogenic callus of Dioscorea zingiberensis. METHODS: Plantlet of Dioscorea zingiberesis in vitro was obtained by using apical meristem as explant. The different parts of the plantlets were cultured to select the best explant used for inducing callus and embryoids. Growing rate and diosgenin content were calculated in orthogonal test to optimize combination of phytohormones for inducing embryogenic callus. RESULTS: The leaves were suitable explants to induce callus and embryoid. The inducing rate of callus and embryoids reached 92.5% and 42.5%, respectively. The optimal medium for inducing embryogenic callus was MS + 6-BA 2.0 mg/L + NAA 0.5 mg/L + 2,4-D 1.0 mg/L. CONCLUSION: The results of this study can be used for effective induction of embryogenic callus of Dioscorea zingiberensis, and lay the foundation for the subsequent research of artificial seeds.

15-Meth-oxy-14,15-di-hydro-andranginine.

The title polycyclic alkaloid, C22H26N2O3, an indole derivative obtained from Melodinus yunnanensis, comprises three chiral C atoms and crystallizes as a racemate. Its seven-membered heterocyclic ring has a twisted conformation, with the N atom within the plane of the indole moiety and with two adjacent C atoms deviating in opposite directions from its plane by 0.756 (3) (methyl-ene C) and -0.802 (3) Š(methine C). In the crystal, pairs of N-H⋯O hydrogen bonds connect the mol-ecules into centrosymmetric dimers.

The pharmacokinetics and conversion of the lactone to the carboxylate forms of ginkgolide B in rat plasma.

Ginkgolide B consists of three lactone groups, which may undergo hydrolysis, and lead to the rings opening in aqueous solution with different pHs. From mechanisms of pharmacological activity in vivo, the lactone appears to be the active form of the drug. Pharmacokinetics of lactone form (GB-lac) and the total of the lactone and carboxylate form (GB-tot) of ginkgolide B were investigated after intravenous administration of a dose of 4 mg/kg ginkgolide B. The rate of lactone hydrolysis was also studied in plasma in vitro. After intravenous administration, ginkgolide B in the original form was converted to its carboxylate form under simulated physiological conditions. The AUC0 - ∞ of GB-lac constituted 63.5 ± 17.4% of the AUC0 - ∞ of GB-tot. The ratio of average cumulation of excretion of lactone to carboxylate reached approximately 1 to 1 in urine. From the equilibrium of lactone hydrolysis in rat plasma in vitro, the k obs was - 0.0176 min(- 1) and t 1/2 was 39.38 min. In conclusion, the equilibrium existed between lactone of ginkgolide B and its carboxylate form in vivo at physiological pH, which suggested that more attention should be focused on the original and the ionization forms of ginkgolide B and the conversion of the lactone into carboxylate in vivo.

Solid lipid nanoparticles as delivery systems for Gambogenic acid.

In this study, Gambogenic acid loaded by solid lipid nanoparticles (GNA-SLNs) was explored to reduce toxicity and improve therapeutic efficacy. GNA-SLNs were prepared by emulsification and low temperature solidification methods, and the freeze-dried powders were then developed to improve the stability. The physical-chemical properties of the products in terms of particle size, zeta potential, morphology and entrapment efficiency were well evaluated. The results revealed that the mean diameter, polydispersivity index (PI), zeta potential, and the entrapment efficiency of the nanoparticles were 163.3 nm, 0.203, -16.9 mV and 61.2%, respectively. In comparion with GNA-SLNs, the freeze-dried solid lipid nanoparticles (SLNs) showed a slight augmentation in the mean particle size (from 163.3 to 173 nm) and PI (from 0.203 to 0.253), and no significant modification in the zeta potential, entrapment efficiency and drug loading. In vitro release kinetics based on a dialysis method demonstrated that Gambogenic acid (GNA) was released in a prolonged fashion for 96 h and followed Higuchi equation unitarily. The release profile did not show any significant modification after the freeze-drying process. The Pharmacokinetic study was carried out, the i.p. administration of GNA formulations to rats at doses of 2.5mg/kg. AUC((0-t)) was increased (up to 3.1-fold) and clearance was decreased (up to 3.03-fold) when GNA entrapped in SLNs. In conclusions, the freeze-dried powders form could enhance the long-term stability of SLN, and solid lipid nanoparticles encapsulation could effectively strategy to change the poor aqueous solubility and prolong the half-life of GNA.