ABSTRACT
OBJECTIVE：To establish a method for the determination of aloesin in plasma of rats ，and to investigate pharmacokinetic characteristics of aloesin. METHODS ：The plasma samples were precipitated with methanol. Using aloeresin D as internal standard ，the plasma concentration of aloesin was determined by LC-MS/MS. The determination was performed on Synergi Hydro-RP column with mobile phase consisted of 0.1‰ formic acid-methanol （gradient elution ）at the flow rate of 0.50 mL/min. The column temperature was 30 ℃，and sample size was 5 µL. The electrospray ionization source was applied to carry out negative ion detection with multiple reaction monitoring mode . The ion transitions for quantitative analysis were m/z 393.1→272.9（aloesin） and m/z 555.3→144.9（internal standard ），respectively. The concentration of aloesin in venous blood was determined by above method at 0.083，0.167，0.333，0.667，1，1.5，2.5，4，6，8，10 h after intravenous injection （3.35 mg/kg）and intragastric administration（16.75 mg/kg）of aloesin. DAS 3.0 software was used to calculate pharmacokinetic parameters. RESULTS ：The linear range of aloesin were 1-600 ng/mL（r＝0.994 5）. The lower limit of quantification was 1 ng/mL，and RSDs of within and between batches were less than 15％；accuracies within and between batches were within ±15％. The matrix factors were （92.74± 4.33）％-（94.84±2.57）％，and extraction recoveries were （69.04±2.13）％-（75.03±2.84）％；the deviation between the measured results of the stability test and the theoretical values were within ±15％. After intravenous injection and intragastric administration of aloesin ，main pharmacokinetic parameters were as follows ：cmax were（10 693.3±2 745.3）and（223.3±36.2）ng/mL；t1/2 were （2.45±1.45）and（3.33±1.91）h；AUC0－24h were（4 190.6±883.6）and（1 210.1±93.9）ng·h/mL（n＝3）. Absolute bioavailabi- lity was 11.13％. CONCLUSIONS ：The established method is rapid and sensitive for plasma determination of aloesin ，and suitable for its pharmacokinetic study.
ABSTRACT
Objective:To study the mechanism of aloesin in inducing apoptosis in human non-small cell lung cancer (NSCLC) A549 cells, so as to inhibit its proliferation. Method:A549 cells in logarithmic growth phase were collected, and cell counting kit-8 (CCK-8) was used to detect the effect of different concentrations of aloesin (2, 4, 8, 16, 32, 64, 128 μmol·L-1) on the proliferation of A549. Effect of aloesin (0, 16 μmol·L-1) on the number of clones formed in A549 cells and the size of clone formation was determined by crystal violet staining. effect of aloesin on apoptosis of A549 cells was detected by annexin V/propidium iodide(PI)apoptosis kit staining. Hoechst staining was used to detect the phenomenon of apoptotic nuclear pyknosis. Western blot was used to detect aloesin's effect on death-related protein expressions of Bcl-xl/Bcl-2 associated death promoter (Bad), cleaved-Caspase-3,cl-Caspase-3(Asp175), Caspase-3, cleaved poly ADP-ribose polymerase (cl-PARP), poly ADP-ribose polymerase (PARP) in A549 cells. In vivo, 5-week-old nude mice were subcutaneously inoculated with 2×106 A549 cells, and randomly divided into the medication group and the blank group. aloesin or normal saline was intraperitoneally injected for 4 weeks, and the tumor volume of nude mice was measured weekly. The body weight of the mice was observed, and the appearance of the nude mice was observed. Result:Aloesin inhibited the proliferation and cloning of A549 cells in a concentration-dependent manner (PPPPPPin vivo, aloesin significantly shrank the volume of subcutaneous tumors in mice, reduced tumor weight, with a better appearance than that of the control group. Conclusion:Aloesin may inhibit the expression of NSCLC by inducing apoptosis of A549 cells, and is safe to use, with no inhibitory effect on the body weight of mice.
ABSTRACT
Zinc oxide quantum dots (ZnO QDs) were synthesized by gel-sol method and employed as the transdermal aloesin (Alo) carriers. ZnO QDs were surface-functionalized with amino using aminopropyltriethoxysilane (APTES). Alo was covalently bonded on the surface of ZnO QDs via N,N'-carbonyldiimidazole to obtain Alo NPs, which were characterized by transmission electron microscope (TEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR) and thermal gravimetric analyzer (TGA). TEM images showed that ZnO QDs were analogously sphere and monodisperse with a reasonably narrow size distribution, of which was around 4 nm. The size of Alo NPs increased to around 8 nm due to the surface modification. The intense bands at around 3 400 cm and 1 200 cm in the FTIR spectrum of Alo NPs from the vibration of -OH indicated the linkage of Alo on the surface of ZnO QDs. The results of TGA analysis showed that the mass ratio of ZnO QDs and Alo were 39.27% and 35.14%, respectively. The penetration of Alo NPs was much higher than raw Alo according to the passive penetration experiments with Franz-type diffusion cells instrument using full-thickness cavy skin, which manifested the improvement of the penetration for Alo delivered by ZnO QDs. The pH-controlled drug release behavior was investigated. At pH 7.4, only a small amount of Alo (1.45% ± 0.21%) had been released after 2 h. In contrast, as incubation at pH 5.0 of which pH was similar to endosomal environment, Alo was released very fast (87.63% ± 0.46% in 2 h) from Alo NPs, confirming that Alo NPs could response to the pH and realize the intracellular drug release. The inhibitory effect of Alo NPs on tyrosinase was in a dose dependent manner. When the concentration of Alo NPs was 12.5 μg/mL, the inhibition rate was up to 40.32% ± 1.57%. All the results show that the Alo NPs hold a great potential in transdermal tyrosinase inhibition.
Subject(s)
Animals , Administration, Cutaneous , Chromones , Drug Delivery Systems , Glucosides , Guinea Pigs , Monophenol Monooxygenase , Metabolism , Nanoparticles , Quantum Dots , Zinc OxideABSTRACT
Aloe products are one of the top selling health-functional foods in Korea, however the adequate level of intake to achieve desirable effects are not well understood. The objective of this study was to determine the intestinal uptake and metabolism of physiologically active aloe components using in vitro intestinal absorption model. The Caco-2 cell monolayer and the everted gut sac were incubated with 5-50 micrometer of aloin, aloe-emodin, and aloesin. The basolateral appearance of test compounds and their glucuronosyl or sulfated forms were quantified using HPLC. The % absorption of aloin, aloe-emodin, and aloesin was ranged from 5.51% to 6.60%, 6.60% to 11.32%, and 7.61% to 13.64%, respectively. Up to 18.15%, 18.18%, and 38.86% of aloin, aloe-emodin, and aloesin, respectively, was absorbed as glucuronidated or sulfated form. These results suggest that a significant amount is transformed during absorption. The absorption rate of test compounds except aloesin was similar in two models; more aloesin was absorbed in the everted gut sac than in the Caco-2 monolayer. These results provide information to establish adequate intake level of aloe supplements to maintain effective plasma level.