Betulin, a kind of small molecular compound, was reported that has hypoglycemic effect. Due to its low aqueous solubility and high permeability, betulin has low and variable oral bioavailability. In this work, betulin nanoparticles were thus prepared by antisolvent precipitation for accelerating dissolution of this kind of poorly water-soluble drugs. Ethanol was used as solvent and deionized water was used as antisolvent. The effects of various experimental parameters on the mean particle size (MPS) of nanocrystallization betulin were investigated. The MPS of betulin nanoparticles suspension basically remain unchanged when precipitation time was within 60 min and then increased from 304 nm to 505 nm later. However, the MPS of betulin nanoparticles suspension decreased with increased betulin solution concentration. On the contrary, the MPS of betulin nanoparticles suspension decreased along with the increase of temperature. Stirring intensity and the speed ratio of solvent adding into antisolvent had no significant influences on the MPS of betulin nanoparticles suspension. Betulin nanoparticles suspension with a MPS of approximately 110 nm was achieved under the optimal precipitation conditions. FTIR, Liquid chromatography coupled with tandem mass spectrometry (LC-MS), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to analyze the characteristic of betulin nanoparticles powder. These results show that betulin nanoparticles powder has the same chemical structure as raw drug, but a smaller size and lower crystallinity. The dissolution rate and solubility of betulin nanoparticles powder were separately 3.12 and 1.54 times of raw drug. The bioavailability of betulin nanoparticles powder increased 1.21 times compared with raw betulin. The result of in vivo evaluation on diabetic animals demonstrates that the betulin nanoparticles powder show an excellent hypoglycemic effect compared with raw betulin. In addition, the residual ethanol is less than the ICH (International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human) limit for class 3 solvents of 5000 ppm or 0.5% for solvents.

The present study was conducted to screen a laccase-producing fungal endophyte, optimize fermentation conditions, and evaluate the decolorization ability of the laccase. A new fungal endophyte capable of laccase-producing was firstly isolated from pigeon pea and identified as Myrothecium verrucaria based on a ITS-rRNA sequences analysis. Meanwhile, various fermentation parameters on the laccase production were optimized via response surface methodology (RSM). The optimal fermentation conditions were a fermentation time of five days, temperature 30 °C and pH 6.22. Laccase activity reached 16.52 ± 0.18 U/mL under the above conditions. Furthermore, the laccase showed effective decolorization capability toward synthetic dyes (Congo red, Methyl orange, Methyl red, and Crystal violet) in the presence of the redox mediator ABTS, with more than 70% of dyes decolorizing after 24 h of incubation. Additionally, the activity of laccase was relatively stable with pH (4.5–6.5) and a temperature range of 35–55 °C. Therefore, the high laccase production of the strain and the new fungal laccase could provide a promising alterative approach for industrial and environmental applications.

Silymarin (SM), a well-known hepatoprotective drug, is widely used to treat liver disorders. However, its application was seriously restricted because of its poor aqueous solubility. In this study, silymarin nanoparticles (SMNs) were prepared through emulsion solvent evaporation and freeze-drying methods to improve their solubility. SM nanoemulsion was optimized through a single-factor experiment. SMNs with MPS of 107.1 ± 13.7 nm were produced under optimum conditions. These SMNs were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, differential scanning calorimetry, and thermal gravimetric analysis to determine their solvent residue, equilibrium solubility, dissolution rate, stability, antioxidant activity, bioavailability, and absorption in the liver. The results showed a smaller particle size and lower crystallinity in SMNs than those in raw SM. The solubility of SMNs was 4.87 times higher in simulated gastric fluid and 3.70 times higher in simulated intestinal fluid than that of raw silymarin. In addition, the residual amounts of chloroform and ethanol were separately less than the amount indicated by the international conference on harmonization limit for class II. The antioxidant activity after incubation with plasma in vitro of SMNs was higher than that of raw SM. Moreover, the oral bioavailability of SMNs was 3.66 times higher than that of raw SM. The silybin absorption of SMNs was also significantly higher than that of raw SM in the other organs, and very high silybin concentrations were observed in the liver with a long retention time. Overall, the results concluded that SMNs can be applied in oral delivery formulations and show potential application value for liver disease therapy.