Resveratrol Enhances Anticancer Effects of Silybin on HepG2 Cells and H22 Tumor-bearing Mice via Inducing G2/M Phase Arrest and Increasing Bax/Bcl-2 Ratio.

BACKGROUND: Silybin, a major flavonoid extracted from the seeds of milk thistle, has a strong hepatoprotective but weak anti-hepatoma activity. Screening another natural ingredient and combining it with silybin is expected to improve the anti-hepatoma efficacy of silybin. OBJECTIVE: The objective of this study was to investigate the synergistic anti-hepatoma effect of resveratrol and silybin on HepG2 cells and H22 tumor-bearing mice in hepatocellular carcinoma (HCC) in vitro and in vivo, respectively. METHODS: Cell viability, scratch wound, clone formation, cell apoptosis, cell cycle, and western blot analysis of HepG2 cells were used to investigate the synergistic effects in vitro of the combination resveratrol with silybin. Growth rates, tumor weights, organ indexes, and histological pathological examination in H22 tumor-bearing mice were used to investigate the synergistic effects in vivo. RESULTS: The combination of resveratrol (50 µg/mL) and silybin (100 µg/mL) significantly suppressed cell viability, whose combination index (CI) was 1.63 (>1.15), indicating the best synergism. The combination exhibited the synergistic effect in blocking the migration and proliferative capacity of HepG2 cells in the measurement in vitro. In particular, resveratrol enhanced the upregulation of Bcl-2 expression and the downregulation of Bax expression with a concurrent increase in the Bax/Bcl-2 ratio. The combination of resveratrol (50 mg/kg) and silybin (100 mg/kg) reduced the tumor weight, inhibited the growth rate, increased the organ indexes, and destroyed the tumor tissue morphology in H22 tumor-bearing mice. CONCLUSION: Resveratrol was found to exhibit synergistic anti-cancer effects with silybin on HepG2 cells and H22 tumor-bearing mice.

Immunomodulatory activity of puerarin in RAW264.7 macrophages and cyclophosphamide-induced immunosuppression mice.

CONTEXT: Puerarin, a natural isoflavone extracted from Radix puerariae, is famous for treating various cardiovascular and cerebrovascular diseases. However, little is known about its direct immunomodulatory activity. OBJECTIVE: This study was designed to investigate the in vitro and in vivo immunomodulatory effects of Radix puerariae by using the murine monocyte-macrophage cell line RAW264.7 and immunosuppressed cyclophosphamide-induced mice. METHODS: MTT and neutral red phagocytosis assays were conducted to evaluate the in vitro immunomodulatory activities of puerarin on cell viability and phagocytosis by measuring the proliferation, phagocytic, nitric oxide (NO) ability, and TNF-α production ability of stimulated and lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Immunosuppressed cyclophosphamide-induced mice were used to evaluate the in vivo immunomodulatory activities of puerarin by measuring IL-4 and IFN-γ, the serum half hemolysis value, spleen and thymus index, and proliferation assay for splenic lymphocytes. RESULTS AND DISCUSSION: Results showed that puerarin improves immunomodulatory activity by increasing cell proliferation, cell phagocytosis, and NO secretion in RAW264.7 macrophages and reduces the abnormal immunologic activity by decreasing cell phagocytosis and NO secretion in LPS-stimulated RAW264.7 macrophages. In addition, puerarin enhanced the immunologic activity of cyclophosphamide-induced immunosuppression mice by increasing the secretion of NO, IFN-γ, and IL-4, the serum half hemolysis value (HC50), the spleen and thymus index, and proliferation for splenic lymphocytes. CONCLUSION: Puerarin exhibited an upregulated immunomodulatory effect on RAW264.7 macrophages and immunosuppression mice. In addition, puerarin had a downregulated immunomodulatory effect on RAW264.7 macrophages. The results suggest that puerarin could be a promising immunomodulator to assist in the treatment of tumors.

Solid lipid nanoparticles for sustained pulmonary delivery of Yuxingcao essential oil: Preparation, characterization and in vivo evaluation.

The objective of this study was to prepare solid lipid nanoparticles (SLNs) for sustained pulmonary delivery of Yuxingcao essential oil (YEO). Three YEO loaded SLNs (SLN-200, SLN-400 and SLN-800) with different particle size were prepared and separated following a high-shear homogenization technique using Compritol 888 ATO as lipid and polyvinyl alcohol as an emulsifier. The particle size, zeta potential, drug encapsulation efficiency and drug loading of the SLNs were determined to be between 171 and 812nm, -17.1 and -19.3mV, between 76.6 and 90.2% and between 2.34 and 3.12%, respectively whereas the in vitro release data showed that the SLNs led to sustained drug release up to 48h. In addition, the SLN suspensions after nebulization conferred the fine particle fractions (<5.4µm) of 67.4-75.8%. Following intratracheal administration to rats, YEO loaded SLNs not only prolonged pulmonary retention up to 24h, but also increased AUC values (15.4, 18.2 and 26.3µg/gh for SLN-200, SLN-400 and SLN-800, respectively) by 4.5-7.7 folds compared to the intratracheally dosed YEO solution and by 257-438 folds to the intravenously dosed YEO solution, respectively. The present results were the first to show that YEO loaded SLNs may sustain YEO inhalation delivery and improve local bioavailability, representing a promising inhalable carrier to attain once daily application.