Purification of total flavonoids from Ginkgo biloba flowers with resin column chromatography and evaluation of antioxidant activities in vitro.

Purification of total flavonoids from Ginkgo biloba flowers (GBF) extracts were studied using six resins. Adsorption-desorption experiments indicated that polyamide resin is the most suitable resin. The optimal purification process of total flavonoids of GBF was as follows: a loading concentration of 5.85 mg/mL, a loading volume of 1 bed volume (BV), a loading flow rate of 2 BV/h, a water volume of 2.67 BV, and a desorption solution of 40% ethanol. Under these conditions, the maximum purity of total flavonoids was 37.1 ± 1.1%. The antioxidant activity of purified flavonoids was further evaluated in vitro. It showed that the 40% ethanol purified fraction (Fr. B) group had the strongest antioxidant activity of the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity concentration for 50% of maximal effect (EC50, 145.4 ± 13.8 µg/mL) and ferric reducing ability (2.5 ± 0.2 mM FeSO4 equivalent mg-1 Fr. B). In addition, at the concentration of 160 µg/mL, the Fr. B strikingly increased the viability rate of hydrogen peroxide stimulated PC-12 cells to normal levels (***p < 0.001). This method provides a basis for the application and development of GBF resources. It indicated that the purified GBF flavonoids can be used as a source of potential antioxidant.

Inhalable Andrographolide-ß-cyclodextrin Inclusion Complexes for Treatment of Staphylococcus aureus Pneumonia by Regulating Immune Responses.

Bacterial pneumonia is a serious disease with high mortality if no appropriate and immediate therapy is available. Andrographolide (AG) is an anti-inflammatory agent extracted from a traditional Chinese herb andrographis paniculata. Oral AG tablets and pills are clinically applied for treatment of upper respiratory tract infections. However, the low solubility and bioavailability of AG lead to high doses and long-term therapy. Here we developed an andrographolide-ß-cyclodextrin inclusion complex (AG-ß-CD) for inhalation therapy of Staphylococcus aureus pneumonia. AG-ß-CD was identified with X-ray diffraction and FT-IR. Surprisingly, both AG-ß-CD and AG showed little in vitro anti-S. aureus activity. However, pulmonary delivery of AG, AG-ß-CD, or penicillin had significant anti-S. aureus pneumonia effects. Leukocytes, neutrophils, white blood cells, total proteins, TNF-α, IL-6, NF-κB p65 expression, and bacterial colonies in the bronchoalveolar lavage fluids were detected. Pulmonary delivery of AG and AG-ß-CD led to bacterial inhibition and inflammation alleviation by regulating immune responses, while penicillin only killed bacteria without significant immune regulation. Moreover, the antipneumonia activity of AG-ß-CD was much higher than that of AG, probably resulting from locally accelerated AG dissolution due to ß-CD inclusion. The aerodynamic diameter of AG-ß-CD powders was 2.03 µm, suitable for pulmonary delivery. Inhalable AG-ß-CD is a promising antibacterial and anti-inflammatory medicine for the treatment of S. aureus pneumonia by regulating immune responses, and the effect is enhanced by ß-CD inclusion. AG and its formulations might be potent weapons against the resistant bacterial pneumonia due to their specific mechanism in the future.