Three-dimensional printing: review of application in medicine and hepatic surgery.

Three-dimensional (3D) printing (3DP) is a rapid prototyping technology that has gained increasing recognition in many different fields. Inherent accuracy and low-cost property enable applicability of 3DP in many areas, such as manufacturing, aerospace, medical, and industrial design. Recently, 3DP has gained considerable attention in the medical field. The image data can be quickly turned into physical objects by using 3DP technology. These objects are being used across a variety of surgical specialties. The shortage of cadaver specimens is a major problem in medical education. However, this concern has been solved with the emergence of 3DP model. Custom-made items can be produced by using 3DP technology. This innovation allows 3DP use in preoperative planning and surgical training. Learning is difficult among medical students because of the complex anatomical structures of the liver. Thus, 3D visualization is a useful tool in anatomy teaching and hepatic surgical training. However, conventional models do not capture haptic qualities. 3DP can produce highly accurate and complex physical models. Many types of human or animal differentiated cells can be printed successfully with the development of 3D bio-printing technology. This progress represents a valuable breakthrough that exhibits many potential uses, such as research on drug metabolism or liver disease mechanism. This technology can also be used to solve shortage of organs for transplant in the future.

Xanthones from Swertia mussotii as multitarget-directed antidiabetic agents.

Oxidative stress has been suggested to play a causative role in the development of obesity-induced insulin resistance and type 2 diabetes. Given the antioxidant potency of previously reported xanthones isolated from Swertia mussotii. These natural products were further evaluated against other targets in diabetes, aldose reductase and α-glucosidase, in order to identify novel multitarget-directed antidiabetic agents. Among the 14 xanthones screened, 1,3,7,8-tetrahydroxyxanthone (6), 1,3,5,8-tetrahydroxyxanthone (7), and 2,3,6,8-tetrahydroxyxanthone-7C-(ß-D-glucoside) (12) were confirmed as good antioxidants and α-glucosidase inhibitors. Xanthone 7 was also confirmed as a potent inhibitor of aldose reductase (ALR2). Xanthone 7 was the most active α-glucosidase and ALR2 inhibitor, with IC50 values of 5.2±0.3 µM and 88.6±1.6 nM, respectively, while compound 12 was shown to be the most active antioxidant. Given the overall profile, xanthone 7 is considered to be the most promising multitarget antidiabetic agent, and may have potential for the treatment of both diabetes and diabetic complications.

Xanthones from Swertia mussotii and their α-glycosidase inhibitory activities.

Two new xanthones, 1,8-dihydroxy-3-methoxyxanthone 7-O-[α-L-rhamnopyranosyl(1 → 2)-ß-D-glucopyranoside] (1) and 1,8- dihydroxy-3-methoxyxanthone 7-O-[α-L-rhamnopyranosyl(1 → 3)-α-L-rhamno-pyranosyl (1 → 2)-ß-D-xylopyranoside] (2), together with 26 known xanthones (3-28), were isolated from the aqueous ethanol extract of the traditional Chinese herb Swertia mussotii. Their structures were elucidated via spectroscopic analyses including 2D NMR. The inhibition of α-glucosidase by the isolated xanthones was evaluated by an in vitro high-throughput screening assay. Our results indicated that 1,3,5,8-tetrahydroxyxanthone is the best inhibitor with an IC50 value of 5.33 ± 0.09 µM, while the O-glycosylated xanthones were poor α-glycosidase inhibitors.

Antioxidant xanthones from Swertia mussotii, a high altitude plant.

Four new xanthones, 3,5,6,8-tetrahydroxyxanthone-1-C-ß-D-glucoside (1), 7-hydroxy-3,4,8-trimethoxyxanthone-1-O-(ß-D-glucoside) (2), 6-hydroxy-3,5-dimethoxyxanthone-1-O-(ß-D-glucoside) (3), 3,4,7,8-tetramethoxyxanthone-1-O-(ß-D-glucoside) (4), together with twenty-one known xanthones (5-25) were isolated from the ethanol aqueous extract of Swertia mussotii. Their structures were elucidated via spectroscopic analyses. Oxygen radical absorbance capacity of all the isolated xanthones was systematically evaluated by ORAC(FL) assay. Results disclose that all the tested xanthones display moderate to excellent antioxidant activity, where 1 is the most active compound and 13 is the least one. A preliminary structure-activity relationship is also discussed.