Combined effect of subchondral drilling and hyaluronic acid with/without diacerein in full-thickness articular cartilage lesion in rabbits.

The osteochondral healing potential of hyaluronic acid (HA) plus diacerein was evaluated in subchondral-drilling- (SCD-) induced fibrocartilage generation in rabbits. A full-thickness chondral defect was created along the patellar groove of both knees and then SCD was subsequently performed only in the left knee. A week later, the rabbits were allocated into 3 groups to receive weekly intra-articular (IA) injection for 5 weeks with normal saline solution (NSS) (group 1) or with HA (group 2 and group 3). Starting at the first IA injection, rabbits were also gavaged daily for 9 weeks with NSS (group 1 and group 2) or with diacerein (group 3). The animals were then sacrificed for evaluation. The newly formed tissue in SCD lesions showed significantly better histological grading scale and had higher content of type II collagen in HA-treated group compared to NSS control. In addition, adding oral diacerein to HA injection enhanced healing potential of HA.

Properties and biocompatibility of chitosan and silk fibroin blend films for application in skin tissue engineering.

Chitosan/silk fibroin (CS/SF) blend films were prepared and evaluated for feasibility of using the films as biomaterial for skin tissue engineering application. Fourier transform infrared spectroscopy and differential scanning calorimetry analysis indicated chemical interaction between chitosan and fibroin. Chitosan enhanced ß-sheet conformation of fibroin and resulted in shifting of thermal degradation of the films. Flexibility, swelling index, and enzyme degradation were also increased by the chitosan content of the blend films. Biocompatibility of the blend films was determined by cultivation with fibroblast cells. All films showed no cytotoxicity by XTT assay. Fibroblast cells spread on CS/SF films via dendritic extensions, and cell-cell interactions were noted. Cell proliferation on CS/SF films was also demonstrated, and their phenotype was examined by the expression of collagen type I gene. These results showed possibility of using the CS/SF films as a supporting material for further study on skin tissue engineering.

In vitro and in vivo anti-inflammatory potential of Cryptolepis buchanani.

Cryptolepis buchanani Roem. & Schult. (Asclepiadaceae), a climbing tree, is used as folk medicine in southeast Asia. In Thailand, the stem of this plant is traditionally used for the treatment of inflammation, including arthritis, and muscle and joint pain. In the current study, the potential anti-inflammatory activity of a 50% ethanol extract of this plant was evaluated in a number of experimental models. For anti-acute inflammatory activity, results showed that the extract caused reduction of carrageenan-induced rat paw edema in addition to significant reduction of eicosanoid production from calcium ionophore A23187-stimulated rat peritoneal leukocytes. In a test for anti-chronic inflammatory potential utilizing the cotton thread-induced granuloma, the extract caused significant lowering of granulation tissue formation. The reduction of tumor necrosis factor-alpha (TNF-alpha) release from LPS-stimulated human monocytic cell line (THP-1) was also demonstrated in cells that were pre-incubated with the extract. An additional important feature of Cryptolepis buchanani is its low toxicity, especially by oral treatment, which significantly encourages clinical trials of this extract in the human. In conclusion, the results give scientific support to the traditional use of this plant for combating inflammation. Further investigations are required to identify the active constituents responsible for the anti-inflammatory activity of Cryptolepis buchanani. Subacute and chronic toxicological studies in animals are also needed before clinical trials.

Anti-inflammatory isoflavonoids from the stems of Derris scandens.

Fractionation of the aqueous extract of Derris scandens stems extract using tests for eicosanoid inhibition resulted in the isolation of three isoflavonoids, genistein, its 7- O-alpha-rhamno(1-->6)-beta-glucosyl glycoside, a new compound, and two known isoprenyl derivatives 3'-gamma,gamma-dimethylallylweighteone and scandenin. The isoprenylated compounds showed a high inhibitory effect on eicosanoid production in vitro but HPLC analysis showed that the genistein accounted for most of the activity of the total extract. Antioxidant studies showed that genistein and the isoprenylated compounds showed activity comparable to standard antioxidants. Genistein and its glycoside demonstrated no cytotoxicity in the MTT test but the prenylated compounds showed some toxicity and also increased LDH release from polymorphonucleocytes, at concentrations much greater than would be encountered in an aqueous extract of D. scandens.