In vivo and in vitro evaluation of the osteogenic potential of Davallia mariesii T. Moore ex Baker.

ETHNOPHARMACOLOGICAL RELEVANCE: Postmenopausal osteoporosis is a major bone health issue worldwide. There is an unmet medical need for osteoporosis treatments, a disease which disproportionately impacts women. Exploring botanicals to prevent or treat osteoporosis is currently an interest of investigations. Rhizomes of Davallia mariesii T. Moore ex Baker (Davalliacea) are used an indigenous herbal medicine in Asia for injuries due to fractures, contusions, and strains. AIM OF THE STUDY: In the present study, we investigated the osteogenic effect of the water extract of rhizomes of D. mariesii (DMH) on bone loss induced by an ovariectomy (OVX) in mice and also its impact on osteogenesis in primary human osteoblasts (HObs). Additionally, we performed a quantitative analysis of compounds in the DMH extract. MATERIALS AND METHODS: OVX C57BL/6J mice were orally administrated DMH extract for 12 weeks, and microarchitecture parameters were examined by microcomputed tomography. DMH extract was fractionated in a bio-guided manner, and fractions were isolated to obtain active compounds using HObs. Cell viability was evaluated by an MTT assay. Characteristics of early and late osteogenesis were analyzed by alkaline phosphatase activity and a mineralization assay. Molecular mechanisms were explored by a real-time quantitative PCR. Compounds in the DMH extract were identified and quantified using liquid chromatography tandem mass spectroscopy (LC-MS/MS). RESULTS: DMH improved bone mineral densities of vertebrae and the femur. Through microarchitectural observations, DMH significantly decreased the bone surface/volume ratio and trabecular separation, and also increased the connectivity density in the OVX group. Additionally, DMH inhibited osteoclast differentiation in receptor activator of nuclear factor-κB ligand-induced osteoclasts and increased bone formation in HObs. After bio-guided fractionation and isolation, we found that eriodictyol-7-O-ß-d-glucuronide (2) significantly increased alkaline phosphatase activity, and 5-O-ß-d-(6-O-vanilloylglucopyranosyl)gentisic acid (3) substantially enhanced mineral deposition. In HObs, compound 3 was more potent in upregulating expressions of bone morphogenetic protein-2, bone sialoprotein, osteopontin, osterix, and estrogen receptor-α. The amount of bioactive compound 3 in DMH was 5.68 ±â€¯0.64 mg/g of dry weight according to LC-MS/MS. CONCLUSION: For the first time we report that D. mariesii and its isolated compounds demonstrated potent osteogenic activities. Quantitative results of D. mariesii could be a reference for phytochemical analyses.

Nerve guidance conduit with a hybrid structure of a PLGA microfibrous bundle wrapped in a micro/nanostructured membrane.

Nerve repair in tissue engineering involves the precise construction of a scaffold to guide nerve cell regeneration in the desired direction. However, improvements are needed to facilitate the cell migration/growth rate of nerves in the center of a nerve conduit. In this paper, we propose a nerve guidance conduit with a hybrid structure comprising a microfibrous poly(lactic-co-glycolic acid) (PLGA) bundle wrapped in a micro/nanostructured PLGA membrane. We applied sequential fabrication processes, including photolithography, nano-electroforming, and polydimethylsiloxane casting to manufacture master molds for the repeated production of the PLGA subelements. After demolding it from the master molds, we rolled the microfibrous membrane into a bundle and then wrapped it in the micro/nanostructured membrane to form a nerve-guiding conduit. We used KT98/F1B-GFP cells to estimate the migration rate and guidance ability of the fabricated nerve conduit and found that both elements increased the migration rate 1.6-fold compared with a flat PLGA membrane. We also found that 90% of the cells in the hybrid nano/microstructured membrane grew in the direction of the designed patterns. After 3 days of culturing, the interior of the nerve conduit was filled with cells, and the microfiber bundle was also surrounded by cells. Our conduit cell culture results also demonstrate that the proposed micro/nanohybrid and microfibrous structures can retain their shapes. The proposed hybrid-structured conduit demonstrates a high capability for guiding nerve cells and promoting cell migration, and, as such, is feasible for use in clinical applications.