Padam Kumar

Neoflavonoids as potential osteogenic agents from Dalbergia sissoo heartwood

The present study was undertaken to investigate and rationalize the in vitro antiosteoporotic activity of neoflavonoids, isolated from Dalbergia sissoo heartwood. Neoflavonoids were isolated using extensive column chromatography and identified as dalsissooal (1) a new compound and cearoin (2), dalbergin (3), 4-methoxy dalbergion (4), dalbergiphenol (5), dalbergichromene (6), methyl dalbergin (7) and latinone (8) as known compounds by comparison their spectroscopic data with those reported in the literature. Among the screened compounds, compounds 1, 3, 5-8 significantly increased proliferation as assessed by alkaline phosphatase activity and mineralization in calvarial osteoblast cells.

Fast and long acting neoflavonoids dalbergin isolated from Dalbergia sissoo heartwood is osteoprotective in ovariectomized model of osteoporosis: Osteoprotective effect of Dalbergin.

OBJECTIVE This study aims to evaluate the skeletal effects of dalbergin (DBN), isolated from Dalbergia sissoo heartwood, in ovariectomized (OVx) BALB/c mice, a postmenopausal osteoporosis model of bone loss. METHODS Adult BALB/c mice were used and randomly assigned in to six groups with 6 animals (n=6) in each group: sham (surgery operated without ovariectomy) with vehicle, ovariectomy with vehicle, ovariectomy (OVx) with estradiol (E2 5.0μgkg-1day-1), or ovariectomy with dalbergin at three different doses of DBN (1.0, 5.0 and10mgkg-1day-1). Daily oral administration of the vehicle, estradiol, or DBN was started 8 weeks post-surgery and continued for 8 weeks. At the end of experiment, mice were sacrificed and assessed for trabecular bone structure of tibia, lumbar vertebra (L5) and alterations in biochemical and uterine parameters, pharmacokinetic profile and gene expression were monitored for each group. RESULTS Treatment with DBN prevented trabecular bone loss in cancellous bone in the tibial metaphysis and lumbar vertebra region of the ovariectomized mice. Micro-CT data showed that mice treated with DBN at 1.0mgkg-1day-1 exhibited improved bone micro-architecture that was sustained with decreased expression of bone resorption markers like TRAP and RANK and caused an increase in osteogenic markers like RUNX2, BMP2 and OPG/RANKL ratio compared with OVx+vehicle treated mice. Moreover, DBN treatment induced no uterine estrogenicity and significantly lowered the osteocalcin amount in serum when compared with OVx+V group. DBN reached its maximum concentration (Cmax) 238.49±21.37ngml-1 in serum as early as 1h of administration. Overall, DBN (1.0mgkg-1day-1) treatment exhibited similar bone conserving effect against bone-loss as estradiol treatment. CONCLUSION Daily oral administration of DBN for 8 weeks showed significant anabolic effects on bone micro-architectural parameters along with down regulation of bone resorptive markers without compromising safety at uterine level. Therefore, our study provides basis for DBN as a therapeutic candidate against postmenopausal osteoporosis.

Synthesis of novel imbricatolic acid analogues via insertion of N-substituted piperazine at C-15/C-19 positions, displaying glucose uptake stimulation in L6 skeletal muscle cells

A new class of N-substituted piperazine analogues of imbricatolic acid have been designed and synthesized by using the appropriate synthetic routes in excellent yield. All synthesised compounds were screened for their in vitro glucose uptake stimulatory activity. Among them compounds 4b, 4e, 8b, and 8e triggered L6 skeletal muscle cells for glucose uptake at 54.73%, 40.79%, 40.90%, and 39.55% stimulation, respectively. Compound 4b has emerged as important lead compound showing potential antidiabetic activity. Illustration about their synthesis and in vitro glucose uptake activity is described.

A neoflavonoid dalsissooal isolated from heartwood of Dalbergia sissoo Roxb. has bone forming effects in mice model for osteoporosis.

Dalbergia sissoo Roxb. is a well known medicinal plant of India, enriched with various flavonoids used for treating multiple diseases. Earlier, we have shown that extract of Dalbergia sissoo Roxb. leaves mitigate ovariectomy induced bone loss and pure compounds (neoflavonoids) isolated from it, promote osteoblastogenesis in primary calvarial osteoblasts cells in vitro. Here, we hypothesize that dalsissooal (DSL), a novel neoflavonoid isolated from the heartwood of Dalbergia sissoo Roxb. is an important constituent of the extract that imparts bone forming effects. Treatment with DSL enhanced trabecular bone micro-architecture parameters, biomechanical strength, increased bone formation rate and mineral apposition rate in OVx mice comparable to 17β-estradiol. It increased bone formation by enhancing osteoblast gene expression and reduced bone turnover by decreasing osteoclastic gene expressions. Interestingly, we observed that DSL has no uterine estrogenic effects. At cellular levels, DSL promoted differentiation of bone marrow cells as well as calvaria osteoblast cells towards osteoblast lineage by enhancing differentiation and mineralizing ability to form mineralizing nodules via stimulating BMP-2 and RunX-2 expressions. Overall, our data suggest that oral supplementation of a novel neoflavonoid dalsissooal isolated from heartwood of Dalbergia sissoo Roxb. exhibited bone anabolic action by improving structural property of bone, promoting new bone formation and reducing bone turnover rate in post-menopausal model for osteoporosis with no uterine hyperplasia.

Study of conformational stability, structural, electronic and charge transfer properties of cladrin using vibrational spectroscopy and DFT calculations

In the present work, a detailed conformational study of cladrin (3-(3,4-dimethoxy phenyl)-7-hydroxychromen-4-one) has been done by using spectroscopic techniques (FT-IR/FT-Raman/UV-Vis/NMR) and quantum chemical calculations. The optimized geometry, wavenumber and intensity of the vibrational bands of the cladrin in ground state were calculated by density functional theory (DFT) employing 6-311++G(d,p) basis sets. The study has been focused on the two most stable conformers that are selected after the full geometry optimization of the molecule. A detailed assignment of the FT-IR and FT-Raman spectra has been done for both the conformers along with potential energy distribution for each vibrational mode. The observed and scaled wavenumber of most of the bands has been found to be in good agreement. The UV-Vis spectrum has been recorded and compared with calculated spectrum. In addition, 1H and 13C nuclear magnetic resonance spectra have been also recorded and compared with the calculated data that shows the inter or intramolecular hydrogen bonding. The electronic properties such as HOMO-LUMO energies were calculated by using time-dependent density functional theory. Molecular electrostatic potential has been plotted to elucidate the reactive part of the molecule. Natural bond orbital analysis was performed to investigate the molecular stability. Non linear optical property of the molecule have been studied by calculating the electric dipole moment (μ) and the first hyperpolarizability (β) that results in the nonlinearity of the molecule.

Heartwood extract from Dalbergia sissoo promotes fracture healing and its application in ovariectomy‐induced osteoporotic rats

This study was undertaken to investigate the effects of a heartwood ethanolic extract (HEE) made from the Dalbergia sissoo on facture healing and in the prevention of pathological bone loss resulting from estrogen deficiency in ovariectomized (Ovx) rats.

New lignan glycosides from Cissus quadrangularis stems

Abstract Phytochemical investigation of Cissus quadrangularis stems led to the isolation of one new phenolic glycoside (1) and two new lignan glycosides (7 & 8) along with twelve known compounds (2–6 & 9–15). Their chemical structures were determined on the basis of extensive spectroscopic analysis using 1D, 2D NMR, and mass spectrometric analysis. Among the known compounds, 4–6, 9 and 12 were isolated for the first time from the genus Cissus whereas compounds 10, 11 and 13 for the first time from this plant.

Ethanolic extract of Dalbergia sissoo promotes rapid regeneration of cortical bone in drill-hole defect model of rat.

Leaves of Dalbergia sissoo is known to have protective actions against postmenopausal bone loss in rat. In this study, we have evaluated the fracture healing properties of ethanolic extract (EE) of Dalbergia sissoo leaves. To observe the fracture healing property in the drill-hole injury model, we randomly divided total 32 adult female Sprague Dawley rats (180±200g) into 4 groups: (i) Control operated group; (ii) EE (250mg/kg/day); (iii) EE (500mg/kg/day) and (iv) EE (1000mg/kg/day). The right femora were fractured at the mid-diaphysis region and each group of rats received their respective treatment for 15days. Ethanol extract dose dependently induced bone regeneration at the fracture site assessed by fluorochrome labeling. All of three doses, 250mg/kg/day dose significantly increased bone volume fraction, trabecular thickness, trabecular number, and connectivity density and decreased trabecular separation in bone. Furthermore, the extract induced the expression of osteogenic genes including BMP-2, BMP-4, RunX-2 and COL-1 compared to the control group. The EE improved fracture healing much earlier (day 15) than the normal healing process, as assessed by the increased callus volumes and mineralized nodule formation. This extract is found beneficial in fracture healing of rat.

Design and synthesis of dalbergin analogues and evaluation of anti-osteoporotic activity

The chemical modifications of the hydroxyl group of dalbergin have been described via the introduction of cyclic amine, ester and amide groups. Among the twenty-three prepared novel analogues of dalbergin, compound 4d (EC50 2.3μM) showed significantly increased proliferation as assessed by alkaline phosphatase activity and mineralization in calvarial osteoblast cells in vitro. Compound 4d, at a dose of 1.0mg/kg body weight exhibited the significant osteoprotective effect. It showed a significant increase in osteogenic gene expression RunX2 (∼4fold), ALP (∼5fold), OCN (∼4fold) and COL1 (∼4fold) as compared to control group at the same dose in vivo assay.