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(1) Background: Inhibition of osteoclast differentiation is the key approach in treating osteoporosis. However, using state-of-the-art treatments such as bisphosphonates and estrogen-based therapy is usually accompanied by many side effects. As opposed to this, the use of natural products as an osteoporotic remedy delivers promising outcomes with minimal side effects. (2) Methods: In the present study, we implemented a biochemometric workflow comprising (i) chemometric approaches using NMR and mass spectrometry and (ii) cell biological approaches using an osteoclast cytochemical marker (TRAP). The workflow serves as a screening tool to pursue potential in vitro osteoclast inhibitors. (3) Results: The workflow allowed for the selective isolation of two phenylpropanoids (coniferyl alcohol and sinapyl alcohol) from the fruits of neem tree (Azadirachta indica). These two isolated phenylpropanoids showed a very promising dose-dependent inhibition of osteoclast differentiation with negligible effects in terms of cell viability. (4) Conclusion: The presented workflow is an effective tool in the discovery of potential candidates for osteoclast inhibition from complex extracts. The used biochemometric approach saves time, effort and costs while delivering precise hints to selectively isolate bioactive constituents. [ABSTRACT FROM AUTHOR]

The heartwood extract of the Ayurvedic medicinal plant Pterocarpus santalinus L. f. has previously been shown to significantly suppress the expression of CX3CL1 and other pro-inflammatory molecules in IL-1-stimulated human endothelial cells. Here, we identify the pigment-depleted extract PSD as the most promising yet still complex source of metabolites acting as an inhibitor of CX3CL1 gene expression. For the target-oriented identification of the constituents contributing to the observed in vitro anti-inflammatory effect of PSD, the biochemometric approach ELINA (Eliciting Nature's Activities) was applied. ELINA relies on the deconvolution of complex mixtures by generating microfractions with quantitative variances of constituents over several consecutive fractions. Therefore, PSD was separated into 35 microfractions by means of flash chromatography. Their 1H NMR data and bioactivity data were correlated by heterocovariance analysis. Complemented by LC-MS-ELSD data, ELINA differentiated between constituents with positive and detrimental effects towards activity and allowed for the prioritization of compounds to be isolated in the early steps of phytochemical investigation. A hyphenated high-performance counter-current chromatographic device (HPCCC+) was employed for efficient and targeted isolation of bioactive constituents. A total of 15 metabolites were isolated, including four previously unreported constituents and nine that have never been described before from red sandalwood. Nine isolates were probed for their inhibitory effects on CX3CL1 gene expression, of which four isoflavonoids, namely pterosonin A (1), santal (6), 7,3′-dimethylorobol (12) and the previously unreported compound pterosantalin A (2), were identified as pronounced inhibitors of CX3CL1 gene expression in vitro. The biochemometeric approach ELINA facilitated the fast identification of known and so far unreported anti-inflammatory constituents from the heartwood extract of Pterocarpus santalinus. 1H-NMR and bioactivity data of P. santalinus microfractions were correlated via HetCA and, supported by LC-MS-ELSD, active constituents could be distinguished from the inactive ones prior to isolation. [Display omitted] • Red sandalwood exerts an anti-inflammatory activity via CX3CL1 gene suppression. • The biochemometric approach ELINA was applied to unravel bioactive constituents. • An upgraded HPCCC + system enabled a targeted isolation of compounds for assaying. • Experimental testing confirmed the results assessed by ELINA. • In sum, 15 constituents including 4 previously unreported compounds were isolated. [ABSTRACT FROM AUTHOR]