Volatile fingerprints of different parts of Chongming saffron (Crocus sativus) flowers by headspace-gas chromatography-ion mobility spectrometry and in vitro bioactive properties of the saffron tepals.

In this work, the volatile fingerprints of different parts of Chongming saffron flowers (stigmas, stamens, and tepals) were analyzed and compared for the first time by headspace-gas chromatography-ion mobility spectrometry. Three different parts of saffron flowers could be clearly distinguished using principal component analysis based on signal intensity data of gas chromatography-ion mobility spectrometry. Therefore, gas chromatography-ion mobility spectrometry coupled with principal component analysis method could be employed as a new method for authentication and quality control of saffron for the reason of frequent addition with stamens and/or tepals as adulterants in saffron. Moreover, the bioactive composition (total flavonoids, total phenolics, and total anthocyanins) and bioactive properties of saffron tepals were evaluated. The results indicated that aqueous, ethanol, and ethyl acetate extracts of saffron tepals exhibited good radical scavenging (2,2-Diphenyl-1-picrylhydrazyl, ABTS, and OH) and enzyme (α-amylase/α-glucosidase) inhibition activities, which probably were attributed to the bioactive components contained in the extracts. This approach would provide the important information for monitoring the quality of saffron as well as exploring the utilization of saffron tepals in functional food technology. PRACTICAL APPLICATION: This study demonstrated that the HS-GC-IMS method might be used as a new strategy for quality control of saffron, and the saffron tepals were rich source of bioactive components that could be used in health-promoting products.

Proanthocyanidins attenuate breast cancer-induced bone metastasis by inhibiting Irf-3/c-jun activation.

We have previously demonstrated the pivotal role of Jnk-mediated Irf-3/c-Jun in regulating nuclear factor kappa-Β ligand (RANKL)-induced osteoclastogenesis. Here, we demonstrated that proanthocyanidins (PACs) target Irf-3 to alleviate breast cancer-induced activation of osteoclasts. We also found that PACs induced apoptosis of osteoclast precursors by upregulating the ratio of bax/bcl-2 and activating caspase-3 activity. Such bone protective effect also could be observed in a bone metastasis model of breast cancer. These findings provided a novel therapeutic intervention targeting abnormal bone metabolism to alleviate bone metastasis of breast cancer.

Glycyrrhizic acid suppresses osteoclast differentiation and postmenopausal osteoporosis by modulating the NF-κB, ERK, and JNK signaling pathways.

Postmenopausal osteoporosis, mainly caused by osteoclast-induced bone resorption, has become a global public health burden. Natural compounds are emerging as potential therapeutics for postmenopausal osteoporosis. In vitro osteoclastogenesis assay was conducted to investigate the effect of Glycyrrhizic acid (Gly) on osteoclast differentiation without cytotoxity. We applied bone resorption pit assessment and F-actin immunofluoresence to explore the effect of Gly on osteoclasts function in vitro. RT-qPCR was used to evaluate the expression level of RANKL-induced osteoclast-specific gene. Western blotting was conducted for analyzing potential mechanisms of inhibitory influence of Gly on the formation and function of osteoclasts in vitro. Ovariectomized (OVX) mice model, micro-CT and histomorphometry was used to survey the potential effect of Gly on the resorption of bone in vivo. Gly inhibited osteoclast differentiation and function without significant cytotoxicity at a dose of no more than 8 mM in vitro. Gly attenuated mRNA expression of osteoclast-specific genes including NFATc1, c-fos, TRAP, CTR, cathepsin K, and V-ATPase d2 in vitro. Gly inhibited degradation of IκBα, phosphorylation of ERK and JNK without disturbing phosphorylation of p38 after treating osteoclasts in vitro. In OVX mice, Gly attenuates osteoclast formation and preserves bone mass and trabecular structure. Gly can effectively inhibit osteoclast maturation and bone resorption by suppressing NF-κB, ERK, and JNK pathway in vitro and exhibits an osteoprotective effect in OVX mice.

Proanthocyanidins inhibit osteoclast formation and function by inhibiting the NF-κB and JNK signaling pathways during osteoporosis treatment.

Osteoporosis is a metabolic bone lesion in which the bone mass is reduced per unit volume due to increased bone resorption. Its main characteristics are bone pain and increasing danger of fragility fracture. Excessive osteoclast activation is known to be responsible for extensive bone resorption. Thus, inhibition of osteoclastic bone resorption and regulation of the bone microenvironment are vital treatment strategies for osteoporosis. For the first time, we investigated the effect of proanthocyanidins (PACs) extracted from grape seed, which significantly inhibited osteoclast formation and differentiation from bone marrow macrophages (BMMs) and the RAW264.7 cell line and efficiently attenuated osteoclastic bone resorption without toxicity. These findings were confirmed by changes in the NF-κB and JNK/mitogen-activated protein kinase (MAPK) signaling pathways, which are major and classical signaling pathways involved in RANKL-mediated osteoclastogenesis in vitro. The PACs inhibited osteoclast formation and differentiation by inhibiting the NF-κB and JNK signaling pathways and might be useful for the treatment of osteoporosis.