Cudraxanthone D (CD) is a natural xanthone compound derived from the root barks of Cudrania tricuspidata . However, the biological functions of CD in human metabolism have been rarely reported until now. Autophagy is the self-degradation process related to cancer cell metastasis. Here, we elucidated the effects of CD on human oral squamous cell carcinoma (OSCC) cells’ metastatic ability. We confirmed that CD effectively decreased the proliferation and viability of SCC25 human OSCC cells in time- and dose-dependent manners. Also, the metastasis phenotype of the SCC25 cell (migration, invasion, and epithelial–mesenchymal transition [EMT]) was inhibited by CD. To further investigate the mechanism by which CD inhibited the metastatic capacity, we detected the relationship between EMT and autophagy in the SCC25 cells. The results revealed that CD inhibited the metastasis of the SCC25 cells by attenuating autophagy. Thus, our findings produced a potential novel agent for the treatment of human OSCC metastasis.

D-pinitol is an analog of 3-methoxy-D-chiro-inositol found in beans and plants. D-pinitol has anti-inflammatory, antidiabetic, and anticancer effects. Additionally, D-pinitol induces apoptosis and inhibits metastasis in breast and prostate cancers. However, to date, no study has investigated the anticancer effects of D-pinitol in oral cancer. Therefore, in this study, whether the anticancer effects of D-pinitol induce apoptosis, inhibit the epithelialto- mesenchymal transition (EMT), and arrest cell cycle was investigated in squamous epithelial cells. D-pinitol decreased the survival and cell proliferation rates of CAL-27 and Ca9-22 oral squamous carcinoma cells in a concentration- and time-dependent manner. Evidence of apoptosis, including nuclear condensation, poly (ADP-ribose) polymerase, and caspase-3 fragmentation, was also observed. D-pinitol inhibited the migration and invasion of both cell lines. In terms of EMT-related proteins, E-cadherin was increased, whereas N-cadherin, Snail, and Slug were decreased. D-pinitol also decreased the expression of cyclin D1, a protein involved in the cell cycle, but increased the expression of p21, a cyclin-dependent kinase inhibitor. Hence, D-pinitol induces apoptosis and cell cycle arrest in CAL-27 and Ca9-22 cells, demonstrating an anticancer effect by decreasing the EMT.

Piperlongumine (PL) is a natural product found in long pepper (Piper longum ). The pharmacological effects of PL are well known, and it has been used for pain, hepatoprotection, and asthma in Oriental medicine. No studies have examined the effects of PL on bone tissue or bone-related diseases, including osteoporosis. The current study investigated for the first time the inhibitory effects of PL on osteoclast differentiation, bone resorption, and osteoclastogenesis-related factors in RAW264.7 macrophages stimulated by the receptor activator for nuclear factor- κB ligand (RANKL). Cytotoxicity was examined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and osteoclast differentiation and bone resorption were confirmed by tartrate-resistant acid phosphatase (TRAP) staining and pit formation analysis. Osteoclast differentiation factors were confirmed by western blotting. PL exhibited toxicity in RAW264.7 macrophages, inhibiting osteoclast formation and bone resorption, in addition to inhibiting the expression of osteoclastogenesis-related factors, such as tumor necrosis factor receptor-associated factor 6 (TRAF6), c-Fos, and NFATc1, in RANKL-stimulated RAW264.7 macrophages. These findings suggest that PL is suitable for the treatment of osteoporosis, and it serves as a potential therapeutic agent for various bone diseases.

Oral squamous cell carcinoma (OSCC) is the most common type of oral malignancy. Numerous therapies have been proposed for its cure. Research is continually being conducted to develop new forms of treatment as current therapies are associated with numerous side-effects. Luteolin, a common dietary flavonoid, has been demonstrated to possess strong anti-cancer activity against various human cancer cell lines. Nevertheless, research into luteolin-based anticancer activity against oral cancer remains scarce. Thus, the objective of this study was to assess the effect of luteolin as an anti-cancer agent. After treatment with luteolin, Ca9-22 and CAL-27 oral cancer cells showed condensed nuclei and enhanced apoptotic rate with evidence of mitochondria-mediated apoptosis. Epithelial-mesenchymal transition (EMT) is closely related to tumor migration and invasion. Luteolin suppressed cancer cell invasion and migration in the current study. Elevated expression of E-cadherin, an adherens junction protein, was evident in both cell lines after luteolin treatment. Luteolin also significantly inhibited transcription factors (i.e., N-cadherin, Slug, Snail, Twist, and ZEB-1) that regulated expression of tumor suppressors such as E-cadherin based on Western blot analysis and quantitative PCR. Thus, luteolin could induce mitochondrial apoptosis and inhibit cancer cell invasion and migration by suppressing EMT-induced transcription factors.

In the present study, we evaluated the effect of CGM on osteogenic differentiation of cultured osteoblasts, and determined whether combination treatment with LLLT had synergistic effects on osteogenic differentiation. The results indicated that CGM promoted proliferation, differentiation, and mineralization of osteoblasts at the threshold concentration of 10 μg/ml; whereas, CGM showed cytotoxic properties at concentrations above 100 μg/ml. ALP activity and mineralization were increased at concentrations above 10 μg/ml . CGM in concentrations up to 10 μg/ml also increased the expression of osteoblast-activated factors including type I collagen, BMP-2, RUNX2, and Osterix. The CGM (50 μg/ml) and LLLT (80 mW for 15 sec) combination treatment group showed the highest proliferation levels, ALP activity, and mineralization ratios. The combination treatment also increased the levels of phosphorylated forms of p38, ATF2, PKD, ERK, and JNK. In addition, the osteoblast differentiation factors including type I collagen, BMP-2, RUNX2, and Osterix protein levels were clearly increased in the combination treatment group. These results suggested that the combination treatment of CGM and LLLT has synergistic effects on the differentiation and mineralization of osteoblastic cells.

OSCC is currently the most common malignancy of the head and neck, affecting tens of thousands of patients per year worldwide. Natural flavonoids from plants are potential sources for novel anti-cancer drugs. Icariin is the active ingredient of flavonol glycoside, which is derived from the medical plant Herba Epimedii. A metabolite of icariin, icariside II exhibits a variety of pharmacological actions, including anti-rheumatic, anti-depressant, cardiovascular protective, and immunomodulatory functions. However, the exact mechanism causing the apoptosis-inducing effect of icariside II in OSCC is still not fully understood. In the present study, we assessed the anti-cancer effect of icariside II in OSCC cell lines by measuring its effect on cell viability, cell proliferation, and mitochondria membrane potential (MMP). Icariside II treatment of OSCC cells resulted in a dose- and time-dependent decrease in cell viability. Hoechst staining indicated apoptosis in icariside II-treated HSC cells. Icariside II inhibited cell proliferation and induced apoptosis in HSC cells, with significant increases in all present parameters in HSC-4 cells. The results clearly suggested that icariside II induced apoptosis via activation of intrinsic pathways and caspase cascades in HSC-4 cell lines. The collective findings of the study suggested that Icariside II is a potential treatment for OSCC; in addition, the data could provide a basis for the development of a novel anti-cancer strategy.