Theabrownin inhibits the cytoskeleton­dependent cell cycle, migration and invasion of human osteosarcoma cells through NF­κB pathway­related mechanisms.

Considering the high metastatic potential of osteosarcoma, not only pro­apoptosis, but also anti­metastasis is important for anti­osteosarcoma therapy. Previously, the authors reported the pro­apoptotic and tumor­inhibitory effects of theabrownin (TB) on osteosarcoma cells; however, its effects on the metastasis­related migration and invasion of osteosarcoma cells remain unknown. The present study conducted RNA sequencing (RNA­seq) on xenograft zebrafish samples and performed in vitro experiments, including RT­qPCR, cell viability analysis, clone formation assay, cell cycle analysis, immunofluorescence, cell migration assay, cell invasion assay, wound healing assay and western blot (WB) analysis to evaluate the anti­metastatic effects and mechanism of TB against osteosarcoma cells. The RNA­seq data revealed that TB significantly downregulated the expression of genes involved in the microtubule bundle formation of U2OS cells, which was verified by RT­qPCR. The cell viability and clone formation data indicated that TB significantly inhibited U2OS cell viability and colony numbers. The results of cell cycle analysis revealed the blocked cell cycle progression of U2OS by TB. The immunofluorescent data revealed an evident cytoskeleton­inhibitory effect of TB against the microfilament and microtubule formation of U2OS cells. The results of cell migration and invasion demonstrated that TB significantly inhibited U2OS cell migration and invasion. The results of WB analysis revealed that TB significantly regulated key molecules of epithelial­mesenchymal transition [EMT; e.g., E­cadherin, vimentin, Snail­1, Slug and zinc finger E­box­binding homeobox 1 (ZEB­1)] and those of the nuclear factor (NF)­κB pathway (e.g., NF­κB, phospho­IKKα and phospho­IKKß), indicating that NF­κB pathway­related EMT suppression may mediate the mechanisms underlying the anti­migratory and anti­invasive effects of TB against osteosarcoma. To the best of our knowledge, this is the first study on the inhibitory effects and mechanisms of TB on the cytoskeleton­dependent cell cycle, migration and invasion of human osteosarcoma cells. The findings presented herein suggest that TB may be a promising anti­metastatic candidate for anti­osteosarcoma therapy.

Theabrownin triggers DNA damage to suppress human osteosarcoma U2OS cells by activating p53 signalling pathway.

Osteosarcoma becomes the second leading cause of cancer death in the younger population. Current outcomes of chemotherapy on osteosarcoma were unsatisfactory to date, demanding development of effective therapies. Tea is a commonly used beverage beneficial to human health. As a major component of tea, theabrownin has been reported to possess anti-cancer activity. To evaluate its anti-osteosarcoma effect, we established a xenograft model of zebrafish and employed U2OS cells for in vivo and in vitro assays. The animal data showed that TB significantly inhibited the tumour growth with stronger effect than that of chemotherapy. The cellular data confirmed that TB-triggered DNA damage and induced apoptosis of U2OS cells by regulation of Mki67, PARP, caspase 3 and H2AX, and Western blot assay showed an activation of p53 signalling pathway. When P53 was knocked down by siRNA, the subsequent downstream signalling was blocked, indicating a p53-dependent mechanism of TB on U2OS cells (p53 wt). Using osteosarcoma cell lines with p53 mutations (HOS, SAOS-2 and MG63), we found that TB exerted stronger inhibitory effect on U2OS cells than that on p53-mut cell lines, but it also exerted obvious effect on SAOS-2 cells (p53 null), suggesting an activation of p53-independent pathway in the p53-null cells. Interestingly, theabrownin was found to have no toxicity on normal tissue in vivo and could even increase the viability of p53-wt normal cells. In sum, theabrownin could trigger DNA damage and induce apoptosis on U2OS cells via a p53-dependent mechanism, being a promising candidate for osteosarcoma therapy.

Theabrownin Inhibits Cell Cycle Progression and Tumor Growth of Lung Carcinoma through c-myc-Related Mechanism.

Green tea, the fresh leaves of Camellia sinensis, is not only a health-promoting beverage but also a traditional Chinese medicine used for prevention or treatment of cancer, such as lung cancer. Theabrownin (TB) is the main fraction responsible for the medicinal effects of green tea, but whether it possesses anti-cancer effect is unknown yet. This study aimed to determine the in vitro and in vivo anti-lung cancer effect of TB and explore the underlying molecular mechanism, by using A549 cell line and Lewis lung carcinoma-bearing mice. In cellular experiment, MTT assay was performed to evaluate the inhibitory effect and IC50 values of TB, and flow cytometry was conducted to analyze the cell cycle progression affected by TB. In animal experiment, mice body mass, tumor incidence, tumor size and tumor weight were measured, and histopathological analysis on tumor was performed with Transferase dUTP nick-end labeling staining. Real time PCR and western blot assays were adopted to detect the expression of C-MYC associated genes and proteins for mechanism clarification. TB was found to inhibit A549 cell viability in a dose- and time-dependent manner and block A549 cell cycle at G0/G1 phase. Down-regulation of c-myc, cyclin A, cyclin D, cdk2, cdk4, proliferation of cell nuclear antigen and up-regulation of p21, p27, and phosphate and tension homolog in both gene and protein levels were observed with TB treatment. A c-myc-related mechanism was thereby proposed, since c-myc could transcriptionally regulate all other genes in its downstream region for G1/S transitions of cell cycle and proliferation of cancer cells. This is the first report regarding the anti-NSCLC effect and the underlying mechanism of TB on cell cycle progression and proliferation of A549 cells. The in vivo data verified the in vitro result that TB could significantly inhibit the lung cancer growth in mice and induce apoptosis on tumors in a dose-dependent manner. It provides a promising candidate of natural products for lung cancer therapy and new development of anti-cancer agent.

Anti-Proliferative and Apoptosis-Inducing Effect of Theabrownin against Non-small Cell Lung Adenocarcinoma A549 Cells.

With the highest cancer incidence rate, lung cancer, especially non-small cell lung cancer (NSCLC), is the leading cause of cancer death in the world. Tea (leaves of Camellia sinensis) has been widely used as a traditional beverage beneficial to human health, including anti-NSCLC activity. Theabrownin (TB) is one major kind of tea pigment responsible for the beneficial effects of tea liquor. However, its effect on NSCLC is unknown. The aim of the present study was to evaluate anti-proliferative and apoptosis-inducing effect of TB on NSCLC (A549) cells, using MTT assay, morphological observation (DAPI staining), in situ terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, and annexin-V/PI flow cytometry. Subsequently, the expression of several genes associated with cell proliferation and apoptosis were detected by real time PCR assay to explore its potential underlying mechanism. TB was revealed to inhibit cell proliferation of A549 cells in a concentration-dependent and time-dependent manner. Morphological observation, TUNEL assay and flow cytometric analysis evidenced an apoptosis-inducing effect of TB on A549 cells in a concentration-dependent manner. The real time PCR assay demonstrated that TB down-regulated the expression of TOPO I, TOPO II, and BCL-2, and up-regulated the expression of E2F1, P53, GADD45, BAX, BIM, and CASP 3,7,8,9, which suggests an activation of P53-mediated apoptotic (caspase-dependent) pathway in response to TB treatment. The western blot analysis showed a similar trend for the corresponding protein expression (P53, Bax, Bcl-2, caspase 3,9, and PARP) and further revealed DNA damage as a trigger of the apoptosis (phosphorylation of histone H2A.X). Accordingly, TB can be speculated as a DNA damage inducer and topoisomerase (Topo I and Topo II) inhibitor that can up-regulate P53 expression and subsequently modulate the expression of the downstream genes to induce cell proliferation inhibition and apoptosis of A549 cells. Our results indicate that TB exhibits its anti-NSCLC activity via a P53-dependent mechanism, which may be a promising candidate of natural product for anti-cancer drug development in the treatment of NSCLC.

In Vivo Cardiotoxicity Induced by Sodium Aescinate in Zebrafish Larvae.

Sodium aescinate (SA) is a widely-applied triterpene saponin product derived from horse chestnut seeds, possessing vasoactive and organ-protective activities with oral or injection administration in the clinic. To date, no toxicity or adverse events in SA have been reported, by using routine models (in vivo or in vitro), which are insufficient to predict all aspects of its pharmacological and toxicological actions. In this study, taking advantage of transparent zebrafish larvae (Danio rerio), we evaluated cardiovascular toxicity of SA at doses of 1/10 MNLC, 1/3 MNLC, MNLC and LC10 by yolk sac microinjection. The qualitative and quantitative cardiotoxicity in zebrafish was assessed at 48 h post-SA treatment, using specific phenotypic endpoints: heart rate, heart rhythm, heart malformation, pericardial edema, circulation abnormalities, thrombosis and hemorrhage. The results showed that SA at 1/10 MNLC and above doses could induce obvious cardiac and pericardial malformations, whilst 1/3 MNLC and above doses could induce significant cardiac malfunctions (heart rate and circulation decrease/absence), as compared to untreated or vehicle-treated control groups. Such cardiotoxic manifestations occurred in more than 50% to 100% of all zebrafish treated with SA at MNLC and LC10. Our findings have uncovered the potential cardiotoxicity of SA for the first time, suggesting more attention to the risk of its clinical application. Such a time- and cost-saving zebrafish cardiotoxicity assay is very valid and reliable for rapid prediction of compound toxicity during drug research and development.

Chondroprotective activity of a detoxicated traditional Chinese medicine (Fuzi) of Aconitum carmichaeli Debx against severe-stage osteoarthritis model induced by mono-iodoacetate.

ETHNOPHARMACOLOGICAL RELEVANCE: Fuzi is an effective but toxic traditional Chinese medicine (TCM) derived from Aconitum carmichaeli. In our previous study, detoxicated Fuzi (d-Fuzi) has been originally developed with no toxicity but significant efficacy. However, whether d-Fuzi can be used for therapy of osteoarthritis (OA), remain unknown. MATERIALS AND METHODS: Severe OA model was established by intra-articular mono-iodoacetate (MIA) injection (1.25mg) into rats and orally treated with 2g/ml d-Fuzi at a dosage of 7 ml/kg body weight for 28 days. In vivo, the articular radiographic and histopathologic analyses were performed to qualitatively assess the chondroprotective effect of d-Fuzi, followed by quantitative measurements of bone density and Mankin scores. In vitro, such effect on chondrocyte viability after MIA attack was evaluated. Hybrid quadrupole time-of-flight mass spectrometry (QTOF-MS) was performed for chemical analysis of d-Fuzi. RESULTS: d-Fuzi was demonstrated to possess chondroprotective activity on MIA-induced OA model by in vivo preventing the articular degeneration and the reducing of bone density and Mankin score, as well as by in vitro promoting the chondrocyte proliferation and inhibiting the MIA-induced chondrocyte damage. A total of 23 compounds were identified in d-Fuzi, most of which were deduced as the non-toxic derivatives of aconite alkaloids. CONCLUSIONS: This is the first report regarding chondroprotective effect and chemical profile of d-Fuzi, originally revealing its great anti-OA potential and thereby providing a promising TCM candidate for OA therapy.