Estrogenic activity and toxicity screening of Damnacanthal nanospheres and their metabolites assessed using an in vitro bioluminescent yeast assay.

The root of Morinda citriforia L. (Noni) was used to extract Damnacanthal (Damna), an anthraquinone compound. In this study, Damna was successfully incorporated in N-phthaloylchitosan-grafted poly (ethylene glycol) methyl ether (PhCS-g-mPEG) to form Damna nanospheres (Damna-NS) with the particle size 298 nm and the incorporation efficiency 36.30 %. A bioluminescent yeast-reporter system was used to assess Damna-NS's estrogenic or toxic effects. The initial screening results revealed that both Damna and Damna-NS themselves showed no estrogenic effect. They showed strong effects when treated with a S9 fraction or liver microsomes, showing that their metabolites are estrogenic. Toxicity tests demonstrated that Damna and Damna-NS are harmful when used alone; however, they showed no toxicity when treated with S9 mix. In conclusion, the findings showed that Damna-NS, when taken as an oral phytoestrogen for hormone replacement treatment, has the potential to endanger human health by producing estrogenic effects and minimizing harmful effects in the liver.

Acute oral toxicity of damnacanthal and its anticancer activity against colorectal tumorigenesis.

Damnacanthal is an anthraquinone, extracted, and purified from the root of Morinda citrifolia in Thailand. This study aimed to measure acute oral toxicity and to investigate the anticancer activity of damnacanthal in colorectal tumorigenesis. We found that the growth of human colorectal cancer cells was inhibited by damnacanthal in a dose- and a time-dependent manner. The growth inhibitory effect of damnacanthal was better than that of 5-FU used as a positive control in colorectal cancer cells, along with the downregulation of cell cycle protein cyclin D1. Similarly, an oral treatment of damnacanthal effectively inhibited the growth of colorectal tumor xenografts in nude mice, which was approximately 2-3-fold higher as compared to 5-FU by tumor size as well as expression of bioluminescence. Furthermore, the study of acute oral toxicity in mice exhibited a relatively low toxicity of damnacanthal with a LD50 cut-off value of 2500 mg/kg according to OECD Guideline 423. These results reveal the potential therapeutic activity of a natural damnacanthal compound as an anti-colorectal cancer drug.

Chitosan-based nanoparticles with damnacanthal suppress CRM1 expression.

Cancer is one of the leading causes of mortality worldwide. Phytochemicals may be promising anticancer agents given their various chemical structures and diverse biological activities. Damnacanthal (DAM) is a major bioactive component of Noni, which has been investigated previously as a cancer-preventive or chemotherapeutic agent. DAM has also been reported to exhibit anti-proliferative activity in several cancer types. In the present study, it was identified that DAM downregulates chromosome maintenance protein 1 (CRM1) expression in human cancer cells. The application of chitosan-based nanoparticles (NPs) with DAM also induced CRM1 downregulation, which suggests that chitosan-based NPs may be effective vehicles for delivery of phytochemicals such as DAM. It was also identified that DAM increased the levels of the tumor suppressor non-steroidal anti-inflammatory drugs-activated gene 1 in the nucleus, thereby leading to enhanced anticancer effects. The results of the present study indicate that DAM and its nanoformulation may be a candidate anticancer drug.

Self-assembled nanomicelles of damnacanthal-loaded amphiphilic modified chitosan: Preparation, characterization and cytotoxicity study.

Damnacanthal (Dam) is a phytochemical with many pharmacological properties including anticancer activity. However, its hydrophobicity, poor bioavailability and stability limit its application in many biological approaches. In this study, Dam nanomicelles as an emerging platform were developed to overcome limitations. The deoxycholic and poly(ethylene glycol) methyl ether grafted chitosan (DCA-CS-mPEG) was synthesized and characterized by FTIR and 1H NMR and the degree of substitution (DS) was determined by elemental analysis (EA). This polymer formed self-assembled micelles with a core-shell structure and a critical micelle concentration (CMC) of 37.2µg/mL. Dam-loaded polymeric micelles were prepared by dialysis method and characterized by DLS, TEM, FTIR, DSC and HPLC. The mean particle size of Dam-loaded micelles was about 200nm with spherical shape. The drug entrapment efficiency was up to 57.7%. FTIR and DSC analysis revealed that Dam was entrapped in the micelles in the amorphous state. The in vitro release profiles of Dam from micelles were sustained release and pH-sensitive behavior. Cytotoxic studies exhibited the comparable efficacy and safety of this delivery system. Overall these results indicate the possible utilization of DCA-CS-mPEG micelles as a promising carrier for hydrophobic compounds like Dam.

Damnacanthal, a noni component, exhibits antitumorigenic activity in human colorectal cancer cells.

Damnacanthal, an anthraquinone compound, is isolated from the roots of Morinda citrifolia L. (noni), which has been used for traditional therapy in several chronic diseases including cancer. Although noni has been consumed for a long time in Asian and Polynesian countries, the molecular mechanisms by which it exerts several benefits are starting to emerge. In this report, we examined systematic approaches on the cancer-suppressing capability of damnacanthal in colorectal tumorigenesis. Damnacanthal exhibits cell growth arrest as well as caspase activity induction in colorectal cancer cells. We also examined several potential target proteins and found that the proapoptotic protein nonsteroidal anti-inflammatory activated gene-1 (NAG-1) is highly induced. Subsequently, we have found that damnacanthal also enhances transcription factor CCAAT/enhancer binding protein ß (C/EBPß), which controls NAG-1 transcriptional activity. Blocking of C/EBPß by shRNA results in the reduction of NAG-1 expression as well as caspase activity in the presence of damnacanthal. Taken together, these results indicate that damnacanthal increases antitumorigenic activity in human colorectal cancer cells and that C/EBPß plays a role in damnacanthal-induced NAG-1 expression.

Damnacanthal-induced anti-inflammation is associated with inhibition of NF-κB activity.

Morinda citrifolia L. (Rubiaceae), commonly called noni, is a traditional folk medicinal plant with a long history of use for several diseases. Its anti-inflammation activity has been proposed, but detailed knowledge of this antiinflammation mechanism remains unclear. Here, we investigated the effects of noni extract and its major bioactive component damnacanthal on anti-inflammation in vivo as well as in vitro. Our data demonstrate that noni extract and its bioactive component damnacanthal exhibit suppression of inflammation as evidenced by the suppression of paw and ear edema in rats and mice, and down-regulation of lipopolysaccharide-induced nuclear factor-κB (NF-κB) activity, respectively. As a result, the expression of pro-cytokines, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) were suppressed in the presence of damnacanthal. These results provide a potential use of damnacanthal in the treatment of inflammatory-related diseases.

Molecular targets of apigenin in colorectal cancer cells: involvement of p21, NAG-1 and p53.

Persuasive epidemiological and experimental evidence suggests that dietary flavonoids have anti-cancer activity. Since conventional therapeutic and surgical approaches have not been able to fully control the incidence and outcome of most cancer types, including colorectal neoplasia, there is an urgent need to develop alternative approaches for the management of cancer. We sought to develop the best flavonoids for the inhibition of cell growth, and apigenin (flavone) proved to be the most promising compound in colorectal cancer cell growth arrest. Subsequently, we found that pro-apoptotic proteins (NAG-1 and p53) and cell cycle inhibitor (p21) were induced in the presence of apigenin, and kinase pathways, including PKCδ and ataxia telangiectasia mutated (ATM), play an important role in activating these proteins. The data generated by in vitro experiments were confirmed in an animal study using APC(MIN+) mice. Apigenin is able to reduce polyp numbers, accompanied by increasing p53 activation through phosphorylation in animal models. Our data suggest apparent beneficial effects of apigenin on colon cancer.