Nexrutine inhibits azoxymethane-induced colonic aberrant crypt formation in rat colon and induced apoptotic cell death in colon adenocarcinoma cells

Transcriptomic and proteomic insights into patulin mycotoxin-induced cancer-like phenotypes in normal intestinal epithelial cells

Patulin (PAT) is a natural contaminant of fruits (primarily apples) and their products. Significantly, high levels of contamination have been found in fruit juices all over the world. Several in vitro studies have demonstrated PAT's ability to alter intestinal structure and function. However, in real life, the probability of low dose long-term exposure to PAT to humans is significantly higher through contaminated food items. Thus, in the present study, we have exposed normal intestinal cells to non-toxic levels of PAT for 16 weeks and observed that PAT had the ability to cause cancer-like properties in normal intestinal epithelial cells after chronic exposure. Here, our results showed that chronic exposure to low doses of PAT caused enhanced proliferation, migration and invasion ability, and the capability to grow in soft agar (anchorage independence). Moreover, an in vivo study showed the appearance of colonic aberrant crypt foci (ACFs) in PAT-exposed Wistar rats, which are well, establish markers for early colon cancer. Furthermore, as these neoplastic changes are consequences of alterations at the molecular level, here, we combined next-generation RNA sequencing with liquid chromatography mass spectrometry-based proteomic analysis to investigate the possible underlying mechanisms involved in PAT-induced neoplastic changes.

Safety studies of Nexrutine, bark extract of Phellodendron amurense through repeated oral exposure to rats for 28 days

Nexrutine (NX), a marketable herbal extract from a traditional Chinese herbal plant, Phellodendron amurense, is majorly used for the resolution of inflammation, gastroenteritis, and some tissue-specific cancer. Strategies for the identification of the safety of anticancer solutions of plant origin are an important area of study. The present investigation assesses the single and repeated dose (28 days) toxicity of NX following OECD guidelines 425 and 407, respectively. Briefly, to identify acute toxic properties of NX, a dose of 2000 mg/kg b. wt was administered once orally. Simultaneously, repeated dose toxicity was evaluated through daily administration of the three different doses (250, 500, 750 mg/kg b. wt) of NX for 28days. The single administration of NX showed no signs of toxicity and morbidity, suggesting LD50 of NX more than 2000 mg/kg b. wt. Furthermore, repeated dose exposure of NX for 28 days did not show any sign of toxicity. Hematology, serum biochemistry, and histopathological analysis also did not show any significant abnormalities. However, a marginal decrease in triglyceride, cholesterol, and glucose levels along with mild tubular degeneration in the kidney was also noticed in the high dose NX treatment group. Overall, the findings of the study suggest that NX is safe for use up to 500 mg/kg b.wt.

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Single dose toxicity confirms LD₅₀ of NX to be greater than 2000 mg/kg b. wt.

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Repeated dose toxicity study used three doses of NX (250, 500, 750 mg/kg b. wt).

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Minimal aberrations in hematology and biochemical parameters.

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Histopathology depicts mild tubular degeneration at a high dose in the kidney.

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No morbidity or mortality was recorded in both the experimental setups.

Piperine and Celecoxib synergistically inhibit colon cancer cell proliferation via modulating Wnt/β-catenin signaling pathway

BACKGROUND

Celecoxib (CXB), a selective COX-2 inhibitor NSAID, has exhibited prominent anti-proliferative potential against numerous cancers. However, its low bioavailability and long term exposure related cardiovascular side effects, limit its clinical application. In order to overcome these limitations, natural bioactive compounds with lower toxicity profile are used in combination with therapeutic drugs. Therfore, in this study Piperine (PIP), a natural chemo-preventive agent possessing drug bioavailability enhancing properties, was considered to be used in combination with low doses of CXB.

PURPOSE

We hypothesized that the combination of PIP with CXB will have a synergistic anti-proliferative effect on colon cancer cells.

STUDY DESIGN

The potency of PIP and CXB alone and in combination was evaluated in HT-29 human colon adenocarcinoma cells and mechanism of growth inhibition was investigated by analyzing the players in apoptotic and Wnt/β-catenin signaling pathways.

METHODS

The effect of PIP on the oral bioavailability of CXB in mice was investigated using HPLC analysis. The study investigated the synergistic anti-proliferative effect of CXB and PIP on HT-29 cells and IEC-6 non-tumorigenic rat intestinal epithelial cells by SRB cell viability assay. Further, the cellular and molecular mechanism(s) involved in the anti-proliferative combinatorial effect was extensively explored in HT-29 cells by flow cytometry and western blotting. The in vivo efficacy of this combination was studied in CT26.WT tumor syngeneic Balb/c mice model.

RESULTS

PIP as a bioenhancer increased the oral bioavailability of CXB (129%). The IC50 of CXB and PIP were evaluated to select doses for combination treatment of HT-29 cells. The drug combinations having combination index (CI) less than 1 were screened using CompuSyn software. These combinations were significantly cytotoxic to HT-29 cells but IEC-6 were least effected. Further, the mechanism behind CXB and PIP mediated cell death was explored. The co-treatment led to reactive oxygen species generation, mitochondrial dysfunction, caspase activation and enhanced apoptosis in HT-29 cells. Additionally, the combination treatment synergistically modulated Wnt/β-catenin pathway, downregulated the stemness markers and boosted therapeutic response in CT26 syngeneic Balb/c mice.

CONCLUSION

The outcomes of the study suggests that combining CXB and PIP offers a novel approach for the treatment of colon cancer.

Suppression of FAK by nexrutine inhibits gastric cancer progression

AIM

Nexrutine, an herbal extract of Phellodendron amurense, has been found to play a tumor-suppressive role in many cancers. However, its role in the pathogenesis of gastric cancer remains unclear.

MATERIALS AND METHODS

Gastric cancer cells (SGC-7901 and MGC-803) were treated with nexrutine, and cell proliferation, invasion and apoptosis were analyzed. And the MGC-803 cells-derived xenograft mouse models were fed pelleted diet containing 600 mg/kg nexrutine for 21 days after inoculation. Mechanically, we focused on the influences of nexrutine on the levels and activation of STAT3 and NF-κB as well as their upstream regulator FAK. Additionally, we further verified whether nexrutine affected the proliferation, invasion and apoptosis of gastric cancer cells via FAK by upregulating FAK expression before nexrutine treatment.

KEY FINDINGS

We found nexrutine inhibited the viability, invasion, and expression levels of PCNA, CyclinD1 and Bcl-2, promoted the apoptosis and Bax expression, decreased levels of STAT3, phospho-STAT3, NF-κB p65, phospho-p65, FAK and phospho-FAK in gastric cancer cells. Overexpression of FAK reversed the impacts of nexrutine on the levels of STAT3, phospho-STAT3, NF-κB p65, phospho-p65, as well as the malignant characteristics of gastric cancer cells. Moreover, nexrutine suppressed tumor volumes and weights, and decreased expression and phosphorylation of FAK, STAT3 and NF-κB p65 in vivo.

SIGNIFICANCE

Nexrutine inhibited the malignant progression of gastric cancer via negatively regulating STAT3/NF-κB signaling pathway by suppressing FAK expression and activation.

Chemopreventive Potential of 2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-glucoside on the Formation of Aberrant Crypt Foci in Azoxymethane-Induced Colorectal Cancer in Rats

2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-glucoside (THSG) has been shown to have antioxidative and anti-inflammatory effects. Oxidative and inflammatory reactions are related to the development of colorectal carcinoma (CRC). In the present study, we characterized the preventive activities of THSG on colon carcinogenesis using the azoxymethane- (AOM-) mediated rat colon carcinogenesis model. F344 male rats were randomly divided into 5 groups (untreated and AOM model rats treated with or without THSG at 30, 150, or 250 mg/kg) after which the numbers of aberrant crypt foci (ACF) were assessed in the colon tissues of all rats. The expressions of nuclear factor-κB (NF-κB), cyclooxygenase-2 (COX-2), matrix metalloproteinase proteins (MMPs), and carcinoembryonic antigen (CEA) were measured as effective early predictors of CRC using western blot analysis. Treatment with THSG (150 or 250 mg/kg) induced a 50% reduction in total colonic ACF formation (P < 0.05). Furthermore, our results revealed a downregulation of CEA and NF-κB protein levels in the reduced number of ACF elicited by treatment with THSG, whereas levels of COX-2 and MMPs proteins were not changed. Collectively, THSG may be a promising natural lead compound or drug candidate for treating early phases of CRC.

In vitro investigation of the effect of matrix molecules on the behavior of colon cancer cells under the effect of geldanamycin derivative

The chaperone-binding drug, 17-allylamino-17-demethoxygeldanamycin, has recently come into clinical use. It is a derivative of geldanamycin, an ansamycin benzoquinone antibiotic with anti-carcinogenic effect. Understanding the effect of this drug on the cancer cells and their niche is important for treatment. We applied 17-allylamino-17-demethoxygeldanamycin to colon cancer cell line (Colo 205) on matrix molecules to investigate the relationship of apoptosis with terminal deoxynucleotidyl transferase dUTP nick end labeling immunocytochemistry and related gene expression. We used laminin and collagen I for matrix molecules and vascular endothelial growth factor for angiogenic structure. We also examined apoptosis-related signaling pathway including mitochondrial proteins, cytochrome c, Bcl-2, caspase-9, Apaf-1 expression using real-time polymerase chain reaction. There was clear effect of 17-allylamino-17-demethoxygeldanamycin that killed more cells on tissue culture plastic compared to matrix molecules. The IC₅₀ value was 0.58 µg/mL for tissue culture plastic compared with 0.64 µg/mL for laminin and 0.75 µg/mL for collagen I. The analyses showed that more cells on matrix molecules underwent apoptosis compared to that on tissue culture plastic. Apoptosis-related gene expression was similar in which Bcl-2 expression decreased and proapoptotic gene expression of the cells on matrix molecules increased compared to that on tissue culture plastic. However, the application of 17-allylamino-17-demethoxygeldanamycin was more effective for the cells on collagen I compared to the cells on laminin. There was also a decrease in angiogenesis as shown by the vascular endothelial growth factor staining. This was more pronounced by coating of the tissue culture plastic with matrix molecules. Our results supported the anti-cancer effect of 17-allylamino-17-demethoxygeldanamycin, and this effect depended on matrix molecules. This effect occurs through apoptosis, and related genes were also altered. All these genes may serve for novel target under the effect of matrix substrate. However, correct interpretation of the results requires further studies.

Topical application of Nexrutine inhibits ultraviolet B-induced cutaneous inflammatory responses in SKH-1 hairless mouse

BACKGROUND

Ultraviolet B (UVB) radiation is the major contributor to skin inflammation which leads to the development of skin cancer. Hence, in this study, we studied the effect of Nexrutine (NX) on UVB-induced cutaneous inflammation and its mediators.

METHODS

Ultraviolet absorption spectra of NX were measured by spectrophotometer. To conduct the photoprotective studies, SKH-1 hairless mice were topically treated with NX, 30 minutes before to the UVB (180 mJ/cm² ) exposure. Twenty hours of post-UVB irradiation, mouse skin was used for edema measurements, H & E staining, myeloperoxidase (MPO) activity, and estimation of plasma cytokines. In addition, expression levels of inflammatory cytokines, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) were also determined by Western blot analysis.

RESULTS

Nexrutine displayed absorbance over the UVB spectrum. NX significantly decreased the UVB-induced epidermal edema, skin thickness, leukocyte infiltration, number of the sunburn, and TUNEL-positive cells. NX treatment also decreased the number of mast cells, MPO activity, expression of pro-inflammatory cytokines, and inflammation mediator protein in mouse skin.

CONCLUSION

These results provide evidences that NX inhibits the UVB-induced cutaneous inflammatory responses in SKH-1 mouse skin.

Screening the active compounds of Phellodendri Amurensis cortex for treating prostate cancer by high-throughput chinmedomics

Screening the active compounds of herbal medicines is of importance to modern drug discovery. In this work, an integrative strategy was established to discover the effective compounds and their therapeutic targets using Phellodendri Amurensis cortex (PAC) aimed at inhibiting prostate cancer as a case study. We found that PAC could be inhibited the growth of xenograft tumours of prostate cancer. Global constituents and serum metabolites were analysed by UPLC-MS based on the established chinmedomics analysis method, a total of 54 peaks in the spectrum of PAC were characterised in vitro and 38 peaks were characterised in vivo. Among the 38 compounds characterised in vivo, 29 prototype components were absorbed in serum and nine metabolites were identified in vivo. Thirty-four metabolic biomarkers were related to prostate cancer, and PAC could observably reverse these metabolic biomarkers to their normal level and regulate the disturbed metabolic profile to a healthy state. A chinmedomics approach showed that ten absorbed constituents, as effective compounds, were associated with the therapeutic effect of PAC. In combination with bioactivity assays, the action targets were also predicted and discovered. As an illustrative case study, the strategy was successfully applied to high-throughput screening of active compounds from herbal medicine.

Downregulation of STAT3/NF-κB potentiates gemcitabine activity in pancreatic cancer cells

There is an unmet need to develop new agents or strategies against therapy resistant pancreatic cancer (PanCA). Recent studies from our laboratory showed that STAT3 negatively regulates NF-κB and that inhibition of this crosstalk using Nexrutine® (Nx) reduces transcriptional activity of COX-2. Inhibition of these molecular interactions impedes pancreatic cancer cell growth as well as reduces fibrosis in a preclinical animal model. Nx is an extract derived from the bark of Phellodendron amurense and has been utilized in traditional Chinese medicine as antidiarrheal, astringent, and anti-inflammatory agent for centuries. We hypothesized that "Nx-mediated inhibition of survival molecules like STAT3 and NF-κB in pancreatic cancer cells will improve the efficacy of the conventional chemotherapeutic agent, gemcitabine (GEM)." Therefore, we explored the utility of Nx, one of its active constituents berberine and its derivatives, to enhance the effects of GEM. Using multiple human pancreatic cancer cells we found that combination treatment with Nx and GEM resulted in significant alterations of proteins in the STAT3/NF-κB signaling axis culminating in growth inhibition in a synergistic manner. Furthermore, GEM resistant cells were more sensitive to Nx treatment than their parental GEM-sensitive cells. Interestingly, although berberine, the Nx active component used, and its derivatives were biologically active in GEM sensitive cells they did not potentiate GEM activity when used in combination. Taken together, these results suggest that the natural extract, Nx, but not its active component, berberine, has the potential to improve GEM sensitivity, perhaps by down regulating STAT3/NF-κB signaling. © 2016 Wiley Periodicals, Inc.