Chemopreventive effects of curcumin analogs in DMH-Induced colon cancer in albino rats model

Siah2 inhibitor and the metabolic antagonist Oxamate retard colon cancer progression and downregulate PD1 expression

BACKGROUND

Solid tumors such as colon cancer are characterized by rapid and sustained cell proliferation, which ultimately results in hypoxia, induction of hypoxia-inducible factor-1α (HIF-1α), and activation of glycolysis to promote tumor survival and immune evasion. We hypothesized that a combinatorial approach of menadione (MEN) as an indirect HIF-1α inhibitor and sodium oxamate (OX) as a glycolysis inhibitor may be a promising treatment strategy for colon cancer.

OBJECTIVES

We investigated the potential efficacy of this combination for promoting an antitumor immune response and suppressing tumor growth in a rat model of colon cancer.

METHODS

Colon cancer was induced by once-weekly subcutaneous injection of 20 mg/kg dimethylhydrazine (DMH) for 16 weeks. Control rats received the vehicle and then no further treatment (negative control) or MEN plus OX for 4 weeks (drug control). Dimethylhydrazine-treated rats were then randomly allocated to four groups: DMH alone group and other groups treated with MEN, OX, and a combination of (MEN and OX) for 4 weeks. Serum samples were assayed for the tumor marker carbohydrate antigen (CA19.9), while expression levels of HIF-1α, caspase-3, PHD3, LDH, and PD1 were evaluated in colon tissue samples by immunoassay and qRT-PCR. Additionally, Ki-67 and Siah2 expression levels were examined by immunohistochemistry.

RESULTS

The combination of MEN plus OX demonstrated a greater inhibitory effect on the expression levels of HIF-1α, Siah2, LDH, Ki-67, and PD1, and greater enhancement of caspase-3 and PHD3 expression in colon cancer tissues than either drug alone.

CONCLUSION

Simultaneous targeting of hypoxia and glycolysis pathways by a combination of MEN and OX could be a promising therapy for inhibiting colon cancer cell growth and promoting antitumor immunity [1].

Curcumin and Capsaicin-Loaded Ag-Modified Mesoporous Silica Carriers: A New Alternative in Skin Treatment

Biologically active substances of natural origin offer a promising alternative in skin disease treatment in comparison to synthetic medications. The limiting factors for the efficient application of natural compounds, such as low water solubility and low bioavailability, can be easily overcome by the development of suitable delivery systems. In this study, the exchange with the template procedure was used for the preparation ofa spherical silver-modified mesoporous silica nanocarrier. The initial and drug-loaded formulations are fully characterized by different physico-chemical methods. The incipient wetness impregnation method used to load health-promoting agents, curcumin, and capsaicin in Ag-modified carriers separately or in combinationresulted in high loading efficiency (up to 33 wt.%). The interaction between drugs and carriers was studied by ATR-FTIR spectroscopy. The release experiments of both active substances from the developed formulations were studied in buffers with pH 5.5, and showed improved solubility. Radical scavenging activity and ferric-reducing antioxidant power assays were successfully used for the evaluation of the antiradical and antioxidant capacity of the curcumin or/and capsaicin loaded on mesoporous carriers. Formulations containing a mixture of curcumin and capsaicin were characterized bypotentiation of their antiproliferative effect against maligning cells, and it was confirmed that the system for simultaneous delivery of both drugs has lower IC₅₀ values than the free substances.The antibacterial tests showed better activity of the obtained delivery systems in comparison with the pure curcumin and capsaicin. Considering the obtained results, it can be concluded that the obtained delivery systems are promising for potential dermal treatment.

Amelioration of DMH-induced colon cancer by eupafolin through the reprogramming of apoptosis-associated p53/Bcl2/Bax signaling in rats

Introduction: Colorectal cancer is the third most common malignancy and the second most deadly cancer worldwide. In this present study, the effects of eupafolin on DMH-induced colon cancer in rats were assessed.

Methods: The acute and sub-acute oral toxicity study in the balb/c mice was performed to evaluate the LD50 dose and the chemotherapeutic doses of eupafolin. The colon cancer was induced in the animals through a single intraperitoneal injection (i.p) of 30 mg/kg of dimethylhydrazine followed by 2% DSS for 7 days in the drinking water in male Wistar rats. The rats were treated with eupafolin (50, 100, and 200 mg/kg) through oral route for 18 weeks. The animals were sacrificed and colon tissues were subsequently investigated for aberrant crypt foci (ACF), in vivo antioxidant studies, histology and immunohistochemical analysis, and apoptosis by TUNNEL technique after 18 weeks of eupafolin therapy.

Results: The acute oral toxicity data represented the LD50 dose of eupafolin which was found to be 500 mg/kg body weight. Along with that, the sub-acute toxicity study suggested the chemotherapeutic doses of eupafolin, that is, 50, 100, and 200 mg/kg body weight. Eupafolin therapy inhibits ACF development in rat colon mucosa efficiently. Additionally, eupafolin has improved the colonic lesions and the structural integrity of the colonic mucosa. Eupafolin therapy causes anti-oxidant enzymes such as superoxide dismutase, catalase, and glutathione to increase as well. Increased levels of P53, BAX, and PCNA and a simultaneous decrease in Bcl2 and IL-6 expressions show eupafolin therapy successfully regulated these biological markers in colorectal cancer. Eupafolin also induced apoptosis efficiently in the rat colon mucous membrane.

Conclusion: These results show that eupafolin can improve colon cancer by modulating the p53, Bcl2, BAX, and IL-6 pathways in rats.

Piperidine nucleus in the field of drug discovery

Background

Piperidine is an essential heterocyclic system and a pivotal cornerstone in the production of drugs. Piperidine byproducts showed several important pharmacophoric features and are being utilized in different therapeutic applications.

Main text

Piperidine derivatives are being utilized in different ways as anticancer, antiviral, antimalarial, antimicrobial, antifungal, antihypertension, analgesic, anti-inflammatory, anti-Alzheimer, antipsychotic and/or anticoagulant agents.

Conclusions

This review article sheds a light on the most recent studies proving the importance of piperidine nucleus in the field of drug discovery.

Bavachinin mitigates DMH induced colon cancer in rats by altering p53/Bcl2/BAX signaling associated with apoptosis

Bavachinin is a flavanone obtained from the Chinese herb, Fructus Psoraleae. Flavonoids and flavanones are recognized as cancer preventive agents. We investigated the anticancer properties of bavachinin using a model of dimethylhydrazine (DMH and dextran sodium sulfate (DSS) induced rat colon cancer. We investigated aberrant crypt foci (ACF), hyperplastic lesions, catalase (CAT), superoxide dismutase (SOD) and glutathione (GST) levels in Wistar rats. Expression of cancer biomarkers including IL-6, p53, Bcl2 and BAX was investigated. We found that bavachinin administered to rats re-established the colonic crypts that were damaged by DMH and prevented progression of the cancer.

In vitro and in silico protein corona formation evaluation of curcumin and capsaicin loaded-solid lipid nanoparticles

Nanotechnology has been an important tool for the production of nanoparticles with controlled release of drugs for therapeutic applications. Here, we produced solid lipid nanoparticles (SLN) loaded with curcumin and capsaicin (NCC) following the overarching goals of green chemistry. Currently, besides evaluating the composition, and size of these, it is necessary to understand the interactions between nanoparticles and the biomolecules present in the biological medium. For this, assays were conducted in order to evaluate the potential formation of the protein 'corona', and to better understand the results obtained in vitro, we also performed an interaction study, in silico, between the NCC components and the main serum protein, albumin. In the first hour of contact between the NCC and the culture medium showed fluctuation in the diameter of the NCC. However, after 24 and 48 h of the incubation period, all NCC concentrations showed an increase in size, which can be attributed to plasma protein adsorption. Since, hard corona takes a few seconds, while the soft corona can be formed in minutes up to a few hours. On the other hand, best docking binding-poses of interaction for the formed docking complexes evaluated suggest interactions following the docking affinity like free energy FEB (Tween 80-bovine serum albumin) ≈ FEB (Span 80-bovine serum albumin) showing a pharmacodynamic pattern based in non-covalent hydrophobic interactions with the bovine serum albumin binding-site. Our in silico results clarify and reinforce our in vitro findings of corona formation, which represents the real interaction with cell membranes in vivo.

ANIMAL MODELS FOR COLORECTAL CANCER

Introduction:

Colorectal cancer is a very frequent sort of neoplasm among the population, with a high mortality rate. It develops from an association of genetic and environmental factors, and it is related to multiple cell signaling pathways. Cell cultures and animal models are used in research to reproduce the process of disease development in humans. Of the existing animal models, the most commonly used are animals with tumors induced by chemical agents and genetically modified animals.

Objective:

To present and synthesize the main animal models of colorectal carcinogenesis used in the research, comparing its advantages and disadvantages.

Method:

This literature review was performed through the search for scientific articles over the last 18 years in PubMed and Science Direct databases, by using keywords such as “animal models”, “colorectal carcinogenesis” and “tumor induction”.

Results:

1,2-dimethylhydrazine and azoxymethane are carcinogenic agents with high specificity for the small and large intestine regions. Therefore, the two substances are widely used. Concerning the genetically modified animal models, there is a larger number of studies concerning mutations of the APC, p53 and K-ras genes. Animals with the APC gene mutation develop colorectal neoplasms, whereas animals with p53 and K-ras genes mutations are able to potentiate the effects of the APC gene mutation as well as the chemical inducers.

Conclusion:

Each animal model has advantages and disadvantages, and some are individually efficient as to the induction of carcinogenesis, and in other cases the association of two forms of induction is the best way to obtain representative results of carcinogenesis in humans.

Effect of eriodictyol on preneoplastic lesions, oxidative stress and bacterial enzymes in 1,2-dimethyl hydrazine-induced colon carcinogenesis

Eriodictyol, one of the strong flavonoids extracted from Eriodictyon californicum, is known for its antioxidant and anticarcinogenic properties. We estimated the chemopreventive effect of eriodictyol on 1,2 dimethylhydrazine (DMH)-induced experimental colon carcinogenesis in male albino Wistar rats. The rats were randomized into six groups. Our results evaluated the effect of eriodictyol supplementation (200 μg per kg b.w.) on DMH (20 mg per kg b.w)-induced rats (Groups 4-6). The incidence of polyps, aberrant crypt foci (ACF) and the lipid peroxidation levels were significantly decreased as compared to those in the DMH-alone treated rats (Group 2). In eriodictyol-supplemented DMH-treated rats, we observed increased activity of enzymatic and non-enzymatic antioxidants in the circulatory system, liver, and colon. The bacterial enzymes activities of mucosa and faecal were significantly decreased in the group with treatment of eriodictyol on DMH-induced rats. Moreover, in the eriodictyol-supplemented DMH-exposed rats, we observed reduced malignant glands of a histopathological appearance in both liver and colon tissue. Furthermore, we also observed reduced AgNORs counts of eriodictyol supplemented to the DMH-exposed rats. Therefore, we can conclude that eriodictyol can be used as an effective chemopreventive agent against DMH-induced colon carcinogenesis in experimental animal models.

Biological activities of curcuminoids, other biomolecules from turmeric and their derivatives - A review

In recent years, several drugs have been developed deriving from traditional products and current drug research is actively investigating the possible therapeutic roles of many Ayruvedic and Traditional Indian medicinal therapies. Among those being investigated is Turmeric. Its most important active ingredient is curcuminoids. Curcuminoids are phenolic compounds commonly used as a spice, pigment and additive also utilized as a therapeutic agent used in several foods. Comprehensive research over the last century has revealed several important functions of curcuminoids. Various preclinical cell culture and animals studies suggest that curcuminoids have extensive biological activity as an antioxidant, neuroprotective, antitumor, anti-inflammatory, anti-acidogenic, radioprotective and arthritis. Different clinical trials also suggest a potential therapeutic role for curcuminoids in numerous chronic diseases such as colon cancer, lung cancer, breast cancer, inflammatory bowel diseases. The aim of this review is to summarize the chemistry, analog, metal complex, formulations of curcuminoids and their biological activities.

Highly active anticancer curcumin analogues

Curcumin, a compound in the human food supply, represents a near-perfect starting point for drug discovery. Consequently, a number of research groups have taken the natural product as a starting point to prepare and biologically evaluate a wide variety of curcumin analogues. One widely used structural modification truncates the central conjugated beta-diketone in curcumin to the monocarbonyl dienone. A diverse array of the latter compounds exhibit cytotoxicities against an equally diverse set of cancer-related cell lines. Importantly, these compounds still retain toxicity profiles in rodents comparable to the parent natural product, whereas some analogues (e.g., EF-24, 41) exhibit good oral bioavailability and good pharmacokinetics in mice. Thiol conjugates of EF-24 analogues have been prepared that address stability and solubility issues while demonstrating cellular activities similar to the unmodified dienones. In parallel experiments, the factor VIIa-tissue factor complex (fVIIa-TF) has been exploited to develop a targeting strategy for the analogues. In particular, the EF24-FFRck-fVIIa protein conjugate is not only somewhat more effective relative to the drug alone against breast cancer and melanocyte cells. Both simple curcumin analogues and the protein conjugate evidence antiangiogenic activity in cell culture. The implication is that the fVIIa-TF targeting process, like the dienone drugs, permits a double-pronged attack with the potential to destroy a tumor directly by apoptosis.