Dimethylbenz(a)anthracene-induced mammary tumorigenesis in mice

Anticancer potentiality of Hottentotta saulcyi scorpion curd venom against breast cancer: an in vitro and in vivo study

Scorpion venom may include pharmacological substances that have the potential to provide benefits. Multiple scientific investigations have shown that particular scorpion venoms induce apoptosis and inhibit the development of cancerous cells. The present study investigated the potential anticancer properties of the crude venom derived from Hottentotta saulcyi (H. saulcyi) on both in vivo mice models and in vitro breast carcinoma cells. The venom of scorpions belonging to the species H. saulcyi was obtained with the application of electrical stimulation at voltages of 8 and 10 V. The determination of the Average Lethal Dose 50 (LD50) was conducted. The present work assessed the in vitro cytotoxicity and morphological characteristics of H. saulcyi venom using fluorescence microscopy, MTT assay, and flow cytometry assessment. Additionally, research was performed to assess the cytotoxic effects in vivo on a mouse model with breast cancer. The examination of MCF-7 cells treated with scorpion venom at a microscopic level revealed the existence of cells undergoing apoptosis. The venom of H. saulcyi has anticancer properties, as shown by the observation that MCF-7 cells had a 62.12% apoptotic rate when exposed to a dose of 1.47 mg/L. Based on the results obtained, it can be shown that the viability of MCF-7 cells has exhibited a substantial reduction (P < 0.01). Furthermore, the findings indicated that the venom of H. saulcyi resulted in a significant increase in the synthesis of TNF-α, IL-6, IL-10, TGF-β, and caspase (P < 0.05). The treatment groups administered with H. saulcyi venom exhibited a significant augmentation in the expression of proapoptotic genes compared to the control group of healthy individuals. The transcription of the BCL2 gene exhibited a statistically significant increase in the healthy control group compared to both the healthy venom-treated group (P < 0.05) and the malignant venom-treated group (P < 0.01). The crude venom of H. saulcyi has considerable promise in demonstrating anticancer properties. Further investigation may be warranted to explore the potential of using H. saulcyi crude venom as a medicinal platform for the prevention of breast cancer.

Peri-weaning cholera toxin consumption suppresses chemically-induced carcinogenesis in mice

Gastrointestinal bacteria are known to have an impact on local and systemic immunity, and consequently either promote or suppress cancer development. Following the notion that perinatal bacterial exposure might confer immune system competency for life, we investigated whether early-life administration of cholera-toxin (CT), a protein exotoxin of the small intestine pathogenic bacterium Vibrio cholerae, may shape local and systemic immunity to impart a protective effect against tumor development in epithelia distantly located from the gut. For that, newborn mice were orally treated with low non-pathogenic doses of CT and later challenged with the carcinogen 7,12-dimethylbenzanthracene (DMBA), known to cause mainly mammary, but also skin, lung and stomach cancer. Our results revealed that CT suppressed the overall incidence and multiplicity of tumors, with varying efficiencies among cancer types, and promoted survival. Harvesting mouse tissues at an earlier time-point (105 instead of 294 days), showed that CT does not prevent preneoplastic lesions per se but it rather hinders their evolution into tumors. CT pretreatment universally increased apoptosis in the cancer-prone mammary, lung and nonglandular stomach, and altered the expression of several cancer-related molecules. Moreover, CT had a long-term effect on immune system cells and factors, the most prominent being the systemic neutrophil decrease. Finally, CT treatment significantly affected gut bacterial flora composition, leading among others to a major shift from Clostridia to Bacilli class abundance. Overall, these results support the notion that early-life CT consumption is able to affect host's immune, microbiome and gene expression profiles toward the prevention of cancer.

Relevance of Carcinogen-Induced Preclinical Cancer Models

Chemical agents can cause cancer in animals by damaging their DNA, mutating their genes, and modifying their epigenetic signatures. Carcinogen-induced preclinical cancer models are useful for understanding carcinogen-induced human cancers, as they can reproduce the diversity and complexity of tumor types, as well as the interactions with the host environment. However, these models also have some drawbacks that limit their applicability and validity. For instance, some chemicals may be more effective or toxic in animals than in humans, and the tumors may differ in their genetics and phenotypes. Some chemicals may also affect normal cells and tissues, such as by causing oxidative stress, inflammation, and cell death, which may alter the tumor behavior and response to therapy. Furthermore, some chemicals may have variable effects depending on the exposure conditions, such as dose, route, and duration, as well as the animal characteristics, such as genetics and hormones. Therefore, these models should be carefully chosen, validated, and standardized, and the results should be cautiously interpreted and compared with other models. This review covers the main features of chemically induced cancer models, such as genetic and epigenetic changes, tumor environment, angiogenesis, invasion and metastasis, and immune response. We also address the pros and cons of these models and the current and future challenges for their improvement. This review offers a comprehensive overview of the state of the art of carcinogen-induced cancer models and provides new perspectives for cancer research.

Zingiberene exerts chemopreventive activity against 7,12-dimethylbenz(a)anthracene-induced breast cancer in Sprague-Dawley rats

Breast cancer is the primary cause of cancer-related death in females, wherein increased mortality of breast cancer patients is recorded worldwide. Zingiberene is a monocyclic sesquiterpene from the ginger plant and has many pharmacological benefits. In this exploration, we assessed the anticancer actions of Zingiberene against the 7,12-dimethylbenz(a)anthracene (DMBA)-stimulated mammary carcinogenesis in rats and MDA-MB-231 cells. Breast cancer was induced in the Female Sprague-Dawley rats through the 25 mg/kg of DMBA in 0.5 ml of corn oil and then treated with 20 and 40 mg/kg of Zingiberene, respectively. The body weight of animals and tumor volume was measured. Hematological parameters, transaminases, lipid profile, lipid peroxidation, and antioxidants status were scrutinized using standard techniques. The estrogen receptor-α and inflammatory markers were inspected by using respective assay kits. Histological damage scores were determined. In vitro experiments were conducted to scrutinize Zingiberene's effect on cell viability and apoptotic cell death in MDA-MB-231 cells. Zingiberene substantially modulated the DMBA-stimulated physiological and hematological changes and decreased the transaminases, and lipid peroxidation in the DMBA-stimulated animals. Zingiberene also elevated the antioxidant level and suppressed the inflammatory markers. Histological study revealed the protective effects of Zingiberene. The viability of MDA-MB-231 cells was noticeably diminished by the Zingiberene, thus inducing apoptotic cell death. Overall, our findings reliably proved the anticancer potential of Zingiberene against the DMBA-stimulated mammary tumorigenesis, and it could be a promising chemotherapeutic agent.