Radioprotection of 1,2-dimethylhydrazine-initiated colon cancer in rats using low-dose γ rays by modulating multidrug resistance-1, cytokeratin 20, and β-catenin expression

Asiatic acid rescues intestinal tissue by suppressing molecular, biochemical, and histopathological changes associated with the development of ulcerative colitis

Asiatic acid (AA) is a polyphenolic compound with potent antioxidative and anti-inflammatory activities that make it a potential choice to attenuate inflammation and oxidative insults associated with ulcerative colitis (UC). Hence, the present study aimed to evaluate if AA can attenuate molecular, biochemical, and histological alterations in the acetic acid-induced UC model in rats. To perform the study, five groups were applied, including the control, acetic acid-induced UC, UC-treated with 40 mg/kg aminosalicylate (5-ASA), UC-treated with 20 mg/kg AA, and UC-treated with 40 mg/kg AA. Levels of different markers of inflammation, oxidative stress, and apoptosis were studied along with histological approaches. The induction of UC increased the levels of lipid peroxidation (LPO) and nitric oxide (NO). Additionally, the nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream antioxidant proteins [catalase (CAT), superoxide dismutase (SOD), reduced glutathione (GSH), glutathione peroxidase (GPx), and glutathione reductase (GR)] were down-regulated in the colon tissue. Moreover, the inflammatory mediators [myeloperoxidase (MPO), monocyte chemotactic protein 1 (MCP1), prostaglandin E2 (PGE2), nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β)] were increased in the colon tissue after the induction of UC. Notably, an apoptotic response was developed, as demonstrated by the increased caspase-3 and Bax and decreased Bcl2. Interestingly, AA administration at both doses lessened the molecular, biochemical, and histopathological changes following the induction in the colon tissue of UC. In conclusion, AA could improve the antioxidative status and attenuate the inflammatory and apoptotic challenges associated with UC.

Radioprotective Effect of Piperine, as a Major Component of Black Pepper, Against Radiation-induced Colon Injury: Biochemical and Histological Studies

BACKGROUND

Patients undergoing radiotherapy are prone to radiation-induced gastrointestinal injury. Piperine is an alkaloid component in black pepper with a unique chemopreventive activity against oxidative stress-related damage in healthy tissues. The purpose of this study was to investigate the effects of piperine on intestinal damage.

METHODS

In this study, mice were divided into eight groups: including the control, piperine (10, 25, and 50 mg/kg), radiation (6 Gy), and piperine+radiation (10, 25 and 50 mg/kg + 6 Gy) groups. The radioprotective effects of piperine were evaluated by biochemical (MDA, GSH, and PC) and histopathological assessments in colon tissues.

RESULTS

The 10 mg/kg dose of piperine significantly reduced the levels of oxidative stress biomarkers compared to the group that received only radiation. In addition, pre-treatment with 10 mg/kg piperine diminished the histopathological changes like vascular congestion in the submucosa, while the dose of 50 mg/kg led to the infiltration of inflammatory cells.

CONCLUSION

Based on this study, it is concluded that piperine, at low dose, with its antioxidant properties, could reduce the colon damage caused by radiation.

Hesperetin and Capecitabine Abate 1,2 Dimethylhydrazine-Induced Colon Carcinogenesis in Wistar Rats via Suppressing Oxidative Stress and Enhancing Antioxidant, Anti-Inflammatory and Apoptotic Actions

Colon cancer is a major cause of cancer-related death, with significantly increasing rates of incidence worldwide. The current study was designed to evaluate the anti-carcinogenic effects of hesperetin (HES) alone and in combination with capecitabine (CAP) on 1,2 dimethylhydrazine (DMH)-induced colon carcinogenesis in Wistar rats. The rats were given DMH at 20 mg/kg body weight (b.w.)/week for 12 weeks and were orally treated with HES (25 mg/kg b.w.) and/or CAP (200 mg/kg b.w.) every other day for 8 weeks. The DMH-administered rats exhibited colon-mucosal hyperplastic polyps, the formation of new glandular units and cancerous epithelial cells. These histological changes were associated with the significant upregulation of colon Ki67 expression and the elevation of the tumor marker, carcinoembryonic antigen (CEA), in the sera. The treatment of the DMH-administered rats with HES and/or CAP prevented these histological cancerous changes concomitantly with the decrease in colon-Ki67 expression and serum-CEA levels. The results also indicated that the treatments with HES and/or CAP showed a significant reduction in the serum levels of lipid peroxides, an elevation in the serum levels of reduced glutathione, and the enhancement of the activities of colon-tissue superoxide dismutase, glutathione reductase and glutathione-S-transferase. Additionally, the results showed an increase in the mRNA expressions of the anti-inflammatory cytokine, IL-4, as well as the proapoptotic protein, p53, in the colon tissues of the DMH-administered rats treated with HES and/or CAP. The TGF-β1 decreased significantly in the DMH-administered rats and this effect was counteracted by the treatments with HES and/or CAP. Based on these findings, it can be suggested that both HES and CAP, singly or in combination, have the potential to exert chemopreventive effects against DMH-induced colon carcinogenesis via the suppression of oxidative stress, the stimulation of the antioxidant defense system, the attenuation of inflammatory effects, the reduction in cell proliferation and the enhancement of apoptosis.

The Antioxidant and Antitumor Efficiency of Litophyton sp. Extract in DMH-Induced Colon Cancer in Male Rats

One of the most common tumors to cause death worldwide is colon cancer. This study aims to investigate the antitumor potency of Litophyton sp. methanolic extract (LME) against DMH-induced colon cancer in adult male rats. Group (1) normal rats served as the control, group (2) normal rats were ip-injected with LME at a dose of 100 μg/kg/day, group (3) DMH-induced colon cancer animals, and group (4) colon cancer-modeled animals were treated with LME (100 μg/kg/day) for six weeks. The results revealed that injection of LME markedly regenerated the colon cancer pathophysiological disorders; this was monitored from the significant reduction in the values of serum biomarkers (CEA, CA19.9, AFP), cytokines (TNF-α and IL1β), and biochemical measurements (ALAT, ASAT, urea, creatinine, cholesterol, and triglycerides) matched significant increase of apoptotic biomarkers (CD4+); similarly, colon DNA fragmentation, MDA, and NO levels were down-regulated. In contrast, a remarkable upregulation in colon SOD, GPx, GSH, and CAT levels was noted. Moreover, the colon histopathological architecture showed obvious regenerations. Chromatography of LME resulted in the purification of two polyhydroxylated steroids (1 and 2) with potential cytotoxic activities. LME performed therapeutic potential colon tumorigenesis; therefore, LME may have a promising chemo-preventive feature against colon cancer, probably via enhancement of the apoptosis pathway, improvement of the immune response, reduction of inflammation, or/and restoration of the impaired oxidative stress.

Antitumor Potential of Berberine and Cinnamic Acid against Solid Ehrlich Carcinoma in Mice

BACKGROUND

Berberine and cinnamic acid are natural compounds that exhibit potent anticancer activities through distinct molecular mechanisms.

OBJECTIVE

In the present study, we aimed to investigate the proapoptotic potential of cinnamic acid and berberine in cancer cells by examining their effect on the expression of proapoptotic and antiapoptotic genes. Moreover, the effects of berberine and cinnamic acid on the antitumor activity of cisplatin were investigated in Ehrlich solid tumor-bearing mice.

METHODS

For the study, 90 male mice were inoculated intramuscularly with Ehrlich ascites tumor cells (2.5 × 106/mouse), and then on day 4, mice were randomly divided into six experimental groups (group 1-untreated Ehrlich solid tumor (EST), group 2-EST treated CDDP, group 3-EST treated CA, group 4-EST treated BER, group 5-EST treated CA + CDDP, and group 6-EST treated BER + CDDP).

RESULTS

The results showed that berberine and cinnamic acid significantly decreased tumor growth and tumor volume (-74.8 and -75.5%, respectively) both as single agents and in combination with cisplatin. Moreover, both berberine and cinnamic acid increased the ratio of tumor growth inhibition (-91.5 and -92.6%, respectively), mean survival time (61.5 and 26 days, respectively), and percentage increase in lifespan (559 and 263%, respectively) of the treated mice. Our results also showed that both berberine and cinnamic acid-induced apoptosis by increasing the Bax/Bcl-2 ratio (74.1 and 45.1, respectively) and caspase-3 expression (14.3- and 11.6-fold increase, respectively). Additionally, berberine and cinnamic acid decreased oxidative stress markers, as shown by the decrease in lipid peroxidation and nitric oxide levels and an increase in reduced glutathione level.

CONCLUSION

These results suggest that berberine and cinnamic acid have potential as antitumor and antioxidant agents derived from natural sources, which could be used alone or in combination with regular chemotherapeutic agents, such as cisplatin. These effects could be attributed to the proapoptotic activity of berberine and cinnamic acid.

Triggering of apoptosis and cell cycle arrest by fennel and clove oils in Caco-2 cells: the role of combination

Background: Fennel (Foeniculum vulgare) and clove (Syzygium aromaticum) oils are known for their various biological effects, including anticancer properties. Objective: To investigate the anticancer effect of combined fennel and clove oil treatment on Caco-2 cells and normal human lymphocytes (NHL). Methods: GC-MS, in vitro cytotoxicity, morphological, apoptosis-related marker, and flow cytometric cell cycle distribution analyses were conducted. Results: Seventeen volatile compounds were identified in fennel oil, including trans-anethole (68.3%) and (+)-fenchone (8.1%). In clove oil, 22 compounds, including eugenol (71.4%) and caryophyllene (8.7%), were identified. IC₅₀ of the fennel, clove, and oil mixture were 300 ± 5.0, 150 ± 4.0, and 73 ± 2.5 µg/mL, respectively with combination index (CI) < 1.0. Mechanistic anticancer properties were investigated using 30, 45, and 60 µg/mL oil mixture. Analysis of apoptotic morphology, flow cytometric cell cycle distribution, and apoptosis-related markers, such as Bcl-2 and Ki-67, confirmed cell cycle arrest and apoptosis induction in Caco-2 cells by the fennel and clove oil combination. Moreover, the oil mixture did not exert significant (p < 0.01) toxicity on NHL in vitro. Conclusion: The oil mixture exerted selective cytotoxicity towards Caco-2 cells through cell cycle arrest and apoptosis, which may occur through synergistic effects between fennel and clove oil active ingredients.

Re-evaluation of the linear no-threshold (LNT) model using new paradigms and modern molecular studies

The linear no-threshold (LNT) model is currently used to estimate low dose radiation (LDR) induced health risks. This model lacks safety thresholds and postulates that health risks caused by ionizing radiation is directly proportional to dose. Therefore even the smallest radiation dose has the potential to cause an increase in cancer risk. Advances in LDR biology and cell molecular techniques demonstrate that the LNT model does not appropriately reflect the biology or the health effects at the low dose range. The main pitfall of the LNT model is due to the extrapolation of mutation and DNA damage studies that were conducted at high radiation doses delivered at a high dose-rate. These studies formed the basis of several outdated paradigms that are either incorrect or do not hold for LDR doses. Thus, the goal of this review is to summarize the modern cellular and molecular literature in LDR biology and provide new paradigms that better represent the biological effects in the low dose range. We demonstrate that LDR activates a variety of cellular defense mechanisms including DNA repair systems, programmed cell death (apoptosis), cell cycle arrest, senescence, adaptive memory, bystander effects, epigenetics, immune stimulation, and tumor suppression. The evidence presented in this review reveals that there are minimal health risks (cancer) with LDR exposure, and that a dose higher than some threshold value is necessary to achieve the harmful effects classically observed with high doses of radiation. Knowledge gained from this review can help the radiation protection community in making informed decisions regarding radiation policy and limits.