Protective effects of rosmarinic acid against azoxymethane-induced colorectal cancer in rats

Colorectal cancer (CRC) incidence is increasing gradually and has been become one of the most common cancers worldwide. Hence, it is important to discover cheap, naturally occurring compounds to be effective in suppressing the devastating effect of colon-related tumors. Rosmarinic acid (RA), one of the compounds of plant origin, possesses attractive features for use as an agent for cancer prevention and treatment. This study investigated the ability of RA to prevent azoxymethane (AOM)-induced rat colon carcinogenesis by evaluating the effect of RA on tumor formation and circulatory oxidant-antioxidant status. Moreover, plasma levels of adiponectin (APN) monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6) were detected by enzyme linked immunosorbent assay. The animals were divided into three groups: Control, AOM, and AOM + RA. Rats were fed a modified pellet diet (15.8% peanut oil was added to the standard diet) during the experimental period. Colon cancer was formed by applying 15 mg/kg AOM intraperitoneal once a week for 4 weeks in both the CRC group and AOM + RA group. Besides AOM, AOM + RA group received 5 mg/kg body weight RA orally every day during the study. The results showed that adenocarcinoma rates formed 87.5% of the AOM group. With treatment of RA, a reduction in the incidence of adenocarcinoma was observed in the AOM + RA group. The plasma MCP-1, IL-6, and TO levels were significantly higher, APN and TAS levels were significantly lower in the AOM group with respect to controls. In addition, there was a significant increase in TAS levels in the RA treatment group compared to the AOM group. These findings suggested that RA may be beneficial in preventing AOM-induced colon carcinogenesis formation.

The evaluation of antioxidant and anticancer effects of Lepidium Sativum Subsp Spinescens L. methanol extract on cancer cells

In recent years, there is an increased research interest for plants which are natural sources of antioxidants. Lepidium sativum Subsp spinescens L., commonly found in South West Asia, is a plant known as a healthy nutritional source containing bio-molecules that carry anti-hypertensive, hypoglycemic, anti-asthmatic, antispasmodic, hepato-protective, chemoprotective, anti-inflammatory and anti-oxidant effects. In this study, we aimed to investigate the antioxidant content and activity of Lepidium sativum Subsp spinescens L. methanol extract on cancer cells. Methanol extract of dried Lepidium sativum Subsp spinescens L. was prepared. Total amount of phenolic compounds was determined by Slinkard and Singleton method using Folin-Ciocalteu reagent. Total flavonoid amount was determined according to Zhishen method. Antioxidant activity of the extract was evaluated by CUPRAC and ABTS radical scavenging activity assays. Cytotoxic effects of the plant extract on colon and endometrium cancer cells, and human peripheral lymphocyte cells were investigated in vitro by MTT and neutral red assays. Furthermore, the plant extract was investigated for necrotic effects by LDH assay; apoptotic activity by DNA ladder fragmentation, ELISA and acridine orange/ethidium bromide staining; and genotoxic effect by comet assay methods. Methanol extract of Lepidium sativum Subsp spinescens L. was found to have a high content of phenolic and flavonoid compounds. The extract showed significant antioxidant activity and also cytotoxic activity on colon and endometrium cancer cells in a concentration-dependent manner. Apoptotic activity and genotoxic effects were significantly increased, especially with 200 μg/ml concentrations at 48 hours incubation. In conclusion, it was determined that the extract evaluated in this study could be a natural source of antioxidants. Further molecular studies explaining chemo-preventive and chemotherapeutic effects on cancer cells are required to support anticancer efficacy of the plant.