Effects of Echinacoside on Ehrlich Carcinoma in Rats by Targeting Proliferation, Hypoxia and Inflammation

Background and objectives Ehrlich solid carcinoma (ESC) is a type of tumor originating from a spontaneous mammary adenocarcinoma in mice. It is highly aggressive and fast-growing and can create a solid undifferentiated mass when inserted under the skin. This makes it an ideal model for assessing cancer biology and tumor immunology. Echinacoside is a natural phenylethanoid glycoside with anti-inflammatory, anti-endoplasmic reticulum stress, anti-oxidative stress, and other beneficial properties. This study explored the potential anti-cancer benefits of echinacoside in rats with ESC. The study also analyzed its effects on tumor cell proliferation, differentiation, motility, and inflammation. Methods The study involved injecting rats with tumors in their left hind limb using an intramuscular injection of 2×10⁶ cells. After 14 days, some rats were given a daily intraperitoneal dose of 30 mg/kg echinacoside for three weeks. Muscle samples were then analyzed under an electron microscope. In addition, gene expression and protein levels of various factors such as phosphoinositide 3-kinases (PI3K), mammalian target of rapamycin (mTOR), hypoxia-inducible factor (HIF)-1α, cyclin D1, cyclin-dependent kinase 2 (CDK2), tumor necrosis factor (TNF)-α, and nuclear factor (NF)κB were evaluated in another part of the muscle samples. Results After being treated with echinacoside, the ESC rats experienced a significant increase in their mean survival time from 27 days to 48 days. This treatment also resulted in a decrease in the volume and weight of the tumor. Upon examining the tumor tissue under an electron microscope, signs of damage such as pleomorphic cells, necrosis, nuclear fragmentation, membrane damage with cytoplasmic content spilling, and loss of cellular junction were observed. However, the treatment with echinacoside was effective in improving these effects. Furthermore, the expression of PI3K, mTOR, HIF-1α, cyclin D1, CDK2, TNF-α, and NFκB was significantly reduced due to the echinacoside treatment. Conclusions Our research found that echinacoside has antitumor properties that resulted in a substantial decrease in tumor size and weight, leading to an increase in the average survival time of rats and an improvement in muscle structure. Additionally, echinacoside was shown to ameliorate hypoxia by suppressing HIF-1α, reduce inflammation by decreasing NFκB and TNF-α, decrease proliferation by reducing PI3K, and block cyclin D1 and CDK2 to inhibit differentiation.