Effect of Vitamin B2 and Vitamin E on Cancer-Related Sarcopenia in a Mouse Cachexia Model

Cancer-related sarcopenia is associated with impaired energy metabolism and increased oxidative stress production in skeletal muscles. With an aim to treat cancer-related sarcopenia using dietary intervention, we investigated the effects of vitamin B2 (VB2) and vitamin E (VE), which are recognized to have antioxidant effects, on CT26 mouse colon cancer cells and skeletal muscles in vitro and in vivo. VB2 suppressed tumor growth by suppressing cell proliferation and inducing more pronounced apoptosis by increasing the production of adenosine triphosphate (ATP) and reactive oxygen species (ROS). VE suppressed tumor growth by suppressing cell proliferation and increasing apoptosis by decreasing the production of ATP and ROS. In C2C12 mouse skeletal myoblast cells, VB2 treatment increased the production of ATP and ROS and VE treatment decreased the production of ATP and ROS; both treatments suppressed skeletal myoblast maturation. In the mouse model, intraperitoneal inoculation (peritoneal model) resulted in marked macrophage infiltration and elevated blood tumor necrosis factor-α and high-mobility group box-1 inflammatory cytokine levels, leading to cachexia. In contrast, subcutaneous inoculation (subcutaneous model) showed poor macrophage infiltration and low inflammatory cytokine levels, without cachexia. VB2 and VE activated macrophages and exacerbated cancer-related sarcopenia in the peritoneal model, whereas VB2 and VE treatment did not exhibit significant changes in sarcopenia in the subcutaneous model. In order to improve cancer-related sarcopenia by dietary intervention, it is important to consider the effect on inflammatory cytokines.