Vitamin B1 Involved in Dendrobium Taiseed Tosnobile Extract Mediates Protection Against Cancer-Induced Muscle Wasting by Suppressing IL-6 Pathogenicity and Enhancing Myoblast Fusion

In this report, we showed that oral administration of Dendrobium Taiseed Tosnobile (DTT, also known as Taiwan Emperor No.1) allowed Lewis Lung Carcinoma (LLC) tumor-bearing mice to maintain body weight and grip strength in a dose-dependent manner. Histological analysis showed that treatment of DTT water extracts significantly reduced muscle fiber damage via inducing muscle regeneration and improved the cross-sectional area of the rectus femoris, soleus, and gastrocnemius of LLC tumor-bearing C57BL/6 female mice. Further studies revealed that DTT water extracts also reduced the expression of inflammatory cytokines such as IL-6 and TNF-α both in vitro and in vivo. Other analyses showed that DTT water extracts promoted the differentiation of C2C12 myoblast with or without IL-6 via maintaining myosin heavy chain (MyHC) level, suggesting DTT water extracts against muscle wasting via multiple manners. Interestingly, vitamin B1 was identified as an ingredient in DTT water extracts through an HPLC analysis. The vitamin B1 ameliorates IL-6 but not TNF- generation of active THP-1 cells and the protects C2C12 myotubes against IL-6. Further studies showed that DTT and vitamin B1 promoted the multi-nucleus fusion step of the C2C12 differentiation by inducing the expression of E-cadherin-catenin with or without IL-6 treatment. In summary, DTT water extracts protect muscle cells under cancer conditions through direct and indirect mechanisms, with vitamin B1 being a key functional ingredient that reduces IL-6 generation and aids muscle cell fusion against IL-6 treatment.