Ganoderma lucidum extract stimulates glucose uptake in L6 rat skeletal muscle cells.
The effect of Ganoderma lucidum extract on glucose uptake was studied in L6 rat skeletal muscle cells. G. lucidum extract increased glucose uptake about 2-fold compared to control. The extract stimulated the activity of phosphatidylinositol (PI) 3-kinase which is a major regulatory molecule in the glucose uptake pathway. About 7-fold increased activity of a PI 3-kinase was observed after treatment with G. lucidum extract, whereas PI 3-kinase inhibitor, LY294002, blocked the G. lucidum extract-stimulated PI 3-kinase activity in L6 skeletal muscle cells. Protein kinase B, a downstream mediator of PI 3-kinase, was also activated by G. lucidum extract. We then assessed the activity of AMP-activated protein kinase (AMPK), another regulatory molecule in the glucose uptake pathway. G. lucidum extract increased the phosphorylation level of both AMPK alpha1 and alpha2. Activity of p38 MAPK, a downstream mediator of AMPK, was also increased by G. lucidum extract. Taken together, these results suggest that G. lucidum extract may stimulate glucose uptake, through both PI 3-kinase and AMPK in L6 skeletal muscle cells thereby contributing to glucose homeostasis.
Jung
Kyung Hee
KH
Department of Pharmacology, College of Medicine, Kyung Hee University, Seoul, Republic of Korea.
Ha
Eunyoung
E
Kim
Mi-Ja
MJ
Uhm
Yoon Kyung
YK
Kim
Hye Kyung
HK
Hong
Seung-Jae
SJ
Chung
Joo-Ho
JH
Yim
Sung-Vin
SV
D055372:AMP-Activated Protein Kinases; D000818:Animals; D050260:Carbohydrate Metabolism / Q000187:drug effects; D018929:Cell Culture Techniques; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005947:Glucose / Q000493:pharmacokinetics*; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism; D009097:Multienzyme Complexes / Q000378:metabolism; D018485:Muscle Fibers, Skeletal / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D020940:Reishi; D015398:Signal Transduction; D015854:Up-Regulation
D055372:AMP-Activated Protein Kinases; D004365:Drugs, Chinese Herbal; D005947:Glucose; D020930:MAP Kinase Kinase Kinases; D009097:Multienzyme Complexes; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; C069937:MAP3K8 protein, human