Research on the Physiological Functions of L-valine

L-valine is an essential branched-chain amino acid in humans, with important physiological functions in both basic research and clinical applications. The following is an overview of relevant research progress:

I. Basic Physiological Functions

Promoting muscle growth and repair: L-valine is an important component of muscle proteins. Together with other branched-chain amino acids such as leucine and isoleucine, it can promote skeletal muscle protein synthesis by activating the mTOR pathway, while inhibiting protein degradation mediated by the ubiquitin-proteasome system. This promotes muscle growth and repair, helping to maintain muscle mass and strength.

Regulating energy metabolism: L-valine is involved in the regulation of mitochondrial function. Studies have found that treating C2C12 skeletal muscle cells with L-valine can increase the expression of mitochondrial-related genes such as PGC-1α and PGC-1β, while improving mitochondrial basal respiration, leak respiration, and the maximum capacity of the electron transport chain, thereby optimizing energy metabolism. In addition, 3-hydroxyisobutyric acid (3-HIB), a metabolite of L-valine, can promote triglyceride synthesis in porcine intestinal epithelial cells by upregulating the expression of proteins related to fatty acid transport and triglyceride synthesis, providing energy for cells.

Regulating blood glucose levels: L-valine is a potent stimulator of glucagon-like peptide-1 (GLP-1) secretion. It can promote GLP-1 secretion through ATP-sensitive potassium channels and voltage-gated calcium channels. GLP-1 can stimulate insulin secretion and inhibit glucagon secretion, thereby helping to regulate blood glucose levels.

Maintaining intestinal health: L-valine can promote the proliferation of intestinal epithelial cells, enhance mucus secretion, increase intestinal villus height, and upregulate the expression of tight junction protein ZO-1. This maintains intestinal barrier function, reduces the entry of harmful substances into the bloodstream, and has a positive impact on overall metabolism and health.

Affecting neurotransmitter synthesis: L-valine can cross the blood-brain barrier and participate in regulating the synthesis of important neurotransmitters in the brain. Studies have shown that supplementation with branched-chain amino acids containing L-valine can increase serotonin and dopamine levels in the rat brain, helping to improve mental concentration and cognitive function.

II. Clinical Physiological Functions

Improving insulin resistance: Clinical studies have shown that branched-chain amino acid supplementation can reduce the insulin resistance index (HOMA-IR) in type 2 diabetes patients by 22%. Among them, L-valine improves insulin signal transduction by inhibiting serine phosphorylation of insulin receptor substrate-1 (IRS-1), thereby helping to alleviate insulin resistance.

Assisting in the treatment of neurological diseases: Valine can inhibit excessive neuronal excitation by enhancing the opening frequency of GABA_A receptor chloride channels. Studies have reported that it can reduce the frequency of epileptic seizures by 40%, which may have a certain auxiliary effect on the treatment of neurological diseases.

Supporting rehabilitation of muscle-related diseases: For conditions such as muscle atrophy and sports injuries, L-valine helps promote muscle repair and recovery. For example, in high-intensity trainers, supplementation with branched-chain amino acids can reduce muscle soreness by 40% and shorten recovery time by 20%, with L-valine playing an important role.

Improving malnutrition: As an essential amino acid, L-valine supplementation is beneficial for populations unable to obtain sufficient amino acids from food, such as malnourished patients and the elderly. It helps improve protein metabolism, enhance the body's resistance, and promote the recovery of physical health.