Betaine Supplementation Improves Beneficial Effects of Boxthorn (Lycium chinense Mill.) Leaf on Body Weight/Body Fat Increase and Plasma/Liver Triglycerides Accumulation in High‐Fat Diet‐Fed C57BL/6 Mice

In the present study, we investigated the combinatorial effects of betaine supplementation and boxthorn (Lycium chinense Mill.) leaf on high‐fat diet (HFD)‐induced body weight/body fat increase, plasma lipid profile and liver damage. Suboptimal dosage of hot water extract of boxthorn leaf (Lycium chinense water extract, LWE) exerted partial inhibitory effect on body weight/body fat increase in HFD‐fed mice. Betaine supplementation potentiated the effect of LWE showing a significant inhibition against HFD‐induced increase in body weight/body fat. However, both LWE alone and LWE plus betaine had no effect on plasma cholesterols, including total cholesterol, low‐density lipoprotein cholesterol and high‐density lipoprotein cholesterol in HFD‐fed mice. In contrast, HFD‐induced increases in plasma and liver triglycerides were partially suppressed by LWE treatment and this was potentiated by betaine supplementation. In addition, both LWE alone and LWE plus betaine significantly suppressed HFD‐induced glutamic‐oxaloacetic transaminase and glutamic‐pyruvic transaminase. Collectively, our results suggest that the combination of boxthorn leaf and betaine might be beneficial for the management of obesity and nonalcoholic fatty liver disease. PRACTICAL APPLICATIONS: For a long time, a combination of various substances was used to treat diseases effectively in traditional Chinese medicine. In the present study, we demonstrated that the supplementation of betaine synergizes with boxthorn leaf for improvement of high‐fat diet‐induced body weight/body fat increase and plasma/liver triglycerides accumulation. The results presented in this report suggest that the combination of boxthorn leaf and betaine might be beneficial for the treatment of obesity and related metabolic disorders.