In a study published in Journal of Ethnopharmacology on January 29, researchers from the Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences identified a rare natural compound derived from the Teak tree (Tectona grandis) which works in two distinct ways to combat diabetes and lipid disorders.

Using a bioactivity-guided isolation approach, researchers isolated a rare double-quinone molecule named Tectograndone (TG1), and for the first time showed that TG1 could both increase glucose absorption in fat cells and block a key enzyme involved in breaking down dietary fats.

Through methodologies including cellular imaging techniques (immunofluorescence and Western blot analysis), enzymatic assays, and computational modeling approaches (molecular docking and dynamics simulations), researchers revealed that TG1 significantly enhanced glucose uptake in adipocytes, while potently inhibiting pancreatic lipase, a crucial enzyme for lipid digestion.

Mechanistic investigations revealed that TG1 activated 5′-AMP-activated protein kinase, a key cellular energy sensor implicated in metabolic regulation. This activation induced the translocation of the glucose transporter GLUT4 to the plasma membrane, facilitating cellular glucose uptake. This effect occurred independently of insulin signaling pathways, suggesting potential therapeutic efficacy in insulin-resistant conditions.

Furthermore, researchers found that TG1 acted as a "mixed-type inhibitor" of pancreatic lipase, forming a stable complex with the enzyme and suppressing its ability to digest fats, which could help manage postprandial lipid levels. When given to normal mice, TG1 significantly improved glucose tolerance, confirming its glucose-lowering effect in a living organism.

This study not only provide a validation for the traditional use of Tectona grandis in Indian medicine, but also identify TG1 as a promising multi-target lead candidate for the treatment of diabetes and lipid disorders. "The dual action of TG1 on two interconnected metabolic pathways (glucose uptake and lipid digestion) makes it a promising lead molecule," said ZHANG Yumei from XTBG, an author of this study.

Tectona grandis (Image by ZHU Renbin)