GLUT4 translocation in C2C12 myoblasts and primary mouse hepatocytes by an antihyperglycemic flavone from Tillandsia usneoides.

BACKGROUND: Type 2 Diabetes (T2D) is characterized by deregulation in carbohydrate and lipid metabolism, with a very high mortality rate. Glucose Transporter type 4 (GLUT4) plays a crucial role in T2D and represents a therapeutic target of interest. Tillandsia usneoides (T. usneoides) is a plant used as a remedy for diabetes. T. usneoides decreased blood glucose in different experimental models. However, the involvement of GLUT4 in this effect has not yet been explored. PURPOSE: This study aimed to investigate whether any component in T. usneoides might participate in the effect on blood glucose through a bioassay-guided fractionation, testing its potential antihyperglycemic effect in mice, as well as its influence on GLUT4 translocation in C2C12 myoblasts and primary hepatocytes. METHODS: The aqueous extract and the Ethyl Acetate fraction (TU-AcOEt) of T. usneoides were evaluated in a hypoglycemic activity bioassay and in the glucose tolerance test in CD-1 mice. TU-AcOEt was fractionated, obtaining five fractions that were studied in an additional glucose tolerance test. C1F3 was fractioned again, and its fractions (C2F9-12, C2F22-25, and C2F38-44) were examined by HPLC. The C2F38-44 fraction was analyzed by Mass Spectrometry (MS) and subjected to additional fractionation. The fraction C3F6-9 was explored by Nuclear Magnetic Resonance (NMR), resulting in 5,7,4´-trihydroxy-3,6,3´,5´-tetramethoxyflavone (Flav1). Subsequently, a viability test was performed to evaluate the cytotoxic effect of Flav1 and fractions C2F9-12, C2F22-25. C2F38-44, and C3F30-41 in C2C12 myoblasts and primary mouse hepatocytes. Confocal microscopy was also performed to assess the effect of Flav1 and fractions on GLUT4 translocation. RESULTS: The TU-AcOEt fraction exhibited a hypoglycemic and antihyperglycemic effect in mice, and its fractionation resulted in five fractions, among which fraction C1F3 decreased blood glucose. MS and NMR analysis revealed the presence of Flav1. Finally, Flav1 significantly promoted the translocation of GLUT4 in C2C12 myoblasts and primary hepatocytes. CONCLUSION: To date, Flav1 has not been reported to have activity in GLUT4; this study provides evidence that T. usneoides is a plant with the potential to develop novel therapeutic agents for the control of T2D.

The Tillandsia genus: history, uses, chemistry, and biological activity / El género Tillandsia: historia, usos, química y actividad biológica

Tillandsia L. genus comprises 649 species, with different uses at different times. T. usneoides L. uses are reported since the late- archaic and pre-Columbian cultures. In XIX-XX centuries, T. usneoides was used in some manufactured products, as polish and packing fruit. Tillandsia has a favorable reputation as medicine: for leucorrhea, rheumatism, ulcers, hemorrhoid treatment, as an anti-diabetic remedy, emetic, analgesic, purgative, contraceptive, antispasmodic and diuretic. Tillandsia chemical composition includes cycloartane triterpenes and hydroxy-flavonoids, which are present in at least 24 species. Several extracts and compounds from Tillandsia spp. have been reported with pharmacological actions, as anti-neoplasia, hypolipidemic, antifungal, anti-HSV-1, hypoglycemic and microbicide. This review communicates the economic importance, ethnobotany, chemistry composition and biological activities of the Tillandsia genus, and analyze its biological and economic perspective. Tillandsia genus has cultural, economic and pharmacological relevance, with a high potential in many essential aspects of the modern society.

El género Tillandsia L. comprende 649 especies, con diferentes usos en diferentes épocas. T. usneoides L. se han reportado desde el arcáico tardío hasta las culturas precolombinas. En los siglos XIX-XX, T. usneoides se usó en productos manufacturados: como abrasivo y embalaje de fruta. Como medicina tradicional, el género Tillandsia se reporta para leucorrea, reumatismo, úlceras, hemorroides, remedio antidiabético, emético, analgésico, purgante, anticonceptivo, antiespasmódico y diurético. Su composición química incluye triterpenos de tipo ciclo-artano e hidroxi-flavonoides, presentes en al menos 24 especies. Los extractos y compuestos del género Tillandsia se han reportado con propiedades antineoplásicas, hipolipidémicas, antifúngicas, anti-HSV-1, hipoglucemiantes y microbicidas. Esta revisión comunica la importancia económica, etnobotánica, composición química y las actividades biológicas del género Tillandsia, y analiza su perspectiva biológica y potencial económica. Tillandsia tiene importancia cultural, económica y farmacológica, con gran potencial en muchos aspectos esenciales de la sociedad moderna.