Silvia ZambranaHigher University of San Andrés , Bolivia
Title: Glycemia-reducing effects of Bolivian nutraceutical plants
The prevalence of diabetes type 2 is increasing worldwide, leading to the search of novel coadjuvant therapies. According to their traditional use, we studied five Bolivian plants Chenopodium quinoa (CQ) Ama-ranthus caudatus (AC), Chenopodium pallidicaule (CP), Lupinus mutabilis (LM) and Smallanthus sonchifolius (SS). We evaluated the effect of a single oral administration of Ethanolic (EtOH), hydro-ethanolic (EtOH70) and aqueous (Aq) extracts from all plant species over blood glucose levels in non-fasted mice and during the oral glucose tolerance test (OGTT). EtOH70 extracts of all the plants showed glucose-reducing effect at the highest dose evaluated (2000 mg/kg b.w.). The extracts have different effects on glucose homeostasis since just extracts of LM, AC and CQ but not CP and SS increased insulin secretion as shown on mice pancreatic islets. The phytochemical qualitative characterization of EtOH70 extracts detected alkaloids in LM; phenolic acids and flavonoids in AC, CP and CQ; and anthocyanidins in SS. None of EtOH70 extracts tested showed in vitro or in vivo acute toxicity at concentrations where they exhibit glucose lowering effects. Further in vitro studies of LM EtOH70 extract showed that LM (10mg/ml) stimulated the insulin secretion (glucose 16.7 mM) from 526±33 to 1288.3±18.6 and LM (20mg/ml) from 2380±11.9 µIU/mL/Islet/h (P<0.0001). Regarding the modulation of gene expression, LM modulated the expression of insulin gene (Ins) by 1.89-fold (10 mg/mL) (P<0.01) and 3.2-fold (20 mg/ml) (P<0.00001); additionally, the Glucose transporter gene (Glut2) expression increased 2.5-fold by LM (10mg/ ml) (P<0.01) and 2.7-fold by LM (20mg/mL) (P<0.001). In conclusion, the extracts from AC, CQ, CP, LM and SS exhibit glucose lowering effect while LM, AC and CQ and LM stimulate directly the insulin secretion. Furthermore, LM hydroethanolic extracts induce insulin secretion by increasing the gene expression of Insulin gene and glucose transporter 2 in pancreatic islets.
Silvia Zambrana has completed his PHD at the age of 38 years from Karolinska Institutet, Stockholm Sweden. Currently she is researcher at the Instituto de Investigaciones Fármaco Bioquímicas from Universidad Mayor de San Andrés, La Paz Bolivia. She has developed research in the field of natural productcs and nutraceuticasl to treat type 2 diabetes mellitus.