Screening of Natural Plants that Activate Glucose Metabolism‐related Enzymes and Those Metabolic Mechanisms

This study was carried out to estimate beneficial effects of increase in the glucose inflow and reduction in blood glucose by natural plants. Natural substances have been identified in blood sugar by measuring glucose inflow from hepatocytes (HepG2) to cells, including activities of enzymes such as glucokinase (GK), pyruvate dehydrogenase (PDH), which was investigated via reverse transcription polymerase chain reaction (RT‐PCR) and western blot analyses. With the exception of materials, which are cytotoxic, the effects of water extracts from 15 natural substances were analyzed by measuring the activities of glucokinase (GK)/pyruvate dehydrogenase (PDH), which are the key enzymes involved in glucose uptake and metabolism, followed by consideration of the mutual relations. Of these, the substances demonstrating the best activities were selected. CM (428%), AS (296%), and CML (222%) materials were selected from glucose uptake experiments, CM (220%), CML (210%), and AS (150%) materials that showed the best activity were selected based on the GK activity test. LC (290%), CM (136%), and CML (122%) materials were selected by the PDH activity test. In order to study the underlying metabolic regulatory mechanisms, highest GK activity of CM, AS, and CML materials was observed at a density of 1.0 mg/ml for 24 h. In addition, for the best PDH activity, the LC material was set at a density of 1.0 mg/ml for 36 h, while that of the CM and CML materials was set at 1.0 mg/ml and 0.25 mg/ml/for 24 h. The findings of this study suggested that CM, AS, and CML aided glucose uptake and induced glucose metabolism, thereby suggesting that these are candidate materials that can be used for the prevention and treatment of anti‐hyperglycemia in the future. Support or Funding Information This work was supported by Well‐being Bioproducts Regional Innovation Center project (B0009702) and kangwon national university institute of bioscience & biotechnology (320130015). 1Concentration‐dependent effects of natural plants water extracts on HepG2 cell growth. HepG2 cell were cultured for 24hr with various concentration(0.1, 0.2, 0.5, 1.0 mg/mL) of natural plants water extracts. Cytotoxicity was determined by MTT assay. Results are presented as Mean±S.D of three independent experiments.2Induction of glucose uptake following natural plants water extracts treatment in HepG2 cell. HepG2 cells were incubated with the natural plants water extracts (0.25 mg/mL) with and without insulin treatments for 20 minutes after, uptakes of 2‐DG was determined. Results are presented as Mean±S.D of three independent experiments. The different letters denote significant differences between groups at p<0.05 by Tukey's range test(n=3).3Induction of GK activity by natural plants water extracts treatment on HepG2 cell. HepG2 cells were incubated with the natural plants water extracts (1.0 mg/mL) for 24 hr. Results are expressed as mean±S.D of three independent experiments. The different letters denote significant differences between groups at p<0.05 by Tukey's range test(n=3).4Induction of PDH activity by natural plants water extracts treatment on HepG2 cell. HepG2 cells were incubated with the natural plants water extracts (1.0 mg/mL) for 24 hr. Results are expressed as mean±S.D of three independent experiments. The different letters denote significant differences between groups at p<0.05 by Tukey's range test(n=3).