Antioxidant activities of underexplored Chinese medicinal plant parts and their effect against high glucose-induced modulation of fibronectin expression

Diabetes has been a long-standing disorder and its management has been challenging various medical and research experts for several decades because of its complex causative factors and pathophysiological processes leading to complications. Medicinal plants have been explored in several countries and traditional Chinese medicine is one of the well-recognized alternative treatment methods. In this study, we have chosen some of the underexplored plant parts of Chinese medicinal herbs and analyzed their antioxidant activity and ability to modulate the expression of fibronectin during high glucose conditions. Extraction of the plant materials with different solvent led to 17 extracts and among which, 3 extracts (2, 12 & 17) were observed to render more than 50 μg/ml vitamin C equivalents of DPPH free radical scavenging ability and 2 of them (2 & 17) showed more than 25 μg/ml of vitamin C equivalents of ferric ion reducing power. Based on the antioxidant activity and comparison of their total phenolic content, we used extracts 2 & 17 to check their effect on fibronectin expression in MES-13 cells under high sugar conditions. We observed that both extracts showed a significant reduction of fibronectin expression compared to untreated cells with high glucose levels. The expression was much lesser than the normal untreated, normal sugar supplemented cells and this was not observed in vitamin C supplemented cells. In conclusion, crude extracts containing a group of phenolic compounds have shown significant effects against fibronectin expression leading to reduced ECM deposition and tissue fibrosis. Further exploration might provide insights into the exact mechanism and checkpoints of the extract that can successfully reduce diabetes-induced renal complications.