Planta Med 2014; 80 - P1L110
DOI: 10.1055/s-0034-1394767

Flavonoid-glycosides from Rumex aquaticus with neuroprotective activity

O Orban-Gyapai 1, A Raghavan 2, A Vasas 1, P Forgo 1, ZA Shah 2, J Hohmann 1
  • 1University of Szeged, Department of Pharmacognosy, H-6720 Szeged Eötvös u. 6., Hungary
  • 2University of Toledo, Department of Medicinal and Biological Chemistry, College of Pharmacy and Pharmaceutical Sciences, 3000 Arlington Ave., Toledo, OH 43614, USA

According to the WHO, 15 million people suffer stroke worldwide each year. The only effective drug for acute stroke therapy is the recombinant tissue plasminogen activator. There is a great intention to develop neuroprotective agents that would prevent the occurrence and/or aid recovery from stroke. A host of in vitro models have been devised to test the effects of drugs in cerebral ischemia, of which the oxygen glucose deprivation (OGD) model is considered to be one of the most reliable and frequently used models to induce ischemia. In this study we investigated the neuroprotective effects of RUA1: quercetin-3-O-galactoside and RUA2: quercetin-3-O-arabinoside, isolated from Rumex aquaticus. For neuroprotective agents to be valuable, they should not only preserve neuronal viability but also aid in the functional reorganization of the neuronal network. A major element of this process involves re-formation of synaptic connections through activation of the surviving immature and mature neurons, and is thus accelerated by agents that promote neurogenesis and neurite outgrowth. We evaluated the effects of RUA1 and RUA2 on cell viability and neurite outgrowth under OGD conditions. The experiments were conducted on the rat pheochromocytoma (PC12) cell line and tested with MTT assay. Low micromolar doses (10µM) of both compounds brought about a 100% increase (relative to control) in viability, thereby underlying their potent neuroprotective effects. The neurorestorative effect of the compounds was tested at 1 and 10µM concentrations. A drastic reduction (56%) was found in the neurite length when dPC12 cells were subjected to OGD. This effect was entirely reversed by RUA1 (173% at 10µM) and RUA2 (282% at 1µM and 297% at 10µM).Both of the compounds have promising neuroprotective effect and they are worth for further investigation.

Acknowledgements: This work was supported by the European Union and the European Social Fund TÁMOP 4.2.4.A/2 – 11 – 1-2012 – 0001, and OTKA PD 101432.

Keywords: Rumex aquaticus, Polygonaceae, flavonoid-glycosides, neuroprotective, neurorestorative