Biofabrication of Reduced Graphene Oxide using Rhododendron micranthum Turcz. Aqueous Leaf Extract and its Analgesia Efficiency and Local Anesthetic Effect

The biosynthesis of Reduced Graphene Oxide (RGO) was shown using an aqueous leaf extract of Rhododendron micranthum Turcz. as a reductant by deoxygenation of Graphene Oxide (GO). The reduction of GO to RGO was shown as a shift in UV-Vis peak from 230 nm to 270 nm. X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Raman spectroscopy confirmed the GO reduction. Thermal gravimetry and zeta potential measurements exhibited the good stability of RGO. Transmission Electron Microscopy (TEM) results showed thin and transparent RGO sheets. Cell viability results showed that the mesenchymal stem cells (MSCs) of adult goats were viable in the presence of RGO at a concentration of 0.1 mg/mL, and their properties were retained. The analgesic effect of RGO was assessed in mice through the oral administration of different doses of RGO. Writhing episodes induced by acetic acid were decreased dose-dependently. Also, the inflammatory effect of RGO was shown by measuring the hind paw volume of rat exhibited the decreased inflammation with increased RGO concentration. The local anesthetic activity was assessed in guinea pig models and frog, revealing that the RGO exhibited a substantial local anesthetic effect in both the animals with decreased response in dose dependent manner.