Physicochemical and nanomedicine applications of phyto-reduced erbium oxide (Er₂O₃) nanoparticles

Hyphaene thebaica fruits were used for the fabrication of spherical erbium oxide nanoparticles (HT-Er₂O₃ NP_S) using a one-step simple bioreduction process. XRD pattern revealed a highly crystalline and pure phase with crystallite size of ~ 7.5 nm, whereas, the W-H plot revealed crystallite size of 11 nm. FTIR spectra revealed characteristic Er-O atomic vibrations in the fingerprint region. Bandgap was obtained as 5.25 eV using K-M function. The physicochemical and morphological nature was established using Raman spectroscopy, reflectance spectroscopy, SAED and HR-TEM. HT-Er₂O₃ NP_S were further evaluated for antidiabetic potential in mice using in-vivo and in-vitro bioassays. The synthesized HT-Er₂O₃ NP_S were screened for in vitro anti-diabetic potentials against α-glucosidase enzyme and α-amylase enzyme and their antioxidant potential was evaluated using DPPH free radical assay. A dose dependent inhibition was obtained against α-glucosidase (IC₅₀ 12 μg/mL) and α-amylase (IC₅₀ 78 μg/mL) while good DPPH free radical scavenging potential (IC₅₀ 78 μg mL^-1) is reported. At 1000 μg/mL, the HT-Er₂O₃ NP_S revealed 90.30% and 92.30% inhibition of α-amylase and α-glucosidase enzymes. HT-Er₂O₃ NPs treated groups were observed to have better glycemic control in diabetic animals (503.66 ± 5.92*** on day 0 and 185.66 ± 2.60*** on day 21) when compared with positive control glibenclamide treated group. Further, HT-Er₂O₃ NP_S therapy for 21 days caused a considerable effect on serum total lipids, cholesterol, triglycerides, HDL and LDL as compared to untreated diabetic group. In conclusion, our preliminary findings on HT-Er₂O₃ NP_S revealed considerable antidiabetic potential and thus can be an effective candidate for controlling the post-prandial hyperglycemia. However, further studies are encouraged especially taking into consideration the toxicity aspects of the nanomaterial.