Neuroprotective effects of biogenic silver nanoparticles in Parkinson's disease: In vitro and in vivo study

The study aimed to develop immunomodulatory silver nanoparticles (CHT-PCT/AgNPs) using a green chemistry approach with Umbilicaria esculenta (U.E.) extract to protect neurons from Parkinson's disease. The synthesized CHT-PCT/AgNPs measured 88.2 ± 33.7 nm in size, with a zeta potential of approximately 24.5 ± 1.9 mV. In vitro assays demonstrated that the green-synthesized nanoparticles exhibited greater biocompatibility and antioxidant properties compared to chemically synthesized AgNPs. The MTT assay indicated that CHT-PCT/AgNPs were cytocompatible up to 50 μg/mL, but higher concentrations resulted in significant toxicity. The DPPH assay revealed dose-dependent antioxidant activity, although it was lower than that of ascorbic acid. In animal studies of MPTP-induced Parkinsonism, the count of tyrosine hydroxylase (TH)-positive cells varied across groups, with healthy controls showing 145.3 ± 11.0 cells compared to the negative control group with only 21.6 ± 4.1. Additionally, the number of DRD1-positive cells also reflected a similar trend. These findings suggest that CHT-PCT/AgNPs may serve as a potential neuroprotective agent to mitigate Parkinson's disease.