Dose-dependent Effects of Fermented Mucuna pruriens Extract on Dopaminergic Neuron Viability in vitro

¹ Veterinary Medicine Study Program, Faculty of Medicine, Universitas Negeri Semarang, Central Java, 50237, Indonesia
² Department of Reproduction and Obstetrics, Faculty of Veterinary Medicine, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia
³ Lap-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR
⁴ Department of Anatomy, Faculty of Veterinary Medicine, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Mucuna pruriens are traditionally used as the main ingredient for fermented food called Tempe Koro Benguk. In addition to their value as food commodities, M. pruriens seeds are rich in levodopa (L-DOPA), a precursor to dopamine that holds potential therapeutic benefits for several neurodegenerative disorders such as Parkinson’s disease. This study investigated the effects of ethanolic and propanolic extracts derived from fermented Tempe Koro Benguk on the viability of dopaminergic neurons cultured from fetal rat ventral midbrains. Tempe Koro Benguk extracts were obtained using ethanol and n-propanol as solvents and were administered at varying concentrations (0.05 µM, 0.5 µM, 5 µM and 50 µM) to primary midbrain cultures harvested on gestational period day 14. After 10 days of exposure, the cells were fixed and immunohistochemically stained for tyrosine hydroxylase (TH) to visualize the dopaminergic neurons. Our study demonstrated that the highest viability of TH-immunoreactive cells was observed in cultures treated with ethanolic extract at 0.05 µM concentration. Although not statistically significant, this number was slightly higher than that of the control levels. However, both ethanolic and propanolic extracts at concentrations of 5 µM and 50 µM were associated with a complete loss of TH-immunoreactive neurons. Notably, although the ethanolic extract at 0.5 µM yielded well defined morphological features of dopaminergic neurons, viability remained below control levels. These findings suggest that Tempe Koro Benguk extract may offer dose-dependent neuroprotective properties, with low concentrations potentially supporting dopaminergic neurons survival. Further studies are required to elucidate the mechanisms involved and to evaluate its safety and efficacy profiles.