The lees extracts of Philippine rice wine (Tapuy) protect transgenic Caenorhabditis elegans from glyphosate-induced neurotoxicity

Tapuy is an indigenous rice wine traditionally prepared during rituals and ceremonies in the northern regions of the Philippines. Its fermentation by-product, the Tapuy lees, is nutrient-dense but is underutilized for human consumption. This study aims to explore the potential of Tapuy lees as a functional food capable of neuroprotection from glyphosate-induced toxicity in Caenorhabditis elegans. We prepared Tapuy wine and lees extracts from traditionally- and laboratory- fermented Tapuy. We performed lifespan assays to measure the reduction in the mean lifespan of glyphosate-challenged worms and its improvement with Tapuy extracts. Four transgenic strains of C. elegans expressing GFP-labelled neurons were examined under a fluorescence microscope to measure the susceptibility of different neuronal types to glyphosate-induced toxicity and their response to Tapuy extracts. A DPPH assay was performed to analyze the antioxidant capacity of the Tapuy extracts. We found that 12% glyphosate reduced the mean lifespan of C. elegans by 64%. GABAergic neurons were revealed to be the most sensitive to glyphosate toxicity, followed by the dopaminergic neurons. The resulting neurodegeneration in these specific neuronal types was ameliorated by Tapuy lees extracts by 84% and 91%, respectively. The neuroprotective effect of Tapuy lees did not improve the cognitive ability of the nematodes after exposure to 12% glyphosate. The observed neuronal loss in glyphosate-challenged nematodes translated to a deterioration in associative learning by 57% but not in memory. This study is the first to explore the neuroprotective effect of Tapuy lees extracts in the context of glyphosate-induced neurotoxicity in C. elegans. This may serve as the basis for further development of Tapuy lees as a potential medicinal food in the Philippines.