O. A. EDENE

Geophagy, the deliberate consumption of clay or soil, is a common cultural practice in many
parts of the world, including Nigeria. Although often believed to have therapeutic benefits, some
geophagic clays may contain toxic elements that pose health risks. This study assessed the
toxicity potential of Uzalla geophagic clay by exposing Drosophila melanogaster to varying
concentrations of the clay and assessing their survival rate, locomotor performance, and
neurotoxic gene expression. Flies were exposed to different concentrations of the clay (0.025
g/mL, 0.05 g/mL, and 0.1 g/mL) for five days, and assessments were made on survival rate,
locomotor performance (negative geotaxis), and neurotoxic gene expression. The results revealed
a concentration-dependent decline in survival, with the highest mortality recorded at 0.1 g/mL.
However, negative geotaxis assays indicated improved locomotor performance across all
exposed groups in contrast to the control group, suggesting a possible stimulatory effect. Gene
expression analysis showed upregulation of Spitz, Eiger, and Hedgehog, reflecting activation of
stress and neuroprotective pathways, while Wingless and Keap1 were downregulated, indicating
oxidative imbalance and neuronal disruption. This study shows that Uzalla geophagic clay
exhibited neurotoxic potential at higher concentrations, evidenced by reduced survival, altered
locomotor performance, and disrupted gene expression associated with neural stress.

Given the widespread global use of hair dyes, which contain chemicals like aromatic amines and oxidative agents, understanding their toxic potential is a critical component of assessing human safety. Drosophila melanogaster served as a model organism due to its well-characterized genome, conserved neurological pathways, and ease of genetic tractability. The flies were exposed to three treatment concentrations of the hair dye (0.05%, 0.5%, and 2.0%). The study assessed overall survival rates and observed climbing ability of the flies using the negative geotaxis assay. Flies were exposed to various concentrations of the dye through dietary administration, and survival was monitored over a 7-day period for the pilot study and a 5-day period for the main study. The relative expression of several key genes including Spitz(Spi), Wingless(Wnt), Eiger(egr), Forkhead box(FOXO), Hedgehog(HH), and Kelch-like ECH-associate protein 1(Keap1) was analyzed. Results demonstrated a dose-dependent response of the organism. The locomotor behavior analysis showed declining climbing ability of the flies at increasing concentrations. The Spi gene, associated with the EGFR pathway, showed a significant increase at the highest (2.0%) concentration. Wnt gene was significantly decreased at the 0.5% and 2.0% concentrations while Eiger gene was increased. The transcription factor FOXO was decreased while the signaling gene HH was significantly increased at high concentrations, indicating the activation of stress-induced and developmental response mechanisms. Conversely, the stress regulator Keap1, involved in the Nrf2 pathway was decreased at the 0.5% and 2.0% concentrations. These findings collectively establish that exposure to the hair dye induces significant neurotoxicity and disturbs fundamental regulatory mechanisms in Drosophila melanogaster, highlighting the need for accurate toxicological evaluation of these cosmetic products.

Benny seasoning is a cooking powder that is commonly used in Africa for improving the taste, aroma and color of food. The potential health risk from the use of Benny seasoning powder remains unclear. Oxidative stress has been implicated in disease onset. Hence in this study, oxidative parameters were assessed in fruit flies (Drosophila melanogaster) exposed to Benny seasoning at various concentrations (Control, 0.025 g/mL, 0.05 g/mL and 0.1g/mL)for seven (7) days. A survival study and climbing assay was conducted and the observations obtained from the study showed that with increasing concentration, mortality rate increased and the climbing activity decreased. After homogenization, specific markers of oxidative stress response (Protein, Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase(GPx), and malondialdehyde (MDA)) were assessed. The results showed that there was no significant difference (p<0.05) when control was compared with the treatment groups. However there were alterations (increase and decrease) in all of the markers indicating a response to oxidative stress. Some genes involved in neurotoxicity were observed (SPITZ, WINGLESS, EIGER, FOXO HEDGEHOG, KEAP1) after exposure to Benny seasoning. There were significant differences with increasing concentrations in the expression of thesegenes indicative of neurotoxicity. Further studies may be needed to fully assess oxidativeeffect at the genetic level in order to completely understand the oxidative stress responses of Drosophila melanogaster to Benny seasoning powder