AMELIORATIVE EFFECT OF BLACK PEPPER OIL ON CHEMICAL NOCICEPTION AND REDUCED GLUTATHIONE (GSH) IN DROSOPHILA MELANOGASTER (HARWICH STRAIN)

ABSTRACT The study investigated the ameliorative effect of black pepper (Piper nigrum) extract on vincristine-induced peripheral neuropathy using Drosophila melanogaster as an experimental model. Peripheral neuropathy is a common and debilitating side effect of chemotherapeutic agents like vincristine, often resulting in sensory, motor, and biochemical dysfunctions. In this study, adult flies were divided into four groups: normal control, vincristine-treated, vincristine plus black pepper extract, and vincristine plus gabapentin (standard treatment). Nociceptive responses were evaluated using, chemical pain sensitivity assays, while motor coordination was assessed using the negative geotaxis test. Biochemical assays were also conducted to measure oxidative stress markers, including superoxide dismutase (SOD), and catalase (CAT). The results showed that vincristine induced significant hyperalgesia, impaired locomotor activity, and elevated oxidative stress levels. However, co-treatment with black pepper extract significantly reduced pain sensitivity, improved motor performance, and restored antioxidant enzyme activity. These findings suggest that black pepper possesses neuroprotective properties, likely mediated through its antioxidant and anti-inflammatory effects, and may offer a natural, affordable therapeutic alternative for managing vincristine-induced peripheral neuropathy, particularly in low-resource settings.