Purple onion in combination with garlic exerts better ameliorative effects on selected biomarkers in high-sucrose diet-fed fruit fly (Drosophila melanogaster)

Garlic and purple onion are two vegetables widely used globally for culinary purposes. These vegetables have been previously reported to exhibit several medicinal properties including antidiabetic, antihypertensive, and renoprotective properties owing to their constituent bioactive phytochemicals. However, both vegetables are often combined in popular culinary practices and there is a dearth of information on their combinatorial effects. Therefore, this study evaluated the effect of garlic, onion, and their combination on high-sucrose diet (HSD)-Drosophila melanogaster model. HSD-drosophila is gaining popularity as a rapid, economical, and refined alternative model for studying biochemical and molecular mechanisms of impaired glucose homeostasis, as well as potential therapeutic targets. Wild-type D. melanogaster were raised for 7 days on HSD diets supplemented with garlic, onion, or their combination. Thereafter, their survival rate, total glucose, and triglyceride levels, as well as α-amylase and α-glucosidase activities were determined. Results showed that HSD-fed flies showed significant elevation in total sucrose and triglyceride levels, as well as activities of both α-amylase and α-glucosidase, with no significant changes in survival rate compared to control. However, HSD-fed flies supplemented with the vegetables showed significant amelioration of these impairments, with garlic supplementation being better than onion. It was also observed that HSD-fed flies supplemented with combination of garlic and onion showed better amelioration of these impairments, compared to both vegetables alone. Therefore, this study suggests that combination of these vegetables could enhance their antihyperglycemic properties, with further studies recommended to justify these findings.