Natural and Artificial Sweeteners a Blessing or Curse: A Phyto-genotoxic Study in Allium cepa L. Root Tip Cells

The study investigated the comparative phyto-genotoxic impacts of natural and artificial sweetener brands using the Allium cepa L. (onion) assay to predict potential phyto-genotoxic associated with long-term intake. Onion bulbs were exposed for 48hours to 1% aaqueous solutions of natural and artificial sweeteners (Honey, Date, Jaggery, Canderel, Sucral, Stiva and Refined sugar) and distilled water was used as the negative control. All the tested sweeteners exhibited significant variations at LSD≤0.05 for all phytotoxicity and genotoxicity parameters. The results phytotoxicity, characterized by a marked failure of root emergence and reduction in root length and Mitotic index (M.I.%). Genotoxic analysis showed that both sweetener categories induced a substantial increase in Abnormality Index (A.I.%), escalating from 14.2% at the lowest concentration to 47.2% at the highest. The most prevalent chromosomal aberration was DNA fragmentation in all the tested sweeteners and while occurrences of sticky metaphase and micronuclei were also recorded in low number. Stiva induced nuclear lesions, and impaired chromosome condensation. These two are checkpoints of carcinogenesis in addition to chromosomal aberrations. The high frequency of nuclear damage and cellular membrane irregularities suggests that exposure to 1% solutions of both natural and artificial sweeteners can induce measurable genetic instability. Overall results suggest that Stiva followed by Canderel, Sucral and refined sugar were severely phyto-genotoxic, while honey was moderately phyto-genotoxic and Dates followed by jaggery were the mild phyto-genotoxic. It is concluded that sweetener intake must be minimized to avoid possible cellular and DNA damages. A dose dependent animal-based study must be conducted to estimate cancer risk to humans. Reactive oxygen species generation, lipid peroxidation profiling is also recommended.