Turmeric (Curcuma longa L.) tends to reduce the toxic effects of nickel (II) chloride in Allium cepa L. roots.

The immense protection potential of plant-derived products against heavy metal toxicity has become a considerable field of research. The goal of the present study was to evaluate the mitigative ability of turmeric against nickel (II) chloride (NiCl)-related toxicity in the roots of Allium cepa L. For this purpose, one control (treated with tap water) and five treatment groups (treated with 440 mg/L turmeric, 880 mg/L turmeric, 1 mg/L NiCI, 1 mg/L NiCI + 440 mg/L turmeric, and 1 mg/L NiCI + 880 mg/L turmeric, respectively) of Allium bulbs were established. Experimental conditions were maintained at room temperature for 3 days. Physiological, biochemical, cytogenetic, and meristematic integrity parameters were analyzed in all groups. NiCl reduced germination percentage, root elongation, and weight gain. Following NiCl application, the frequency of aberrant chromosomes and micronuclei increased, while mitotic index decreased. NiCl caused an increase in oxidative stress, which was evident by increased malondialdehyde level and catalytic activities of superoxide dismutase and catalase. Epidermal and cortex cell injuries as well as deformed cell nuclei and indistinct transmission tissue were observed as a result of NiCl treatment. When applied alone, turmeric, which did not cause any negative effects, led to an improvement in all parameters depending on the dose when applied together with NiCl. Data from the study suggests that turmeric has remarkable protection potential against NiCl in Allium cepa.