Comparison of the Effects of Nigella sativa Oil and Nano-silver on Wound Healing in an Experimental Rat Model

Background: Various topical treatments are available for skin defects. Chronic and complicated wounds can affect a patient’s quality of life and cause significant economic burden and even mortality. Nigella sativa (NS) oil and silver-containing solutions are separately used to treat various skin disorders. Objectives: The current study aimed at examining the healing potential of NS oil, Nano-silver (AgNPs) solution, and their combination to manage skin wounds in a rat model. Methods: The current clinical experimental study was conducted in the Experimental Animal Unit of Abant Izzet Baysal University, Bolu, Turkey, in 2017. Full-thickness skin defects with a 1 cm surface area were created on the backs of 20 adult Wistar albino rats. The wounds were covered with 1 cm of absorbable oxidized regenerated cellulose (SURGICEL). The rats were numbered and assigned to four groups by simple random sampling. The agents to be compared (saline, NS oil, and AgNPs solution) were administered to the wounds twice daily for 15 days. The wounds were observed for the percentage reduction in original wound size every three days. Scars were harvested on day 15 for histological morphometric analysis. Results: There were no significant differences in the mean vertical scar thickness among the saline (group 1) [1.06 ± 0.18], NS oil (group 2) [0.76 ± 0.14], AgNPs (group 3) [0.98 ± 0.44], and NS oil + AgNPs (group 4) [0.87 ± 0.38] groups (P = 0.556). However, the mean collagen density was significantly lower in groups 1 and 3 [56.50± 11.18 and 59.60± 3.16] compared with groups 2 and 4 [73.57 ± 6.30 and 80.99 ± 7.19] (P < 0.001). Conclusions: Wounds treated with the combination of NS oil and Nano-silver healed significantly faster, with less scar formation, than the ones treated with NS oil or Nano-silver alone.