Oral Nigella sativa Oil Modulates Interleukin-1β and Interleukin-10, Improves Neurological Function, and Reduces Neuronal Necrosis after Traumatic Brain Injury in Rats

Abstract

BACKGROUND: Current management of traumatic brain injury (TBI) is primarily directed toward preventing secondary brain injury, while specific pharmacological therapies targeting post-traumatic neuroinflammation remain limited. Bioactive constituents of Nigella sativa, particularly thymoquinone, have demonstrated anti-inflammatory and antioxidant properties that may modulate mechanisms involved in secondary brain injury. This study was conducted to evaluate the effects of oral N. sativa oil on serum interleukin (IL)-1β and IL-10 levels as inflammatory parameters, neurological function and necrosis in a rat model of TBI.

METHODS: Sixteen male Wistar rats underwent Marmarou weight-drop TBI and were randomly assigned into two groups given either oral N. sativa oil or distilled water (n=8/group) for 7 days. Serum IL-1β and IL-10 concentrations were measured using rat-specific enzyme-linked immunosorbent assays (ELISA), and neurological function was assessed using the modified Neurological Severity Score (mNSS) at post-injury baseline and on treatment day-1, -3, and -7. After day-7, brain tissue was examined using hematoxylin–eosin (H&E) staining, and necrotic-cell count was assessed.

RESULTS: IL-1β concentrations were significantly lower in the N. sativa group from day-1 onward, whereas IL-10 concentrations were significantly higher and mNSS scores were significantly lower from day-3 onward. By day-3, all three outcomes differed significantly: lower IL-1β (56.38±10.21 vs. 111.98±47.64 pg/mL; p=0.013), higher IL-10 (102.38±33.42 vs. 40.20±6.02 pg/mL; p=0.001), and lower mNSS (median: 4 (3-5) vs. 5 (5-6); p=0.003) than placebo group. These differences persisted through day-7, which also supported by lower necrotic-cell counts in the N. sativa group (3164.13±771.38 vs. 4028.38±204.58; p=0.008).

CONCLUSION: Administration of oral N. sativa oil shifted the circulating cytokine profile toward an anti-inflammatory pattern and was accompanied by better neurological function and fewer neuronal necrosis after TBI. These findings suggest that N. sativa oil may have beneficial effect on neuroinflammation after TBI.

KEYWORDS: Nigella sativa, traumatic brain injury, interleukin-1 beta, interleukin-10, neuroinflammation, modified Neurological Severity Score