Anti-Stress Effects of Urtica dioica L. Leaf Extract against Experimentally Induced Oxidative Stress in Wistar Rats

Abstract

Background: Urtica dioica L. (stinging nettle, Urticaceae) is a widely used sub-Himalayan medicinal herb rich in flavonoids, phenolic acids, and other free-radical-scavenging phytoconstituents. Although antioxidant, anti-inflammatory and neuroprotective properties of the plant have been reported repeatedly, no study has yet examined the anti-stress activity of an extract prepared from nettle grown in Uttarakhand.
Objective: The present work assessed the anti-stress potential of an ethanolic leaf extract of Urtica dioica (UD) using two acute rodent stress models: Acute Restraint Stress (ARS) and the Tail Suspension Test (TST).
Methods: Wistar rats (150–200 g) received oral UD extract at 100, 200 or 400 mg/kg, or Ashwagandha (100 mg/kg, standard adaptogen), three hours before induction of ARS or TST over 14 days. On day 14th Plasma glutathione (GSH), malondialdehyde (MDA), nitrite, superoxide dismutase (SOD), and serum cortisol were measured and Group comparisons used one-way ANOVA with Tukey's post hoc test.
Results: Both ARS and TST significantly depleted GSH and SOD and elevated MDA, nitrite, and cortisol relative to vehicle controls (p < 0.05). Oral UD reversed these changes dose-dependently in both models; the 100 mg/kg dose was generally non-significant relative to the negative control, while 200 and 400 mg/kg produced significant, dose-dependent restoration of all five biomarkers. Ashwagandha (100 mg/kg) produced comparable or numerically greater normalisation than UD 400 mg/kg across most parameters.
Conclusion: The ethanolic leaf extract of Uttarakhand-grown Urtica dioica exhibits dose-dependent anti-stress and antioxidant activity in acute stress paradigms, restoring redox balance and attenuating HPA-axis hyperactivation, supporting its further development as an adaptogenic phytotherapeutic candidate.