Nettle Leaf Water Extracts for Hepatoprotection: Insights into Bioactivity and Mitochondrial Function

Area of Science:

• Biochemistry and Molecular Biology
• Pharmacology and Toxicology
• Cell Biology

Background:

• Hepatic steatosis, or fatty liver disease, is a growing health concern with limited therapeutic options.
• Oxidative stress and mitochondrial dysfunction play critical roles in the pathogenesis of fatty liver disease.
• Natural compounds, such as those found in *Urtica dioica* (nettle), are being investigated for their potential therapeutic benefits.

Purpose of the Study:

• To evaluate the hepatoprotective effects of nettle leaf water extracts on liver cells (*in vitro* HepG2 model).
• To investigate the impact of nettle extracts on mitochondrial oxygen consumption in the fatty acid oxidation (FAO) pathway.
• To assess the influence of nettle extracts on lipid accumulation and cell viability under oxidative stress conditions.

Main Methods:

• Extraction of nettle leaves using maceration and sonication techniques, with and without preservatives.
• Chemical composition analysis of extracts, focusing on polyphenols, vitamins, and minerals.
• In vitro bioactivity assays including antioxidant and antiglycation tests, oxygraphy for mitochondrial respiration, and HepG2 cell-based assays for lipid accumulation and viability.

Main Results:

• Sonication yielded higher polyphenol content and enhanced antioxidant and antiglycation activities compared to maceration.
• Nettle extracts significantly improved HepG2 cell viability and reduced lipid accumulation in a fatty liver model under oxidative stress.
• Extracts enhanced mitochondrial oxygen consumption in the FAO pathway, specifically at mitochondria complex I, indicating improved mitochondrial function.

Conclusions:

• Nettle leaf water extracts exhibit significant hepatoprotective properties against hepatic steatosis.
• The protective effects are mediated through multiple mechanisms, including potent antioxidant activity, lipid metabolism modulation, and mitochondrial protection.
• These findings support the therapeutic potential of *Urtica dioica* for managing liver conditions associated with oxidative stress and lipid dysregulation.