Assessing the Antioxidant Properties of Larrea tridentata Extract as a Potential Molecular Therapy against Oxidative Stress.

Rachid Skouta,Karine Fenelon,Abimael Vasquez,Carlos Valenzuela,Karla Morán-Santibañez

doi:10.3390/molecules23071826

Abstract

Oxidative stress has been linked to neurodegenerative diseases such as Huntington’s, Parkinson’s, Alzheimer’s and amyotrophic lateral sclerosis diseases. Larrea tridentata (LT) also known as Creosote Bush is an evergreen shrub found in the Chihuahuan desert which has been used medicinally by Native American tribes in southwestern North America and the Amerindians of South America. However, studies of the antioxidant capacity of the crude extract of LT towards the discovery of novel molecular therapies bearing antioxidants and drug-like properties are lacking. In this study, we assessed the antioxidant properties of Larrea tridentata, collected specifically from the Chihuahuan desert in the region of El Paso del Norte, TX, USA. LT phytochemicals were obtained from three different extracts (ethanol; ethanol: water (60:40) and water). Then the extracts were evaluated in eight different assays (DPPH, ABTS, superoxide; FRAP activity, nitric oxide, phenolic content, UV visible absorption and cytotoxicity in non-cancerous HS27 cells). The three extracts were not affecting the HS27 cells at concentrations up to 120 µg/mL. Among the three extracts, we found that the mixture of ethanol: water (60:40) LT extract has the most efficient antioxidant properties (IC50 (DPPH at 30 min) = 111.7 ± 3.8 μg/mL; IC50 (ABTS) = 8.49 ± 2.28 μg/mL; IC50 (superoxide) = 0.43 ± 0.17 μg/mL; IC50 (NO) = 230.4 ± 130.4 μg/mL; and the highest phenolic content was estimated to 212.46 ± 7.05 mg GAE/L). In addition, there was a strong correlation between phenolic content and the free-radical scavenging activity assays. HPLC-MS study identified nine compounds from the LT-ethanol: water extract including Justicidin B and Beta peltain have been previously reported as secondary metabolites of Larrea tridentata.

Highlights

Radical species including reactive oxygen species (ROS) and reactive nitrogen species (RNS) have been linked to oxidative stress and neurodegenerative diseases such as Huntington’s, Parkinson’s, Alzheimer’s and amyotrophic lateral sclerosis [1]
We investigated the antioxidant activity of Larrea tridentata (LT) plant extracts in ethanol, ethanol: water
The ethanol: water extract at 40 ◦ C for 4 h proved to be the strongest radical scavenger in the DPPH assay, which was closely followed by ethanol, and water extracts obtained at 40 ◦ C for

Summary

Introduction

Radical species including reactive oxygen species (ROS) and reactive nitrogen species (RNS) have been linked to oxidative stress and neurodegenerative diseases such as Huntington’s, Parkinson’s, Alzheimer’s and amyotrophic lateral sclerosis [1]. Oxidative stress occurs when this critical balance is disrupted under depletion of free radicals, antioxidants or both [3]. Free radicals are highly reactive chemical species that contain one or more unstable unpaired electrons. These unpaired electrons are continuously produced in the human body due to their various functions such as chemical signaling, energy supply, detoxification, and immune function. Excess of these unstable unpaired electrons is likely altering several molecules (e.g., proteins, RNA, DNA, and lipids) in the human body, through the known radical propagation pathways (initiation, propagation and termination). The discovery of novel antioxidant compounds bearing better pharmaceutical properties (e.g., better solubility, bioavailability and stability while no significant toxicity) is a major thrust area [11]

Methods

Discussion

Conclusion