Assessment of the Protective Effect of Moringa oleifera against Inflammatory and Oxidative Stress Responses Induced by Biomass Smoke Particles in Bronchial and Alveolar Lung Mucosa Models

Abstract

Exposure to biomass smoke (BMS) poses a significant risk for the development of chronic obstructive pulmonary disease (COPD), mainly affecting women and children in low and lower-middle-income countries due to their domestic roles. Incorporating phytochemicals in the diet could offer an easy and affordable solution. This study explores the potential protective effect of Moringa oleifera (M. oleifera) to prevent inflammatory and oxidative stress responses induced by biomass smoke particles (BMP) in bronchial and alveolar lung mucosa models. The bronchial model was developed using human primary bronchial epithelial cells (PBEC), and the alveolar model using a representative type-II pneumocyte cell line (H441), both from one donor. The models were exposed to a lower and higher dose of both M. oleifera and BMP particles, with four technical replicates per condition. Gene expression levels of pro-inflammatory markers (Interleukin-6 (L-6), Interleukin-8 (IL-8), and nuclear factor Kappa B (NF-κB)) and oxidative stress markers (heme oxygenase 1 (HMOX1) and superoxide dismutase 3 (SOD3)) were determined by RT-qPCR. IL-8 protein expression levels were measured by ELISA. A screening strategy was developed to identify toxic compounds in the BMP from two households (one with COPD and one without) using toxicology data provided by the Environmental Protection Agency (EPA). Multiple toxic compounds were found with no distinct difference between the two households. No cytotoxicity was observed in either model, as assessed by Lactate Dehydrogenase (LDH) Cytotoxicity Assay. The high dose of BMP resulted in a decrease in IL-8 secretion at protein level in both models and the gene expression levels of all investigated markers in the alv-ALI model. The lower dose showed no significant impact; however, there was a slight increase in NF-kB and a decrease in HMOX1. Pre-treatment with M. Oleifera revealed no clear trend regarding an increase or decrease in the expression of the investigated markers. No definitive conclusion about the protective effect of M. Oleifera against BMP-induced pro-inflammatory and oxidative responses could be drawn. Further research is needed to enhance understanding of the findings, particularly addressing limitations such as the absence of gene expression data from the bro-ALI model and a low number of replicates.