Effect of humic acids on lead poisoning in bones and on a subcellular level in mitochondria

Lead (Pb) Induces Osteotoxicity Through the Activation of Mutually Reinforced ER Stress and ROS in MC3T3-E1 Cells

Lead (Pb) is the most common contaminant of heavy metals and is widely present in the environment. Destruction of bone structure, malformation of bone development, and loss of bone mass are important pathological features of lead-exposed individuals. However, the exact molecular mechanisms associated with lead exposure and osteogenic injury are still not fully understood. MC3T3-E1 mouse embryonic osteoblast is a cell line widely used in osteoblast cytology. It can differentiate into mature osteoblasts and express bone-specific genes in cell culture. The doses of 1, 2, and 4 mM Pb were adopted to study the toxicity of Pb on MC3T3-E1 proliferation and differentiation. In this study, the results show that Pb increases the expression of apoptosis-related proteins, including PARP1, cleaved caspase-3, Bax, and cleaved caspase-9. More importantly, Pb activated endoplasmic reticulum stress and oxidative stress, as evident by elevated PERK/ATF4/CHOP and ROS/NRF2 signaling pathway. Pb induced ROS production in MC3T3-E1 cells through endoplasmic reticulum stress and produced a lethal effect. NAC mitigated these effects. Endoplasmic reticulum stress inhibitor 4-PBA can block the ER stress pathway, reduce ROS production, and enhance cell viability. In addition, studies have shown that ERO1 activation in the ER stress pathway is responsible for inducing ROS production. ROS produced by the mitochondrial pathway also aggravates ER stress. This study suggests that Pb induces MC3T3-E1 cell apoptosis by inducing PERK-mediated ER stress and NRF2-mediated oxidative stress via mutual enhancement, which may be an important mechanism leading to skeletal toxicity.

Therapeutic Efficiency of Humic Acids in Intoxications

Humins, humic and fulvic acids represent molecules with complex structures. These compounds comprising humic substances (HS) exist naturally in soil, brown coal, peat, and water. They are formed during the decomposition and transformation of organic matter (animal and plant remains) and their formation explains several theories. Within their chemical structures, there are numerous phenolic and carboxyl groups and their derivatives that affect their different properties, such as their solubility in water or their absorption of cations or mycotoxins. The manifold chemical structure of HS alters their polyelectrolyte character and thus their chelating efficiency. For many years, HS have been studied due to their detoxification, anti-, and pro-inflammatory or anticancer and antiviral ability. This article summarizes the antioxidant and adsorption properties of humic acids, highlighting their usefulness in intoxications.

Effect of Broilers Chicken Diet Supplementation with Natural and Acidified Humic Substances on Quality of Produced Breast Meat

Simple Summary

Meat quality can be influenced by incorporating additives into an animal’s diet. Humic substances (HS) are natural products which have the potential to improve the meat quality of broiler chickens. HS are used as antidiarrheal, analgesic, immunostimulatory, and antimicrobial agents in poultry production. The effects of natural and acidified HS supplements on broiler meat quality traits (growth performance, carcass yield, physicochemical composition, lipid oxidation, antioxidant activity of meat extracts, and sensory and colour characteristics) were studied. Both supplements were composed of Leonardite, whereby the acidified HS were treated with formic acid for better digestibility. The breast meat quality of experimental broiler groups fed with HS were affected in total protein and fat content, and both showed lower lipid oxidation and higher antioxidant activity of meat extracts after the storage period (7 days at 4 ± 2 °C).

Abstract

This study was conducted to examine the effect of two humic substances (HS) supplemented in broilers’ diet on the breast meat quality of broiler chickens. In this experiment, 120 pieces of one-day-old COBB500 broiler chickens were used. Broilers were divided into three groups, each containing 40 birds with three replications (13, 13, and 14 per one pen). Fattening lasted 38 days. The first experimental diet was supplemented with 0.7% of HS (HS0.7) and the second was enriched with 0.7% of acidified HS (HSA0.7). The control group of broilers (C) was fed a basal diet without the addition of any supplements. HS0.7 samples had the highest total protein content and the lowest content of fat (p < 0.01). The effects of broiler diet and storage had a significant impact on the pH of breast samples, p < 0.001 and p < 0.05, respectively. Supplementation of HS in broiler diet positively affected the lipid oxidation of breast meat samples, as indicated by the lower malondialdehyde content (p < 0.05). HSA0.7 samples had significantly better juiciness after the storage period (p < 0.001). The quality of meat produced with supplementation of HS in broilers’ feed can be considered as valuable in human nutrition due to improved protein and fat content with decreased lipid oxidation.