Effect of Dietary Salicin Standardized Extract from Salix alba Bark on Oxidative Stress Biomarkers and Intestinal Microflora of Broiler Chickens Exposed to Heat Stress

Abstract

The implication of heat stress (HS) in the oxidative stress phenomenon and its related diseases in chickens has been widely reported. Salicin is a precursor for the synthesis of salicylic acid and aspirin obtained from the bark of Salix alba, with an undeniable anti-inflammatory effect. However, little attention has been paid to salicin’s antioxidant/oxidative stress-reducing effect compared to its well-known anti-inflammatory effect. The purpose of the study was to investigate the effect of dietary salicin standardized extract from Salix alba bark (SAB) on oxidative stress biomarkers and intestinal microflora of broiler chickens exposed to heat stress. In our study, chickens (14 days) were randomly allocated to three treatment groups (SAB0; SAB25; SAB50), each of which included five replicates with eight birds per replicate. Broilers were exposed to heat stress (32 ± 2 °C) between 14 and 42 days. The liver tissues were collected to analyze oxidative stress biomarkers (total antioxidant capacity, glutathione, catalase, superoxide dismutase). The intestinal content was collected and measurements of the intestinal microbial population were performed (E. coli, staphylococci, lactobacilli). Results indicated that liver malondialdehyde and protein carbonyls activity decreased (p < 0.05) in SAB50 treatment concomitantly with linearly increased total antioxidant capacity, and glutathione concentration. Dietary supplementation with SAB reduced (p < 0.05) the abundance of staphylococci and increased the number of lactobacilli. Taken together, SAB possesses an advantageous effect on liver oxidative status and the balance of intestinal microflora in broilers exposed to heat stress. These findings provide new insight into the potential use of salicin standardized extract from Salix alba bark for liver damage prevention and dysbiosis related to heat stress.

Effects of medical plants on alleviating the effects of heat stress on chickens

“…Heat stress reduces the efficiency of feed, metabolism, hormones, and the immune system ( Zhao et al, 2023 ), and intestinal tissue ( Saracila et al, 2023 ). Moreover, HS triggers inflammation, and causes microbiota dysbiosis ( Zwirzitz et al, 2023 ).…”

“…Reinforcing the defense system of chickens through the administration of immune-stimulants natural compounds in their diet has become a priority for ameliorating stress in the poultry sector. Amongst different immuno-stimulants, medicinal herbs incorporate chemical component that improve immunity, antioxidant capacity, enhance gut microbitoa and health as well as reduce the oxidative/inflammation pathways ( Yang et al, 2021 ; Reith et al, 2022 ), making the animal more resistant to external stressors ( Al-Garadi et al, 2023 ; Saracila et al, 2023 ). The mode of action of medicinal plants on heat-stressed broilers can be one of the following: 1) stimulating health state by improving the antioxidant system which can directly remove ROS produced as a result of stress (Abo Ghanima et al, 2023 ), and 2) MPs can also activate antioxidant enzymes and constrain pro-oxidant enzymes, supporting the health status of broiler exposed to HS.…”

“…During HS situations, the TJ barrier was damaged and luminal substances arrive into the blood flow ( Yang et al, 2021 ; Deng et al, 2023 ). Consequently, leaky gut persuades chronic systemic inflammation which decreases the disease-resistance capability of broilers ( Zhang et al, 2022 ; Saracila et al, 2023 ). Recently, Xu et al (2023) proposed that HS could increase the intestinal inflammation via increasing the circulating lipopolysaccharides ( LPS ) level and decrease DNA methylation level in the promoter region of TRPV4 (Transient Receptor Potential Cation Channel Subfamily V Member 4), which constrain TRPV4 expression, thus dropping Ca 2+ influx, and lastly aggravating inflammation via disturbing NF-κB signaling pathway in broilers ( Figure 4 ).…”