Effect of Willow Bark Extract on The Activity of Gram-Negative Intestinal Bacteria: A Review
Abstract
The increased growth of pathogenic Gram-negative bacteria such as Escherichia coli and Klebsiella pneumoniae contributes significantly to chronic gastrointestinal diseases like inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS). These bacteria stimulate the immune system, releasing pro-inflammatory cytokines that cause additional inflammation and further tissue damage. The increase in antibiotic resistance of many Gram-negative bacteria makes treatment more difficult and calls for different approaches. Willow bark extract (WBE) from Salix species, in particular, has recently been noted to have the ability to inhibit pathogenic bacteria and modulate inflammation. WBE is rich in bioactive compounds such as salicin, flavonoids, and tannins, which are known to disrupt cell membrane of bacteria, inhibit biofilm formation and interfere with metabolic processes. Its anti-inflammatory activities, inhibiting NF-κB and oxidative stress, provide a more comprehensive way to manage gut health. This review was inspired by the gap for natural anti-microbial agents to explore the WBE mechanisms of action, applications for targeting Gram-negative bacteria, and restoring the gut microbiota diversity. On the other hand, WBE is limited by its variability in composition and extract, with little clinical validation and formulation challenges. Bridging these gaps would enable using WBE as a natural therapeutic for gastrointestinal and systemic disorders.
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