Peptic ulcer disease (PUD) is a gastrointestinal tract disorder that affects many people worldwide. Apart from Helicobacter pylori (H. pylori), which is strongly considered as the main etiological agent, certain factors have been recognized in its etiology in humans. These include excessive alcohol consumption, abuse of drugs such as aspirin and non- steroidal anti-inflammatory drugs (NSAIDs), emotional and physical stress. With so many other health challenges often stealing the limelight, the disorder is often not given the attention it warrants.

Diagnosis and treatment of this chronic disease is very challenging. However, recent advances in natural science and medicine have introduced new technologies to study and understand the biochemical and molecular mechanisms underlying PUD pathology. The in-depth knowledge of the disorder has led to the development of models and the design of novel assays and techniques to investigate PUD. Over the years, many orthodox drug agents have been used to treat PUD, especially in H. pylori infected-associated cases in the developing world where the disease is endemic and modern health facilities and services are inadequate. Most of these orthodox drugs, which are relatively expensive, leave in their wake adverse effects. The use of natural products, which are cheap and accessible, is an attractive alternative treatment regime for PUD patients.

This Special Issue aims to invite researchers to contribute original research, review, and clinical case study manuscripts dealing with the pathophysiology, diagnosis, and treatment of gastric ulcer, duodenal ulcer, and esophageal ulcer. Techniques used in studying these disease conditions including model systems would be considered. Submission of research outputs of investigations on the mechanism of action of natural products as therapeutic agents at the cellular, molecular, and in silico levels would be received. Additionally, other novel / emerging and repurposed therapies are welcomed. Authors are also encouraged to submit review manuscripts that describe recent knowledge and discoveries in the area of peptic ulcer research.

Potential topics include but are not limited to the following:

• Unusual and rare clinical presentations and complications of peptic ulcer diseases
• Latest technologies such as rapid diagnostic kits for the diagnosis of H. pylori infection
• Pathogenesis of Helicobacter pylori-induced peptic ulcer infection and clinical outcomes
• Clinical application of plant-based drug agents in the treatment of peptic ulcer diseases
• Cellular and molecular mechanisms of natural product anti-peptic ulcer agents
• Nanotechnology and natural product agents with anti-peptic ulcer properties
• Bioinformatics application in the discovery of compounds from natural products with anti- peptic ulcer potential
• Development of algorithms, models, and biocomputing resources to augment drug discovery and pathogenesis
• Natural product effects on gut microbiota and the host’s metabolism reprogramming restoration related to peptic ulcers
• Biochemistry and molecular insights into peptic ulcers