The goal of this clinical trial is to evaluate whether holy basil extract can reduce gastric inflammation and improve symptoms in adult patients with dyspepsia.

The main questions it aims to answer are:

• Does holy basil extract reduce gastric mucosal inflammation as measured by histopathology?
• Does holy basil extract improve dyspeptic symptoms, endoscopic findings, gastric pH, duodenal eosinophil counts, and systemic inflammation (serum IL-6)?

Participants will:

• Take 300 mg of holy basil extract orally once daily for 28 days
• Complete symptom questionnaires and diaries during treatment
• Undergo upper endoscopy with biopsy and intragastric pH monitoring before and after treatment
• Provide blood samples for inflammatory marker measurement
• Be monitored for safety and adverse events

Functional dyspepsia is a common condition that causes chronic upper abdominal discomfort, bloating, and early satiety in the absence of structural disease. Conventional therapies such as acid suppression medications or prokinetics provide incomplete symptom relief for many patients, and newer approaches are needed. Increasing evidence suggests that mucosal inflammation, duodenal eosinophilia, and systemic immune activation may play a key role in the disorder.

Holy basil (Ocimum sanctum), or tulsi, is a traditional medicinal herb with anti-inflammatory and gastroprotective properties demonstrated in preclinical studies. It has been shown to reduce gastric acid secretion, increase mucus production, and decrease inflammatory cell infiltration in animal models, but its clinical effects in patients with dyspepsia have not been studied.

This single-center, open-label trial will enroll 27 adults with dyspeptic symptoms at Siriraj Hospital, Mahidol University. All participants will receive 300 mg of holy basil extract once daily for 28 days. The primary outcome is the change in gastric mucosal inflammation assessed by histopathology before and after treatment. Secondary outcomes include improvement in dyspeptic and reflux symptoms, reduction in duodenal eosinophil counts, changes in gastric mucosal appearance on endoscopy, alterations in intragastric pH, and changes in serum interleukin-6 levels as a marker of systemic inflammation. Safety and tolerability will also be evaluated.

Participants will undergo baseline evaluations, including symptom assessment, blood tests, 24-hour pH monitoring, and upper endoscopy with biopsy. These procedures will be repeated at the end of the 28-day treatment period. Weekly monitoring will include review of symptoms, adverse events, and medication compliance.

The study is designed to provide clinical evidence on whether holy basil extract can improve gastric inflammation and relieve symptoms in patients with dyspepsia. Results may support its role as a novel herbal-based therapy for functional dyspepsia.

Inclusion Criteria:

• Participants aged 18 years and older.
• Presence of dyspeptic symptoms, assessed by the Leeds Dyspepsia Questionnaire with a score of at least 5 or higher.

Exclusion Criteria:

• Presence of Helicobacter pylori infection.
• Diagnosis of peptic ulcer or erosive esophagitis Los Angeles Classification grade B or greater.
• Use of acid-suppressant therapy including proton pump inhibitors (PPIs) or histamine-2 receptor antagonists (H2RAs) that cannot be discontinued at least 2 weeks prior enrolment and during the study period.
• Use of mucosal protective agents, such as rebamipide, sucralfate, or irsogladine that cannot be discontinued at least 4 weeks prior enrolment and during the study period.
• History of gastric cancer or duodenal cancer.
• Previous upper gastrointestinal surgery.
• Current pregnancy or lactation.
• Known allergic to the medicine.

To protect participant confidentiality and comply with institutional and regulatory requirements, no IPD will be shared unless with reasonable request.