Silver Fir Safety in Healthy Volunteers

Not Applicable

Completed

• Conditions: Safety / Toxicology; Liver Function; Kidney Function; Dietary Supplement; Healthy Volunteers

• Registration Number: NCT07189143
• Lead Sponsor: University of Ljubljana

Brief Summary

This study evaluated the safety of Belinal®, a dietary supplement made from silver fir (Abies alba) branch extract, in healthy volunteers. Fifteen adults took 900 mg of Belinal® daily for 14 days. Blood tests were performed at several time points to measure liver and kidney function (enzymes and other biochemical markers).

Detailed Description

This was a prospective, open-label, single-arm interventional study conducted to assess the toxicological safety of Belinal®, a standardized water extract from silver fir (Abies alba) branches. Belinal® contains polyphenols, including lignans, flavonoids, and phenolic acids, which have demonstrated various pharmacological activities in previous studies.

The study enrolled 15 healthy volunteers (8 men, 7 women; age range 37-55 years). Participants received Belinal® capsules at a total daily dose of 900 mg (4 × 225 mg) for 14 consecutive days.

The study design included three consecutive two-week periods:

Wash-out period: to eliminate potential effects of prior supplement use. Comparative period: to assess natural variability in laboratory parameters without supplementation.

Test period: during which participants consumed Belinal® daily. Safety was evaluated by measuring liver and kidney biochemical parameters (AST, ALT, ALP, GGT, bilirubin, urea, creatinine, uric acid) at baseline, day 14, day 28, and day 42. Adverse events were monitored throughout the study.

Study Timeline

• Study Start: 2018-08-20
• Primary Completion: 2018-10-29
• Study Completion: 2018-10-29
• Study First Submitted: 2025-08-19
• Status Verified: 2025-09
• Study First Submitted QC: 2025-09-15
• Last Update Submitted: 2025-09-15
• Study First Posted: 2025-09-23
• Last Update Posted: 2025-09-23

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 15

Inclusion Criteria

• Healthy adult volunteers
• Age 37-55 years
• Both sexes (male and female)
• Willingness to comply with study protocol and attend all study visits
• Signed informed consent

Exclusion Criteria

• Known acute or chronic illness
• Use of any medications other than occasional analgesics (none were used by participants)
• Use of dietary supplements prior to or during the study
• Known mental illness (e.g., depression, psychosis, severe alcoholism, drug abuse)
• Consumption of more than 2 alcohol units per day (20 g ethanol, equivalent to ~2 dl wine, 5 dl beer, or 0.3 dl brandy)
• Participation in other research studies concurrently

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Primary Outcome Measures

Name	Time	Method
Change in serum AST	Baseline, Day 14, Day 28, and Day 42.	Change in aspartate aminotransferase (AST) to evaluate potential hepatotoxic effects. Unit of Measure: U/L
Change in serum ALT	Baseline, Day 14, Day 28, Day 42.	Change in alanine aminotransferase (ALT) to evaluate potential hepatotoxic effects. Unit of Measure: U/L
Change in serum ALP	Baseline, Day 14, Day 28, Day 42.	Change in alkaline phosphatase (ALP) levels to evaluate potential hepatobiliary effects. Unit of Measure: U/L
Change in serum GGT	Baseline, Day 14, Day 28, Day 42.	Change in gamma-glutamyl transferase (GGT) levels to evaluate potential hepatobiliary effects. Unit of Measure: U/L
Change in serum bilirubin	Baseline, Day 14, Day 28, Day 42.	Change in total bilirubin as a marker of liver function. Unit of Measure: µmol/L
Change in serum urea	Baseline, Day 14, Day 28, Day 42.	Change in blood urea levels as a marker of kidney function. Unit of Measure: mmol/L
Change in serum creatinine	Baseline, Day 14, Day 28, Day 42.	Change in serum creatinine levels as a marker of kidney function. Unit of Measure: µmol/L
Change in serum uric acid	Baseline, Day 14, Day 28, Day 42.	Change in uric acid levels as a marker of kidney function. Unit of Measure: µmol/L

Trial Locations

Locations (1)

University of Ljubljana; 🇸🇮 Ljubljana, Slovenia