Annex A: Summary of Studies COT/2025/01

Herb-drug interactions

COT/2025/01

Last updated: 22 May 2025

Author

Test System

Study size

Exposure

Characterisation of test substance

Duration

Main outcome measure

Outcome

Al-Omari et al., 2012

Albino rat, M

30: 5 groups of 6; 72: 12 groups of 6. 

25, 50 and 100 mg/kg bw by gavage; single dose (50 mg/kg bw) and up to one week.

Ginger crude extract.

Multiple dose: 2 weeks; single dose: 1 week.

Effect on glibenclamide and insulin; hypoglycaemic and antihyperglycemic effects in normoglycemic- and streptozotocin-induced (STZ) diabetic rats.

Significant decrease in blood glucose level (BGL) in normoglycemic rats after 1 & 2 hrs (50 mg/kg). Significant decrease in non-fasting BGL (N-FBGL) in STZ- diabetic rats.

Egashira et al., 2012

Sprague-Dawley rat, M (7 weeks old)

Not specified.

10 mL/kg orally.

50% ginger juice.

1-3 days.

interaction between ginger juice and tacrolimus.

Significant increase in tacrolimus blood concentrations in rats treated with ginger juice, compared to those treated with water or orange juice.

Okonta et al., 2008

Rabbits (3F, 2M)

5

1 ml/kg, orally.

Ginger extract.

3 days.

Effect of ginger on the pharmacokinetics of metronidazole.

Significant increase in absorption and plasma half-life; significant decrease in the elimination rate constant and clearance of metronidazole.