A Double-Blind, Placebo-Controlled Study of Fermented Deglycyrrhizinated Licorice Extract

This double-blind, placebo-controlled study evaluated the efficacy of oral α-amylase enzyme replacement therapy in treating early-stage diabetic polyneuropathy (DPN). The study was conducted at Al-Azhar University Hospitals with 83 diabetic patients randomized to receive either fermented deglycyrrhizinated licorice extract (FDGL) containing α-amylase enzyme (2500 IU/gm) or placebo for 6 months. Primary outcomes measured improvements in nerve conduction velocity and vibration perception threshold.

Diabetes mellitus complications continue to develop despite optimal glycemic control with insulin. Recent studies suggest that serum amylase deficiency correlates with the severity of diabetic complications. This study hypothesizes that α-amylase enzyme deficiency represents an enzymatic defect in the cascade between activated insulin receptors and mitochondrial energy liberation, contributing to diabetic complications. α-amylase is a glycolytic enzyme that undergoes entero-pancreatic circulation and is proposed to be a precursor to key phosphorylating enzymes (glycogen phosphorylase, glucokinase, and hexokinase) essential for glycolysis. Supplementation with α-amylase may restore normal carbohydrate metabolism and prevent diabetic complications. The study drug is a formulation rich in α-amylase enzyme prepared from fermented deglycyrrhizinated licorice root extract, also containing acid-lipase enzyme and naturally occurring flavonoids. The intervention was administered as 500mg capsules twice daily, one hour before meals, for 6 months alongside regular antidiabetic medications.