Investigation of antidiabetic, hypolipidemic and hypocholesterolemic effects of antioxidant-enriched microcrystalline cellulose

A large amount of almond shells and hulls remain as agro-industrial waste in almond processing. Since these wastes are generally not utilized, they cause environmental pollution. However, the almond hull is rich in phenolic compounds, whereas the almond shell is rich in lignocellulosic compounds. In this study, the antidiabetic, hypolipidemic and hypocholesterolemic effects of a complex of phenolic extract and microcrystalline cellulose (antioxidant-enriched microcrystalline cellulose) produced from almond hull and shell were investigated. Firstly, inhibitory activities on α-amylase and α-glucosidase were examined to determine the antidiabetic activity of phenolic extract obtained from almond hull (PE-AH), microcrystalline cellulose obtained from almond shell (MCC-AS) and antioxidant-enriched microcrystalline cellulose (AE-MCC-AS). In these examinations, it was found that PE-AH (IC₅₀:11.24 for α-amylase and IC₅₀:10.95 for α- glucosidase) had the highest activity against both enzymes, followed by AE-MCC-AS (IC₅₀: 14.10 for α-amylase and IC₅₀: 15.77 for α- glucosidase) and MCC-AS (IC₅₀:51.37 for α-amylase and IC₅₀: 28.99 for α- glucosidase), respectively. It was determined that MCC-AS and AE-MCC-AS showed glucose absorption even at low glucose concentrations and had similar effects in terms of glucose diffusion. Similar to the antidiabetic activity, PE-AH had the highest activity on lipase (IC₅₀: 3.64), followed by AE-MCC-AS (IC₅₀: 13.90) and MCC-AS (IC₅₀: 71.92), respectively. Regarding cholesterol adsorption capacity, AE-MCC-AS had approximately 8-fold more adsorption capacity than MCC-AS, indicating that phenolic compounds were more effective than MCC on cholesterol adsorption capacity. In conclusion, the study results demonstrated that AE-MCC-AS is a versatile MCC-phenolic extract complex that exhibits antidiabetic, hypolipidemic and hypocholesterolemic effects.