In Vitro Antidiabetic, Anti-Inflammatory, Antioxidant, and Anticoagulatory Effects of Costus afer Ker Gawl. Leaf Fractions

Diabetes mellitus especially type 2 is associated with pro-coagulatory, and oxidative stress states resulting in high levels of pro-inflammatory cytokines. Hyperglycemia increases blood viscosity which triggers coagulation leading to vascular dysfunction. This study explored the in vitro antidiabetic, anti-inflammatory, anticoagulation, and antioxidant effects of Costus afer Ker Gawl. leaf extract and fractions. Crude ethanol extract of C. afer leaves were partitioned using solvent-partitioning technique to obtain hexane, ethyl acetate, butanol, and aqueous   fractions respectively, in the order of increasing polarity. The fractions were subjected to in vitro assessments for antidiabetic (alpha-amylase and alpha-glucosidase inhibition), anti-inflammatory (erythrocyte stabilization and protein denaturation inhibition), and antioxidant (2,2-diphenyl-1-picrylhydrazyl (DPPH), lipid peroxidation, reducing power activity and NO inhibition) assays. Clotting profiles on blood sample collected from non-diabetic and diabetic human volunteers were also assayed (clotting time, prothrombin time, and activated partial thromboplastin time). A statistical analysis was done using ANOVA which is then followed by Tukey’s post-hoc test for comparison and Microsoft Excel 2016 for graphs. C. afer leaf fractions showed a significant increase in antidiabetic, anti-inflammatory, and antioxidant activities, and significant prolongation in clotting profiles of healthy and diabetic human volunteers. This study demonstrated that C. afer leaf fractions possess antidiabetic, anti-inflammatory, antioxidant, and anticoagulation activities. It is therefore recommended that further research could be done to explore the in vivo effects and the bioactive compounds responsible could be identified and isolated for therapeutic purposes.