title: In vitro α-amylase and α-glucosidase inhibitory effects and cytotoxic activity of Albizia antunesiana extracts.
abstract: BACKGROUND
  Diabetes mellitus is a chronic disease, and its incidence is tremendously increasing globally. Decreasing postprandial hyperglycemia by retarding glucose absorption through inhibiting carbohydrates digesting enzymes (α-amylase and α-glucosidase) is one of many approaches used for the management of this disease.
  
  
  OBJECTIVE
  The leaf and root aqueous and ethanol extracts of Albizia antunesiana were investigated for α-amylase and α-glucosidase inhibitory and cytotoxic activity in vitro.
  
  
  METHODS
  The α-amylase and α-glucosidase activities were measured in the presence of aqueous and ethanol extracts of the plant parts using starch and p-nitrophenyl-D-glucopyranoside as substrates respectively. Furthermore, cytotoxic effects of the extracts were investigated on HEK (human embryonic kidney) 293 cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay.
  
  
  RESULTS
  The results showed that ethanolic root extract of A. antunesiana had mild α-amylase and strong α-glucosidase inhibitory activity with half-maximal inhibitory concentration values of 30.68 and 4.35 µg/mL, respectively. The aqueous root extract showed mild α-glucosidase but no α-amylase inhibitory activity. Cytotoxicity studies on the extracts using the MTT assay revealed that the ethanolic (leaf and root) extracts were relatively nontoxic at tested concentrations on the HEK 293 cell lines. However, the aqueous extracts (leaf and root) were cytotoxic at concentrations above 50 µg/mL.
  
  
  CONCLUSIONS
  Data from this study suggest that the ethanolic root extract of A. antunesiana possess in vitro α-amylase and α-glucosidase inhibitory activities and are not cytotoxic at least in an in vitro condition.
authors.affiliation: Department of Biochemistry, School of Life Sciences, University of KwaZulu-Natal (Westville Campus), Durban, 4000, South Africa.
authors.forename: Talent
authors.initials: T
authors.lastname: Chipiti
authors.affiliation: Department of Biochemistry, School of Life Sciences, University of KwaZulu-Natal (Westville Campus), Durban, 4000, South Africa.
authors.forename: Mohammed Auwal
authors.initials: MA
authors.lastname: Ibrahim
authors.affiliation: Department of Biochemistry, School of Life Sciences, University of KwaZulu-Natal (Westville Campus), Durban, 4000, South Africa.
authors.forename: Moganavelli
authors.initials: M
authors.lastname: Singh
authors.affiliation: Department of Biochemistry, School of Life Sciences, University of KwaZulu-Natal (Westville Campus), Durban, 4000, South Africa.
authors.forename: Md Shahidul
authors.initials: MS
authors.lastname: Islam
keywords: Albizia antunesiana; cytotoxicity; diabetes; α-amylase; α-glucosidase