In vitro α-amylase and α-glucosidase Inhibitory and Cytotoxic Activities of Extracts from Cissus cornifolia Planch Parts

Abstract

Context: Hyperglycemia is the hallmark of type 2 diabetes mellitus, and its prevention will go a long way in managing the disease and its associated complications. Reduction of postprandial hyperglycemia through retarding carbohydrates digesting enzymes is one of the major therapeutic approaches used in the management of diabetes.

Objective: The aim of the present study was to investigate the antidiabetic and cytotoxic effects of Cissus cornifolia extracts in vitro.

Materials and methods: The α-amylase and α-glucosidase inhibitory activities of ethanolic and aqueous extracts of C. cornifolia root and leaves were investigated when the cytotoxic effects of these extracts were analyzed using MTT assay on human embryonic kidney (HEK 293) cell lines.

Results: The root ethanolic extract showed a mild α-amylase inhibitory activity with IC₅₀ value of 22.75 ± 1.23 μg/ml, but strong α-glucosidase inhibitory activity with IC₅₀ value 2.81 ± 0.97 μg/ml and the aqueous root extract indicated moderate inhibition for both α-amylase and α-glucosidase with IC₅₀ values of 33.70 ± 3.75 and 37.48 ± 2.35 μg/ml, respectively. The ethanolic root extract was found nontoxic at tested concentrations on HEK 293 cell lines as confirmed by the MTT assay with 93% cell viability at the highest concentration (200 μg/ml) tested. However, the aqueous extracts (leaf and root) were found cytotoxic at concentrations above 50 μg/ml.

Conclusion: Data of this study suggest that the root ethanolic extracts of C. cornifolia possesses moderate α-amylase, but strong α-glucosidase inhibitory activity in vitro and did not show significant cytotoxicity with the tested concentrations.

Summary: Present study was conducted to examine effects of antidiabetic and cyctotoxic effects of Cissus conrnifolia root and leaves extracts in vitro. Data of this study suggest that the root ethanolic extract of C. cornifolia possesses mild to moderated antidiabetic activity via inhibiting carbohydrate digesting enzymes when no significant toxicity was observed with tested concentrations. Abbreviations used: alex: Aqueous leaf extract; arex: Aqueous root extract; CC: Cissus cornifolia; DNS: Dinitrosalicylic acid; DMSO: Dimethylsulfoxide; elex: Ethanolic leaf extract; erex: Ethanolic root extract; IDF: International Diabetes Federation; MEM: Minimum essential medium; NIDDM: Noninsulin-dependent diabetes mellitus; pNPG: Para-nitrophenyl glucopyranoside; SD: Standard deviation; T2D: Type 2 diabetes.

Keywords: Cissus cornifolia; cytotoxicity; diabetes; α-amylase; α-glucosidase.

Figure 1

The α-amylase (a) and α-glucosidase (b) inhibitory activities of Cissus cornifolia extracts. Data are presented as mean ± standard deviation values of triplicate determinations. ^a-dDifferent superscripts letters for a given value within the figure are significantly different from each other (Tukey's - HSD multiple range post hoc test, P < 0.05). CC: Cissus cornifolia; elex: Ethanolic leaf extract; alex: Aqueous leaf extract; erex: Ethanolic root extract; arex: Aqueous root extract

Figure 2

Cytotoxicity activity Cissus cornifolia extracts on human embryonic kidney 293 kidney cells lines as confirmed by MTT cell proliferation assay. Data are presented as mean ± standard deviation values of triplicate determinations. ^a-cDifferent superscripts letters for a given concentration are significantly different from each other extracts (Tukey's - HSD multiple range post hoc test, P < 0.05). CC: Cissus cornifolia; elex: Ethanolic leaf extract; alex: Aqueous leaf extract; erex: Ethanolic root extract; arex: Aqueous root extract