In vitro biological effects of two anti-diabetic medicinal plants used in Benin as folk medicine

Abstract

BackgroundExtracts from Polygonum senegalensis (Polygonaceae) and Pseudocedrela kotschyi (Meliaceae) are two important traditionally used medicinal plants in rural Benin to treat many diseases and notably type 2 diabetes. The aim of the study was to investigate the α-glucosidase inhibition, antioxidant and antibacterial activities of those plants extract: Polygonum senegalensis leaves, and Pseudocedrela kotschyi root.MethodsHydro-alcoholic (50%) extracts were analyzed for their phytochemical content and tested for their inhibition potency on α-glucosidase from Saccharomyces cerevisiae. Antioxidant activities were assessed using the DPPH, ORAC, FRAP and DCFH-DA (cell based) assay. Finally, the antibacterial activity was evaluated using MIC determination on four Gram-positive cocci (Bacillus subtilis, Clostridium difficile, Enterococcus faecalis, Staphylococcus aureus), three Gram-negative bacilli (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae), and the yeast Candida albicans.ResultsEach extract presented significant α-glucosidase inhibition and antioxidant activities. Polygonum senegalensis leaf extracts were the most active in each in vitro assay with an IC50 = 1.5 μg/ml for α-glucosidase inhibition and an IC50 = 6.8 μg/ml for DPPH scavenging, - 4.5 μmol Fe II/g of dry matter - 9366 μmol Trolox / g DW - for FRAP and ORAC values, respectively. IC50 = 2.3 μg GA / ml for DCFH-DA assay. Concerning its antibacterial activity, a growth inhibitory effect was observed only against three Gram negative bacilli: B. subtilis, E. faecalis, S. aureus and the yeast C. albicans at high concentration.ConclusionThe results showed that the semi alcoholic extract of the two studied plants possess α-glucosidase inhibitory activity, antioxidant potency, and low antibacterial effect.

Costus aferPossesses Carbohydrate Hydrolyzing Enzymes Inhibitory Activity and Antioxidant CapacityIn Vitro

“…A positive relationship between the antioxidant (total polyphenol and flavonoid content) capacity and inhibition of intestinal α -glucosidase and α -amylase has been previously reported [32–35], which might be the case in this study. Like earlier mentioned, polyphenols have the potential of inhibiting carbohydrate metabolizing enzymes ( α -glucosidase and α -amylase) because of their ability to bind with proteins [36, 37]. We also observed that while the extracts were potent inhibitors of α -amylase activity (low IC 50 ), even better than the reference drug acarbose, they could only inhibit α -glucosidase activity weakly (very high IC 50 ).…”

In vitro Antidiabetic Activities of Two Sorbus Species

“…The α-glucosidase inhibitory effects of the fruit extracts were evaluated using a procedure described by Bothon et al (11). For the α-glucosidase assay, 25 μL of the fruit extract was mixed with 75 μL of 0.1 M sodium phosphate buffer (pH 6.8) and 50 μL of α-glucosidase solution (1 U/mL) and preincubated at 37°C for 10 minutes.…”

Investigation of the Phytochemicals, Antioxidant, and Antimicrobial Activity of the <i>Andrographis paniculata</i> Leaf and Stem Extracts

“…On the other hand, synthetic drugs bring about various side effects such as gastrointestinal disturbances, hypoglycemia, and liver dysfunction [1]. Due to the toxicity and side effects of modern therapeutic drugs, people across the world are looking for the alternative medicines from natural sources and herbal plants are the most sought after [2].…”