Yeast alpha glucosidase inhibitory and antioxidant activities of six medicinal plants collected in Phalaborwa, South Africa

dc.contributor.authorShai, Leshweni Jeremia
dc.contributor.authorMasoko, Peter
dc.contributor.authorMokgotho, Matlou Phineas
dc.contributor.authorMagano, Solomon Ramagoai
dc.contributor.authorMogale, A.M.
dc.contributor.authorBoaduo, Nana Kwaku Kyei
dc.contributor.authorEloff, Jacobus Nicolaas
dc.date.accessioned2010-05-26T07:49:27Z
dc.date.available2010-05-26T07:49:27Z
dc.date.issued2010-08
dc.description.abstractRecent decades have experienced a sharp increase in the incidence and prevalence of diabetes mellitus. One antidiabetic therapeutic approach is to reduce gastrointestinal glucose production and absorption through the inhibition of carbohydrate-digesting enzymes such as α-amylase and α-glucosidase and α-amylase. The aim of the current study was to screen six medicinal plant species,with alleged antidiabetic properties for α-glucosidase inhibitory activities. Powdered plant materials were extracted with acetone, and tested for ability to inhibit baker's yeast α-glucosidase and α-amylase activities. The largest mass (440 mg from 10 g) of the extract was obtained from Cassia abbreviata, while both Senna italica and Mormordica balsamina yielded the lowest mass of the extracts. Extracts of stembark of C. abbreviata inhibited baker's yeast α-glucosidase activity with an IC50 of 0.6 mg/ml. This plant species had activity at low concentrations, with 1.0 mg/ml and above resulting in inhibition of over 70%. The other five plant extracts investigated had IC50 values of between 1.8 and 3.0 mg/ml. Senna italica only managed to inhibit the activity of enzyme-glucosidase at high concentrations with an IC50 value of 1.8 mg/ml, while Tinospora fragosa extracts resulted in about 55% inhibition of the activity of the enzyme at a concentration of 3.5 mg/ml, with an estimated IC50 value of 2.8 mg/ml. The bark extract of C. abbreviata was the most active inhibitor of the enzyme, based on the IC50 values (0.6 mg/ml). The bark extract of C. abbreviata contains non-competitive inhibitor(s) of α-glucosidase, reducing Vmax value of this enzyme from 5 mM·s–1 to 1.67 mM·s–1, while Km remained unchanged at 1.43 mM for para-nitrophenyl glucopyranoside. Antioxidant activity of the extracts was also investigated. The C. abbreviata extractwasmore active as an antioxidant than the positive control, trolox. The extracts did not inhibit alphaamylase activity more than about 20% at the highest concentration tested.en
dc.identifier.citationShai, L.J., et al., Yeast alpha glucosidase inhibitory and antioxidant activities of six medicinal plants collected in Phalaborwa, South Africa, South African Journal of Botany, vol. 76, no. 3, pp. 465-470 (2010), doi:10.1016/j.sajb.2010.03.002en
dc.identifier.issn0254-6299
dc.identifier.other10.1016/j.sajb.2010.03.002
dc.identifier.other7005589445
dc.identifier.urihttp://hdl.handle.net/2263/14128
dc.language.isoenen
dc.publisherElsevieren
dc.rightsElsevieren
dc.subjectAntioxidantsen
dc.subjectα-Amylaseen
dc.subjectα-Glucosidaseen
dc.subjectCassia abbreviataen
dc.subjectDiabetes mellitusen
dc.subject.lcshMedicinal plants -- South Africaen
dc.subject.lcshMateria medica, Vegetableen
dc.subject.lcshDiabetes -- Researchen
dc.titleYeast alpha glucosidase inhibitory and antioxidant activities of six medicinal plants collected in Phalaborwa, South Africaen
dc.typePostprint Articleen

Files

Original bundle

Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Shai_Yeast(2010).pdf
Size:
334.99 KB
Format:
Adobe Portable Document Format
Description:
Postprint Article

License bundle

Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
license.txt
Size:
2.43 KB
Format:
Item-specific license agreed upon to submission
Description: