Determination of the antimicrobial and antioxidanteffects of the leaves of sodom apple (Calotropis procera)

In this study, antimicrobial effect and antioxidant activity of the leaves of Calotropis procera plant obtained from Niger and used to coagulate milk in the production of West African cheese (Wagashi) was investigated. The leaves freshly supplied from Niger, were freeze dried. The dried leaves were ground and leaf contents were extracted using two different solvents (methanol and ethanol). Firstly, phytochemical composition and antioxidant activity of Calotropis procera leaves were determined. Then antimicrobial effect of this plant extracts on various bacteria (Listeria innocua, Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella Typhi), yeasts (Debaryomyces hansenii, Candida rugosa) and molds (Aspergillus niger ve Penicillium chrysogenum) were determined. Analyses were done using SPSS (ver. 25). As a result of the analysis, the presence of tannins, saponins, flavonoids and terpenoids were detected in the leaves except cardiac glycosides. Total phenolic content was 7.683 ± 0.362 mg gallik acid/g, total flavonoid substance was 3.966 ± 0.573 mg quercetin/g and 43.62 % antioxidant activity was obtained from a 10 % diluted extract. It was found that more effective results were obtained with methanolic extract of the leaves. Inhibition zone diameters against Salmonella Typhi, Listeria innocua, Debaryomyces hansenii and Candida rugosa were 16.5, 17, 17.25 and 18 mm, respectively. The highest inhibitions were found against Staphylococcus aureus, Aspergillus niger, Bacillus subtilis and Escherichia coli with 20, 26.25, 26.5 and 29.5 mm inhibition zone respectively, for the antimicrobial effect. In addition, it was concluded that neither ethanolic nor methanolic leaf extract of Calotropis procera had inhibitory effect against Penicillium chrysogenum. The minimum inhibitor concentration was 160 mg/mL for all bacteria and Debaryomyces hansenii. This concentration was found to be a lethal concentration for Bacillus subtilis and Escherichia coli.