IN-VITRO AND IN-VIVO ANTIMICROBIAL ACTIVITIES OF CALOTROPIS PROCERA (LINN) USING SELECTED PATHOGENIC MICROORGANISMS

Abstract

Traditional medicine also known as indigenous or folk medicine comprises of knowledge systems that developed over generations within various societies before the era of modern medicine. This work investigated on the in-vitro and in-vivo antimicrobial activities of the crude extracts (stem and leaf) of Calotropis procera against clinical and typed microorganisms (Shigella dysenteriae, Escherichia coli, Staphylococcus aureus, Salmonella typhi, Pseudomonas aeruginosa, Klebsiella pneumoniae, Aspergillus flavus, Candida albicans, Shigella dysenteriae ATCC 24162, Escherichia coli ATCC 35218, Staphylococcus aureus ATCC 25923, Samonella typhi ATCC 22648, Pseudomonas aeruginosa ATCC 27853 and Klebsiella pneumoniae ATCC 34089, Aspergillus flavus ATCC 204304, Malazessia furfur ATCC 44349, Candida albicans and Candida albicans ATCC 10231). The proximate, qualitative and quantitative phytochemical components were examined using standard method. Time-kill kinetics and the amount of sodium/potassium ions released by the leaf and stem extracts using the selected microorganisms were also accessed. The in-vivo activities were also determined using experimental animals (albino rats). The cytotoxicity assay was carried out using the method of Artemia salina. Proximate components of the leaf and stem extracts showed that there was highest amount of carbohydrates, ash, protein in leaf than stem except in crude fibre whereby stem had highest yield than leaf of about 23.30%. The qualitative phytochemical components showed the presence of alkaloids, tannins, saponins, flavonoids, terpenoids and other components in little quality. The quantitative phytochemical screening of the leaf extracts revealed alkaloids, terpenoids and flavonoids with high values of 1343.33, 666.67 and 941.67 mg/100 g respectively while in the stem, alkaloids yielded highest value of 1476.67 mg/100 g. The zones of inhibition with the leaf extracts on tested bacteria ranged from 4.0±0.02 mm to 20.67±0.15 mm and the stem extracts from 1.0±0.01 mm to 20.0±0.45 mm. However, E. coli ATCC 35218 was inhibited by methanol leaf extract of 10.33 mm which was resistant to tested antibiotics. Minimum inhibitory concentrations and minimum bactericidal concentrations of the extracts were effective at 200 and 400 mg/ml respectively. The antifungal activities of the extracts showed that C. albicans was the most susceptible among the fungal isolates. The antimicrobial activities of the partially purified fractions had the highest inhibition in E. coli and K. pneumoniae ATCC 34089 with zones of inhibition of 30 mm and 25 mm respectively. The time killing kinetics of the extracts exhibited killing rates on some of the tested microorganisms before 48 hours. Candida albicans was killed by the extracts before 24 hours compared to the other fungal isolates. The result showed that the concentration of sodium was higher than that of potassium ion. The antioxidant properties of the plant extracts showed that ethanol and aqueous extracts had high ferric reducing potentials for the leaf extracts (15.71 and 15.51 GAE) while stem extracts had the highest values for methanol and aqueous extracts (17.21 and 22.04 GAE) respectively. The structural elucidation of the bioactive compounds in the extracts revealed the chemical compounds of phenol, methyl palmitate, phthalic acid, 9-octadecenoic acid and other compounds known for valuable antimicrobial and antioxidant properties. The cytotoxicity activities showed that the extracts were non-toxic. The acute toxicity of the plant extracts were also analyzed (haematology, biochemistry and histopathology); there was no death recorded but there was a mild toxicity effects on the liver, kidney, stomach and heart of the animals at 1000-3000 mg/kg in this research. Calotropis procera extracts have appreciable amount of antioxidant properties and could be prepared into soup, decoction, concoction and beverage. Based on the results obtained in this research study, it can be said that the plant has a good antimicrobial efficacy. However, there is need for good hygiene practice during preparation coupled with the use of appropriate doses of the plant extracts.