ANTIMICROBIAL, ANTIOXIDANT AND PROTECTIVE EFFICACY OF FLOWER AND LEAF EXTRACTS OF CALOTROPIS PROCERA AGAINST FREE RADICAL DAMAGE

Abstract

Different soluble fractions viz., hexane, ethyl acetate, butanol and ethanol of Calotropis procera (Ait.) R. Br. were screened for their antimicrobial properties by using agar-well diffusion method against the human pathogens viz., Escherichia coli and Salmonella typhi (Gram negative), methcillin resistant Staphylococcus aureus and Micrococcus luteus (Gram positive), in vitro antioxidant properties were analyzed by means of DPPH free radical scavenging method, reducing ability assay and lipid peroxidation inhibition method. Furthermore, in vivo protective efficacy of C. procera extract against (NSAID) ibuprofen-induced nephrotoxicity in rat model was also determined by evaluating renal function markers, plasma measure of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) along with the determination of tissue lipid peroxidation markers, i.e. aldehyde products malonyldialdehyde (MDA) and 4- hydroxy-nonenal (4-HNE). Phytochemical analysis was also carried out for the detection of phenolic constituents, amino acids, protein, carbohydrates, reducing and non-reducing sugars in test plant. In the present findings the hexane fraction of C. procera flower and leaf have been proved very significant with maximum zones of inhibition i.e., flower (22mm) and leaf (23mm) against M. luteus. While, other tested fractions of C. procera flower and leaf showed significant antimicrobial activity against all pathogens. Whereas, in the present finding it was also determined that the flower ethanol extract showed the highest DPPH free radical scavenging activity (88.19% with 8 mg/ml) as compared to BHA which showed 85% scavenging activity as standard. Similarly, C. procera flower and leaf extracts were also analyzed for reducing capacity. The highest absorbance (i.e., 1.827 with 10mg/ml) was recorded in C. procera flower water extract as compared to standard which showed (0.238) absorbance. In vitro lipid peroxidation inhibition, another model was used to check the antioxidant capacity of C. procera. Flower water extract exhibited a concentration dependent increase in lipid peroxidation inhibition, the highest value is (89.58% with 10mg/ml) while the lipid peroxidation value in C. procera leaf water extract (i.e., 75.11% with 10mg/ml) and leaf ethyl acetate extract showed (75.11% with 8mg/ml). While, BHA (85%) and ascorbic acid (75.5%) showed lower values as compared to tested plant. However, body weight loss was successfully restored by the coadministration of Ibuprofen with C. procera hexane extract. While, increased level of renal function markers (urea, creatinine) was normalized by the administration of C. procera hexane with ibuprofen treatment. The imbalance in oxidative status was determined by evaluating decreased level of catalase, superoxide dismutase and glutathione along with increased levels of malonyldialdehyde and 4- hydroxynonenal, which was counteracted by the co-administration of C. procera hexane extract with ibuprofen which maintained cell sustainability and indicated nephro-protective activity of C. procera. Besides the above results C. procera leaf and flower aqueous extract were also used to check enzymatic activities of glucoamylase, α-amylase and urease enzymes. The flower extract is found proved to be a good enhancer of glucoamylase, α-amylase and urease activity as compared to leaf extract. A number of phytoconstituents were also detected. The presence of phytochemicals in C. procera may indicate a good correlation with that of antibacterial, antioxidant potential and protective role for in vivo model which also proved as a good enhancer of enzyme activities. Thus due to aforementioned activities, Calotropis procera may serve as a better and a protective therapeutic agent than any other synthetic drug.