Investigating the bioactive compounds in aqueous extract of Calotropis procera and its toxicological evaluation using Drosophila melanogaster model

Abstract

Background/Aim: Phytochemicals are present in various plant tissues. These compounds provide beneficial effects on the plants, however,
limited harmful effects have been reported. This study investigated the bioactive compounds in the aqueous extract of Calotropis procera (AECP) and their toxic effects. Materials and Methods: The presence of bioactive compounds in the plant was determined using standard methods and high-performance liquid chromatography, while the toxicological evaluation was done using Drosophila melanogaster. Flies
were grouped into 6 (n = 5), comprising control and AECP-treated groups. Flies were homogenized after 21 days of exposure to AECP, and toxicological parameters such as total thiol, reduced glutathione, catalase, nitric oxide, geotaxis, and survival tests were investigated. Results: The plant extract was found to be rich in phenols, flavonoids, tannins, reducing sugars, and glycosides, with the total phenols content
of 14.05 ± 0.07 mg Tannic acid/g equivalent and total flavonoids content of 9.218 ± 0.05 mg Quercetin/g equivalent. Sixteen compounds were identified in the plant with the highest abundance in the order: quercetin, cymbopogon, hydroquinone, chlorogenic acid, ferulic acid, and
luteolin. It was also observed that the plant was not toxic to flies exposed to doses up to 2 mg/g diet as indicated by a non-significant difference in the parameters investigated but a significant change (p < 0.05) was noted in catalase, reduced glutathione and nitric oxide at 4 mg/g diet when compared with the control. Conclusions: The presence of the secondary metabolites could ensure the plant of its pharmacological properties, and the plant could be considered safe up to a dose of 2 mg/g diet at short and long-term exposure.