Effect on Physicochemical Characters and Bioactivity of Argemone mexicana in Different Plant Extraction Methods

Abstract

A study was conducted to find out the variation in physicochemical characters and bioactivity in plant extract prepared by two different methods, in order to decide a preferential method. Methanolic extract of Argemone mexicana plant extract was prepared by Soxhlet extraction method and reflux method. Bioactivity of plant extract was ascertained by a brine shrimp lethality test. The percentage yield of methanolic extract was 18% and 42% in soxhlet and reflux extraction methods respectively. In the first method, extract was greenish brown and sticky, but blackish and nonsticky in later method. Soxhlet method showed solubility in ethanol, chloroform, methanol and acetone whereas the reflux method extract did not show solubility in methanol. In both the method, plant extract was positive for alkaloids and saponins tested with standard methods. Nauplii of brine shrimp were hatched in artificial seawater with routine technique and collected in a test tube. The methanolic extract at concentrations of 250, 500 and 750µg/ml was tested on quantified numbers of larvae, in comparison to negative and positive control to test bioactivity. Mortalities were noted after 24 hrs post treatment and calculated as LC₅₀.  The LC₅₀ was lower (118.23µg/ml) in Soxhlet extraction method, as compared to the reflux method (192.69µg/ml). The above results indicated that soxhlet extraction is superior to the reflux method to obtain better bioactivity.