The screening of aqueous extract of Clerodendrum serratum revealed its broad-spectrum antimicrobial potential against Gram positive, Gram negative bacteria, and yeast. Optimizing the extraction strategies, revealed 15% concentration of aqueous extract prepared at 40 °C by extracting for 40 min, as optimum parameters and its statistical optimization by Box-Behnken design led to 1.16-1.35 folds enhancement in activity. Organic solvent extraction further improved the activity where methanol proved to be the best organic extractant which was effective against all the 13 pathogens tested with inhibition zone ranging from 14 to 32 mm. Minimum Inhibitory Concentration (MIC) study endorsed the methanolic extract to be the best organic extractant, as it showed the lowest MIC (0.5-10 mg/ml) in comparison to aqueous extract (1-10 mg/ml) as well as Partially Purified Phytoconstituents i.e., flavonoids (1-5 mg/ml), diterpenes (5-10 mg/ml) and cardiac glycosides (5-10 mg/ml). All these were found to be biosafe in both In-vitro (Ames and MTT assay) and In-vivo toxicity studies. Acute oral toxicity testing of flavonoids (2000 mg/ml) on Wistar rats did not reveal any significant change in relative organ weight, biochemical, hematological parameters and organs' architecture in comparison to control. Antiproliferative potential of flavonoids against human cancerous cell lines i.e., HeLa, HCT-15, and U87-MG, further increase the importance of this plant as a promising candidate for drug development. The overall study justified the medicinal importance of this plant.
Keywords: Antimicrobial; Clerodendrum serratum; acute oral toxicity; minimum inhibitory concentration; phytoconstituents.