Antimicrobial, Antiquorum-sensing and Ex-vivo Antispasmodic Activity of Adhatoda vasica

Aims: To investigate the antimicrobial, antiquorum-sensing and Ex-vivo antispasmodic activity of the stem extract, fractions and isolated compounds of Adhatoda vasica. Study Design: Preparation of the total extract, fractions of A. vasica and isolation of its phytoconstituents for investigation of antimicrobial, antiquorum-sensing and Ex-vivo antispasmodic activity. Place and Duration of Study: Faculty of Pharmacy, Mansoura University, Egypt and College of Pharmacy, Prince Sattam Bin Abdulaziz University, KSA, between November 2014 and May 2019. Methodology: Different phytoconstituents in obtained liquid-liquid fractionations were isolated by repeated column chromatography. The preliminary antimicrobial activity was measured via agar disc-diffusion method. The minimum inhibitory concentration (MIC) was further determined using broth microdilution method in 96-well plates. Antiquorum-sensing activity was tested against Chromobacterium violaceum in LB agar medium. While, antispasmodic activity was performed using Ach-induced contraction on rat ileum. Results: Seven compounds have been isolated from the stems extract of Adhatoda vasica viz., β-sitosterol, daucosterol palmitate, monopalmitin, vanillin, vanillic acid, vasicinolone and vasicinone. The petroleum ether fraction, daucosterol palmitate, monopalmitin, vanillin and vanillic acid showed strong antibacterial activity towards E. coli and S. aureus. Whereas daucosterol palmitate and vanillic acid showed pronounced antifungal activity against C. albicans. Antiquorum-sensing assay showed that β-sitosterol, vanillin and vanillic acid were the most active compounds. While, petroleum ether and methylene chloride fractions, vasicinolone and daucosterol palmitate showed moderate antiquorum-sensing activity. For antispasmodic activity, petroleum ether fraction showed a remarkable inhibition of Ach-induced contraction at 200 and 250 μg/mL (89.5 and 95.2%, respectively). Also, methylene chloride fraction showed remarkable inhibition (97.6%) at 150 μg/mL. Vasicinone and vasicinolone showed significant inhibition at 150 μg/mL (89.9% and 84.8%, respectively). Conclusion: The isolated compounds and extracts from the stem of the studied plant showed remarkable activities. This work provides further evidences for the traditional medicinal uses of A. vasica in treatment of various ailments.