Isolation, Characterization and Preliminary Cytotoxic and Antifungal Evaluations of Novel Lancifoliate Isolated from Methanol Extract of Conocarpus lancifolius.

Abstract

Combretaceae is a large family comprising of 500 species and 20 genera distributed in subtropical and tropical regions of the world. Conocarpus genus is an ornamental tree native to coastal and riverine areas of East Africa and is also planted as an ornamental plant in different areas of Pakistan. This genus has proved medicinal value as a cytotoxic, antibacterial, antiprotozoal, anti-leishmanial, antifungal and antidiabetic agent. The current study was designed to screen the selected pharmacological attributes of sulphur containing novel compound isolated from Conocarpus lancifolius using a series of in vitro and molecular docking models. After collection and authentication of plant material, methanolic extract was prepared from which various secondary metabolites were qualitatively examined. The compound was isolated using open column chromatography and the structure was established with spectroscopic techniques such as UV-visible, infrared spectroscopy, proton nuclear magnetic resonance (1H-NMR), 13C NMR (BB, DEPT-135, 90), twodimensional correlation techniques (HMBC, HSQC) and mass spectrometry (HRMS) respectively. C. lancifolius extract and isolated compound were studied for cytotoxic and antifungal potentials using in vitro Sulforhodamine B (SRB) and disc diffusion methods, respectively. Molecular docking studies were conducted to check the interaction of the isolated compound with major oncogenic proteins. Qualitative phytochemical screening revealed the presence of saponins, steroids, flavonoids, anthraquinones, and cardiac glycosides while alkaloids were absent in C. lancifolius extract. Isolated compound was characterized as lancifoliate, which showed cytotoxic activity towards a variety of cancer cell lines including murine lymphocytic leukemia (P-388, IC50 = 2.65μg/ml), human colon cancer (Col-2, IC50 = 0.84μg/ml), human breast cancer (MCF-7, IC50 = 0.72μg/ml) while no cytotoxic activity was observed towards human lung cancer (Lu-1), rat normal glioma cells (ASK, IC50 = 11.6μg/ml) and human embryonic kidney cells (Kek293, IC50 = 6.74μg/ml) respectively. Minimum Inhibitory Concentration (MIC) of Lancifoliate towards Aspergillus fumigatus, Aspergillus nigar (skin sample), Aspergillus flavus (pleural fluid) and Candida albicans (urine and blood samples) was found to be 54.5, 44.8, 43.5, 22.4 and 20.2μg/ml respectively. Moreover, docking results are in strong agreement with our experimental finding, which has identified lancifoliate to be a more potent antiproliferative agent than previously known compound ellipticine. C. lancifolius extract and lancifoliate possess potent cytotoxic and antifungal properties and thus has potential to be further studied. To the best of our knowledge, this is the first study that highlights isolation, identification and pharmacological activities of lancifoliate from Conocarpus lancifolius.