Chemical profiling of endangered Citrus macroptera leaf extracts and evaluation of its cytotoxic activity

Abstract

The main component of drug production and formulation, with minimal to no adverse effects, is plant-based medicine. Citrus macroptera is an endangered species of North-Eastern India and has a diverse array of pharmaceutical applications owing to the presence of several bioactive compounds. The study aimed to evaluate the presence of bioactive metabolites, antioxidants, and cytotoxic mechanisms of the in vitro and ex-vitro leaf extracts of C.macroptera. Gas chromatography–mass spectrometry (GC-MS) profiling was performed using the ethanolic leaf extracts. Methanolic and aqueous extracts were profiled using High-performance thin-layer chromatography (HPTLC). Moreover, the cytotoxicity of the methanolic leaf extracts was assessed using the 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) test against SH-SY5Y, human neuroblastoma cell lines. GC-MS analysis revealed the existence of numerous pharmacologically significant components such as esters, hydrocarbons, fatty alcohols, and ester compounds. The presence of flavonoids and stigmasterol was exhibited by the HPTLC profile. The in-situ HPTLC analysis revealed white fluorescence after derivatization under white light that explicitly confirms the antioxidant potential of the extracts and can serve as a lead source of natural antioxidants. The cytotoxic efficacy of the extracts was observed in a concentration-dependent manner. However, the in vitro leaf extract displayed better suppressive effects against the SH-SY5Y cells with a 24-h IC50 of 167.71?g/mL compared to the ex-vitro leaf extract. Further, a comprehensive study is necessary to identify the cytotoxic compounds and their mode of action. The outcome of our investigation provides empirical evidence that phytoconstituents present in the leaf extracts of C. macroptera can be used as an effective pharmaceutical agent to combat several diseases.