Pharmacognostic standardisation and antiproliferative activity of Aegle marmelos (L.) Correa leaves in various human cancer cell lines

Therapeutic management of cancer is a great clinical challenge and alternative medicines are being extensively explored to have integrated approach to cure cancer. Aegle marmelos (L.) Correa (Rutaceae) is known for its hypoglycaemic, radioprotective, antidiarrhoeal and many other pharmacological activities. The present study is designed to carryout pharmacognostic standardisation and evaluation of antiproliferative activity of the leaf extracts Aegle marmelos (L.) Correa (Rutaceae) and the chromatographic fractions of the most active extract. Hexane, petroleum ether, chloroform and ethanol extracts of the shade dried leaves were prepared by soxhelation and antiproliferative activity was assessed using human cancer cell lines of lung (A-549), colon (CoLo-05), ovary (IGR-OV-1), prostrate (PC3), leukaemia (THP-1) and breast (MCF-7) cancer. Bioactivity-derived fractionation was carried out for most active extract by column chromatography. The phytochemical studies indicated alkaloids, anthraquinones, terpenoids in the alcohol, chloroform extracts and tannins, terpenoids, reducing sugars in the petroleum ether and hexane extracts. Ethanol extract showed maximum inhibition in colon and breast carcinoma cell lines at a dose of 100 μg/ml. Column chromatography of the ethanol extract yielded five fractions. Out of this, fractions 2, 4 and 5 showed significant inhibition in leukaemia cell line with IC₅₀ of 12.5, 86.2 and >100 μg/ml for fractions 2, 4 and 5, respectively. High-performance thin layer chromatography of the fraction 2 revealed imperatorin as one of the major phytoconstituents. Among the different extracts investigated, ethanol extract exhibited significant antiproliferative activity and its fraction 2 containing furanocoumarin imperatorin showed antiproliferative activity against leukaemia cell line with IC₅₀ of 12.5 μg/ml.