To Evaluate the Anti-leukaemic Activity of Methanolic and Chloroform Extracts of Persea americana Fruit Against Myeloid Leukaemia

Abstract

Acute Promyelocytic Leukaemia (APL), a subtype of acute myeloid leukaemia is a highly aggressive form of leukaemia while, Chronic Myeloid Leukaemia (CML) progresses slowly but is a chronic condition in which it is difficult to achieve complete remission. With the advent of differentiating agents such as ATRA and ATO, APL became a highly curable form of the leukaemia and in the same way, tyrosine kinase inhibitors revolutionized the CML treatment. However, these treatment options for both APL and CML are limited due to the development of resistance by cancer cells against the standard drugs. Moreover, the differentiation syndrome caused by ATRA in APL is a serious concern that must be addressed to prevent unnecessary outcomes. Plant extracts are known to have cytotoxic potential with the natural compounds having a lot better safety profile compared to the synthetic drugs. One such plant is Persea americana that has shown cytotoxic activity against a number of cancer cell lines. Therefore, this study was designed with an aim to target PML-RARA positive APL cells and BCR-ABL1 positive CML cells with P. americana fruit extracts in order to assess their cytotoxic activity against APL and CML, respectively. For this purpose, P. americana extracts of seed, pulp and peel in 80% methanol and chloroform were prepared. In the first step, the compounds present in these extracts were identified by GC-MS analyses of all the extracts. Subsequently, the bioactive lead compounds were shortlisted and their molecular interactions with the hub proteins of APL and CML were investigated via molecular docking. After in-silico validation of interactions of the bioactive compounds with hub proteins, these extracts were taken for in-vitro confirmation of their cytotoxic potential against NB4 and K562 cells. For this purpose, both NB4 and K562 cells were treated with the seed and pulp extracts of P. americana and the cell viabilities after Abstract XXVIII treatment were assessed by MTT assay. The results obtained were subjected to statistical analysis by using Grahpad PRISM 5.01. The apoptosis inducing potential of these extracts in NB4 and K562 cells was investigated by performing the DNA fragmentation assay. The results obtained indicate that P. americana extracts possess compounds that have a potential of interacting with hub proteins that have a central role in the disease progression of APL and CML. Moreover, these extracts have shown a significant cytotoxic potential against NB4 and K562 cells when given as monotherapies and also in combination with standard drugs, ATRA and imatinib, respectively. The reduction in cell viabilities in cells treated with these extracts is possibly due to induction of apoptosis, as indicated by DNA fragmentation assay. To conclude, P. americana fruit extracts have shown a remarkable inhibitory effect on NB4 and K562 cells. However, it needs further validation by the mechanistic and the proteomics studies, identifying the interaction of extracts with deregulated pathways and the proteins of APL and CML