Iron-Chelating, Free Radical Scavenging and Anti-Proliferative Activities of Azadirachta indica
Kanjana Pangjit PhD*, Payungsak Tantiphaipunwong PhD**, Wittawas Sajjapong MSc**, Somdet Srichairatanakool PhD***
Affiliation : * College of Medicine and Public Health, Ubon Ratchathani University, Ubon Ratchathani, Thailand ** Division of Biochemistry, Faculty of Medical Sciences, University of Phayao, Phayao, Thailand *** Department of Biochemistry, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
Background : Excessive production of reactive oxygen species leads to oxidative stress which occurs in various diseases,
such as diabetes, cancer, neurodegenerative diseases, and secondary iron overload in thalassemia. Antioxidants are compounds
that inhibit the oxidative processes and delay or suppress oxidative stress. Phytochemicals in herbs are interesting sources of
natural antioxidants with cancer preventive properties. The use of natural products is beneficial for the prevention and/or
treatment of oxidative stress mediated diseases.
Objective : The study aimed to investigate the antioxidant and anti-proliferative properties of ethanolic extract from Azadirachta
indica (neem) leaves.
Material and Method: Neem leaves were extracted by 80% ethanol (v/v). The ethanolic extract was tested for free radical
scavenging activity by 2,2’-azino-bis-3-ethylbenzothiaziline-6-sulfonic acid (ABTS) and for the reduction of the power of
ferric ion (Fe3+) to ferrousion (Fe2+) by ferric reducing antioxidant plasma (FRAP) assay. Furthermore, the ability of iron-
binding activity was investigated by the spectrophotometry technique. The inhibitory effect on the growth of human promyelocytic
leukemic cell line (HL-60 cells) was determined by MTT assay.
Results : The ethanolic extract from neem leaves exhibited free radical scavenging activities and reduced the power of ferric
ion (Fe3+) to ferrous ion (Fe2+) in dose responses. Furthermore, it was able to bind with iron rapidly within 5 minutes.
Interestingly, this extract inhibited human promyelocytic leukemic cell line (HL-60 cells) growth in concentration response (0-
500 μg/ml) for 24 hour treatment.
Conclusion : The ethanolic extract from neem leaves had strong antioxidant activity and an anti-proliferative effect on cancer
cells.
Keywords : Antioxidant, Iron-chelating, Anti-proliferative, Reactive oxygen species, Free radicals
