hanani razali
Phone: +603-79674953
Address: Dept. of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Lembah Pantai, Kuala Lumpur.
Address: Dept. of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Lembah Pantai, Kuala Lumpur.
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Background: Tamarindus indica L. (T. indica) or locally known as “asam jawa” belongs to the family Leguminosae. T.
indica seeds as by-products from the fruits were previously reported to contain high polyphenolic content. However,
identification of their bioactive polyphenols using recent technologies is less well researched but nonetheless
important. Hence, it was the aim of this study to provide further information on the polyphenolic content and
antioxidant activities as well as to identify and quantify its bioactive polyphenols.
Methods: T. indica seeds were extracted with methanol and were then fractionated with different compositions of
hexane, ethyl acetate and methanol. Polyphenolic contents were measured using Folin-Ciocalteu assay while
antioxidant activities were measured using DPPH radical scavenging and ferric reducing (FRAP) activities. The cytotoxic
activities of the crude extract and the active fraction were evaluated in HepG2 cells using MTT assay. The cells were
then pre-treated with the IC20 concentrations and induced with H2O2 before measuring their cellular antioxidant
activities including FRAP, DPPH, lipid peroxidation, ROS generation and antioxidant enzymes, SOD, GPx and CAT.
Analyses of polyphenols in the crude extract and its active fraction were done using UHPLC and NMR.
Results: Amongst the 7 isolated fractions, fraction F3 showed the highest polyphenolic content and antioxidant
activities. When HepG2 cells were treated with fraction F3 or the crude extract, the former demonstrated higher
antioxidant activities. F3 also showed stronger inhibition of lipid peroxidation and ROS generation, and enhanced
activities of SOD, GPx and CAT of HepG2 cells following H2O2-induced oxidative damage. UHPLC analyses revealed the
presence of catechin, procyanidin B2, caffeic acid, ferulic acid, chloramphenicol, myricetin, morin, quercetin, apigenin
and kaempferol, in the crude seed extract of T. indica. UHPLC and NMR analyses identified the presence of caffeic acid
in fraction F3. Our studies were the first to report caffeic acid as the active polyphenol isolated from T. indica seeds
which likely contributed to the potent antioxidant defense system of HepG2 cells.
Conclusion: Results from this study indicate that caffeic acid together with other polyphenols in T. indica seeds can
enhance the antioxidant activities of treated HepG2 cells which can provide protection against oxidative damage.
synthase, malate dehydrogenase, and ATP synthase as among proteins of which abundances were markedly altered.
Conference Presentations
Background: Tamarindus indica L. (T. indica) or locally known as “asam jawa” belongs to the family Leguminosae. T.
indica seeds as by-products from the fruits were previously reported to contain high polyphenolic content. However,
identification of their bioactive polyphenols using recent technologies is less well researched but nonetheless
important. Hence, it was the aim of this study to provide further information on the polyphenolic content and
antioxidant activities as well as to identify and quantify its bioactive polyphenols.
Methods: T. indica seeds were extracted with methanol and were then fractionated with different compositions of
hexane, ethyl acetate and methanol. Polyphenolic contents were measured using Folin-Ciocalteu assay while
antioxidant activities were measured using DPPH radical scavenging and ferric reducing (FRAP) activities. The cytotoxic
activities of the crude extract and the active fraction were evaluated in HepG2 cells using MTT assay. The cells were
then pre-treated with the IC20 concentrations and induced with H2O2 before measuring their cellular antioxidant
activities including FRAP, DPPH, lipid peroxidation, ROS generation and antioxidant enzymes, SOD, GPx and CAT.
Analyses of polyphenols in the crude extract and its active fraction were done using UHPLC and NMR.
Results: Amongst the 7 isolated fractions, fraction F3 showed the highest polyphenolic content and antioxidant
activities. When HepG2 cells were treated with fraction F3 or the crude extract, the former demonstrated higher
antioxidant activities. F3 also showed stronger inhibition of lipid peroxidation and ROS generation, and enhanced
activities of SOD, GPx and CAT of HepG2 cells following H2O2-induced oxidative damage. UHPLC analyses revealed the
presence of catechin, procyanidin B2, caffeic acid, ferulic acid, chloramphenicol, myricetin, morin, quercetin, apigenin
and kaempferol, in the crude seed extract of T. indica. UHPLC and NMR analyses identified the presence of caffeic acid
in fraction F3. Our studies were the first to report caffeic acid as the active polyphenol isolated from T. indica seeds
which likely contributed to the potent antioxidant defense system of HepG2 cells.
Conclusion: Results from this study indicate that caffeic acid together with other polyphenols in T. indica seeds can
enhance the antioxidant activities of treated HepG2 cells which can provide protection against oxidative damage.
synthase, malate dehydrogenase, and ATP synthase as among proteins of which abundances were markedly altered.