Munro B1,2,
Vuong QV3,4,
Chalmers AC5,
Goldsmith CD6,7,
Bowyer MC8,9,
Scarlett CJ10,11,12.
- 1Pancreatic Cancer
Research, Nutrition Food & Health Research Group, University of
Newcastle, Ourimbah, NSW 2258 Australia. benjamin.munro@uon.edu.au.
- 2School of Environmental and Life Sciences, University of Newcastle, Ourimbah, NSW 2258, Australia. benjamin.munro@uon.edu.au.
- 3Pancreatic Cancer
Research, Nutrition Food & Health Research Group, University of
Newcastle, Ourimbah, NSW 2258 Australia. vanquan.vuong@newcastle.edu.au.
- 4School
of Environmental and Life Sciences, University of Newcastle, Ourimbah,
NSW 2258, Australia. vanquan.vuong@newcastle.edu.au.
- 5School
of Environmental and Life Sciences, University of Newcastle, Ourimbah,
NSW 2258, Australia. anita.chalmers@newcastle.edu.au.
- 6Pancreatic Cancer
Research, Nutrition Food & Health Research Group, University of
Newcastle, Ourimbah, NSW 2258 Australia. chloe.d.goldsmith@uon.edu.au.
- 7School of Environmental and Life Sciences, University of Newcastle, Ourimbah, NSW 2258, Australia. chloe.d.goldsmith@uon.edu.au.
- 8Pancreatic Cancer
Research, Nutrition Food & Health Research Group, University of
Newcastle, Ourimbah, NSW 2258 Australia.
michael.bowyer@newcastle.edu.au.
- 9School of
Environmental and Life Sciences, University of Newcastle, Ourimbah, NSW
2258, Australia. michael.bowyer@newcastle.edu.au.
- 10Pancreatic Cancer
Research, Nutrition Food & Health Research Group, University of
Newcastle, Ourimbah, NSW 2258 Australia. c.scarlett@newcastle.edu.au.
- 11School of Environmental and Life Sciences, University of Newcastle, Ourimbah, NSW 2258, Australia. c.scarlett@newcastle.edu.au.
- 12Cancer Research Program, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia. c.scarlett@newcastle.edu.au.
Abstract
Euphorbia tirucalli is a succulent shrub or small tree
that is native to the African continent, however, it is widely
cultivated across the globe due to its use in traditional medicines to
treat ailments, ranging from scorpion stings to HIV. Recent studies have
identified compounds present in the latex of the plant, including a
range of bi- and triterpenoids that exhibit bioactivity, including
anticancer activity. This study aimed to optimize water extraction
conditions for high-yield total phenolic content recovery, to prepare
methanol and aqueous extracts from the aerial sections of the plant, and
to test the phytochemical, antioxidant, and anti-cancer
properties of these extracts. Water extraction of total phenolic
compounds (TPC) was optimized across a range of parameters including
temperature, extraction time, and plant mass-to-solvent ratio. The water
extract of the
E. tirucalli powder was found to contain TPC of 34.01 mg GAE (gallic
acid equivalents)/g, which was approximately half that of the methanol extract (77.33 mg GAE/g). The results of antioxidant assays showed a uniform trend, with the methanol extract's
antioxidant reducing activity exceeding that of water extracts,
typically by a factor of 2:1. Regression analysis of the antioxidant
assays showed the strongest correlation between extract
TPC and antioxidant activity for the ABTS
(2,2-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) and DPPH
(2,2-diphenyl-1-picrylhydrazyl) methods. The methanol extract also showed greater growth inhibition capacity towards the MiaPaCa-2 pancreatic cancer
cell line. These data suggest that further investigations are required
to confirm the source of activity within the E. tirucalli leaf and stems
for potential use in the nutraceutical and pharmaceutical industries.
KEYWORDS:
Euphorbia tirucalli; antioxidant; pancreatic cancer; polyphenols
