Preventive effects of consuming nutritional supplement of Morinda Citrifilia L. on bax and bcl-2 in early leukemic rats
The most common cancer in Malaysia includes leukaemia and lymphoma. Cancer has been linked with the failure of apoptosis process regulated by Bcl-2 family genes, consisting of pro apoptotic genes such as Bax and anti apoptotic genes such as Bcl-2. The ratio of Bcl-2:Bax determines susceptibili...
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Format: | Thesis |
Language: | English |
Published: |
2012
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Online Access: | http://psasir.upm.edu.my/id/eprint/70316/1/FPV%202012%207%20-%20IR.pdf |
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Summary: | The most common cancer in Malaysia includes leukaemia and lymphoma. Cancer has
been linked with the failure of apoptosis process regulated by Bcl-2 family genes,
consisting of pro apoptotic genes such as Bax and anti apoptotic genes such as Bcl-2.
The ratio of Bcl-2:Bax determines susceptibility towards apoptosis. Meanwhile,
Morinda citrifolia fruit is known to exhibit anticancer properties. Thus, the objectives of
this study were to determine the anticarcinogenic and preventive effects of M. citrifolia
fruit in rats with early leukaemia/lymphoma induced by N-Methyl-N-Nitrosourea
(MNU). Male Sprague Dawley rats were divided into four groups; Group 1 (control
group), Group 2 (M. citrifolia fruit treated group), Group 3 (MNU treated group) and
Group 4 (leukaemia/lymphoma prevention group treated with M. citrifolia fruit). The
rats in the Group 3 and Group 4 were injected with four intraperitoneal injections of the MNU mixture, at a dose of 60 mg/kg of body weight per injection, twice a week for two
consecutive weeks with a total dose of 240 mg/kg of body weight. Rats in Group 1 and
Group 2 were injected with normal saline following the same procedure. Ground dried
M. citrifolia fruit at the dose of 3000 mg/kg of body weight were supplemented daily to
the rats in Groups 2 and 4 for 12 weeks. Blood samples were taken at week 0, week 4
and week 8 of experimental study via cardiac puncture. At week 12, all rats were
sacrificed and blood samples were taken via posterior vena cava. RNA were extracted
from the blood and the relative transcription of Bcl-2 and Bax were quantified using Eva
Green quantitative real time reverse transcription-PCR. For haemogram and serum
biochemical analyses, blood samples were taken at week 4, week 8 and week 12 of the
experimental study and analysed using automated blood analysers. For
histopathological examination, organs were taken after sacrifice at the end of the
experimental period. The organs were spleen, lymph nodes, liver, kidneys, lung and
heart. The organs were processed using standard methods and stained with hematoxylin
and eosin (H&E). Quantitative real time RT-PCR assays (qRT-PCR) for quantification
of Bax and Bcl-2 genes which were successfully developed using an Eva Green dye
showed that the ratio of Bcl-2:Bax in the rats injected with MNU was significantly
higher compared to other groups. Significant reduction of Bcl-2:Bax ratio in Group 4 at
week 12 showed that M. citrifolia fruit limits the progression of leukaemia/lymphoma
through regulation of apoptosis gene transcription. Intraperitoneal injections of MNU at
a total dose of 240 mg/kg of body weight successfully induced leukaemia without
lymphocytosis in Group 3 at 50% and 75% after 8 weeks and 12 weeks of injection,
respectively. Meanwhile, supplementation of dried M. citrifolia fruit did not
significantly reduce the percentages of leukaemia without lymphocytosis in Group 4 at 20% and 60% after 8 weeks and 12 weeks of injection, respectively. All blood results
obtained from the automated analysers in rats injected with MNU were similar to the
control. All organs were macroscopically normal. Histopathology results showed that
the rats in Group 3 developed 100%, 50% and 25% early lymphoma lesions in the
spleen, mesentric lymph nodes and other lymph nodes respectively. Meanwhile,
histopathology results showed that the rats in Group 4 developed 100%, 80% and 20%
early lymphoma lesions in the spleen, mesentric lymph nodes and other lymph nodes
respectively. Lesion scoring results showed that supplementation of M. citrifolia fruit at
the dose of 3000 mg/kg of body weight did not significantly reduced the incidence of
leukaemia and lymphoma Group 4. |
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