Phosphate buffer solution (5mL) was injected into the peritoneal cavity of sacrificed mice. The abdomen of the
mice was then massaged to bring the cells into a suspension. Exactly 3mL of the exudate was then collected and
sonicated. The absorbance of the exudates was then determined at 405nm5. 1ml of Staphylococcus aureus suspended
in nutrient broth was then added to the exudates. The absorbance immediately after the addition of the microbes and
30minutes after the addition of the microbes were determined to calculate percentage of inhibition.
2.2.2. Test against specific immune response
Determination of total antibody titre
Haemagluttination method titre assay was performed to determine primary antibody titre and secondary antibody
titre. On the seventh day, after immunization, blood was collected from individual animals of all the groups from the
vein for serum preparation. The pooled serum was diluted with 50μL phosphate buffer (pH7.4) with 2 fold serial
dilution in 96-well micro-titre plates and mixed with 25μL of 2% SRBC suspension in Phosphate buffer. Plates were
incubated at 37 ºC for 24 hours. The value of primary antibody titre was considered the highest serum dilution
showing 50% haemagluttination. This procedure was repeated on the twelfth day to determine secondary antibody
titre.
Delayed type hypersensitivity test
Seven days after sensitization, the animals were challenged with 0.05mL 2% SRBC in the right hind footpad by
injection. Increase in footpad oedema was measured 24 hours and 48 hours after the challenge using a
plethysmometer.
Number of lymphocytes
After 10 days of powder administration; the mice were sacrificed and the thymus and spleen isolated. The thymus
and spleen were teased in phosphate buffer solution. The solution is then filtered and 100μL of it was observed
under microscope using a haematocytometer and the number of lymphocytes was counted.
Statistical analysis
Statistical analysis was performed using paired-T test7. The significance in difference was accepted at p < 0.05.
The values are expressed as mean ± S.D
3. Results and Discussion
Immunomodulators are substances that have an effect on the immune response. That effect can be to either
stimulate the immune system or to suppress it. This study employed the use of pumpkin seeds which are usually
used as sources of nutrition to determine whether or not these food sources may have effects on the immune
response. If it is indeed possible use these food sources as immunomodulators it can be employed as a form of
medical nutrition therapy.
The carbon clearance test is done to observe the effect of test substances, in this case pumpkin seed powder
against the non-specific immune response. More specifically this test shows phagocytosis by the phagocytic cells in
the body of the mice. Phagocyte cell activity can be determined by observing the speed of carbon particle clearance
administered intravenously as a foreign substance in the blood by determining the transmittance of the blood
samples (in 1% acetic acid) at specific time intervals. The greater the transmittance values the smaller the amount of
carbon particles in the blood. The transmittance was determined at 675nm using a UV-Vis Spectrophotometer.
Once the transmittance values were determined, a graph of 100-%Transmittance versus the time interval was
plotted. The slope of each line corresponds to the rate of the carbon clearance. In turn, the rate of the carbon
clearance can be used to determine the phagocytic index. The phagocytic index is determined by comparing by ratio,