JOURNAL OF MEDICINAL FOOD
J Med Food 10 (1) 2007, 194–196
© Mary Ann Liebert, Inc. and Korean Society of Food Science and Nutrition
Effectiveness of Dried Carica papaya Seeds Against Human Intestinal Parasitosis:
A Pilot Study
John A.O. Okeniyi,
Tinuade A. Ogunlesi,
Oyeku A. Oyelami,
and Lateef A. Adeyemi
Department of Paediatrics and Child Health, College of Health Sciences, Obafemi Awolowo University,
Ile-Ife; and Departments of
Microbiology and Parasitology, Wesley Guild Hospital,
ABSTRACT The tropical fruit Carica papaya and its seeds have proven antihelminthic and anti-amoebic activities. To de-
termine the effectiveness of air-dried C. papaya seeds on human intestinal parasitosis, 60 asymptomatic Nigerian children
with stool microscopic evidence of intestinal parasites received immediate doses (20 mL) of either an elixir composed with
air-dried C. papaya seeds and honey (CPH) or honey alone (placebo) in two randomized treatment groups. Repeat stool mi-
croscopic examinations were conducted 7 days postintervention for intestinal parasites. Significantly more subjects given CPH
elixir than those given honey had their stools cleared of parasites [23 of 30 (76.7%) vs. five of 30 (16.7%); z 4.40, P
.0000109]. There were no harmful effects. The stool clearance rate for the various types of parasites encountered was between
71.4% and 100% following CPH elixir treatment compared with 0–15.4% with honey. Thus, air-dried C. papaya seeds are
efficacious in treating human intestinal parasites and without significant side effects. Their consumption offers a cheap, nat-
ural, harmless, readily available monotherapy and preventive strategy against intestinal parasitosis, especially in tropical com-
munities. Further and large-scale intervention studies to compare C. papaya with standard antiparasitic preparation are de-
UMAN INTESTINAL PARASITOSIS
constitutes a significant
global health problem with enormous financial impli-
Unfortunately, for reasons mainly attributable to
the burden is more in the tropics and sub-
tropics where, particularly among children,
cause noteworthy morbidity such as anemia, diarrhea and
dysentery, malnutrition, apathy, and underdevelopment as
well as severe acute abdominal and surgical conditions.
As most patients particularly from the tropics and partic-
ularly from Africa are from low socioeconomic groups who
can ill-afford imported and expensive medicines,
for affordable and readily available local alternatives can-
not be overemphasized. Carica papaya, a fruit plant also
called papaya, papaw, pawpaw, mamao, or tree melon, is
found in virtually every tropical and subtropical country.
C. papaya contains proven antihelminthic
such as benzyl isothiocyanate and papain
and has other
In folk medicine, C. papaya
seeds have been used to treat helminthiasis.
Thus, we eval-
uated the antiparasitic effects of dried C. papaya seeds. It is
hoped that the information obtained will provide guidance
for further research that may ultimately assist in the formu-
lation of necessary preventive and treatment strategies
against intestinal parasitosis, particularly in tropical com-
MATERIALS AND METHODS
Between November 1, 2003 and January 30, 2004, in the
Children’s Welfare Clinic of the Wesley Guild Hospital,
Ilesa, Nigeria, consecutive children 2–6 years old with nor-
mal weight and height for age and no health complaints were
screened with light microscopic examination of wet prepa-
rations of freshly passed stools to confirm the presence of
intestinal parasites, their cysts, trophozoites, larvae, or ova.
Manuscript received 17 October 2005. Revision accepted 10 January 2006.
Address reprint requests to Dr. John A.O. Okeniyi at his present address: Department of
Paediatrics and Child Health, Wesley Guild Hospital, Ilesa. P.M.B. 5011, Ilesa, Osun
State, Nigeria, E-mail: firstname.lastname@example.org
Following informed parental consents, a total of 60 children
with seven different species of intestinal parasites were re-
cruited into this study.
C. papaya seeds and natural honey were harvested from
an apiary of one of the investigators (O.A.O). The seeds
were air-dried and then machine-blended. An elixir of the
air-dried C. papaya seeds and honey (CPH) was prepared
by mixing 500 g of the blend with honey to make a total
preparation volume of 1,000 mL, i.e., 0.2 g of dried C. pa-
paya seeds/mL. Each subject received immediately received
an oral dose of either 20 mL (equivalent to 4 g of dried,
blended C. papaya seeds) of the CPH elixir or honey alone
in two randomized treatment groups. Thus, honey served not
only as the means of administration of the C. papaya seeds
but also as the placebo/control. All the subjects were ad-
vised to abstain from honey and C. papaya during the study
period. The children then had repeat stool microscopic ex-
amination 7 days later conducted by the same laboratory sci-
entist (L.A.A), who was blinded to each subject’s treatment.
Histories of gastrointestinal symptoms and other possible
side effects were further documented. Data were analyzed
using with the computer program for epidemiologists (PEPI)
Means and standard deviations were com-
pared using Student’s t test and proportions by the z-scores
at 95% confidence interval (CI). Values of P .05 were
considered statistically significant.
Sixty children (41 boys and 19 girls) between 3 and 6
years of age (mean, 4.6 1.1 years) with stool microscopic
evidence of intestinal parasites were recruited, with 30
(50.0%) each treated with CPH elixir or honey. Table 1 de-
tails the types of intestinal parasites and the comparison of
stool clearance in both treatment groups. The most preva-
lent intestinal parasites were Ascaris lumbricoides, Enta-
moeba histolytica, Necator americanus, and Strongyloides
stercoralis, found in 26 (43.3%), 14 (23.3%), nine (15.0%),
and eight (13.3%) of the 60 children, respectively. Only two
(3.3%) children (one in each treatment group) had Taenia
saginata. Fifty-one (85.0%) of the children had single par-
asites only, while nine (15.0%) had polyparasitism; in ad-
dition to A. lumbricoides, six (10.0%) had E. histolytica, and
the remaining three (5.0%) had N. americanus. Among the
children with multiple parasites, five received CPH elixir,
and four had honey treatment.
CPH elixir demonstrated a high stool clearance efficacy
against A. lumbricoides (84.6%) and S. stercoralis (100%)
with statistically significant differences compared with
honey. Although CPH demonstrated 100% efficacy against
Trichuris trichuria, Giardia lamblia, and T. saginata, com-
pared with honey, the efficacy in each instance did not reach
the accepted level of statistical significance. Also, despite a
high stool clearance rate for E. histolytica (71.4%) and N.
americanus (80.0%), these were not statistically significant
relative to honey. Overall, the stools of 23 of 30 (76.67%)
subjects given the CPH elixir compared with five of 30
(16.67%) given honey alone were cleared of parasites (stan-
dard error 0.1029; 95% CI 0.3649; 0.8351, z 4.40;
There were no significant adverse effects, though two of
30 (6.7%) children given the CPH elixir had transient com-
plaints on the day the treatments were given. One had nau-
sea, while the other had an episode of loose stools. None of
the children who received honey alone had complaints. The
difference in the proportion of children with complaints in
either treatment group was not statistically significant (stan-
dard error 0.0456; 95% CI 0.0559, 0.1893; z 0.72;
Our high stool parasite clearance rates of between 71.4%
and 100% are an affirmation of the effectiveness of C. pa-
paya seeds against intestinal parasites.
the most prevalent intestinal helminth (a nematode), was ef-
fectively cleared. Probably because of the limited sample
population, our findings lacked statistical significance de-
spite demonstrable and absolute parasite clearance of cer-
tain other helminths, including a cestode, T. saginata. Our
IN VIVO ANTIPARASITIC EFFICACY OF PAPAYA SEED 195
ARASITES AND THE
Clearance Statistical values
Parasite (number of children CPH elixir Honey-alone z
with parasite) group group score 95% CI P
A. lumbricoides (n 26)
2/13 (15.4%) 3.14 0.3376, 1.0464 .002
E. histolytica (n 14 5/7 (71.4%) 1/7 (14.3%) 1.62 0.0047, 1.1373 .106
N. americanus (n 9)
4/5 (80.0%) 1/4 (25.0%) 0.98 0.2255, 1.3255 .330
S. stercoralis (n 8) 4/4 (100%) 0/4 (0%) 2.12 0.0075, 1.2500 .034
T. trichuria (n 6) 3/3 (100%) 0/3 (0%) 1.63 0.6667, 1.3333 .102
G. lamblia (n 4) 2/2 (100%) 1/2 (50.0%) 0.00 0.6930, 1.6930 1.000
T. saginata (n 2) 1/1 (100%) 0/1 (0%) 0.00 0.0000, 2.0000 1.000
Number (%) of children with stools cleared on parasite/total number of children with the same parasite.
Some children had multiple parasites.
observation of over 70% effectiveness against E. histolytica
was also watered-down by the lack of statistical significance
compared with the honey placebo. Papaya had previously
been documented as having anti-amoebic properties.
had earlier reported a case of hypersensitiv-
ity reaction to papaya. However, it was gratifying to note
the absence of untoward effects in both treatment groups.
This was indeed our expectation ab initio considering the
facts that C. papaya and its seeds are edible
consumed by both humans and animals in the tropics,
though the seeds are less favored because of less palata-
bility. This was why we opted to use honey, a natural
sweetener, as vehicle for our elixir. The transient nausea
and loose stools observed among two of our subjects may
be unrelated to our elixir in view of the fact that all our
subjects had intestinal parasitosis, which may present with
The mechanisms of action of C. papaya are not fully elu-
though it clearly has antihelminthic activity
other immunomodulatory activities.
Though intestinal par-
asite clearance by honey, our placebo in this study, was un-
expected, it is still noteworthy. Could there be a possible
antihelminthic property to honey? Our observations are at
best inconclusive in view of the low clearance rate. This
finding may be a spurious occurrence or possibly a demon-
stration of minimal antihelminthic properties to honey. Also,
could the honey have had synergistic or inhibitory effects
on the therapeutic properties of the C. papaya seeds? Fur-
ther large-scale human studies are required to provide a con-
It is conceivable that C. papaya, which thrives effort-
can be much more readily available and affordable
still if commercial and subsistence farming of the papaya
plant was encouraged in tropical communities. Also, future
studies may revolutionize preventive or therapeutic care
against intestinal parasites by determining the minimal
amounts of C. papaya seeds or its active ingredients required
to be consumed. There is that old English adage that “an ap-
ple a day keeps the doctor away.” Could a papaya a day also
do the same? Especially judging from its luxuriant growth
in the tropics and its richness in -carotene, the main pre-
cursor of vitamin A,
a vitamin reputed to be a magic bul-
let in childhood survival.
We conclude that C. papaya
seeds could be beneficial in the treatment and plausibly pre-
vention of intestinal parasites, more so being readily avail-
able, harmless, and cheap. We therefore recommend their
consumption for not only for their nutritive but their medi-
We wish to thank our numerous subjects and their par-
ents for their cooperation.
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