3. Introduction
Bioactive compounds derived from natural sources could be a
potential candidate as antifungal agent, especially in the
current scenario in which human and plant fungal pathogens
have adopted resistance against antifungal agents.
Carica papaya (Caricaceae) is believed to probably originate
from southern Mexico and Costa Rica and then introduced as
a plantation crop in all tropical and subtropical regions
(Krishna et al., 2008).
Carica papaya is widely grown now and used in different for
the purpose of food as well as decorative purpose. It has also
been used in traditional practices for curing diseases
(Sofowora, A., 1997).
4. Phytochemical analyses Indicate that the extracts
contain alkaloids, tannins, saponins, flavaonids (
Harbone,1973), glycosides, phenols (Doughari, J. H et
al, 2007),vitamins, minerals, proteins and enzymes
(Jean, 1999).
Some studies also report that C. papaya roots has been
suggested as a purgative and in case of dysentery cure
(Akah, P.A., 1997) and its various parts are also being
used to treat a number of infections like gastroenteritis,
uretritis, otitis media, typhoid fever and some wound
infections (Doughari, J. H et al, 2007).
5. The plant has also regarded as a strong amoebicide (Reed,
1976). As prophylactic measure, papaya leaf extracts has also
been reported to use against malaria (Satrija et al., 1994).
Aqueous extracts of green papaya epicarp (GPE) and ripe
papaya epicarp (RPE) were also found improving wounds
significantly applied on induced wounds on mice as it is
traditionally employed in some parts of the world to treat
certain skin diseases (Nor Suhada Anuar et al, 2008).The leaves
of many plants possess tannins in an abundant quantity and may
have biocidal activity( Kumar R, Singh ,1984).
6. Material and methods
Preparation of extracts
The fresh leaves from Papaya tree were plucked gently from
a cosmopolitan city –Karachi-Pakistan in a summer season.
These fresh leaves were thoroughly washed with tap water
and later rinsed with sterile distilled water. The leaves after
washing were equally divided into two parts weighing 5
grams for making 5% concentration of extract preparations
in 100 ml. The extracts were prepared by two treatments.
In one treatment, 5 % leaf extract was prepared by boiling
leaves for 15 minutes by constant stirring.
7. In second treatment, the leaves were pulverized,
using sterile laboratory mortar and pestle, to get
a thick paste, later suspended in 100ml of
sterilized water.
Both the extracts were stored in airtight glass
containers sealed further with parafilm protected
from sunlight till further work.
8. Sterility testing of extracts
The sterility testing of extract was done by passing extract
through Millipore filter (0.22micron meter). Later, inoculate 2ml of
sterile extract into 10ml of sterile nutrient broth. And
Sabourd dextrose broth. Incubation was done at 370c for 24hours.
A sterile extract was indicated by absence of turbidity or clearness
of the broth after the incubation period (I.O. Sule and T.O.
Agbabiaka, 2008).
9. Pathogenic Fungi tested:
The test organisms for this study were members of the 6
saprophytic fungi Penicillium sp, Aspergilus flavus, Aspergillus
niger, Fusarium sp, Rhizopus, Helminthosporum and Neurospora
, 5 dermatophytic Microsporum canis, Microsporum gypseum,
Trichophyton
rubrum,
Trichophyton
mentagrophytes,
Trichophyton tonsurans and 6 yeast including Candida albicans,
Candida albicans ATCC 0383, Saccharomyces cerevisiae,
Candida galbrata, Candida tropicalis, Candida kruzei.
The fungal isolates were obtained from the Deparment of
Microbiology, Federal Urdu University of Arts, Science and
Technology, Karachi-Pakistan. All the fungal isolates were
checked for purity and maintained on Sabourd Dextrose agar
(SDA) at 40c in the refrigerator until required for use.
10. Screening of antifungal activity of crude
and aqueous extracts against pathogenic
fungi
Activity of papaya leaf extract was tested
using agar-well method. Autoclaved distilled
water was used for the preparation of fungal
spore suspension and transferred aseptically
into each SDA plates.
All plates were incubated at 28+ 2°C for 24 -48
hours and after incubation diameter of zone
of inhibition was measured.
11. Papaya
leaf
extract
(Boiled)
Name of tested Fungi
C1
Types of treatments
Papaya
leaf
extract
(crushed
)
Table 1:In vitro Antifungal activity of papaya leaves extract against human and
plant pathogenic fungi.
Key:
C1= Negative control, D w
(-) sign shows no antifungal activity
YEAST
Candida albicans
Candida albicans ATCC 0383 Saccharomyces cerevisiae
-
20
19
-
18
16
-
Candida galbrata
-
19
17
Candida tropicalis
-
21
15
Candida kruzei
-
20
16
12. Table 1:In vitro Antifungal activity of papaya leaves extract against human and
plant pathogenic fungi.
Key:
C1= Negative control, D w
(-) sign shows no antifungal activity
Papaya leaf
extract
(crushed)
Papaya leaf
extract (Boiled)
Types of treatments
C1
Name of tested Fungi
DERMATOPHYTES
Microsporum canis
Microsporum gypseum
-
20
-
19
-
Trichophyton rubrum
-
-
-
Trichophyton mentagrophytes -
18
16
Trichophyton tonsurans
-
-
-
13. Table 1:In vitro Antifungal activity of papaya leaves extract against human and
plant pathogenic fungi.
Key:
C1= Negative control, D w
(-) sign shows no antifungal activity
Papaya leaf
extract
(crushed)
Papaya leaf
extract (Boiled)
Types of treatments
C1
Name of tested Fungi
Saprophytes
Aspergillus flavus
Aspergillus niger
-
19
17
15
16
Fusarium specie
-
-
-
Penicillium sp
-
19
15
14. Table 1:In vitro Antifungal activity of papaya leaves extract against human and
plant pathogenic fungi.
Key:
C1= Negative control, D w
(-) sign shows no antifungal activity
Papaya leaf
extract
(crushed)
Papaya leaf
extract (Boiled)
Types of treatments
C1
Name of tested Fungi
Saprophytes
Rhizopus
Helminthosporum
-
20
-
17
-
Neurospora
-
-
-
16. Conclusion
The inhibitory effect of aqueous and crude extracts of
Carica papaya on some human and pathogenic fungi
indicate its therapeutic potential as antifungal agents and
ideal in the current global challenges of antifungal agents
conventionally prescribed in mycotic infections.
Further, it is in fact preliminary screening;
however, further studies with proper scientific knowledge
and documentation should be carried out to explore other
areas to really make it a successful therapeutic candidate
in future.
