International Journal of Aquaculture, 2017, Vol.7, No.18, 122-127
122
Research Report
Open Access
The Potential of Different Extraction Methods of Soursop (
Annona muricata
Linn) Leaves as Antimicrobial Agents for Aquatic Animals
Olusola S.E.
1
, Fakoya S.
2
, Omage I.B.
2
1 Department of Biological Sciences (Fisheries and Aquaculture Programme), Ondo State University of Science and Technology, Okitipupa, Nigeria
2 Department of Biological Sciences (Microbiology Programme), Ondo State University of Science and Technology, Okitipupa, Nigeria
Corresponding author Email:
International Journal of Aquaculture, 2017, Vol. 7, No.18 doi:
Received: 22 Sep., 2017
Accepted: 20 Oct., 2017
Published: 10 Nov., 2017
Copyright © 2017
Olusola et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
Olusola S.E., Fakoya S., and Omage I.B., 2017, The potential of different extraction methods of soursop (
Annona muricata
Linn) leaves as antimicrobial agents
for aquatic animals, International Journal of Aquaculture, 7(18): 122-127 (doi:
Abstract
A cup plate diffusion method was employed to determine the antibacterial and antifungal activities of aqueous, ethanolic
and methanolic extracts of soursop (
Annona muricata
) leaves against four clinical strains of bacteria isolates from
Clarias gariepinus
and
Oreochromis niloticus
. They were
Bacillus subtilis
,
Staphylococcus aureus
,
Streptococcus iniae
,
Aeromonas hydrophila
and
Aspergillus niger
. Phytochemical screening and Minimum Inhibitory Concentration (MIC) of soursop leaves were established
through standard methods. Data obtained were subjected to ANOVA at P = 0.05. The diameter of zone of inhibition varies depending
on pathogens and method of extraction. An average diameter of zone of inhibition ranges from without inhibition zone in control to
20 ± 0.01 mm, without inhibition zone in control to 21 ± 0.02 mm and without inhibition zone in control 25 ± 0.01 mm for aqueous,
ethanolic and methanolic extracts respectively. The extracts displayed higher activities to the Gram positive organisms.
Chloramphenicol and distilled water were used as control. Phytochemical screening indicated the presence of tannins, glucosinolates,
phenols, amino acids and polysterols and absence of saponins. The result of MIC of soursop leaves extracts on the pathogens
investigated was 500 µg/ ml, 500 µg/ ml and 1000 µg/ml for aqueous, ethanolic and methanolic extracts respectively. The results
indicated that different methods of extraction of soursop leaves had antimicrobial activity on the pathogens (
B. subtilis
,
S. aureus
,
S.
iniae
,
A. hydrophila
and
A. niger
) and suggested that soursop extracts can be used in fish farming to inhibit bacterial growth and
improved fish health.
Keywords
Soursop leaves; Fish pathogen; Phytochemical; Antimicrobial
1 Background
The use of antibiotics and chemotherapeutics for prophylaxis and treatment in fish farming has been widely
criticized for its negative impact (FAO, 2002). Issues associated with the uses of antibiotics in disease
management should therefore focus on the uses of natural plant products that possess immuno-modulatory and
antimicrobial activities. Imunnostimulants are chemical compounds that stimulate the non specific immune
system when given alone or the specific immune mechanism when given with an antigen, thereby making the
animal more resistant to microbial and parasitic infections (Cuesta et al., 2005).
Therefore, using immunostimulants may act as attractive alternative to prevent infections in fish and improve
growth (Secombes, 1994; Raa, 1996). Scientific studies revealed that the inclusion of medicinal plants in the diet
of aquatic animals improved the immune system of fish and increased disease resistant properties (Chakrabartis et
al., 2012). Some plant extracts were shown to have antimicrobial and immunomodulatory activities such plants
include
A. muricata
leaves which appear to have anti-viral activity, anticarcinogenic and genotoxic effects and
wound healing activity (Gajalakshmi et al., 2012).
Annona muricata
Linn were group to the family of Annonaceae with an extensive pan -tropical distribution and it
is known as corosol. It is a prevalent small tree and originated from Central America (Alassane et al., 2004). The
seeds and leaves of these species were found to contain more than 50 mono-THF acetogenins which possess much
of the diverse biological activities (Galalakshmi et al., 2012). However, there is scanty information of its use in
aquaculture or its use in fish farming has not been investigated. The present study was investigated to examine the
