Larvicidal and histopathology effect of endophytic fungal extracts of Aspergillus tamarii against Aedes aegypti and Culex quinquefasciatus

Kannan Baskar; Ragavendran Chinnasamy; Karthika Pandy; Manigandan Venkatesan; Prakash Joy Sebastian; Murugesan Subban; Adelina Thomas; Eliningaya J Kweka; Natarajan Devarajan

doi:10.1016/j.heliyon.2020.e05331

Larvicidal and histopathology effect of endophytic fungal extracts of Aspergillus tamarii against Aedes aegypti and Culex quinquefasciatus

Heliyon. 2020 Oct 28;6(10):e05331. doi: 10.1016/j.heliyon.2020.e05331. eCollection 2020 Oct.

Authors

Kannan Baskar¹, Ragavendran Chinnasamy¹, Karthika Pandy¹, Manigandan Venkatesan², Prakash Joy Sebastian², Murugesan Subban³, Adelina Thomas⁴, Eliningaya J Kweka^{5

6}, Natarajan Devarajan¹

Affiliations

¹ Natural Drug Research Laboratory, Department of Biotechnology, School of Biosciences, Periyar University, Salem 636 011, Tamil Nadu, India.
² Biomedical Zebrafish Laboratory, Department of Medical Biotechnology, Faculty of Allied Health Sciences, Chettinad Academy of Research and Education, Kelambakkam 603 103, Tamil Nadu, India.
³ Department of Botany, School of Life Sciences, Periyar University, Salem 636 011, Tamil Nadu, India.
⁴ School of Pharmacy, Catholic University of Health and Allied Sciences, P.O. Box 1464, Mwanza, Tanzania.
⁵ Division of Livestock and Human Diseases Vector Control, Mosquito Section, Tropical Pesticides Research Institute, P.O. Box 3024, Arusha, Tanzania.
⁶ Department of Medical Parasitology and Entomology, School of Medicine, Catholic University of Health and Allied Sciences, P.O. Box 1464, Mwanza, Tanzania.

Abstract

Background: Mosquitoes biolarvicides remain the most important method for mosquito control. The previous studies have shown Aspergillus sp.-expressed larvicidal properties against mosquito species. The present study evaluated larvicidal and histopathological effect of an endophytic fungus Aspergillus tamarii isolated from theCactus stem (Opuntia ficus-indica Mill).

Method: The molecular identification of isolated A. tamarii was done by PCR amplification (5.8s rDNA) using a universal primer (ITS-1 and ITS-2). The secondary metabolites of A. tamarii was tested for larvicidal activity against Aedes aegypti and Culex quinquefasciatus. Larvicidal bioassay of different concentrations (- 100, 300, 500, 800 and 1000 μg/mL) isolated extracts were done according to the modified protocol. Each test included a set of control groups (i.e. DMSO and distilled water). The lethal concentrations (LC₅₀ and LC₉₀) were calculated by probit analysis. Experimental monitoring duration was 48 h.

Results: The ethyl acetate extract from A. tamarii fungus resulted - excellent mosquitocidal effect against Ae. aegypti and Cx. quinquefasciatus mosquitoes, with least LC₅₀ and LC₉₀ values. -After 48 h, the Ae. aegypti expressed better results (LC₅₀ = 29.10, 18.69, 16.76, 36.78 μg/mL and the LC₉₀ = 45.59, 27.66, 27.50, 54.00 μg/mL) followed by Cx. quinquefaciatus (LC₅₀ = 3.23, 24.99, 11.24, 10.95 μg/mL and the LC₉₀ = 8.37, 8.29, 21.36, 20.28 μg/mL). The biochemical level of A. tamarii mycelium extract on both larvae was measured and the results shown a dose dependent activity on the level of AchE, α- and β-carboxylesterase assay. Gas Chromatography and Mass Spectroscopy (GC-MS) profile of A. tamarii extract reflected three compounds i.e. preg-4-en-3-one, 17. α-hydroxy-17. β-cyano- (7.39%), trans-3-undecene-1,5-diyne (45.77%) and pentane, 1,1,1,5-tetrachloro- (32.16%) which which might had attributed to larvae mortality.

Conclusion: The findings of - present study shows that the use of endophytic A. tamarii fungal metabolites for control of dengue and filariasis vectors is promising and needs a semifield and small scale filed trials.

Keywords: Agriculture; Artemia salina; Danio rerio; Environmental science; GC-MS; PCR; Plant biology.