Toxicological effects of chemical constituents from Piper against the environmental burden Aedes aegypti Liston and their impact on non-target toxicity evaluation against biomonitoring aquatic insects

Abstract

Dengue is the most rapidly spreading mosquito-borne viral disease in the world. The mosquito, Aedes aegypti, also spreads Yellow fever, Chikungunya, and Zika virus. As the primary vector for dengue, Ae. aegypti now occurs in over 20 countries and is a serious concern with reports of increasing insecticide resistance. Developing new treatments to manage mosquitoes are needed. Formulation of crude volatile oil from Piper betle leaves (Pb-CVO) was evaluated as a potential treatment which showed larvicidal, ovipositional, and repellency effects. Gut-histology and enzyme profiles were analyzed post treatment under in-vitro conditions. The Pb-CVO from leaves of field collected plants was obtained by steam distillation and separated through rotary evaporation. The Pb-CVO were evaluated for chemical constituents through GC-MS analyses revealed 20 vital compounds. The peak area was establish to be superior in Eudesm-7(11)-en-4-ol (14.95%). Pb-CVO were determined and tested as four different concentrations (0.25, 0.5, 1.0, and 1.5 mg/L) of Pb-CVO towards Ae. aegypti. The larvicidal effects exhibited dose dependent mortality being greatest at 1.5 mg Pb-CVO/10 g leaves. The LC occurred at 0.63 mg Pb-CVO/L. Larva of Ae. aegypti exposed to Pb-CVO showed significantly reduced digestive enzyme actions of α- and β-carboxylesterases. In contrast, GST and CYP450 enzyme levels increased significantly as concentration increased. Correspondingly, oviposition deterrence index and egg hatch of Ae. aegypti exposed to sub-lethal doses of Pb-CVO demonstrated a strong effect suitable for population suppression. Repellency at 0.6 mg Pb-CVO applied as oil had a protection time of 15-210 min. Mid-gut histological of Ae. aegypti larvae showed severe damage when treated with 0.6 mg of Pb-CVO treatment compared to the control. Non-toxic effects against aquatic beneficial insects, such as Anisops bouvieri and Toxorhynchites splendens, were observed at the highest concentrations, exposed for 3 h. These results suggest that the Pb-CVO may contain effective constituents suitable for development of new vector control agents against Ae. aegypti.

Larvicidal Enzyme Inhibition and Repellent Activity of Red Mangrove Rhizophora mucronata (Lam.) Leaf Extracts and Their Biomolecules against Three Medically Challenging Arthropod Vectors

“…The plants tested in the present study are reported to be eco-friendly and toxic to agriculturally important insect pest [ 20 ]. For example, essential oils from Citronella and Eucalyptus are often used in repellents sold under several brand names [ 21 ]. Recent studies have indicated that phytol, a precursor of synthetic vitamin E and vitamin K (which was identified in our analysis as well), exhibits antioxidant and antinociceptive effects and was cytotoxic against the MCF−7 breast cancer cell line [ 22 ].…”

A Review of Resistance Mechanisms of Synthetic Insecticides and Botanicals, Phytochemicals, and Essential Oils as Alternative Larvicidal Agents Against Mosquitoes

“…aegypti at the minimal dosage of 10 ppm (Lija-Escaline et al, 2015). Similarly, Vasantha-Srinivasan et al (2018) reported that P. betle CVO derived from P. betle at the sub-lethal dosage damage the pM, and major alteration in the alignment of EL and GL of dengue mosquito comparable to the control. Previous research on Andrographolide a major derivative of A. paniculata against dengue mosquito gut cells proved that there was an unembellished collapse in the mid-gut pM, in addition to a chief variation in the El and GL alignment (Edwin et al, 2016).…”

“…Plant volatile oils were also conveyed with mosquitocidal potentials. As studied by Vasantha-Srinivasan et al (2018), the crude volatile oil (CVO) from Piper beetle leaves possessed significant larvicidal, ovipositional, and repellency effects against Ae. Aegypti.…”

“…Previous photomicrographic study on the midgut tissues of the dengue mosquito (Field and laboratory strains of Ae. aegypti) treated with the CVO of P. betle displayed severe injuries to the GL and EL (Vasantha-Srinivasan et al, 2018). Correspondingly, leaf extracts of Aristolochia indica L. (Aristolochiaceae) and their derivatives aristolochic acid I and II showed severe damage on the midgut vacuolated gut epithelial columnar cells (epi), GL, and pM (Pradeepa et al, 2015).…”

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

“…Likewise, Vasantha-Srinivasan et al. reported the level of α- and β-carboxylesterase was significantly altered by the activity of metabolites [ 92 ].…”