Ameliorative activity of medicinal plant fraction for neuroprotection against acrylamide-induced neurotoxicity in Drosophila melanogaster—a comparative study

Background Medicinal plant extracts used in folk medicine seem to be crucial since those are generally accepted by people without worrying about the toxicity. In our present study, we have compared the neuroprotective role of the rhizome of Curculigo orchioides Gaertn. and leaf extracts of Olea dioica Roxb., against acrylamide-induced neurotoxicity in Drosophila melanogaster. Results In-vivo neurotoxic study was carried out using 7-day-old flies (wild-type D. melanogaster). Prior to co-after exposing the flies with acrylamide (8 mM) along with or without OLE-2 and CU-3 fractions (0.2, 0.4 and 0.6% w/v), the heads of flies of both the control and treated groups were homogenized for biochemical assay. ACR-treated groups have shown higher elevation in AChE, SOD, LPO, and CAT activity when compared to control and treated (plant fraction) groups. Biochemical and histopathology studies show that both the plant fractions (OLE-2 and CU-3) have neuroprotective action against acrylamide. Conclusion The present study has demonstrated that dietary supplementation with plant fraction of OLE-2 and CU-3 has increased antioxidant enzymes and decreased AChE activity in D. melanogaster. This activity could be part of the probable mechanisms of action by which OLE-2 and CU-3 fractions have extended the lifespan and locomotory activity in fruit flies. These fruit flies continue to provide an exciting system for metabolic studies and should be more extensively exploited. Based on these results, further studies on the identified bioactive compounds from these two plants are being planned.

Role of Standardized Plant Extracts in Controlling Alcohol Withdrawal Syndrome—An Experimental Study

Patients with alcohol use disorder experience alcohol withdrawal syndrome due to the sudden cessation of alcohol. This study was designed to evaluate the protective effect of Ashwagandha and Brahmi on alcohol withdrawal in rats. Thirty rats of either sex were taken and randomly divided into 6 groups (n = 5). Their normal diet was replaced by a modified liquid diet (MLD). Ethanol was added gradually except in the MLD group for a period of 21 days and withdrawn suddenly. Four treatment groups were administered Ashwagandha (3.75 mg of withanolide glycosides per kg body weight), Brahmi (10 mg of bacosides per kg body weight), Ashwagandha + Brahmi (3.75 mg withanolide glycosides + 10 mg bacosides per kg body weight) orally and diazepam (1 mg/kg body weight, i.p.) 45 min before alcohol withdrawal. Rats were assessed for behavioural changes (agitation score and stereotypic behaviour), anxiety and locomotor activity at 2nd and 6th hours of alcohol withdrawal. Pentylenetetrazol (PTZ) kindling seizures were assessed at 6th hour of alcohol withdrawal. Ashwagandha and Brahmi alone and in combination significantly reduced the behavioural changes in alcohol withdrawal rats at 2nd hour and their combination in 6th hour. Ashwagandha and Brahmi suppressed PTZ kindling seizures effectively and improved locomotory activity at 2nd hour and 6th hour of alcohol withdrawal. Reduction in anxiety was significant among Ashwagandha at 2nd hour and the combination group at 2nd and 6th hour. The results were comparable to diazepam. Ashwagandha and Brahmi have beneficial effects in controlling the behavioural changes, anxiety and seizures in alcohol withdrawal symptoms in rats and improved locomotory activity.

Monoterpenes alter TAR1-driven physiology in Drosophila species

ABSTRACTMonoterpenes are molecules with insecticide properties whose mechanism of action is, however, not completely elucidated. Furthermore, they seem to be able to modulate the monoaminergic system and several behavioural aspects in insects. In particular, tyramine (TA) and octopamine (OA) and their associated receptors orchestrate physiological processes such as feeding, locomotion and metabolism. Here, we show that monoterpenes not only act as biopesticides in Drosophila species but also can cause complex behavioural alterations that require functional type 1 tyramine receptors (TAR1s). Variations in metabolic traits as well as locomotory activity were evaluated in both Drosophila suzukii and Drosophila melanogaster after treatment with three monoterpenes. A TAR1-defective D. melanogaster strain (TAR1PL00408) was used to better understand the relationships between the receptor and monoterpene-related behavioural changes. Immunohistochemistry analysis revealed that, in the D. melanogaster brain, TAR1 appeared to be mainly expressed in the pars intercerebralis, lateral horn, olfactory and optic lobes and suboesophageal ganglion lobes. In comparison to wild-type D. melanogaster, the TAR1PL00408 flies showed a phenotype characterized by higher triglyceride levels and food intake as well as lower locomotory activity. The monoterpenes, tested at sublethal concentrations, were able to induce a downregulation of the TAR1 coding gene in both Drosophila species. Furthermore, monoterpenes also altered the behaviour in wild-type D. suzukii and D. melanogaster 24 h after continuous monoterpene exposure. Interestingly, they were ineffective in modifying the physiological performance of TAR1-defective flies. In conclusion, it appears that monoterpenes not only act as biopesticides for Drosophila but also can interfere with Drosophila behaviour and metabolism in a TAR1-dependent fashion.

High-resolution analysis of baculovirus-induced host manipulation in the domestic silkworm, Bombyx mori

Many parasites manipulate host behaviour to enhance their transmission. Baculoviruses induce enhanced locomotory activity (ELA) combined with subsequent climbing behaviour in lepidopteran larvae, which facilitates viral dispersal. However, the mechanisms underlying host manipulation system are largely unknown. Previously, larval locomotion during ELA was summarized as the distance travelled for a few minutes at several time points, which are unlikely to characterize ELA precisely, as ELA typically persists for several hours. In this study, we modified a recently developed method using time-lapse recording to characterize locomotion of Bombyx mori larvae infected with B. mori nucleopolyhedrovirus (BmNPV) for 24 h at 3 s resolution. Our data showed that the locomotion of the mock-infected larvae was restricted to a small area, whereas the BmNPV-infected larvae exhibited a large locomotory area. These results indicate that BmNPV dysregulates the locomotory pattern of host larvae. Furthermore, both the mock- and BmNPV-infected larvae showed periodic cycles of movement and stationary behaviour with a similar frequency, suggesting the physiological mechanisms that induce locomotion are unaffected by BmNPV infection. In contrast, the BmNPV-infected larvae exhibited fast and long-lasting locomotion compared with mock-infected larvae, which indicates that locomotory speed and duration are manipulated by BmNPV.

Monoterpenes alter TAR1-driven physiology in Drosophila species

Monoterpenes are molecules with insecticide properties whose mechanism of action is however not completely elucidated. Furthermore, they seem to be able to modulate the monoaminergic system and several behavioural aspects in insects. In particular, tyramine (TA) and octopamine (OA) and their associated receptors orchestrate physiological processes such as feeding, locomotion and metabolism. Here we show that monoterpenes not only act as biopesticides in Drosophila species but can cause complex behavioural alterations that require a functional type 1 tyramine receptors (TAR1s). Variations in metabolic traits as well as locomotory activity were evaluated in both Drosophila suzukii and Drosophila melanogaster after treatment with three monoterpenes. A TAR1−/−D. melanogaster strain was used to better understand the relationships between the receptor and monoterpenes-related behavioural changes. Immunohistochemistry analysis revealed that, in the D. melanogaster brain, TAR1 appeared to be expressed in areas controlling metabolism. In comparison to the D. melanogaster wild type, the TAR−/− flies showed a phenotype characterized by higher triglyceride levels and food intake as well as lower locomotory activity. The monoterpenes, tested at sublethal concentrations, were able to induce a downregulation of the TAR1 coding gene in both Drosophila species. Furthermore, monoterpenes also altered the behaviour in D. suzukii and D. melanogaster wild types 24 h after a continuous monoterpene exposure. Interestingly, they were ineffective in modifying the physiological performances of TAR1−/− flies. In conclusion, it appears that monoterpenes not only act as biopesticides for Drosophila but they can also interfere with its behaviour and metabolism in a TAR1-dependent fashion.

Reprogramming of larval locomotory pattern during baculovirus-induced host manipulation

Many parasites manipulate host behaviour to enhance their transmission. Baculovirus induces enhanced locomotory activity (ELA) combined with subsequent climbing behaviour in lepidopteran larvae, which facilitates viral dispersal. Previously, larval locomotion during ELA was summarized as the distance travelled for a few minutes at several time points. However, as ELA continues for several hours, these methods are unlikely to evaluate larval locomotion precisely during ELA. We developed a novel method to continuously trace the locomotion of Bombyx mori larvae using time-lapse imaging. This method successfully quantified the locomotory activities of larvae infected with Bombyx mori nucleopolyhedrovirus (BmNPV) for 24 h. We found that both mock- and BmNPV-infected larvae periodically repeated moving and pausing with a similar frequency. In contrast, BmNPV-infected larvae showed fast and long-lasting locomotion compared with mock-infected larvae, which resulted in longer locomotory distances in infected larvae. Moreover, BmNPV-infected larvae exhibited biphasic behaviour. Initially, BmNPV-infected larvae showed longer locomotory distances, but the locomotory pattern was similar to mock-infected larvae. However, during the second phase, the locomotory pattern was drastically altered, with an extremely larger locomotory area. These results indicate that BmNPV reprograms host locomotory pattern, which is a turning point for the process of BmNPV-induced host manipulation.