Therapeutic evaluation of Martynia annua derived carbon dots in epileptic Drosophila model

Abstract

This study investigates the synthesis and characterization of Carbon dots (MA-CDs) derived from the aqueous extract of Martynia annua and examining their potential effects in an epilepsy model Drosophila melanogaster. Phytochemical analysis confirmed the presence of saponin, terpeniods, and flavanoids in the leaf extract, which facilitated the green synthesis of MA-CDs. Physicochemical characterization revealed an absorbance peak at 326 nm, the mean size of the particle was 3.17 ± 0.16 nm, and moderate stability (-1.6 mV). To assess the therapeutic potential of MA-CDs alongside the antiepileptic drug Carbamazepine (CBZ), we conducted behavioral and cognitive assays in para bang senseless (para^bss1) mutants of Drosophila, a model organism for epilepsy. Seizures induced by vortex and heat shock were significantly mitigated in a dose-dependent manner in flies treated with both MA-CDs and CBZ. However, higher doses of CBZ and MA-CDs increased the climbing ability of the flies. In cognitive assays, CBZ at higher doses improved memory and learning in mutant flies, while MA-CDs also showed significant impact. MA-CDs were consumed at a higher rate than CBZ when incorporated into food. The green synthesized MA-CDs at its higher concentration has garnered its positive effect on the mutants along with the CBZ antiepileptic drug which also has shown its positive effects when different concentration of them were treated to the mutants.

Keywords: Martynia annua; Carbamazepine; Carbon dots; Epilepsy; Para bang senseless.

Scheme 1

Seizure induction methods in para^bss1 mutants (A) Represents the induction of seizures using vortex assay. The flies were vortexed for 10 s at maximum speed and the time required to recover was calculated. (B) Represents the induction of seizures using heat shock assay. The flies were kept in water bath at 45 °C for 60 s at maximum speed and the time required to recover was calculated.

Fig. 1

Calibration curve of the standard tannic acid.

Fig. 2

Calibration curve of the standard quercetin.

Scheme 2

Schematic illustration of the possible mechanism involved in the synthesis of MA-CDs using M. annua as a carbon source.

Fig. 3

UV–Visible spectroscopic studies on the optical characteristics of MA-CDs.

Fig. 4

HR-TEM image showing the morphology of MA-CDs synthesized from the leaf extract of M. annua (a, b), (c) The histogram illustrates the particle size distribution of MA-CDs.

Fig. 5

FTIR graph of MA-CDs fabricated from the leaf extract of M. annua.

Fig. 6

Zeta potential image of MA-CDs derived from the leaf extract of M. annua.

Fig. 7

XRD spectrum of MA-CDs synthesized using the leaf extract of M.annua.

Fig. 8

EDX spectrum of MA-CDs synthesized using the leaf extract of M.annua.

Fig. 9

Adult vortex shock assay of para^bss1 mutants treated with different concentrations of CBZ and MA-CDs. The bars represent the mean ± SD (****p < 0.0001, indicating a highly significant difference when compared with control and at similar concentrations).

Fig. 10

Adult heat shock assay of para^bss1 mutants treated with different concentration of CBZ and MA-CDs. The bars represent the mean ± SD (****p < 0.0001 indicating a highly significant difference when compared with control and at similar concentrations).

Fig. 11

Climbing assay of par^bss1 mutants treated with CBZ and MA-CDs. The bars represent the mean ± SD (****p < 0.0001, *p < 0.05, ^nsp > 0.05, indicating a highly significant difference when compared with control).

Fig. 12

Food intake assay of para^bss1 mutants treated with CBZ and MA-CDs. The bars represent the mean ± SD (****p < 0.0001, indicating a highly significant difference when compared at similar concentrations).

Fig. 13

Gut quantification of para^bss1 flies treated with different concentration of MA-CDs and CBZ The bars represent the mean ± SD (****p < 0.0001, ^nsp > 0.05).

Fig. 14

DNA fragmentation assay carried out using different concentrations of CDs to check the cytotoxicity. M, + , and—denotes ladder (100 bp), positive control and negative control respectively, while 2.5, 5, 10 and 15 refers to those treated with 2.5, 5, 10 and 15 µg/mL MA-CDs respectively.

Scheme 3

Mechanism of action of CBZ.