Assessment of The Effect of Thymbra capitata Ethanolic Extract on Galleria mellonella Hemolymph Antioxidant Enzymes

Abstract

Conehead thyme (Thymbra capitata) is widely distributed in the countries of the Mediterranean region and used due to its medical properties. The antibacterial, antifungal, and strong antioxidant properties of T. capitata are known. The model organism Galleria mellonella is mostly preferred for immunological studies and for the study of human pathogens. The aim of the study was to determine the effect of the ethanolic extract of T. capitata on the antioxidant defense of the hemolymph in G. mellonella larva. Solutions prepared with Phosphate-Buffered Saline (PBS) from the dry matter obtained from ethanolic extract at doses between 2 mg mL-1 and 20 mg mL-1 were injected into G. mellonella larvae. According to our findings, T. capitata extract had no effect on malondialdehyde (MDA) levels. However, it was determined that all doses between 10 to 20 mg mL-1 significantly reduced superoxide dismutase (SOD) and catalase (CAT) activities compared to the control groups. According to the results of our study, high doses of T. capitata extract had negative effects on G. mellonella antioxidant defense.

Immunosuppressive effect of Plantago major on the innate immunity of Galleria mellonella

“…These studies indicate that plant growth regulators and secondary metabolites reduce antioxidant enzyme activity at high doses. According to a study with Tymbra capitata extract, the extract reduced SOD and CAT activity in G. mellonella hemolymph ( Kaya, 2022 ). The results of our study showed that the P. major extract did not cause a significant change in the CAT activity and MDA amount at high doses compared to the control groups.…”

“…In our study, the method of Kaya (2022) was used. All test readings were made in the microplate reader at the appropriate wavelengths and on the microplates.…”

“…Many studies have examined the effects of various natural or chemical substances on the antioxidant enzymes of the model organism G. mellonella ( Dubovskiy, Krukova & Glupov, 2008 ; Büyükgüzel & Kayaoğlu, 2014 ; Dere, Altuntaş & Nurullahoğlu, 2015 ; Kaya, 2022 ). With these studies, the effects of the agent used on G. mellonella oxidative stress were determined, and its physiological effects in this living organism were revealed.…”

The influence of olive leaf extract on the activity of antioxidant enzymes in the Hemolymph of Galleria mellonella (L.) (Lepidoptera: Pyralidae)

“…Experiments were carried out according to the methods specified in [37]. According to this, the [41] method for determination of total protein, [42] for determining of SOD activity, [43] for CAT activity and [44] methods for MDA levels were adapted and used.…”

“…Furthermore, G. mellonella has the ability to endure a range of temperatures (25-37 °C) that are conducive to conducting infection studies, and this characteristic enables researchers to carry out experiments that closely resemble those conducted in mammalian systems [31]. There are many studies on G. mellonella hemolymph antioxidant enzymes and these studies show that G. mellonella hemolymph antioxidant enzymes are affected by plant extracts and other different substances [32][33][34][35][36][37]. Based on the results of studies investigating the effects of olive leaf extract on G. mellonella cell-mediated immunity [38] and phenoloxidase (PO) activity [39], it was observed that the administration of olive leaf extract at low doses led to a notable increase in cellular immune responses.…”