Asiatic acid increased locomotor and head width by inducing brain-derived neurotrophic factor in intrauterine hypoxia-exposed zebrafish

Abstract

Background: Hypoxia ischemia leads to abnormal behavior and growth. Prenatal hypoxia also decreases brain adaptive potential, which can cause fatal effects such as cell death. Asiatic acid (AA) in Centella asiatica is a neuroprotector through antioxidant and anti-inflammatory activities.

Aim: This study aimed to analyze the effect of AA as a neuroprotector against hypoxia during intrauterine development on locomotor activity, head width, and brain-derived neurotrophic factor (BDNF) expression.

Methods: The true experimental laboratory research used a posttest control-only design. Zebrafish embryos (Danio rerio) aged 0-2 dpf (days postfertilization) were exposed to hypoxia with oxygen levels reaching 1.5 mg/l. Then, AA was administered at successive concentrations, namely, 0.36, 0.72, and 1.45 μg/ml, at 2 hpf (hours postfertilization), 3, 6, and 9 dpf. Head width, velocity activity, and BDNF expression were observed.

Results: Intrauterine hypoxia significantly decreased head width, velocity rate, and BDNF expression (<0.001). Administration of AA at all concentrations and age 9 dpf to zebrafish larvae with intrauterine hypoxia exposure increased head width ( p < 0.0001), velocity (p < 0.05), and relative mRNA expression of BDNF (p < 0.05).

Conclusion: AA is potentially neuroprotective to the brain in zebrafish larvae exposed to hypoxia during intrauterine development.

Keywords: Asiatic acid; BDNF; Growth; Hypoxia; Neuron.

Fig. 1.. A). Photomicrograph of head width of zebrafish larvae at 9 dpf in all groups with a 40× objective magnificent. Measurements are taken on the head from the tip of the right eye to the left. B). The size of the head width of zebrafish larvae after exposure to hypoxia to different concentrations of AA. Acetic acid at various concentrations increased the growth of AA administration at concentrations of 0.36, 0.72, and 1.45 μg/ml. It increased the head width of zebrafish larvae exposed to hypoxia compared to the control. The data are presented as the mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001 were considered significant, highly significant and extremely significant differences, respectively. The concentration of 1.45 µg/ml AA significantly increased the head width of zebrafish larvae at 9 dpf compared with normal.

Fig. 2.. Velocity rate at 3, 6, and 9 dpf zebrafish larvae exposed hypoxia in all groups. The data are presented as the mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001 were significant, highly significant, and extremely significant differences, respectively. The control group showed a significantly higher velocity rate than the hypoxia group at 6 and 9 dpf. Observations at 9 dpf showed that a 1.45 µg/ml concentration of AA could increase the velocity rate compared with the control group.

Fig. 3.. The relative mRNA expression of BDNF among the treatment groups showed no significant difference. AA at a 1.45 µg/ml concentration resulted in the highest BDNF expression. Data are presented as the mean ± SEM. The control group showed higher BDNF expression than the hypoxic control group. The higher the concentration of AA given, the higher the expression of BDNF in zebrafish exposed to hypoxia. AA administration at a 1.45 g/ml concentration in zebrafish exposed to hypoxia resulted in high BDNF expression compared with the other groups.