Green honey of Banggi Island: A preliminary anti-diabetic study on zebrafish model

Abstract

Zebrafish is a developing vertebrate model with several advantages, including its small size, and high experimental efficiency. Malaysia exhibit one of the highest diabetes rates in the Western Pacific and incurring an annual cost of 600 million US dollars. The objective of the study is to determine the antidiabetic properties of green honey (GH) using a zebrafish model. Adult zebrafish, aged 3-4 months, were subjected to overfeeding and treated with streptozotocin (STZ) through intraperitoneal injection (IP) on days 7 and 9. The study assessed the oral sucrose tolerance test (OSTT) and the anti-diabetic effects of green honey. The evaluation was conducted at three time points: 30, 60, and 120 min after treatment and sucrose administration. The study utilised a model with a sample size of 5. The study was performed in six groups. These groups are (1) Normal control (non-diabetic, no intervention), (2) Normal control + GH (non-diabetic, supplemented with GH 3 μl), (3) DM control (diabetic, no intervention), (4) DM Gp1 (diabetic, 3 μL GH), (5) DM Gp2 (diabetic, 6 μ L GH), (6) DM Acarbose (diabetic, treated with acarbose). Fasting blood glucose levels for non-diabetic (non-DM) and diabetic (DM) groups were evaluated before and after the 10 days of diabetic induction. DM groups (excess of food and two injections of STZ) have caused a significant increment in the fasting blood glucose to 11.55 mmol/l (p < 0.0001). Both GH treatments effectively decreased postprandial blood glucose levels and the area under the curve in the oral glucose tolerance test (OSTT). Based on these results, it is concluded that green honey could play a role in hyperglycemia management and show potential as a natural alternative to conventional diabetes therapy. The underlying mechanisms need to be clarified, and their potential use in human diabetes therapy needs to be investigated.

Keywords: Acarbose; Antidiabetic; Green honey; STZ; Zebrafish.

Fig. 1

Raw green honey collected from Banggi Island, Sabah. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)

Fig. 2

The timeline of the diabetic induction using two doses of STZ on days 7 and 9 with excess feeding regime.

Fig. 3

Force feeding (Oral administration) of GH, acarbose and sucrose.

Fig. 4

The changes of body weight between the Non-DM and DM, groups at pre- and post-induction of diabetes using excess diet and STZ.

Fig. 5

The differences of the fasting blood glucose level between the non-DM and DM groups during pre- and post-induction of diabetes. (n = 24, paired t-test).

Fig. 6

The effect of GH treatment and acarbose on Oral Sucrose Tolerance Test (OSTT) treatment was orally administered to zebrafish for 30 min before sucrose loading. The postprandial blood glucose level was observed for 2.5 h, are presented as mean ± SEM, with a sample size of n = 15. A nonparametric t-test was employed to assess significant differences between various groups at distinct time intervals. Significance levels were denoted as follows: ****p < 0.0001, indicating variations in means when compared to the control group of healthy, non-diabetic zebrafish.

Fig. 7

Area under the curve (AUC) of the zebrafish blood glucose level after oral sucrose administration. Data are expressed as mean ± SEM. One-way analysis of variance (ANOVA) was used to carry out the significant differences with a t-test using Dunnett's Multiple Comparison. The significant difference was considered at ***p < 0.001 between the means of groups compared to the control normal healthy group.