Application of cyclic peptide COX52-69 in weight reduction

Abstract

One patent obtained in the earlier stage is that the line peptide COX52-69 is cyclized to realize an oral administration route. The invention discovers that the cyclic peptide, namely C * LLPAGWV-[N-Me-Leu]-SHLDSYKKREC *, has the effect of reducing the body weight. In the invention, a diet-induced obesity (DIO) model is established by feeding C57BL / 6J mice with high-fat feed (45% of fat for energy supply) for 14 weeks. After a DIO mouse is obtained, a 17-week administration experiment is carried out by using a PBS buffer solution and a Rybelsus solution as a contrast, and observation finds that the COX52-69 cyclic peptide can relieve weight gain caused by DIO, so that the weight of the DIO mouse is reduced, and multiple metabolic indexes can be improved. Results show that the COX52-69 cyclic peptide has practical application in weight loss and weight gain prevention processes, and also has reagent application in improvement of some metabolic indexes of obese people.

Description

Technical Field

[0001] This invention belongs to the field of biomedicine, specifically relating to the application of a polypeptide in weight loss and prevention of weight gain. Background Technology

[0002] The short peptide COX52-69 is an 18-amino acid polypeptide initially isolated and purified from the small intestine of pigs. Amino acid sequence alignment revealed that it completely overlaps with amino acid sequences 52 to 69 of cytochrome oxidase VIII, hence its name COX52-69. Its sequence is LLPAGWVLSHLDSYKKRE. Functional experiments using the isolated COX52-69 polypeptide showed that it can inhibit insulin secretion from glucose-dependent glucose pathways. This finding was granted a Chinese invention patent in 2018, patent number CN201310471571.9. Subsequently, the biologically active short peptide COX52-69 was obtained through solid-phase synthesis. However, it can only exert its therapeutic effect through injection and cannot be administered orally. To this end, we modified the peptide to achieve oral administration, and obtained Chinese invention patent authorization in May 2022, patent number CN202110380196.1. The amino acid sequence of the modified peptide is: C*LLPAGWV-[N-Me-Leu]-SHLDSYKKREC*. Recently, we found that this cyclic peptide has a weight-loss effect by comparing it with commercially available weight-loss peptides as a positive control. With the improvement of living standards and the increase in social pressure, the obese population is increasing. Currently, the most recognized weight-loss peptides on the market are glucagon-like peptide-1 (GLP-1) receptor agonists, but they have problems such as many adverse reactions, large individual differences in effectiveness, and potential induction of thyroid C-cell tumors; therefore, it is necessary to develop new drugs. The peptide of this invention is a peptide that is completely different from GLP-1 receptor agonists. Summary of the Invention

[0003] This invention relates to the application of our patented cyclic peptide COX52-69 in weight loss. We utilized a high-fat diet-induced obese mouse model (DIO model), a commonly used and recognized model for simulating human obesity and related metabolic syndrome. Using Rybelsus (semagraftide), another existing oral peptide weight-loss drug, as a positive control, we evaluated the weight-loss effect of COX52-69 cyclic peptide through tests of weight change, glucose tolerance, and insulin tolerance. The results showed that COX52-69 cyclic peptide significantly reduced the weight of obese mice, decreasing it by approximately 15% compared to the model group (p<0.0001), an effect comparable to Rybelsus. Furthermore, COX52-69 cyclic peptide improved glucose tolerance and insulin tolerance in mice, demonstrating a clear effect on improving metabolism, indicating its potential to regulate glucose metabolism and improve insulin sensitivity. Attached Figure Description

[0004] Figure 1 : Grouping and treatment of mice during the modeling and treatment phases. Colored squares in the figure represent mouse groups. ND: normal diet; HFD: high-fat diet; PBS: PBS buffer solution administered via gavage; Ryb: Rybelsus solution administered via gavage; COX: COX52-69 solution administered via gavage. The blue lines at the top indicate important time points, and the black lines at the bottom represent time durations. Six-week-old male C57BL / 6J mice were randomly divided into ND and HFD groups one week after the start of the experiment for DIO modeling. After a 14-week modeling phase, mice in the ND and HFD groups were randomly divided into three groups, receiving different drug treatments daily. After 17 weeks of continuous drug administration, the mice were sacrificed and tissues and organs were harvested.

[0005] Figure 2 : Mouse body weight during DIO. After one week of acclimatization, C57BL / 6J mice were divided into two groups: ND (normal diet) and HFD (high-fat diet with 45% fat as the energy source). It was clearly observed that the HFD group gained weight faster than the ND group, and the difference in body weight between the two groups was significant after 14 weeks of modeling (****). P (< 0.0001), the average body weight of mice in the HFD group was about 22% higher than that in the ND group.

[0006] Figure 3Changes in mouse body weight during the treatment phase. At the beginning of the treatment phase, there were no significant differences between the Model, Rybelsus, and COX groups; the body weights of the three groups were comparable and significantly higher than those of the Control group, which was fed a normal diet. As the treatment phase progressed, despite continued high-fat feeding, the body weights of mice in the Rybelsus and COX groups gradually decreased relative to the Model group. At week 11, the Rybelsus group first showed a difference in body weight from the Model group. By the end of the treatment phase, the body weights of mice in both the Rybelsus and COX groups showed a highly significant difference from the Model group. P < 0.0001). Throughout the treatment phase, there was no significant difference in body weight between the Rybelsus and COX groups. At the end of the treatment phase, the average body weight of the Rybelsus and COX groups decreased by approximately 20% and 15% compared to the Model group, respectively. Note: (* indicates comparison between the COX group and the Model group, *...) P < 0.05, **P < 0.01, *** P < 0.001, **** P < 0.0001, & indicates a comparison between the Rybelsus group and the Model group, & P < 0.05, &&& P < 0.001, &&&& P < 0.0001, data are expressed as mean ± SEM).

[0007] Figure 4 Oral glucose tolerance test for mice in each group. The left figure shows the change in blood glucose levels in mice within 120 minutes after gavage administration of 2 g / kg glucose. The higher the curve, the lower the glucose tolerance, indicating that the body's ability to metabolize glucose has been impaired. The Model group, which was fed a high-fat diet, had the highest curve, followed by the Rybelsus group, COX group, and Control group. The right figure shows the area under the curve (AUG) of the blood glucose changes in each group of mice, used to compare the glucose tolerance of each group of mice. Within 120 minutes, the AUG of the Model mice was 41.67% higher than that of the normal mice in the Control group, while the AUG of the Rybelsus group was different from that of the Model group (*). P < 0.05 indicates that glucose tolerance was significantly improved in the Rybelsus group mice. Note: (* indicates comparison with the Model group, *) P < 0.05).

[0008] Figure 5COX52-69 cyclic peptide improves glucose and insulin tolerance in DIO mice. Figure a shows the blood glucose changes in each group of mice within 120 min after insulin injection at 0.75 U / kg. The higher the curve, the worse the body's ability to respond to insulin. Figure b shows the area under the curve (AUC) of blood glucose changes in each group of mice in the IPITT experiment. Statistical analysis showed that the AUC of both treatment groups differed significantly from the Model group (Rybelsus group). P < 0.05, COX group P < 0.001), indicating that both drugs improved insulin sensitivity in DIO mice. Note: (* indicates comparison with the Model group, *) P < 0.05, *** P < 0.001).

Claims

1. The use of a cyclic peptide COX52-69 in the preparation of a medicament for the prevention and / or treatment of obesity.

2. The application according to claim 1, characterized in that... The application of the cyclic peptide COX52-69 in improving glucose and insulin tolerance in obese individuals.

3. The application according to claims 1 and 2, characterized in that... The use of the cyclic peptide COX52-69 in improving some metabolic indicators in obese individuals after improvement in glucose and insulin tolerance.

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