Application of pyrrolquinoline quinone in relieving bluegill fish cyanotoxin poisoning

Abstract

The application discloses application of pyrroloquinoline quinone (PQQ) or a derivative thereof in preparation of a product for relieving or preventing blue-green algae toxin poisoning of yellow catfish, and belongs to the technical field of aquatic animal feed. The PQQ or the derivative thereof can be used as an aquatic feed additive or a medicine, and is added in an amount of 3-6 mg / kg of feed to feed yellow catfish, so as to effectively relieve pathological damage of the liver of the yellow catfish caused by blue-green algae toxin through various ways such as improving key enzyme activity of liver function, inhibiting liver oxidative stress, relieving inflammatory reaction and reducing structural damage of tissues. The PQQ is a new food raw material approved in China in 2022, has advantages of high safety, good water solubility, moderate cost, similar dosage to that of feed vitamins and the like, and provides a safe, economical and convenient new nutritional intervention strategy for blue-green algae toxin poisoning of the yellow catfish, and has a wide industrial application prospect.

Description

Technical Field

[0001] This invention belongs to the field of aquatic animal feed technology, specifically relating to the application of pyrroloquinoline quinone in alleviating cyanobacterial toxin poisoning in yellow catfish. Background Technology

[0002] Cyanobacterial toxins are toxic substances produced by the proliferation of cyanobacteria in eutrophic waters, with microcystins being the most common. These toxins pose a serious threat to organisms, causing liver damage, immunosuppression, and growth disorders in humans and livestock. For farmed fish such as yellow catfish, the harm caused by cyanobacterial toxins is even more direct and severe. Fish are continuously exposed to toxins in the water, leading to their accumulation in their bodies (especially in the liver), causing liver tissue damage and dysfunction. Simultaneously, the toxins induce severe oxidative stress, depleting the fish's antioxidant defense system, causing widespread damage to cell structure, suppressing immune function, and increasing the risk of secondary infections. This not only harms the health of fish but also leads to decreased growth performance, reproductive disorders, and food safety risks.

[0003] Pyrroloquinoline quinone (PQQ) is a naturally occurring redox coenzyme with a unique quinone ring structure, which endows it with excellent antioxidant properties. At the molecular level, PQQ not only acts as a highly efficient antioxidant by directly scavenging free radicals, but also systematically upregulates the synthesis of endogenous antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase by activating key signaling pathways such as Nrf2 / Keap1. Furthermore, PQQ is an important activator of mitochondrial biogenesis, capable of activating PGC-1... This pathway promotes mitochondrial regeneration and functional optimization, thereby fundamentally improving cellular energy metabolism homeostasis, which is crucial for repairing toxin-damaged hepatocytes. Studies have also shown that PQQ possesses good anti-inflammatory properties and can regulate NF-κB levels. It participates in inflammation-related pathways such as B, reduces tissue inflammation, and has unique functions such as promoting nerve growth factor synthesis. In mammalian models, PQQ has demonstrated clear protective effects against chemically induced liver injury, immune enhancement, and growth promotion. The United States, Japan, Canada, and other countries have listed PQQ as a highly safe natural dietary supplement, and my country officially listed it as a new food ingredient in 2022. Therefore, PQQ holds promise as a highly efficient, safe, and green novel functional feed additive for use in aquaculture.

[0004] However, current research on PQQ in aquaculture is relatively limited. Some studies have shown that adding appropriate levels of PQQ to feed can enhance the immune function of yellow catfish, but no research has been reported on the application of PQQ in aquatic animals to combat environmental toxins such as cyanobacterial toxins. Based on the multi-target bioactivity of PQQ, this invention proposes for the first time its use in alleviating cyanobacterial toxin poisoning in yellow catfish. The scientific principle is that PQQ can directly combat toxin-induced oxidative damage through its strong antioxidant effect and reduce inflammatory responses through immune regulation. This provides a novel and safe nutritional intervention strategy for yellow catfish farming, which is of great value in ensuring aquaculture efficiency and food safety. Summary of the Invention

[0005] This invention aims to alleviate and prevent liver damage caused by cyanobacterial toxin poisoning in yellow catfish.

[0006] To achieve the above-mentioned technical objectives and effects, the present invention provides the following technical solution:

[0007] Application of pyrroloquinoline quinone or its derivatives in the preparation of products for alleviating or preventing cyanobacterial poisoning in yellow catfish.

[0008] Furthermore, the derivative is disodium pyrroloquinoline quinone.

[0009] Furthermore, the product is an aquatic feed additive or an aquatic medicine.

[0010] Furthermore, the feed additive is used to prepare yellow catfish feed, wherein the amount of pyrroloquinoline quinone or its derivative added to the yellow catfish feed is 3-6 mg / kg feed.

[0011] Furthermore, the relief or prevention of cyanobacterial toxin poisoning in yellow catfish specifically refers to the relief or prevention of pathological damage to the liver tissue of yellow catfish caused by cyanobacterial toxin poisoning.

[0012] Furthermore, the pyrroloquinoline quinone or its derivatives alleviate cyanobacterial toxin poisoning through one or more of the following pathways: improving the activity of key enzymes in the liver function of yellow catfish, inhibiting liver oxidative stress, alleviating liver inflammatory response, and reducing structural damage to liver tissue.

[0013] Furthermore, the key liver function enzyme is alanine aminotransferase (ALT), and the pyrroloquinoline quinone or its derivatives can reduce the increase in serum ALT activity induced by cyanobacterial toxins in yellow catfish.

[0014] Furthermore, the inhibition of liver oxidative stress involves increasing the total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity in the liver of yellow catfish, and reducing the malondialdehyde (MDA) content.

[0015] Furthermore, the relief of liver inflammation is achieved by reducing the gene expression levels of pro-inflammatory factors IL-1β, IL-8, and TNF-α in the liver of yellow catfish.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] This invention uses PQQ as the main component of a drug or feed additive, adding it to the feed at a rate of 3-6 mg / kg and feeding it to yellow catfish. This reduces liver damage caused by algal toxins through multiple pathways, such as improving the activity of key liver enzymes and inhibiting oxidative stress and inflammatory responses.

[0018] PQQ was listed as a new food ingredient in my country in 2022. In addition to being recognized for its safety in my country, PQQ is also listed as a highly safe natural dietary supplement in the United States, Japan, Canada and other countries. According to calculations, the cost of PQQ in this invention is close to that of multiple vitamins in feed. Moreover, PQQ is easily soluble in water and can be directly added to feed or dissolved in drinking water for feeding.

[0019] Therefore, this invention provides a novel and safe nutritional intervention strategy for cyanobacterial toxin poisoning in yellow catfish, and has broad prospects for industrial application. Attached Figure Description

[0020] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This invention illustrates the effect of PQQ on the expression of inflammatory factor genes in the liver of yellow catfish.

[0022] Figure 2 This invention illustrates the effect of PQQ on the morphological structure of yellow catfish liver tissue in an embodiment of the invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] This invention has discovered a new use for PQQ, specifically in addressing liver damage in yellow catfish caused by algal toxin poisoning. PQQ can be added to the feed of yellow catfish at a dosage of 3–6 mg / kg as a main component of pharmaceuticals or feed additives, thereby alleviating liver damage caused by algal toxins through multiple pathways, including improving the activity of key liver enzymes and inhibiting oxidative stress and inflammatory responses.

[0025] The invention will now be further described with reference to the accompanying drawings.

[0026] In this embodiment, 480 healthy, undamaged yellow catfish of similar size and initial weight (approximately 12 grams) were selected and randomly assigned to four groups: control group (no addition of algal toxin and PQQ), algal toxin group (addition of 30 mg / kg algal toxin), detoxification group A (30 mg / kg algal toxin + 3 mg / kg PQQ) and detoxification group B (30 mg / kg algal toxin + 6 mg / kg PQQ). Each group had three replicates, with 40 fish per replicate. Each group was fed the corresponding feed. Commercial feed was used. The algal toxin and PQQ were dissolved in water and mixed into the feed to prepare the experimental feed. The feed was then bagged and stored at -20°C for later use.

[0027] This embodiment uses outdoor pond suspended net cage culture with 24-hour continuous aeration. Fish are fed twice daily, at 6:30 AM and 6:30 PM, with each feeding amount being 3-5% of the fish's body weight. The feeding amount is adjusted periodically based on the fish's weight gain. The culture cycle is 60 days. After the experiment, the fish are fasted for 24 hours, and all fish are weighed to calculate growth performance. Simultaneously, six fish from each net cage are anesthetized with MS-222 (80 mg / L), and blood is collected from the tail vein to detect liver function indicators. Liver tissue is also taken to determine antioxidant enzyme activity, expression of inflammatory factor-related genes, and liver tissue morphology.

[0028] (1) Effects of PQQ on the growth performance of yellow catfish

[0029] Table 1 shows that the average final weight, weight gain rate, and specific growth rate of the algal toxin group and detoxification groups A and B were significantly lower than those of the control group (P < 0.05), but there were no significant differences between the algal toxin group and detoxification groups A and B (P > 0.05). The survival rates of detoxification groups A and B were significantly higher than those of the algal toxin group (P < 0.05), but significantly lower than those of the control group (P < 0.05). These results indicate that although 3–6 mg / kg PQQ has no effect on the growth performance of yellow catfish fed with algal toxins, it can significantly improve the survival rate of yellow catfish.

[0030] Table 1 Effects of PQQ on the growth performance of yellow catfish

[0031]

[0032] Note: Data with the same lowercase letters in the superscript or no letters in the same row indicates no significant difference (P>0.05), while data with different lowercase letters in the superscript indicates a significant difference (P<0.05). The same applies to the table below.

[0033] (2) Effects of PQQ on liver function indicators of yellow catfish

[0034] AST (aspartate aminotransferase) and ALT (alanine aminotransferase) are important indicators of liver health. These two enzymes are mainly found in hepatocytes. When hepatocytes are damaged (such as by inflammation or necrosis), they are released into the bloodstream, causing elevated levels. Table 2 shows that the aLT activity in the algal toxin group was significantly higher than that in the control group (P < 0.05), indicating that algal toxins cause a certain degree of liver damage. Compared with the algal toxin group, the aLT activities in detoxification groups A and B were significantly reduced (P < 0.05), indicating that adding 3–6 mg / kg PQQ to the feed can significantly reduce the increase in serum aLT activity caused by algal toxins and alleviate liver function damage caused by algal toxins.

[0035] Table 2 Effects of PQQ on Liver Function Indicators of Yellow Catfish

[0036]

[0037] (3) Effects of PQQ on the antioxidant function of yellow catfish liver

[0038] Table 3 shows that the activities of T-AOC and SOD in the algal toxin group were significantly lower than those in the control group (P < 0.05), while the MDA level was significantly higher (P < 0.05). This indicates that algal toxins cause oxidative stress in yellow catfish, leading to oxidative damage to their liver tissue. Compared with the algal toxin group, the detoxification groups A and B showed significantly increased T-AOC and SOD levels (P < 0.05) and significantly decreased MDA levels (P < 0.05), with values ​​close to those of the control group (P > 0.05). This suggests that 3–6 mg / kg PQQ can alleviate oxidative stress in the liver of yellow catfish induced by algal toxins and reduce liver oxidative damage.

[0039] Table 3 Effects of PQQ on the antioxidant function of yellow catfish liver

[0040]

[0041] (4) Effects of PQQ on the expression of inflammatory factor genes in the liver of yellow catfish

[0042] IL-1β, IL-8, and TNF-α are important pro-inflammatory factors in the body, and changes in their levels are positively correlated with the inflammatory response. Figure 1The results showed that the expression levels of IL-1β, IL-8, and TNF-α genes in the algal toxin group were significantly higher than those in the control group (P < 0.05), indicating that algal toxins induced liver inflammation. Compared with the algal toxin group, the expression levels of IL-1β, IL-8, and TNF-α genes in the detoxification groups A and B were decreased (P < 0.05), with IL-8 even approaching the control group level (P > 0.05). This indicates that 3–6 mg / kg PQQ can alleviate the inflammatory response in the liver of yellow catfish induced by algal toxins and protect liver health.

[0043] (5) Effects of PQQ on liver tissue morphology and structure

[0044] Depend on Figure 2 It can be seen that the liver tissue structure in the control group was clearly defined, with clearly distinguishable hepatocyte cords and hepatic sinusoids, and abundant zymogen granules in the pancreatic acinars. Compared with the control group, the algal toxin group induced significant structural liver lesions, mainly manifested as the disappearance of hepatocyte cords and hepatic sinusoids, a decrease in the number of pancreatic acinar cells, scattered distribution of hepatocytes, increased eosinophilia, cell membrane rupture, increased eosinophilia of the cell nucleus, blurred nuclear membrane, and disappearance of nucleoli; nuclear fragmentation and nuclear dissolution were also observed. In the detoxification groups A and B, although some damage was present, the lesions were alleviated compared to the algal toxin group, mainly manifested as abundant zymogen granules in the pancreatic acinars and necrosis of a few hepatocytes. The above structures indicate that 3–6 mg / kg PQQ can alleviate the structural liver damage in yellow catfish caused by algal toxins.

[0045] In summary, algal toxins can inhibit the growth of yellow catfish and cause liver damage, specifically manifested as increased activity of liver function-related enzymes, decreased levels of oxidative stress indicators T-AOC and SOD, increased levels of MDA, and increased gene expression levels of pro-inflammatory factors IL-1β, IL-8, and TNF-α. However, the addition of 3–6 mg / kg of PQQ can alleviate the liver damage caused by algal toxins in yellow catfish.

[0046] This invention has discovered a novel application of PQQ, specifically addressing liver damage in yellow catfish caused by cyanobacterial toxin poisoning. By adding PQQ as a main component of pharmaceuticals or feed additives at a dosage of 3-6 mg / kg to the feed, liver damage caused by cyanobacterial toxins can be alleviated through multiple pathways, including improving the activity of key liver enzymes and inhibiting oxidative stress and inflammatory responses. Therefore, this invention provides a novel and safe nutritional intervention strategy for yellow catfish poisoning from cyanobacterial toxins, with broad prospects for industrial application.

[0047] The pyrroloquinoline quinone used in this embodiment is mainly for scientific research, while its sodium salt derivatives, such as disodium pyrroloquinoline quinone, are the main commercial form. Therefore, it is speculated that pyrroloquinoline quinone and its derivatives may also produce the same efficacy as pyrroloquinoline quinone. Thus, pyrroloquinoline quinone and its derivatives can be used to alleviate liver damage caused by algal toxins.

[0048] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0049] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. Application of pyrroloquinoline quinone or its derivatives in the preparation of products for alleviating or preventing cyanobacterial toxin poisoning in yellow catfish.

2. The application according to claim 1, characterized in that, The derivative is disodium pyrroloquinoline quinone.

3. The application according to claim 1 or 2, characterized in that, The product is an aquatic feed additive or aquatic medicine.

4. The application according to claim 3, characterized in that, The feed additive is used to prepare yellow catfish feed, wherein the amount of pyrroloquinoline quinone or its derivative added to the yellow catfish feed is 3-6 mg / kg feed.

5. The application according to claim 1, characterized in that, The relief or prevention of cyanobacterial toxin poisoning in yellow catfish specifically refers to the relief or prevention of pathological damage to the liver tissue of yellow catfish caused by cyanobacterial toxin poisoning.

6. The application according to claim 5, characterized in that, The pyrroloquinoline quinone or its derivatives alleviate cyanobacterial toxin poisoning through one or more of the following pathways: improving the activity of key enzymes in the liver function of yellow catfish, inhibiting liver oxidative stress, alleviating liver inflammatory response, and reducing structural damage to liver tissue.

7. The application according to claim 6, characterized in that, The key liver function enzyme is alanine aminotransferase (ALT), and the pyrroloquinoline quinone or its derivatives can reduce the increase in serum ALT activity induced by cyanobacterial toxins in yellow catfish.

8. The application according to claim 6, characterized in that, The inhibition of liver oxidative stress is achieved by increasing the total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity in the liver of yellow catfish, and reducing the malondialdehyde (MDA) content.

9. The application according to claim 6, characterized in that, The relief of liver inflammation is achieved by reducing the gene expression levels of pro-inflammatory factors IL-1β, IL-8, and TNF-α in the liver of yellow catfish.

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