Effect of pyrroloquinoline quinone disodium in female rats during gestating and lactating on reproductive performance and the intestinal barrier functions in the progeny

Dietary supplementation with pyrroloquinoline quinone promotes growth, relieves weaning stress, and regulates metabolism of piglets compared with adding zinc oxide

Hindered growth often occurs because of psychological and environmental stress during the weaning period of piglets. This study aimed to compare the effects of growth performance, diarrhea indices, digestibility of nutrients, antioxidant capacity, neurotransmitters levels and metabolism of weaned pigs fed diets supplemented with pyrroloquinoline quinone (PQQ) and zinc oxide (ZnO). Pigs weaned at d 28 (n = 108) were fed with three different diets including: the basal diet (CTRL group), the basal diet supplemented with 3.0 mg/kg PQQ (PQQ group) and the basal diet containing 1,600 mg/kg ZnO (ZNO group). During the first 14 d, weaned pigs fed the diet supplemented with PQQ and ZnO decreased feed to gain ratio and diarrhea rate (P < 0.01). Compared with the CTRL group, average daily gain was increased in weaned pigs in the PQQ group from d 15 to 28 (P = 0.03). Compared with the CTRL group, pigs fed PQQ and ZnO supplemented diets showed improved apparent total tract digestibility (ATTD) of nutrients (P ≤ 0.05). During the overall experimental period, the concentration of malondialdehyde was decreased in plasma of pigs in the PQQ and ZNO groups compared with the CTRL group (P < 0.05). At d 28, the concentration of vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP) was lower in plasma of weaned pigs in the PQQ and ZNO groups compared with the CTRL group (P < 0.05). There was no difference between the PQQ and ZNO group in growth performance, ATTD of nutrition, antioxidant capacity and neurotransmitters levels. PQQ increased 3-methoxy-4-hydroxymandelate (P < 0.05) compared with the CTRL group. According to metabolomic analysis, erucamide, formononetin and 3-methyl-L-histidine were up-regulated in the PQQ group (P < 0.05). Compared with the CTRL group, aloesin and dibutyl adipate were down-regulated in the PQQ group (P < 0.05). In conclusion, similar to ZnO, PQQ improves growth performance, digestibility of nutrients, antioxidant capacity, neuromodulation and metabolism of weaned pigs. Thus, like ZnO, PQQ can be effectively applied in weaned pigs.

Pyrroloquinoline quinone regulates glycolipid metabolism in the jejunum via inhibiting AMPK phosphorylation of weaned pigs

Maintenance of intestinal metabolic function is important for optimal growth performance in post-weaning pigs. This study aimed to evaluate the effect of pyrroloquinoline quinone (PQQ) on maintaining intestinal glycolipid metabolism in weaned pigs. Seventy-two Duroc × Landrace × Yorkshire crossbred pigs were divided into two groups: pigs fed a basal diet (CTRL group) and pigs fed a basal diet supplemented with 3.0 mg kg^-1 PQQ (PQQ group). On d 14, serum was harvested from six pigs per group and the pigs were slaughtered to sample jejunal tissue. Compared with the CTRL group, pigs in the PQQ group had increased average daily gain (P < 0.05), decreased feed : gain (P < 0.05) and tended to have a reduced diarrhea ratio (P = 0.057). Jejunal villus height and villus height/crypt depth ratio were increased, and the crypt depth was decreased in the PQQ group (P < 0.01). The proteomics results showed that PQQ supplementation acted on three metabolic pathways, type I diabetes mellitus, the pancreatic secretion pathway and immune-related signalling. Compared with the CTRL group, PQQ supplementation increased (P < 0.05) serum insulin and jejunal mucosal pyruvate, triglyceride, total cholesterol and low-density lipoprotein cholesterol in the pigs. Jejunal mucosal lactic dehydrogenase and high-density lipoprotein cholesterol levels in the pigs were decreased by PQQ supplementation (P < 0.05). In addition, PQQ supplementation reduced glucose transporter 5 and phosphorylated-AMP-activated protein kinase expression in the jejunal mucosa of the pigs (P < 0.05). In conclusion, dietary supplementation with PQQ improved the growth performance and jejunal morphology and regulated glycolipid metabolism via inhibiting AMPK phosphorylation in weaned pigs.

Pyrroloquinoline Quinone Regulates Enteric Neurochemical Plasticity of Weaned Rats Challenged With Lipopolysaccharide

The enteric nervous system (ENS) is important for the intestinal barrier to defend and regulate inflammation in the intestine. The aim of this study was to investigate the effect of pyrroloquinoline quinone (PQQ) on regulating neuropeptide secretion by ENS neurons of rats challenged with lipopolysaccharide (LPS) to create enteritis. Thirty Sprague Dawley rats were divided into five groups, namely, basal (CTRL), basal plus LPS challenge (LPS), basal with 2.5 mg/kg b.w./day of PQQ plus challenge with LPS (PQQ 2.5), basal with 5.0 mg/kg b.w./day PQQ plus challenge with LPS (PQQ 5), and basal with 10.0 mg/kg b.w./day PQQ plus challenge with LPS (PQQ 10). After treatment with basal diet or PQQ for 14 days, rats were challenged with LPS except for the CTRL group. Rats were euthanized 6 h after the LPS challenge. Rats showed an increased average daily gain in PQQ treatment groups (P &lt; 0.05). Compared with the LPS group, PQQ 5 and PQQ 10 rats showed increased villus height and villus height/crypt depth of jejunum (P &lt; 0.05). In PQQ treatment groups, concentrations of IL-1β and TNF-α in serum and intestine of rats were decreased, and IL-10 concentration was increased in serum compared with the LPS group (P &lt; 0.05). Compared with the LPS group, the concentration of neuropeptide Y (NPY), nerve growth factor (NGF), vasoactive intestinal peptide (VIP), substance P (SP), calcitonin gene-related peptide (CGRP), and brain-derived neurotropic factor (BDNF) in serum were decreased in PQQ treatment groups (P &lt; 0.05). Compared with the LPS group, ileal mRNA levels of BDNF, NPY, and NGF were decreased in PQQ treatment groups (P &lt; 0.05). Jejunal concentrations of SP, CGRP, VIP, BDNF, NPY, and NGF were decreased in PQQ treatment groups compared with the LPS group (P &lt; 0.05). Compared with the LPS group, phosphor-protein kinase B (p-Akt)/Akt levels in jejunum and colon were decreased in PQQ treatment groups (P &lt; 0.05). In conclusion, daily treatment with PQQ improved daily gain, jejunal morphology, immune responses. PQQ-regulated enteric neurochemical plasticity of ENS via the Akt signaling pathway of weaned rats suffering from enteritis.

PQQ Dietary Supplementation Prevents Alkylating Agent-Induced Ovarian Dysfunction in Mice

Alkylating agents (AAs) that are commonly used for cancer therapy cause great damage to the ovary. Pyrroloquinoline-quinine (PQQ), which was initially identified as a redox cofactor for bacterial dehydrogenases, has been demonstrated to benefit the fertility of females. The aim of this study was to investigate whether PQQ dietary supplementation plays a protective role against alkylating agent-induced ovarian dysfunction. A single dose of busulphan (20 mg/kg) and cyclophosphamide (CTX, 120 mg/kg) were used to establish a mouse model of ovarian dysfunction. Feed containing PQQNa₂ (5 mg/kg) was provided starting 1 week before the establishment of the mouse model until the date of sacrifice. One month later, estrous cycle period of mice were examined and recorded for consecutive 30 days. Three months later, some mice were mated with fertile male mice for fertility test. The remaining mice were sacrificed to collect serum samples and ovaries. One day before sacrifice, some mice received a single injection of BrdU to label proliferating cells. Serum samples were used for test hormonal levels. Ovaries were weighted and used to detect follicle counts, cell proliferation, cell apoptosis and cell senescence. In addition, the levels of inflammation, oxidative damage and Pgc1α expression were detected in ovaries. Results showed that PQQ treatment increased the ovarian weight and size, partially normalized the disrupted estrous cycle period and prevented the loss of follicles of mice treated with AAs. More importantly, we found that PQQ treatment significantly increased the pregnancy rate and litter size per delivery of mice treated with AAs. The protective effects of PQQ appeared to be directly mediated by promoting cell proliferation of granulosa, and inhibiting cell apoptosis of granulosa and cell senescence of ovarian stromal cells. The underlying mechanisms may attribute to the anti-oxidative stress, anti-inflammation and pro-mitochondria biogenesis effects of PQQ.Our study highlights the therapeutic potential of PQQ against ovarian dysfunction caused by alkylating agents.

Lycopene modulates lipid metabolism in rats and their offspring under a high-fat diet

The purpose of this study was to investigate the effects of lycopene supplementation on lipid metabolism in rats and their offspring. The experiment was conducted on 60 female rats divided into four groups: normal diet, normal diet with 200 mg kg^-1 lycopene, high-fat diet, and high-fat diet with 200 mg kg^-1 lycopene. The plasma levels of TG, LDL-C, AST and ALT in female rats fed a high-fat diet were significantly increased (P < 0.05). Lycopene supplementation reduced the plasma TG, LEP and AST levels (P < 0.05). In addition, the activity of ACC and mRNA expression of SREBP1c, FAS, PPARγ, CPT1, HMGCR, ACC, PLIN1 and FATP1 in the liver were also increased after feeding a high-fat diet (P < 0.05), whereas the expression of HSL was decreased (P < 0.05). Lycopene increased the activity of HSL and the expression of ATGL in the liver (P < 0.05), and the activity of ACC and mRNA expression of HMGCR and ACC were decreased (P < 0.05). For the offspring, maternal feeding of a high-fat diet reduced the plasma HDL-C levels (P < 0.05), but lycopene supplementation reduced the plasma TC levels (P < 0.05). Maternal high-fat diet also decreased the activity of HSL and the expression of CD36, PLIN1 and FATP1 in the liver while increasing the expression of PPARγ (P < 0.05). Maternal lycopene supplementation decreased the activities of ACC and FAS in the liver and decreased the expression of PPARγ, ACC and PLIN1 (P < 0.05). Maternal feeding of a high-fat diet increased the level of oxidative stress in the liver, the level of blood lipids in plasma and the rate of lipid production in the liver of rats and their offspring. Maternal lycopene supplementation can reduce the level of oxidative stress in rats and their offspring, reduce the level of blood lipids in plasma, and also reduce the rate of lipid production in the liver of rats and offspring.

Pyrroloquinoline-Quinone Is More Than an Antioxidant: A Vitamin-like Accessory Factor Important in Health and Disease Prevention

Pyrroloquinoline quinone (PQQ) is associated with biological processes such as mitochondriogenesis, reproduction, growth, and aging. In addition, PQQ attenuates clinically relevant dysfunctions (e.g., those associated with ischemia, inflammation and lipotoxicity). PQQ is novel among biofactors that are not currently accepted as vitamins or conditional vitamins. For example, the absence of PQQ in diets produces a response like a vitamin-related deficiency with recovery upon PQQ repletion in a dose-dependent manner. Moreover, potential health benefits, such as improved metabolic flexibility and immuno-and neuroprotection, are associated with PQQ supplementation. Here, we address PQQ's role as an enzymatic cofactor or accessory factor and highlight mechanisms underlying PQQ's actions. We review both large scale and targeted datasets demonstrating that a neonatal or perinatal PQQ deficiency reduces mitochondria content and mitochondrial-related gene expression. Data are reviewed that suggest PQQ's modulation of lactate acid and perhaps other dehydrogenases enhance NAD+-dependent sirtuin activity, along with the sirtuin targets, such as PGC-1α, NRF-1, NRF-2 and TFAM; thus, mediating mitochondrial functions. Taken together, current observations suggest vitamin-like PQQ has strong potential as a potent therapeutic nutraceutical.

Anti-inflammatory and Antioxidant Effects of Pyrroloquinoline Quinone in L-NAME-Induced Preeclampsia-Like Rat Model

Preeclampsia (PE) is a pregnancy complication commonly characterized by high blood pressure. Although it is generally believed that the placenta is the root cause of PE, the exact pathogenesis is unknown; consequently, there is no standard clinical treatment. Therefore, it is necessary to explore new therapeutic drugs. Several studies have reported that pyrroloquinoline quinone (PQQ) exhibits anti-inflammatory and antioxidative effects. The purpose of this study was to investigate the protective effect of PQQ diet supplementation on PE-like rat models. L-NAME induced PE-like model rats were intraperitonially administrated with PQQ. The results showed that PQQ significantly improved clinical manifestations and pregnancy outcomes of PE-like rats. The levels of related inflammatory and antioxidant markers were also significantly reversed. A mechanism study showed that PQQ may achieve the above therapeutic effects by inhibiting NF-κB and promoting Nrf2 antioxidant pathways. In conclusion, we showed the protective effect of PQQ on PE-like model rats, by improving anti-inflammation and antioxidation effect through the NF-κB-Nrf2 pathway.

Effect of dietary pyrroloquinoline quinone disodium in sows on intestinal health of the offspring

The objective of this study was to investigate the effects of dietary pyrroloquinoline quinone disodium (PQQ·Na2) supplementation in sows during gestation and lactation on intestinal health in offspring. A total of 40 cross-bred (landrace × large white crossed with Duroc boar) multiparity gestation sows with an average parity of 4.3 were used in this study. Forty sows were allotted to 2 dietary treatments after breeding. One group was the control sows, which were fed a corn-soybean meal control diet (Con treatment, n = 20), and the other group was the treatment sows fed a control diet with 20 mg kg-1 PQQ·Na2 after breeding and through gestation and lactation (PQQ treatment, n = 20). The activities of SOD and GSH-Px were significantly (P < 0.05) increased by PQQ·Na2 supplementation, and MDA activity was decreased (P < 0.05) in the plasma of piglets. CAT, SOD and GSH-Px activities were significantly (P < 0.05) increased, and MDA activity was decreased (P < 0.05) in the small intestine of piglets. The mRNA expression levels of SOD1, CAT and MGST1 in the jejunum were increased in newborn piglets (P < 0.05), and the mRNA expression levels of HO1, SOD1, CAT, SOD2, GPX4, GPX1 and GCLC in the jejunum were increased in weaned piglets (P < 0.05). The mRNA expression of ZO-1 was increased (P < 0.05) in the jejunum of newborn piglets, and the mRNA expression of Occludin and ZO-1 was increased (P < 0.05) in the jejunum of weaned piglets. The villous height of the duodenum and jejunum of weaned piglets was increased (P < 0.05) by dietary PQQ·Na2. In weaned piglets, Bacteroidetes and Firmicutes were the most prevalent phyla in both the Con and PQQ·Na2 treatment groups, and the most prevalent genera were Alloprevotella and Bacteroides. At the phylum level, the abundance of Firmicutes was significantly increased (P < 0.05), and the abundance of Proteobacteria was significantly decreased (P < 0.05). At the genus level, the abundance of Alloprevotella was significantly increased (P < 0.05), and the abundance of Actinobacillus and Escherichia was decreased (P < 0.05). In conclusion, dietary supplementation with PQQ·Na2 in sows during gestation and lactation had positive effects on intestinal health in offspring.

Pyrroloquinoline quinone inhibits the production of inflammatory cytokines via the SIRT1/NF-κB signal pathway in weaned piglet jejunum

The small intestine is an important digestive organ and plays a vital role in the life of a pig. In this study, we explored the regulatory role and molecular mechanism of pyrroloquinoline quinone (PQQ) on intestinal health and to discussed the interaction between PQQ and vitamin C (VC). A total of 160 healthy piglets weaned at 21 d were randomly divided into four treatment groups according to 2 × 2 factoring. The results showed that dietary PQQ could significantly decrease the levels of plasma globulin, albumin/globulin (A/G), indirect bilirubin (IBIL), blood urea nitrogen (BUN), creatinine (CREA) (P < 0.05 for each), total bilirubin, (TBIL) (P < 0.01), diamine oxidase (DAO) (P < 0.01) and immunoglobulin G (IgG) (P < 0.0001) and increase the levels of immunoglobulin A (IgA) and immunoglobulin M (IgM) (P < 0.0001) in the plasma of weaned piglets. Similarly, dietary VC could significantly decrease the levels of plasma globulin, A/G, DAO (P < 0.05 for each) and IgG (P < 0.0001) and increase the levels of IgA and IgM (P < 0.0001) in the plasma of weaned piglets. In addition, dietary PQQ increased (P < 0.05) the mRNA levels of antioxidant genes (NQO1, UGT1A1, and EPHX1), thereby enhancing (oxidized) nicotinamide adenine dinucleotide (NAD+) concentration and sirtuin 1 (SIRT1) activity in tissues. However, the addition of 200 mg kg-1 VC to the diet containing PQQ reduced most of the effects of PQQ. We further show that PQQ reduced (P < 0.05) the expression of inflammation-related genes (IL-2, IL-6, TNF-α, and COX-2) via the SIRT1/NF-κB deacetylation signaling. In conclusion, our data reveals that PQQ exerts a certain protective effect on the intestines of piglets, but higher concentrations of VC react with PQQ, which inhibits the regulatory mechanism of PQQ.

Pyrroloquinoline Quinone Alleviates Jejunal Mucosal Barrier Function Damage and Regulates Colonic Microbiota in Piglets Challenged With Enterotoxigenic Escherichia coli

This study aimed to evaluate the effect of dietary supplementation with pyrroloquinoline quinone (PQQ) on gut inflammation and microbiota dysbiosis induced by enterotoxigenic Escherichia coli (ETEC). Twenty Duroc × Landrace × Yorkshire crossbred barrows were assigned to four groups: two E. coli K88 challenge groups and two non-challenge groups, each provided a basal diet supplemented with 0 or 3 mg/kg PQQ. On day 14, piglets were challenged with 10 mL 1 × 10⁹ CFU/mL of E. coli K88 or PBS for 48 h. The villus height (VH) and villus height/crypt depth (VCR) ratio of the E. coli K88-challenged group supplemented with PQQ was significantly reduced than in the non-supplemented challenge group (P < 0.05), while levels of jejunal zonula occludens-3 (ZO-3), diamine oxidase, secretory immunoglobulin A (SIgA), interleukin-10 (IL-10), and IL-22 proteins were higher (P < 0.05), as were the activities of glutathione peroxidase, total superoxide dismutase, and total antioxidant capability (P < 0.05). Moreover, PQQ supplementation alleviated an increase in levels of mucosal inflammatory cytokines and reduced the activity of nuclear factor-kappa B (NF-κB) pathway by E. coli K88 (P < 0.05). Gene sequencing of 16S rRNA showed dietary supplementation with PQQ in E. coli K88-challenged piglets attenuated a decrease in Lactobacillus count and butyrate, isobutyrate level, and an increase in Ruminococcus and Intestinibacter counts, all of which were observed in non-supplemented, challenge-group piglets. These results suggest that dietary supplementation with PQQ can effectively alleviate jejunal mucosal inflammatory injury by inhibiting NF-κB pathways and regulating the imbalance of colonic microbiota in piglets challenged with E. coli K88.

Transcriptome analysis of the effect of pyrroloquinoline quinone disodium (PQQ·Na2) on reproductive performance in sows during gestation and lactation

Background

Pyrroloquinoline quinone (PQQ), which is a water soluble, thermo-stable triglyceride-quinone, is widely distributed in nature and characterized as a mammalian vitamin-like redox cofactor. The objective of this study was to investigate the effects of pyrroloquinoline quinone disodium (PQQ·Na₂) on reproductive performance in sows.

Results

Dietary supplementation with PQQ·Na₂ significantly increased the total number of piglets born, the number of piglets born alive and the born alive litter weight. It also increased the antioxidant status in the placenta, plasma and milk. The concentration of NO was significantly increased in the plasma and placenta. RNA-seq analysis showed that 462 unigenes were differentially expressed between the control (Con) treatment and PQQ treatment groups. Among these unigenes, 199 were upregulated, while 263 unigenes were downregulated. The assigned functions of the unigenes covered a broad range of GO categories. Reproduction (27, 7.03%) and the reproduction process (27, 7.03%) were assigned to the biological process category. By matching DEGs to the KEGG database, we identified 29 pathways.

Conclusions

In conclusion, dietary supplementation with PQQ·Na₂ in gestating and lactating sows had positive effects on their reproductive performance.

Electronic supplementary material

The online version of this article (10.1186/s40104-019-0369-y) contains supplementary material, which is available to authorized users.