Chemical composition and protective effect of guava (Psidium guajava L.) leaf extract on piglet intestines

Ethnobotany, phytochemistry, and biological activities of Psidium guajava in the treatment of diarrhea: a review

Psidium guajava: is a tropical tree that is widely used in traditional medicine, especially for treating diarrhea. While P. guajava has been the subject of numerous reviews, none have specifically examined its ethnobotany, pharmacology, and phytochemistry in relation to its antidiarrheal activity. This review aims to summarize the evidence of effectiveness and safety of P. guajava in the treatment of diarrhea. Literature searches were conducted through Web of Science, PubMed, and ScienceDirect by using keywords "Psidium guajava" and "diarrhea" in October 2022. A total of 189 studies were included in this review. P. guajava is widely used in traditional medicine in 44 countries. Decoction and oral were the most represented method of preparation and administration, respectively, while leaves represented the most frequently cited part of the plant. Around 27 antidiarrheal or antibacterial compounds have been isolated and identified, including benzophenone glycosides, terpenes, polysaccharides, phenols, and flavonoids. This article presents ethnobotanical and pharmacological evidence for the efficacy of P. guajava leaves in the treatment of diarrhea and provides reference information for further investigation of this plant. However, despite the large number of publications on the topic, there are still some questions to answer: are quercetin and its glycosides the only ones to act as antidiarrheal agents? What is the mechanism of action of P. guajava antidiarrheal compounds? are the use of guava leaves safe in all types of populations including children, and at what dosage? To answer these questions, more complete phytochemical studies and systematic clinical trials are needed.

Quercetin Increases Growth Performance and Decreases Incidence of Diarrhea and Mechanism of Action in Weaned Piglets

This study aimed to investigate the mechanism of quercetin increasing growth performance and decreasing incidence of diarrhea in weaned piglets. Forty-eight Duroc × Landrace × Large White weaned piglets with similar body weight (7.48 ± 0.20 kg, 28 days of age) were randomly divided into four treatments (control, 250 mg/kg quercetin, 500 mg/kg quercetin, and 750 mg/kg quercetin treatments) and fed with basal diet or experimental diet supplemented with quercetin. Performance, diarrhea rate and index, and content of serum anti-inflammatory factors were determined and calculated in weaned piglets; colonic flora and signaling pathways related to anti-inflammation were measured using 16S rDNA sequencing and RNA-seq, respectively. The results showed that compared with control, feed-to-gain ratio and content of serum interferon gamma (IFN-γ) were significantly decreased in the 500 and 750 mg/kg quercetin treatments (P < 0.05); quercetin significantly decreased diarrhea rate and diarrhea index (P < 0.05) and significantly increased the content of serum transforming growth factor (TGF-β) in weaned piglets (P < 0.05); the content of serum NF-κB was significantly decreased in the 750 mg/kg quercetin treatment (P < 0.05); moreover, quercetin significantly increased diversity of colonic flora (P < 0.05), and at the phylum level, the relative abundance of Actinobacteria in the 500 and 750 mg/kg treatments was significantly increased (P < 0.05), and the relative abundance of Proteobacteria in the three quercetin treatments were significantly decreased (P < 0.05) in the colon of weaned piglets; at the genus level, the relative abundance of Clostridium-sensu-stricto-1, Turicibacter, unclassified_f_Lachnospiraceae, Phascolarctobacterium, and Family_XIII _AD3011_group was significantly increased (P < 0.05); the relative abundance of Subdollgranulum and Blautia was significantly decreased in the 500 and 750 mg/kg treatments (P < 0.05); the relative abundance of Eschericha-Shigella, Terrisporobacter, and Eubacterium-coprostanoligenes was significantly increased (P < 0.05); the relative abundance of Streptocococcus, Sarcina, Staphylococcus, and Ruminococcaceae_UCG-008 was significantly decreased in the three quercetin treatments (P < 0.05); the relative abundance of Ruminococcaceae_UCG_014 was significantly increased in the 250 mg/kg quercetin treatment in the colon of weaned piglets (P < 0.05). The results of Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that differentially expressed genes (DEGs) from the quercetin treatments were significantly enriched in nuclear transcription factor-κB (NF-κB) signal pathway (P < 0.05); mRNA expression of tumor necrosis factor-α (TNF-α), interleukin-1R1 (IL-1R1), conserved helix-loop-helix ubiquitous kinase (CHUK), toll-like receptor 4 (TLR4), and IL-1β from quercetin treatments were significantly decreased in colonic mucosa of weaned piglets (P < 0.05). In summary, quercetin increased feed conversion ratio and decreased diarrhea through regulating NF-κB signaling pathway, controlling the balance between anti-inflammatory and proinflammatory factors, and modulating intestinal flora, thus promoting the absorption of nutrients in weaned piglets. These results provided the theoretical foundation for applying quercetin in preventing weaning piglets' diarrhea and animal husbandry practices.

Effects of mixed extract from two tropical plants on gut microbiome and metabolome in piglets

In this study, we performed a quantitative analysis of 12 compounds derived from Piper sarmentosum extract (PSE) and guava leaf extract (GE). In addition, we investigated the effects of mixed extract (ME) of PSE and GE (1:1) on piglets' gut microbiome and metabolome. A total of 200 piglets (Duroc × Landrace × Large Yorkshire, 21-day-old) were randomly assigned into two groups with five replicates of 20 piglets/pen having the same initial body weight. Piglets were fed a basal diet supplemented with ME at 0 (T0) or 200 mg/kg (T1) for 3 weeks. The quantitation results by ultraperformance liquid chromatography linked to triple-quadrupole tandem mass spectrometry showed that vitexin 2-O-rhamnoside and pellitorine were the greatest abundant among six compounds detected in the PSE. In addition, quercetin, isoquercitrin and avicularin were found to be the richest of all detected compounds in the GE. Findings on experimental animals indicated that three differential metabolites, comprising L-alanine, sarcosine and dihydrofolic acid, in T1 compared with T0 groups, have exactly opposite levels trends in serum and faeces. Moreover, two metabolic pathways (i.e., urea cycle and glutamate metabolism) differed significantly in the serum and faeces of piglets between T0 and T1 (p < 0.05). At the same time, T1 had significantly higher relative abundances of Agathobacter and Alloprevotella than T0 at genus level (p < 0.05). Correlation analysis revealed that the genus Agathobacter correlated positively with carbamoyl phosphate (p < 0.01) and oxoglutaric acid (p < 0.05), and negatively with succinic acid (p < 0.01) and ornithine (p < 0.05). These four differential metabolites were also involved in the urea cycle and/or glutamate metabolism pathways. The results here indicated that the tested plant extract mixture represents a worthy feed additive with obvious antioxidative properties.

Antidiarrheal effect of Psidium guajava L. extract in acute diarrhea: a systematic review

Acute diarrheal diseases are a leading cause of childhood mortality and morbidity worldwide. Psidium guajava has been globally used for its antidiarrheal potential. We conducted a systematic review of scientific articles published up to the year 2021, which included in vivo pre-clinical tests and clinical trials involving patients with acute infectious diarrhea to verify the antidiarrheal, antibacterial and antispasmodic effects of galenic preparations or phytopharmaceuticals from P. guajava. PRISMA and Rayyan were used as tools for the selection of studies collected in four databases (Pubmed, Scopus, Web of Science and Science Direct). The keywords used to carry out the search were: 'Psidium guajava', 'guava', 'antidiarrhe*' and 'diarrhe*', joined by Boolean operators 'OR' or 'AND'. The characteristics of studies in animal models of acute diarrhea induction, as well as in vivo and in vitro motility and microbiological tests linked with its main pathophysiological mechanisms, were collected. Twenty-three articles were included. Twenty (87%) of these reported heterogenic preclinical studies, predominating pharmacological studies of efficacy against conventional antidiarrheal agents, which utilized relevant outcomes and models of infectious diarrhea from the top pathogens in the clinic along with classical castor oil-induced diarrhea associated with motility tests. Only three articles (13%) corresponded to clinical trials investigating the efficacy, dose and safety of these preparations. Most studies reported positive results and significant mechanistic evidence from antibacterial, anti-motility, anti-secretory and protective/anti-inflammatory perspectives. However, further studies are needed to define the clinical significance and safety treatment with P. guajava extracts. © 2024 Society of Chemical Industry.

The Influence of Piper sarmentosum Extract on Growth Performance, Intestinal Barrier Function, and Metabolism of Growing Chickens

In the poultry industry, there is an urgent need to evaluate and introduce natural, effective, and safe alternatives for synthetic antibiotics, which have been banned in most countries. The present study aimed to investigate the effects of dietary supplementation with Piper sarmentosum extract (PSE) on the growth performance, intestinal barrier function, and metabolism of growing chickens. A total of 400 seven-day-old female chicks were randomly assigned to four dietary treatments, each of which consisted of five replicates and twenty birds each. The four experimental treatments were fed a basal diet containing 0, 100, 200, and 300 mg PSE/kg (BC, PSE1, PSE2, and PSE3 groups), respectively. The experiment lasted for 28 days. The results showed that dietary supplementation with PSE had no significant effects on the final body weight, average daily gain (ADG), average daily feed intake (ADFI), and the ratio of ADFI to ADG (F/G) (p > 0.05). Compared with the BC group, dietary supplementation with 200-300 mg/kg PSE increased the villus height in the jejunum and ileum of chickens (p < 0.05). The PSE-treated groups significantly increased the mRNA expression of Occludin, ZO-1, and Claudin-1 in the ileal mucosa of chickens (p < 0.05). In addition, a significant decrease in ileal TNF-α and IL-8 mRNA expression (p < 0.05) and a significant increase in IL-22 (p < 0.05) were observed in the PSE2 treatment compared to the BC group. Additionally, three gut metabolites (i.e., citrate, isocitrate, and spermine) showed significant differences among treatments (p < 0.05) and were involved in the tricarboxylic acid (TCA) cycle, the transfer of acetyl groups into mitochondria, and spermidine and spermine biosynthesis, respectively. In conclusion, the findings obtained here indicate that supplemental PSE can enhance the anti-inflammatory capacity and intestinal mucosal barrier function of chickens.

Resveratrol alleviates oxidative stress induced by oxidized soybean oil and improves gut function via changing gut microbiota in weaned piglets

BACKGROUND

Oxidized soybean oil (OSO) has been shown to impair growth and exacerbate inflammation, leading to intestinal barrier injury in animals. Recent evidence suggests important roles for resveratrol (RES) in the promoting growth performance, antioxidant capacity, anti-inflammatory, and regulate intestinal barriers in animals. Therefore, The objectives of this study are to investigate the effects of dietary RES (purity 98%) supplementation on the growth performance, antioxidant capacity, inflammatory state, and intestinal function of weaned piglets challenged with OSO.

METHODS

A total of 28 castrated weaned male piglets with a similar body weight of 10.19 ± 0.10 kg were randomly assigned to 4 dietary treatments for 28-d feeding trial with 7 replications per treatment and 1 piglet per replicate. Treatments were arranged as a 2 × 2 factorial with oil type [3% fresh soybean oil (FSO) vs. 3% OSO] and dietary RES (0 vs. 300 mg/kg).

RESULTS

The results showed that relative to the FSO group, OSO stress tended to decrease the average daily feed intake (ADFI), and decreased the activity levels of lipase, villus/crypt ratio (VCR), the mRNA expression of FABP1, SOD2, IL-10 and ZO-1 in the jejunum, and SOD2, GPX1, occludin and ZO-1 in the colon, the levels of acetic acid in the colonic digesta, whereas up-regulated the mRNA expression of IL-1β and TNF-α in the jejunum (P < 0.05). Moreover, dietary supplementation with RES increased ether extract (EE), the activity levels of sucrase, lipase, α-amylase, villus height (VH) and VCR, the mRNA expression of FABP1, SOD2, IL-10 and occludin in the jejunum, and FABP1, PPAR-γ, GPX1, occludin and ZO-1 in the colon, and the abundance of Firmicutes, acetic and propionic acid, but decreased the levels of D-lactic acid in the plasma, the abundance of Bacteroidetes in the colonic digesta of weaned piglets compared to the non-RES group (P < 0.05). Meanwhile, in the interaction effect analysis, relative to the OSO group, dietary RES supplementation in the diets supplemented with OSO increased the activity levels of trypsin, VH in the jejunum, the abundance of Actinobacteria, the levels of butyric acid of weaned piglets, but failed to influence the activity levels of trypsin and VH, Actinobacteria abundance, the levels of butyric acid when diets were supplemented with FSO (interaction, P < 0.05). Relative to the OSO group, dietary RES supplementation in the diets supplemented with OSO decreased the activity levels of DAO in the plasma of weaned piglets but failed to influence the activity levels of DAO when diets were supplemented with FSO (interaction, P < 0.05). Relative to the FSO group, dietary RES supplementation in the diets supplemented with FSO decreased the level of propionic acid, whereas RES supplementation failed to influence the level of propionic acid when the diet was supplemented with OSO (interaction, P < 0.01).

CONCLUSIONS

Inclusion of OSO intensified inflammatory states and impaired the intestinal health characteristics of weaned piglets. Dietary RES supplementation improved the antioxidant capacity, anti-inflammatory activity, and intestinal morphology. Further studies showed that the protective effects of RES on gut health could be linked to the decreased abundance of Prevotella_1, Clostridium_sensu_stricto_6, and Prevotellaceae_UCG003 and increased levels of acetic and propionic acid.

A comprehensive review on natural phenolic compounds as alternatives to in-feed antibiotics

Intensive livestock and poultry farming in China largely relied on the use of in-feed antibiotics until July 2020. The consequences of antibiotic overuse in animal feed include accumulation in animal products and the development of bacterial antibiotic resistance, both of which threaten food safety and human health. China has now completely banned the circulation of commercial feed containing growth-promoting drug additives (except Chinese herbal medicine). Therefore, alternatives to in-feed antibiotics in animal production are greatly needed. Natural phenolic compounds (NPCs) exist widely in plants and are non-toxic, non-polluting, highly reproducible, and leave little residue. Many natural flavonoids, phenolic acids, lignans, and stilbenes have polyphenol chemical structures and exhibit great potential as alternatives to antibiotics. In this review we delineate the characteristics of plant-derived NPCs and summarize their current applications as alternatives to in-feed antibiotics, aiming to provide new strategies for antibiotic-free feeding and promote the development of more sustainable animal husbandry practices.

Phytogenic feed additives alleviate pathogenic Escherichia coli-induced intestinal damage through improving barrier integrity and inhibiting inflammation in weaned pigs

Background

This study was conducted to investigate the effects of each phytogenic feed additive (PFA; PFA1, bitter citrus extract; PFA2, a microencapsulated blend of thymol and carvacrol; PFA3, a mixture of bitter citrus extract, thymol, and carvacrol; PFA4, a premixture of grape seed, grape marc extract, green tea, and hops; PFA5, fenugreek seed powder) on the growth performance, nutrient digestibility, intestinal morphology, and immune response in weaned pigs infected with Escherichia coli (E. coli).

Results

A total of 63 4-week-old weaned pigs were placed in individual metabolic cages and assigned to seven treatment groups. The seven treatments were as follows: 1) NC; basal diet without E. coli challenge, 2) PC; basal diet with E. coli challenge, 3) T1; PC + 0.04% PFA1, 4) T2; PC + 0.01% PFA2, 5) T3; PC + 0.10% PFA3, 6) T4; PC + 0.04% PFA4, 7) T5; PC + 0.10% PFA5. The experiments lasted in 21 d, including 7 d before and 14 d after the first E. coli challenge. In the E. coli challenge treatments, all pigs were orally inoculated by dividing a total of 10 mL of E. coli F18 for 3 consecutive days. The PFA-added groups significantly increased (P < 0.05) average daily gain and feed efficiency and decreased (P < 0.05) the fecal score at d 0 to 14 post-inoculation (PI). Tumor necrosis factor α was significantly lower (P < 0.05) in the PFA-added groups except for T1 in d 14 PI compared to the PC treatment. The T3 had a higher (P < 0.05) immunoglobulin G and immunoglobulin A concentration compared to the PC treatment at d 7 PI. Also, T3 showed significantly higher (P < 0.05) villus height:crypt depth and claudin 1 expression in ileal mucosa, and significantly down-regulated (P < 0.05) the expression of calprotectin compared to the PC treatment.

Conclusions

Supplementation of PFA in weaned pigs challenged with E. coli alleviated the negative effects of E. coli and improved growth performance. Among them, the mixed additive of bitter citrus extract, thymol, and carvacrol showed the most effective results, improving immune response, intestinal morphology, and expression of tight junctions.

Effect of Early Pathogenic Escherichia coli Infection on the Intestinal Barrier and Immune Function in Newborn Calves

We studied the effect of early pathogenic Escherichia coli infection on newborn calves’ intestinal barrier and immune function. A total of 64 newborn Holstein male calves (40–43 kg) were divided into two groups: normal (NG) and test (TG), each with 32 heads. At the beginning of the experiment, the TG calves were orally administered pathogenic E. coli O1 (2.5 × 10¹¹ CFU/mL, 100 mL) to establish a calf diarrhea model. In contrast, the NG calves were given the same amount of normal saline. During the 30 d trial period, the feeding and management of the two groups remained constant. Enzyme-linked immunosorbent assay, quantification PCR, and high-throughput 16S rRNA sequencing technology were used to detect indicators related to the intestinal barrier and immune function in the calf serum and tissues. Pathogenic E. coli O1 had a significant effect on calf diarrhea in the TG; it increased the bovine diamine oxidase (P < 0.05) and endotoxin levels in the serum and decreased (P < 0.05) the intestinal trefoil factor (P < 0.05), Occludin, Claudin-1, and Zonula Occludens 1 (ZO-1) levels in the colon tissue, as well as downregulated the mRNA expression of Occludin, Claudin-1,and ZO-1 in the colon mucosa, leading to increased intestinal permeability and impaired intestinal barrier function. Additionally, pathogenic E. coli had a significant impact on the diversity of colonic microbial flora, increasing the relative abundance of Proteobacteria at the phylum level and decreasing the levels of Firmicutes and Bacteroides. At the genus level, the relative abundance of Escherichia and Shigella in the TG increased significantly (P < 0.05), whereas that of Bacteroides, Butyricicoccus, Rikenellaceae_RC9_gut_group, Blautia, and Lactobacillus was significantly decreased (P < 0.05). In addition, the level of IL-6 in the serum of the TG calves was significantly increased (P < 0.05), whereas the IL-4 and IL-10 levels were significantly decreased (P < 0.05), compared to those in the NG calves. Thus, pathogenic E. coli induced diarrhea early in life disrupts intestinal barrier and impairs immune function in calves.

Study on the Effective Material Basis and Mechanism of Traditional Chinese Medicine Prescription (QJC) Against Stress Diarrhea in Mice

Stress diarrhea is a major challenge for weaned piglets and restricts pig production efficiency and incurs massive economic losses. A traditional Chinese medicine prescription (QJC) composed of Astragalus propinquus Schischkin (HQ), Zingiber officinale Roscoe (SJ), and Plantago asiatica L. (CQC) has been developed by our laboratory and shows marked anti-stress diarrhea effect. However, the active compounds, potential targets, and mechanism of this effect remain unclear and warrant further investigation. In our study, we verified the bioactive compounds of QJC and relevant mechanisms underlying the anti-stress diarrhea effect through network pharmacology and in vivo experimental studies. After establishing a successful stress-induced diarrhea model, histomorphology of intestinal mucosa was studied, and Quantitative real-time PCR (RT-qPCR) probe was used for the phosphoinositide 3-kinase (PI3K)-Akt signaling pathway to verify the therapeutic effect of QJC on diarrhea. First, using the network pharmacology approach, we identified 35 active components and 130 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in QJC. From among these, we speculated that quercetin, luteolin, kaempferol, scutellarein, and stigmasterol were the main bioactive compounds and assumed that the anti-diarrhea effect of QJC was related to the PI3K-Akt signaling pathway. The RT-qPCR indicated that QJC and its bioactive components increased the expression levels of PI3K and Akt, inhibited the expression of phosphatase and tensin homolog (PTEN), and activated the PI3K-Akt signaling pathway to relieve stress-induced diarrhea. Furthermore, we found that QJC alleviated the pathological condition of small intestine tissue and improved the integrity of the intestinal barrier. Taken together, our study showed that the traditional Chinese medicine QJC, quercetin, luteolin, kaempferol, scutellarein, and stigmasterol alleviated the pathological condition of small intestine tissue and relieved stress-induced diarrhea by increasing the expression levels of PI3K and Akt and inhibiting the expression levels of PTEN.

Effects of Guava (Psidium guajava L.) Leaf Extract on the Metabolomics of Serum and Feces in Weaned Piglets Challenged by Escherichia coli

The effects of dietary supplementation with guava leaf extracts (GE) on intestinal barrier function and serum and fecal metabolome in weaned piglets challenged by enterotoxigenic Escherichia coli (ETEC) were investigated. In total, 50 weaned piglets (Duroc × Yorkshire × Landrace) from 25 pens (two piglets per pen) were randomly divided into five groups: BC (blank control), NC (negative control), S50 (supplemented with 50 mg kg⁻¹ diet GE), S100 (100 mg kg⁻¹ diet GE), and S200 (200 mg kg⁻¹ diet GE), respectively. On day 4, all groups (except BC) were orally challenged with enterotoxigenic ETEC at a dose of 1.0 × 10⁹ colony-forming units (CFUs). After treatment for 28 days, intestinal barrier function and parallel serum and fecal metabolomics analysis were carried out. Results suggested that dietary supplementation with GE (50–200 mg kg⁻¹) increased protein expression of intestinal tight junction proteins (ZO-1, occludin, claudin-1) (p < 0.05) and Na⁺/H⁺ exchanger 3 (NHE3) (p < 0.05). Moreover, dietary supplementation with GE (50–200 mg kg⁻¹) increased the level of tetrahydrofolic acid (THF) and reversed the higher level of nicotinamide-adenine dinucleotide phosphate (NADP) induced by ETEC in serum compared with the NC group (p < 0.05), and enhanced the antioxidant capacity of piglets. In addition, dietary addition with GE (100 mg kg⁻¹) reversed the lower level of L-pipecolic acid induced by ETEC in feces compared with the NC group (p < 0.05) and decreased the oxidative stress of piglets. Collectively, dietary supplementation with GE exhibited a positive effect on improving intestinal barrier function. It can reprogram energy metabolism through similar or dissimilar metabolic pathways and finally enhance the antioxidant ability of piglets challenged by ETEC.