Antimicrobial properties of plant secondary metabolites

In vitro antibacterial activity of fruit pulp extracts of Tamarindus indica against Staphylococcus aureus and Klebsiella pneumoniae

BACKGROUND

Infectious diseases are increasingly recognized as public health concern worldwide as the rising incidence in multidrug resistance bacteria. This consequently enforces the need to find a new antimicrobial agent where plants have a potential source. This study investigated the antibacterial activity of fruit pulp extract of the Tamarindus indica against Staphylococcus aureus (S. aureus) and Klebsiella pneumoniae (K. pneumoniae).

METHODS AND MATERIALS

Maceration technique was employed for subsequent extraction of the sample using acetone and ethanol. Antibacterial activity of the plant extract was investigated based on minimum inhibitory concentration (MIC) against Gram-negative strain (K. pneumoniae (ATCC 700603)) and Gram-positive strain (S. aureus (ATCC 25923)) using agar disc-diffusion technique.

RESULTS

It was found that both acetone and ethanol extracts showed significant antibacterial activities, against both S. aureus and K. pneumoniae as compared to the negative control (P = 0.00), but no significantly different from the drug (P > 0.05). However, K. pneumoniae showed more sensitivity to the extracts than S. aureus with MIC value of 18.75 mg/mL and 9.38 mg/mL for both acetone and ethanol extracts against S. aureus and K. pneumoniae respectively.

CONCLUSION

This study suggested that the fruit pulp have antibacterial properties, which might validate their traditional uses.

Dietary supplementation of phytoncide and soybean oil increases milk conjugated linoleic acid and depresses methane emissions in Holstein dairy cows

The objective of this study was to determine whether adding phytoncide oil (PO) and soybean oil (SBO) to the dairy cow diet could increase milk conjugated linoleic acid (CLA) and depress methane (CH4) emissions in Holstein dairy cows. Rumen fermentation was conducted at four levels of SBO (0, 1, 2, and 4%, on DM basis) and two levels of PO (0 and 0.1%, on DM basis) with in vitro experiment. To evaluate blood parameters, fecal microbe population, milk yield and fatty acid compositions, and CH4 production, in vivo experiment was conducted using 38 Holstein dairy cows divided into two groups of control (fed TMR) and treatment (fed TMR with 0.1% PO and 2% SBO as DM basis). In the in vitro study (Experiment 1), PO or SBO did not affect rumen pH. However, SBO tended to decrease ruminal ammonia-N (p = 0.099). Additionally, PO or SBO significantly decreased total gas production (p = 0.041 and p = 0.034, respectively). Both PO and SBO significantly decreased CH4 production (p < 0.05). In addition, PO significantly increased both CLA isomers (c9, t11 and t10, c12 CLA) (p < 0.001). Collectively, 0.1% PO and 2% SBO were selected resulting in most effectively improved CLA and decreased CH4 production. In the in vivo study (Experiment 2), 0.1% PO with 2% SBO (PSO) did not affect complete blood count. However, it decreased blood urea nitrogen and magnesium levels in blood (p = 0.021 and p = 0.01, respectively). PSO treatment decreased pathogenic microbes (p < 0.05). It increased milk yield (p = 0.017) but decreased percentage of milk fat (p = 0.013) and MUN level (p < 0.01). In addition, PSO treatment increased both the concentration of CLA and PUFA in milk fat (p < 0.01). Finally, it decreased CH4 emissions from dairy cows. These results provide compelling evidence that a diet supplemented with PSO can simultaneously increase CLA concentration and decrease CH4 production with no influence on the amount of milk fat (kg/day) in Holstein dairy cows.

Immunity, rumen metagenomics, ruminal variables, and growth performance of calves fed milk with sage (Salvia officinalis) essential oil

The study aimed to determine the effect of sage (Salvia officinalis) essential oil (EO) to the drinking milk until the weaning stage of Holstein calves on the growth performance, body measurements, ruminal fermentation, rumen metagenomic profile, proinflammatory cytokines [interleukin-6 (IL-6), tumor necrosis factor (TNF-α), and IL-1β], immune globulins (IgG, IgM, and IgE), and acute phase proteins (serum amyloid-A, SAA). In the study, 24 Holstein calves were divided into three groups as 0 μL (SAG0; control group), 100 μL (SAG100), or 200 μL (SAG200) of sage EO to the milk per calf per day. The addition of sage EO to the milk linearly increased the live weight, feed intake, and daily body weight gain (P < 0.05). The addition of sage EO to the milk in calves linearly increased serum IgG titter dose dependently (P < 0.05), but serum IgM and IgE titters did not change (P > 0.05). The concentrations of serum TNF-α, IL-1β, and IL-6 in the weaned calves linearly decreased by the sage aromatic oil addition to the milk (P < 0.05). The serum SAA concentrations of calves did not differ among the control and treatment groups (P > 0.05). Probiotic Bifidobacterium and Acidaminococcus genus in calf rumen fluid can increase by sage EO addition to milk. The relative abundance of genus Prevotella, Prevotellaceae_NK3B31_group, and Prevotella_9 increase with sage EO. The ruminal ammonia-nitrogen (NH3-N) concentration and total short chain fatty acid (T-SCFA) molarity decreased by sage EO addition to the drinking milk (P < 0.05). The molarities of iso butyric (IBA) and iso valeric acids (IVA) in rumen fluid of the weaned calves linearly reduced by the increasing sage EO dose to the milk (P < 0.05). The butyric acid (BA) and iso caproic acid (ICA) molarities in rumen fluid did not change by the sage EO addition (P > 0.05). Consequently, it has been observed that sage EO addition to the milk of calves positively affected the immune system variables and performance parameters. Sage EO addition of calves before weaning may support the immune system in the eventual immunosuppression at the weaning stage.

Assessing the In Vitro and In Vivo Effect of Supplementation with a Garlic (Allium sativum) and Oregano (Origanum vulgare) Essential Oil Mixture on Digestibility in West African Sheep

This study assessed the impact of a mixture of garlic (Allium sativum) and oregano (Origanum vulgare) essential oils (EOGOs) on in vitro dry matter digestibility (IVDMD) and in vivo apparent nutrient digestibility. Different EOGO inclusion levels were evaluated to assess the dose response and potential effects of the mixture. Three EOGO inclusion levels (0.5, 0.75, and 1 mL/kg of incubated dry matter) were evaluated in vitro, while four treatments (0.5, 0.75, and 1 mL/day of EOGO and a control group) were tested in vivo on 12 West African sheep. A randomized controlled trial was conducted using a 4 × 4 design. Blood parameters (glucose, blood urea nitrogen, and β-hydroxybutyrate) were measured to observe the effect of EOGO on the metabolism. The results showed that the inclusion of EOGO significantly enhanced IVDMD at low levels (p < 0.052) compared with the highest levels in treatments containing 0.5 and 0.75 mL/kg of EOGO dry matter. A higher intake of dry matter (DM), crude protein (CP), and neutral detergent fiber (NDF) (p < 0.05) was observed in the in vivo diets with the inclusion of EOGO. In terms of in vivo apparent digestibility, significant differences were found among treatments in the digestibility coefficients of DM, CP, and NDF. EOGO inclusion increased the digestibility of DM. CP digestibility displayed a cubic effect (p < 0.038), with the lowest values of digestibility observed at 1 mL EOGO inclusion. Additionally, NDF digestibility showed a cubic effect (p < 0.012), with the highest value obtained at 0.75 mL of EOGO inclusion. The inclusion levels above 0.75 mL EOGO showed a cubic effect, which indicates that higher concentrations of EOGO may not be beneficial for the digestibility of CP and NDF. Although no significant difference was observed in total digestible nutrients, a linear trend was observed (p < 0.059). EOGO improved the intake of DM, CP, and NDF. EOGO supplementation improved the digestibility of DM and NDF, with optimal levels observed at 0.5 mL/day. No significant effects were observed in the blood parameters. These results suggest that EOGO has the potential as an additive in ruminal nutrition to improve food digestibility and serve as an alternative to antibiotic additives. The use of EOGO potentially improves fiber digestion and may reduce the use of antibiotics in livestock production. Garlic (A. sativum) and oregano (O. vulgare) essential oils effectively modulated fiber digestibility at 0.75 mL/day. Garlic (A. sativum) and oregano (O. vulgare) essential oils have the potential to improve digestibility at low inclusion levels and serve as an alternative to antibiotic additives. The effectiveness of essential oils is greater in a mixture and at lower doses.

Can a blend of integrated feed additives modulate ruminal fermentation patterns and performance of growing lambs? In vitro and in vivo assessments

Two in vitro and in vivo experiments were accomplished to investigate the impacts of integrated feed additives (IFA, combination of protected fat, lysine, and methionine plus yucca extract, eucalyptus essential oil, and direct-fed microbial) on gas production (GP), ruminal fermentation and degradability parameters and lamb performance, digestibility, and nitrogen balance. In the in vitro experiment, responses of graded doses (0, 25, 50, 75, 100, and 125 g IFA/kg DM) were evaluated. In the in vivo experiment, 15 Barki male lambs (30.43 ± 0.74 kg BW ± SE) were individually allotted in complete randomized design into three treatments (five animal/treatment) as control (basal diet without additive), low dose (50 g/kg DM) and high dose (100 g/kg DM) for 120 days. In vitro results showed that both doses (100 and 125 g/kg DM) quadratically decreased (p < 0.001) GP and ammonia nitrogen (NH-3N) concentration. In vivo experiment revealed that dry matter intake was increased (p = 0.016) with low dose compared to high dose. Inclusion of high dose decreased blood serum glucose concentrations (p > 0.05) and ruminal protozoal populations (p = 0.094) compared with low dose and control diet. Both doses of IFA increased (p < 0.05) serum urea, creatinine, and triglyceride concentrations, while decreased (p < 0.001) ruminal NH3-N concentrations. These results suggested that, although IFA was effective to modify in vitro ruminal fermentation process and feed degradability, such aspects did not improve in vivo performance of growing lambs.

Evaluation of radioactivity levels and radiological hazards of some endemic plants used as medicine in Ankara, Turkey

In this study, natural radioactivity levels (226Ra, 232Th, and 4 K) of some medicinal plant samples with known anti-oxidative properties, which are frequently consumed by animals and humans, were obtained from Ankara province and its surroundings (Mamak, Kızılcahamam, Beypazarı, Kahramankazan, and Polatlı districts) were determined using a thallium-doped sodium iodide NaI(Tl) gamma spectrometry. By using the determined natural radioactivity concentrations in the collected plant samples, the number of radiological doses that people could be exposed by consuming these plants was calculated. As a result of the study, 226Ra, 232Th, and 4 K radioactivity concentration ranges of the plant samples were found be 14.69 ± 1.27-59.08 ± 3.12 Bq kg-1, 1.78 ± 0.04-50.05 ± 2.76 Bq kg-1 and 207.24 ± 34.09-826.13 ± 25.40 Bq kg-1, respectively. The highest 226Ra, 232Th, and 4 K activity concentrations were measured in Astragalus densifolius subsp. ayashensis (Kahramankazan), Astragalus kochakii (Kahramankazan) and Rumex patientia (Patience Dock) (Kahramankazan) plants, respectively. The lowest 226Ra, 232Th and,4 K activity concentration plants were determined respectively as Rumex patientia (Mamak), Lavandula angustifolia (Kızılcahamam), and Astragalus acikirensis (Polatlı). The establishment and routine repetition of environmental radioactivity monitoring programs in each region are important for human and animal health, and the results of this study gain importance for Ankara and its surroundings in terms of environmental health.

Antimicrobial Properties of Capsaicin: Available Data and Future Research Perspectives

Capsaicin is a phytochemical derived from plants of the genus Capsicum and subject of intensive phytochemical research due to its numerous physiological and therapeutical effects, including its important antimicrobial properties. Depending on the concentration and the strain of the bacterium, capsaicin can exert either bacteriostatic or even bactericidal effects against a wide range of both Gram-positive and Gram-negative bacteria, while in certain cases it can reduce their pathogenicity by a variety of mechanisms such as mitigating the release of toxins or inhibiting biofilm formation. Likewise, capsaicin has been shown to be effective against fungal pathogens, particularly Candida spp., where it once again interferes with biofilm formation. The parasites Toxoplasma gondi and Trypanosoma cruzi have been found to be susceptible to the action of this compound too while there are also viruses whose invasiveness is significantly dampened by it. Among the most encouraging findings are the prospects for future development, especially using new formulations and drug delivery mechanisms. Finally, the influence of capsaicin in somatostatin and substance P secretion and action, offers an interesting array of possibilities given that these physiologically secreted compounds modulate inflammation and immune response to a significant extent.

Protective Effects of a Polyphenolic Phytochemical Quercetin against Oxidative Dysfunctions in Rats

Background

Quercetin hastraditionally been used in various oxidative and urinary tract dysfunctions. Thecurrent project is consequently set to evaluate the defensive efficacy ofQuercetin against potassium bromate (KBrO3) induced testiculartissue oxidative dysfunctions through biochemical, hormonal, and genotoxicmarkers.

Methods

To observe theprotective efficacy of Quercetin against urinogenital oxidative dysfunction inrats, thirty six albino male rats were divided into six groups. Protectiveefficacies of Quercetin were checked on reproductive hormonal levels,antioxidant enzyme activities, lipids peroxidation (LP), and DNA damages.

Results

Potassium bromate exposure in experimentalanimals caused a reduction in the activities of antioxidant enzymes and disturbedhormonal secretions while enhancing the peroxidation of lipids andfragmentations of DNA. Cotreatment of Quercetin considerably (P<0.01)reversed these abnormalities with admiration to levels of hormones, antioxidantenzymes activities, and peroxidations of lipids secure to those seen inuntreated rats. (P < 0.01).

Conclusion

The findings of the current project revealedthat various doses of Quercetin are able to keep the testicular organ fromabnormal free radical dysfunctions. These improvements might be due to theantioxidant ability of polyphenolic bioactive constituent, i.e., Quercetin.

Effects of Supplemented Resveratrol on In Vitro Ruminal Fermentation and Growth Performance of Hanwoo Calves

We investigated the effects of resveratrol supplementation on in vitro ruminal fermentation and growth performance of Hanwoo calves. Treatment with three resveratrol concentrations (0%, 0.1%, 0.3%, and 0.5%) was used for in vitro ruminal fermentation. Resveratrol concentrations and pH of rumen fluid were negatively correlated (p < 0.05); therefore, total gas production, total volatile fatty acids, and acetate, propionate, and butyrate levels were significantly higher in the treatments than in the control at all time periods (p < 0.05). The appropriate resveratrol concentration that could be added without negative effects on the rumen was 0.3%. In farm experiments, we divided 14 Korean cattle calves into control (C) and 0.3% resveratrol (T) groups. There were no significant differences in the daily weight gain, feed conversion, final body weight, body length, withers height, and height at hip cross in the resveratrol-fed Hanwoo calves. Immunoglobulin G level was significantly higher in the treatment than in the control (p < 0.05), but IgA and IgM levels did not differ. Supplemental feeding of resveratrol is beneficial to in vitro ruminal fermentation, but it is important to supplement it at 0.3%. Furthermore, resveratrol affects calf immunoglobulin G.

Hydrolats from Humulus lupulus and Their Potential Activity as an Organic Control for Varroa destructor

Varroa destructor is a parasitic mite, which is considered a severe pest for honey bees causing serious losses to beekeeping. Residual hydrolats from steam extraction of hop essential oils, generally considered as a waste product, were tested for their potential use as acaricides on V. destructor. Four hop varieties, namely Cascade, Spalt, Victoria, and Mapuche, showed an interesting performance as feasible products to be used in the beekeeping industry. Some volatile oxidized terpenoids were found in the hydrolats, mainly β-caryophyllene oxide, β-linalool, and isogeraniol. These compounds, together with the presence of polyphenols, flavonoids, and saponins, were probably responsible for the promissory LC₅₀ values obtained for mites after hydrolat exposition. Victoria hydrolat was the most toxic for mites (LC₅₀: 16.1 µL/mL), followed by Mapuche (LC₅₀ value equal to 30.1 µL/mL), Spalt (LC₅₀ value equal to 114.3 µL/mL), and finally Cascade (LC₅₀: 117.9 µL/mL). Likewise, Spalt had the highest larval survival, followed by Victoria and Mapuche. Cascade was the variety with the highest larval mortality. In addition, none of the extracts showed mortality higher than 20% in adult bees. The Victoria hydrolat presented the best results, which makes it a good compound with the prospect of an acaricide treatment against V. destructor.

Kaempferol: Antimicrobial Properties, Sources, Clinical, and Traditional Applications

Flavonoids are a category of plant-derived compounds which exhibit a large number of health-related effects. One of the most well-known and studied flavonoids is kaempferol, which can be found in a wide variety of herbs and plant families. Apart from their anticarcinogenic and anti-inflammatory effects, kaempferol and its associated compounds also exhibit antibacterial, antifungal, and antiprotozoal activities. The development of drugs and treatment schemes based on these compounds is becoming increasingly important in the face of emerging resistance of numerous pathogens as well as complex molecular interactions between various drug therapies. In addition, many of the kaempferol-containing plants are used in traditional systems all over the world for centuries to treat numerous conditions. Due to its variety of sources and associated compounds, some molecular mechanisms of kaempferol antimicrobial activity are well known while others are still under analysis. This paper thoroughly documents the vegetal and food sources of kaempferol as well as the most recent and significant studies regarding its antimicrobial applications.

Digestibility, Blood Parameters, Rumen Fermentation, Hematology, and Nitrogen Balance of Goats after Receiving Supplemental Coffee Cherry Pulp as a Source of Phytochemical Nutrients

This research examines the impact of adding dried coffee cherry pulp (CoCP) to goat feed on the digestibility of the feed, rumen fermentation, hematological, and nitrogen balance. A goat feeding experiment employed four male crossbreds (Thai Native × Anglo Nubian) aged 12 months and weighing 21.0 ± 0.2 kg each. The treatment was conceived as a 4 × 4 Latin square with four specific CoCP levels at 0, 100, 200, and 300 g/day. Dry matter intake (DMI), organic matter intake (OMI), and crude protein intake (CPI) were unaffected by the addition of CoCP. However, across treatment groups, there was a linear increase in ether extract intake (EEI) (p < 0.01), neutral detergent fiber intake (NDFI) (p = 0.06), and acid detergent fiber intake (ADFI) (p = 0.04), as well as a quadratic effect on DMI% BW (p = 0.04). The findings showed that rumen temperature, pH, ammonia-nitrogen, or pack cell volume did not change with CoCP supplementation. Total volatile fatty acid showed linear effects on acetate (p = 0.03) and was quadratically affected by propionate concentration (p = 0.02), acetate to propionate ratio (p = 0.01), acetic plus butyric to propionic acid ratio (p = 0.01), and methane estimation (p = 0.01). With increased CoCP supplementation, there was a linear decrease in protozoa count by about 20.2% as the amount of CoCP supplemented increased (p = 0.06). CoCP supplementation in animal feed resulted in a linear decrease in urinary nitrogen (p = 0.02) and a quadratic effect on absorbed nitrogen (p = 0.08) among treatment groups, with greater N utilization values found in goats fed 200 g/d CoCP. In light of this, supplementing CoCP into animal feed may improve animal digestion and rumen fermentation effectiveness while having no effect on feed intake, rumen microbes, or blood metabolites.

Effect of Zanthoxylum bungeanum essential oil on rumen enzyme activity, microbiome, and metabolites in lambs

Antibiotics were once used in animal production to improve productivity and resistance to pathogenic microbiota. However, due to its negative effects, the search for a new class of substances that can replace its efficacy has become one of the urgent problems to be solved. Plant essential oils (EOs) as a natural feed additive can maintain microbiota homeostasis and improve animal performance. However, its specific mechanism of action needs to be further investigated. Therefore, we added different doses of essential oil of Zanthoxylum bungeanum (EOZB) to the diets of Small Tail Han Sheep hybrid male lambs (STH lambs) to evaluate the effect of EOZB on rumen enzyme activity, rumen microbiology, and its metabolites in STH lambs. Twenty STH lambs were randomly divided into four groups (n = 5/group) and provided with the same diet. The dietary treatments were as follows: basal diet (BD) group; BD+EOZB 5 ml/kg group; BD+EOZB 10 ml/kg group; BD+EOZB 15 ml/kg group. We found that EOZB 10 ml/kg helped to increase rumen pectinase (P<0.05) and lipase (P<0.05) activities. Microbial 16S rRNA gene analysis showed that EOZB significantly altered the abundance of rumen microbiota (P<0.05). LC/GC-MS metabolomic analysis showed that the addition of EOZB produced a total of 1073 differential metabolites, with 58 differential metabolites remaining after raising the screening criteria. These differential metabolites were mainly enriched in glycerophospholipid metabolism, choline metabolism in cancer, retrograde endocannabinoid signaling, benzoxazinoid biosynthesis, and protein digestion and absorption. Correlation analysis showed that some rumen microbiota were significantly correlated with differential metabolite and enzyme activities.

Residual feed intake in peripartal dairy cows is associated with differences in milk fat yield, ruminal bacteria, biopolymer hydrolyzing enzymes, and circulating biomarkers of immunometabolism

Residual feed intake (RFI) measures feed efficiency independent of milk production level, and is typically calculated using data past peak lactation. In the current study, we retrospectively classified multiparous Holstein cows (n = 320) from 5 of our published studies into most feed-efficient (M-eff) or least feed-efficient (L-eff) groups using performance data collected during the peripartal period. Objectives were to assess differences in profiles of plasma biomarkers of immunometabolism, relative abundance of key ruminal bacteria, and activities of digestive enzymes in ruminal digesta between M-eff and L-eff cows. Individual data from cows with ad libitum access to a total mixed ration from d -28 to d +28 relative to calving were used. A linear regression model including dry matter intake (DMI), energy-corrected milk (ECM), changes in body weight (BW), and metabolic BW was used to classify cows based on RFI divergence into L-eff (n = 158) and M-eff (n = 162). Plasma collected from the coccygeal vessel at various times around parturition (L-eff = 60 cows; M-eff = 47 cows) was used for analyses of 30 biomarkers of immunometabolism. Ruminal digesta collected via esophageal tube (L-eff = 19 cows; M-eff = 29 cows) was used for DNA extraction and assessment of relative abundance (%) of 17 major bacteria using real-time PCR, as well as activity of cellulase, amylase, xylanase, and protease. The UNIVARIATE procedure of SAS 9.4 (SAS Institute Inc.) was used for analyses of RFI coefficients. The MIXED procedure of SAS was used for repeated measures analysis of performance, milk yield and composition, plasma immunometabolic biomarkers, ruminal bacteria, and enzyme activities. The M-eff cows consumed less DMI during the peripartal period compared with L-eff cows. In the larger cohort of cows, despite greater overall BW for M-eff cows especially in the prepartum (788 vs. 764 kg), no difference in body condition score was detected due to RFI or the interaction of RFI × time. Milk fat content (4.14 vs. 3.75 ± 0.06%) and milk fat yield (1.75 vs. 1.62 ± 0.04 kg) were greater in M-eff cows. Although cumulative ECM yield did not differ due to RFI (1,138 vs. 1,091 ± 21 kg), an RFI × time interaction due to greater ECM yield was found in M-eff cows. Among plasma biomarkers studied, concentrations of nonesterified fatty acids, β-hydroxybutyrate, bilirubin, ceruloplasmin, haptoglobin, myeloperoxidase, and reactive oxygen metabolites were overall greater, and glucose, paraoxonase, and IL-6 were lower in M-eff compared with L-eff cows. Among bacteria studied, abundance of Ruminobacter amylophilus and Prevotella ruminicola were more than 2-fold greater in M-eff cows. Despite lower ruminal activity of amylase in M-eff cows in the prepartum, regardless of RFI, we observed a marked linear increase after calving in amylase, cellulase, and xylanase activities. Protease activity did not differ due to RFI, time, or RFI × time. Despite greater concentrations of biomarkers reflective of negative energy balance and inflammation, higher feed efficiency measured as RFI in peripartal dairy cows might be associated with shifts in ruminal bacteria and amylase enzyme activity. Further studies could help address such factors, including the roles of the liver and the mammary gland.

Effect of Amomum villosum essential oil as an additive on the chemical composition, fermentation quality, and bacterial community of paper mulberry silage

Paper mulberry (Broussonetia papyrifera L., PM) is being used as a new type of animal protein feed to address the feed crisis. To investigate the effect of additives on the chemical composition, fermentation quality, and bacterial community of PM silage (at room temperature, 25°), paper mulberry was fermented with formic acid (FA), Amomum villosum essential oil (AVEO) and lactic acid bacteria (LAB) inoculant treatments. The results showed that fresh PM had a low water-soluble carbohydrate (WSC) content and large amounts of unclassified bacteria. Compared with the CK and LAB treatments, the FA and AVEO treatments significantly (P &lt; 0.05) decreased the pH and increased the lactic acid content of PM silage after 60 days of ensiling. In the AVEO-treated silages the abundance of Lactococcus in the early stage of ensiling increased by 14.09%, the abundances of Levilactobacillus and Lentilactobacillus in the late stage of ensiling increased by 58.34 and 91.12%, respectively, and the abundance of Stenotrophomonas decreased by 94.71%, resulting in improved PM silage quality. These results confirmed that AVEO could potentially be developed as a new additive for improving the fermentation quality of silage.

Plant secondary metabolites and primate food choices: A meta-analysis and future directions

The role of plant secondary metabolites (PSMs) in shaping the feeding decisions, habitat suitability, and reproductive success of herbivorous mammals has been a major theme in ecology for decades. Although primatologists were among the first to test these ideas, studies of PSMs in the feeding ecology of non-human primates have lagged in recent years, leading to a recent call for primatologists to reconnect with phytochemists to advance our understanding of the primate nutrition. To further this case, we present a formal meta-analysis of diet choice in response to PSMs based on field studies on wild primates. Our analysis of 155 measurements of primate feeding response to PSMs is drawn from 53 studies across 43 primate species which focussed primarily on the effect of three classes of PSMs tannins, phenolics, and alkaloids. We found a small but significant effect of PSMs on the diet choice of wild primates, which was largely driven by the finding that colobine primates showed a moderate aversion to condensed tannins. Conversely, there was no evidence that PSMs had a significant deterrent effect on food choices of non-colobine primates when all were combined into a single group. Furthermore, within the colobine primates, no other PSMs influenced feeding choices and we found no evidence that foregut anatomy significantly affected food choice with respect to PSMs. We suggest that methodological improvements related to experimental approaches and the adoption of new techniques including metabolomics are needed to advance our understanding of primate diet choice.

Effect of environment and field management strategies on phenolic acid profiles of hard red winter wheat genotypes

BACKGROUND

Integrated wheat management strategies can affect grain yield and flour end-use properties. However, the effect of integrated management and its interaction with environmental factors on the phenolic acid profiles of wheat has not been reported. The phenolic acid profile has become another parameter for the evaluation of wheat quality due to its potential health benefits.

RESULTS

Year × location × management and year × management × genotype interactions were significant for the total phenolic content (TPC) of wheat samples. The year × location × management × genotype interaction was significant for the concentration of trans-ferulic acid and several other phenolic acids. Field management practices with no fungicide application (e.g., farmer's practice, enhanced fertility) may lead to increased accumulation of phenolic compounds, especially for WB4458, which is more susceptible to fungi infection. However, this effect was also related to growing year and location. Higher soil nitrogen content at sowing also seems to affect the TPC and phenolic acid concentration positively.

CONCLUSION

Wheat phenolic acid profiles are affected by genotype, field management, environment, and their interactions. Intensified field management, in particular, may lead to decreased concentration of wheat phytochemicals. The level of naturally occurring nitrogen in the soil may also affect the accumulation of wheat phytochemicals. © 2021 Society of Chemical Industry.

Effects of essential oil mixtures on nitrogen metabolism and odor emission via in vitro simulated digestion and in vivo growing pig experiments

BACKGROUND

Essential oils (EOs) are extensively used in swine production because of their bioactive action in gut health. In addition, some EOs have the potential to reduce waste emission. The present study aimed to find an optimal combination of carvacrol, thymol and cinnamaldehyde to promote nitrogen utilization and reduce waste emission by a model in vitro and an animal study.

RESULTS

In the study in vitro, various dosages of essential oils (EOs) were used to evaluate the effect on nitrogen metabolism through a three-step model. Compared with other EO combinations, 2EO (10 ppm cinnamaldehyde and 20 ppm thymol), and 3EO (10 ppm cinnamaldehyde, 20 ppm thymol and 200 ppm carvacrol) displayed greater nitrogen digestibility, lesser ammonia production and lower activity of microbial enzymes. In the animal study, growing male Landrace × Yorkshire pigs (initial body weight: 31.8 ± 3.3 kg, n = 18) were randomly divided into three groups and fed the control, 2EO or 3EO diet for 4 weeks. Pigs fed 3EO exhibited the greatest nitrogen digestibility (85.4%, P < 0.05). EO supplementation decreased the emission of ammonia (130-140 vs. 223 mg g^-1 ) and total fecal nitrogen (8.0-9.9 vs. 12.4 g d^-1 ) (P < 0.05). Microbial protease and urease activities were inhibited by EO treatments (P < 0.01). Both 2EO and 3EO reduced the content of indole and 3-methylindole (P < 0.01), whereas only 2EO caused a decrease in p-cresol (P < 0.1).

CONCLUSION

2EO was suitable for reducing waste emission and odorous compounds in growing pigs, whereas 3EO was optimal for increasing nitrogen utilization and partially reducing waste odorous compounds. © 2021 Society of Chemical Industry.

Changes in Carbohydrate Composition in Fermented Total Mixed Ration and Its Effects on in vitro Methane Production and Microbiome

The purpose of this experiment was to investigate the changes of carbohydrate composition in fermented total mixed diet and its effects on rumen fermentation, methane production, and rumen microbiome in vitro. The concentrate-to-forage ratio of the total mixed ration (TMR) was 4:6, and TMR was ensiled with lactic acid bacteria and fibrolytic enzymes. The results showed that different TMRs had different carbohydrate compositions and subfractions, fermentation characteristics, and bacterial community diversity. After fermentation, the fermented total mixed ration (FTMR) group had lower contents of neutral detergent fiber, acid detergent fiber, starch, non-fibrous carbohydrates, and carbohydrates. In addition, lactic acid content and relative abundance of Lactobacillus in the FTMR group were higher. Compared with the TMR group, the in vitro ammonia nitrogen and total volatile fatty acid concentrations and the molar proportion of propionate and butyrate were increased in the FTMR group. However, the ruminal pH, molar proportion of acetate, and methane production were significantly decreased in the FTMR group. Notably, we found that the relative abundance of ruminal bacteria was higher in FTMR than in TMR samples, including Prevotella, Coprococcus, and Oscillospira. At the same time, we found that the diversity of methanogens in the FTMR group was lower than that in the TMR group. The relative abundance of Methanobrevibacter significantly decreased, while the relative abundances of Methanoplanus and vadinCA11 increased. The relative abundances of Entodinium and Pichia significantly decreased in the FTMR group compared with the TMR group. These results suggest that FTMR can be used as an environmentally cleaner technology in animal farming due to its ability to improve ruminal fermentation, modulate the rumen microbiome, and reduce methane emissions.

Dose-response effects of the Savory (Satureja khuzistanica) essential oil and extract on rumen fermentation characteristics, microbial protein synthesis and methane production in vitro

The objective of the present study was to investigate dose-response effects of the essential oil (EO) and dry extract (EX) of Satureja khuzistanica (SK) on in vitro gas production kinetics, rumen fermentation, ruminal methanogenesis and microbial protein synthesis. So, EO and EX were tested at 0 (as control); 150 (low dose); 300, 450 (intermediate doses) and 600 mg/L (high dose). The gas produced over 24 h of incubation (GP24) decreased linearly with both EO and EX dosages (P<0.01). In vitro methane production was reduced by both EO (14–69%, depending on the included dose) and EX (7–58%). Microbial protein (MP) as well as the efficiency of microbial protein synthesis (EMPS) were improved by EO (18.8–49.8% and 20.4–61.5% for MP and EMPS, respectively) and to a lesser extent by EX (8.3–25.7% and 4.6–24.2% for MP and EMPS, respectively). Ammonia concentration was dropped in linear and quadratic manners with EO (P<0.05), and linearly with EX dosages (P<0.01). EO and EX exhibited depressive effects (in linear and quadratic (P<0.05), and linear manners (P<0.01), respectively) on total protozoa count. A mixed linear and quadratic effect was observed from both EO and EX on total VFA concentration (P<0.01). Total VFA concentration increased at 300 mg/L of EX, but decreased at high dose of both EO and EX. The acetate proportion increased with EO intermediate and high dosages, but it decreased at the expense of propionate at low and intermediate doses of EX. In total, these findings confirmed previous research on the great capacity of plant-based feed additives in positively modulating rumen fermentation that their effects may vary depending on the used doses. Specifically, these results suggest that EO and EX have high potentials to improve rumen functions at intermediate doses, which needs to be confirmed by in vivo experiments.

Monensin associated or not with virginiamycin or functional oil for feedlot beef cattle

The objective of this study was to evaluate diets containing monensin (MON) associated or not with virginiamycin (VM) or functional oil based on cashew nut shell and castor beans (FO_cc) for beef cattle in feedlots on nutritional (intake and digestibility) and productive parameters. A total of 1410 non-castrated Nellore cattle were selected, with an average age of 18 months and with an initial mean body weight (BW) of 305 ± 41.52 kg. The diet showed a roughage to concentrate ratio of 23:77, with the supply of corn silage as a source of roughage. The following additive inclusions in the diet were evaluated: (1) MON: 27 mg MON/kg dry matter (DM); (2) MON + VM: 22 mg MON/kg DM + 19 mg VM/kg DM; and (3) MON + FO_cc: 22 mg MON/kg DM + 500 mg FO_cc/kg DM. Statistical analyses were obtained through a linear model using initial BW and days of feedlot as covariables and comparisons between treatments using mutually orthogonal linear contrasts with a 5% significance level. The association or not of MON with VM or FO_cc does not affect any of the nutritional and productive parameters evaluated. Animals that receive diets with MON + VM have higher average daily gain and feed efficiency (FE) than those that receive MON + FO_cc without showing differences in nutritional parameters. The supply of MON associated with VM or FO_cc does not increase intake and productive performance and, consequently, efficiency of feedlot beef cattle. However, in the case of use associated with MON, the VM provides greater performance than FO_cc without changing food intake.

Growth Performance, Biochemical Blood Indices, and Large Intestine Physiology of Rats Fed Diets with Alfalfa Protein-Xanthophyll Concentrate

The effect of dietary levels of alfalfa protein-xanthophyll concentrate (PXC) was determined in growing rats. Three groups of eight four-week-old male Wistar rats, with an average initial body weight of 61 g, were fed for 28 days either natural-ingredient diets without PXC or supplemented with 1.5% or 3% PXC. Growth performance, blood biochemistry, caecal fermentation, morphology of the large intestine, and mucin gene expression were evaluated. PXC did not affect growth performance but tended to decrease relative liver weight. Among biochemical blood parameters, only bilirubin decreased and uric acid increased in response to 1.5% and 3% PXC, respectively. Caecal fermentation was not affected, with the exception of isovaleric acid concentration, which tended to be higher in rats fed the diet containing 3% PXC. Colonic crypts tended to be deeper in rats fed the 3% PXC diet and the thickness of the colonic mucus layer was reduced by both PXC levels. In conclusion, PXC did not affect growth performance or caecal fermentation but decreased thickness of the protective mucus layer in the colon.

Phytochemistry and pharmacological studies of Plumbago zeylanica L.: a medicinal plant review

Plumbago zeylanica L. (Plumbaginaceae) commonly known, as chitrak is pharmacologically important plant. Various studies have been undertaken to assess the pharmacological potential of different parts of the plant namely like roots, stem, flower, and leaves as antimicrobial, hepatoprotective, anticancer, antifertility, antiulcer, antifungal and wound healing. The intention of the present review is to deliver a concise account on its ethnobotanical uses, phytochemistry with an in-depth study of its phytoconstituents, facts and prospects of its potential pharmacological activities of this golden plant. An extensive literature survey was undertaken through different online platforms viz. Google Scholar and online databases namely PubMed, Science Direct and Springer. All papers based on traditional medicinal uses and pharmacological properties were included. Sixty three research articles and review articles were found to be apt for inclusion into the review. About 150 articles were retrieved for the purpose. The elaborative results vindicated that Plumbago zeylanica L. holds significant prospects in major health conditions such as diabetes, cardiovascular disorders, ulcer, liver problems, obesity, wound healing, cancer etc.

Effects of Cornus and Its Mixture with Oregano and Thyme Essential Oils on Dairy Sheep Performance and Milk, Yoghurt and Cheese Quality under Heat Stress

The effect of a diet supplemented with a novel cornus extract, enriched with essential oils of oregano and thyme, on the performance of Chios cross-bred dairy sheep was investigated during the summer period. The plant extracts were prepared using a "green" method based on aqueous extraction. A total of 45 lactating ewes were allocated into three equal groups in a randomized block design. The three groups were fed the same feed allowance, roughage based on Lucerne hay and wheat straw and a concentrate based on cereals and oil cakes (the control diet). The diet of two groups was fortified with cornus extract, with or without oregano and thyme essential oils, at a level 0.515 g of plant extract/essential oils per kg of concentrate. Individual milk yield was recorded weekly and feed refusals were recorded on a pen basis daily, during a six-week period of lactation. Milk samples were analyzed for the chemical composition of protein, fat, lactose and solids-not-fat constituents, somatic cell counts and total viable bacteria counts. Moreover, the milk of each group was used for yoghurt and Feta cheese production. The lipid oxidative stability, protein carbonyl content and fatty acid composition of milk, yoghurt and cheese samples were also evaluated. The results showed that the incorporation of novel plant extracts and essential oils increased the milk production per ewe. Dietary supplementation with cornus extracts and essential oils lowered lipid and protein oxidation in milk, yoghurt and cheese samples, compared to the control. However, diet supplementation with herbal extracts did not affect the fatty acid profile in milk, cheese and yoghurt or the serum biochemical parameters. In conclusion, dietary supplementation with cornus in combination with oregano and thyme has the potential to improve feed utilization and the performance of high-yield dairy Chios cross-bred ewes reared under heat stress.

In Vitro Screening of East Asian Plant Extracts for Potential Use in Reducing Ruminal Methane Production

Indiscriminate use of antibiotics can result in antibiotic residues in animal products; thus, plant compounds may be better alternative sources for mitigating methane (CH₄) production. An in vitro screening experiment was conducted to evaluate the potential application of 152 dry methanolic or ethanolic extracts from 137 plant species distributed in East Asian countries as anti-methanogenic additives in ruminant feed. The experimental material consisted of 200 mg total mixed ration, 20 mg plant extract, and 30 mL diluted ruminal fluid-buffer mixture in 60 mL serum bottles that were sealed with rubber stoppers and incubated at 39 °C for 24 h. Among the tested extracts, eight extracts decreased CH₄ production by >20%, compared to the corresponding controls: stems of Vitex negundo var. incisa, stems of Amelanchier asiatica, fruit of Reynoutria sachalinensis, seeds of Tribulus terrestris, seeds of Pharbitis nil, leaves of Alnus japonica, stem and bark of Carpinus tschonoskii, and stems of Acer truncatum. A confirmation assay of the eight plant extracts at a dosage of 10 mg with four replications repeated on 3 different days revealed that the extracts decreased CH₄ concentration in the total gas (7-15%) and total CH₄ production (17-37%), compared to the control. This is the first report to identify the anti-methanogenic activities of eight potential plant extracts. All extracts decreased ammonia (NH₃-N) concentrations. Negative effects on total gas and volatile fatty acid (VFA) production were also noted for all extracts that were rich in hydrolysable tannins and total saponins or fatty acids. The underlying modes of action differed among plants: extracts from P. nil, V. negundo var. incisa, A. asiatica, and R. sachalinensis resulted in a decrease in total methanogen or the protozoan population (p < 0.05) but extracts from other plants did not. Furthermore, extracts from P. nil decreased the population of total protozoa and increased the proportion of propionate among VFAs (p < 0.05). Identifying bioactive compounds in seeds of P. nil by gas chromatography-mass spectrometry analysis revealed enrichment of linoleic acid (18:2). Overall, seeds of P. nil could be a possible alternative to ionophores or oil seeds to mitigate ruminal CH₄ production.

Meta-analysis of the effects of essential oil as an alternative to monensin in diets for beef cattle

Additives used to improve feed efficiency of beef cattle on high-grain diets requires products that not only increase animal performance but also provide food safety for consumers. Since phytogenic additives such as essential oils (EO) are the main substitutes for monensin in the diet of cattle fed high-grain diets, this study aimed to evaluate, through meta-analysis, the effects of EO as an alternative to monensin in diets for beef cattle on feed intake, performance, carcass characteristics and ruminal fermentative parameters. Ten peer-reviewed publications with 27 treatment means were included in the data set. These effects were evaluated using random-effect models to examine the weighted mean differences (WMD) between EO treatment and control treatment (diets with monensin). Heterogeneity was explored by meta-regression and subgroup analysis. The substitution of EO for monensin did not affect methane production, ruminal pH values, average daily gain, feed efficiency or carcass weight. However, carcass dressing percentage (WMD = 0.38%; P = 0.03), ribeye area (WMD = 0.82 cm²; P < 0.0001) and subcutaneous fat thickness (WMD = 0.56 mm; P < 0.0001) values increased. Although the use of EO instead of monensin had no influence on the performance of beef cattle fed high-grain diets, the prevalence of hepatic abscesses increased 84.9% and the replacement of monensin by EO increased the risk ratio of hepatic abscess prevalence by 107%. Therefore, the use of EO in high-grain beef cattle diets was ineffective in protecting the liver against abscesses.

Strategic supplementation of Flemingia silage to enhance rumen fermentation efficiency, microbial protein synthesis and methane mitigation in beef cattle

Background

Good quality protein as an on-farm feed resource has been in great demand to support the productivity of ruminants. A digestion trial using beef cattle crossbreds was conducted to assess the four dietary treatments of Flemingia macrophylla silage (FMS) supplementation at 0, 0.2, 0.4 and 0.6 kg dry matter (DM)/day in a 4 × 4 Latin square design. Feed DM intakes were measured during the 14 days and sample of feeds, feces, urine, as well as rumen fluid and blood were collected during the 7 days while the animals were on metabolism crates.

Results

Based on this experiment strategic supplementation of FMS increased (P < 0.05) nutrients digestibility (organic matter, crude protein, and acid detergent fiber) enhanced rumen total volatile fatty acid production especially propionic acid (C₃), C₂:C₃ ratio while, remarkably promoted the microbial protein synthesis (MPS) by increasing N-balance and retention of purine derivatives.

Conclusions

Under this experiment, the results revealed the potential use of FMS as a good-quality feed to improve nutrients digestibility, rumen fermentation, microbial protein synthesis, and to mitigate methane production. FMS supplementation at 0.6 kg DM/day exhibited the best result.

Nematocidal Effects of a Coriander Essential Oil and Five Pure Principles on the Infective Larvae of Major Ovine Gastrointestinal Nematodes In Vitro

The anthelmintic effects of extracted coriander oil and five pure essential oil constituents (geraniol, geranyl acetate, eugenol, methyl iso-eugenol, and linalool) were tested, using larval motility assay, on the third-stage larvae (L3s) of Haemonchus contortus, Trichostrongylus axei, Teladorsagia circumcincta, Trichostrongylus colubriformis, Trichostrongylus vitrinus and Cooperia oncophora. Coriander oil and linalool, a major component of tested coriander oil, showed a strong inhibitory efficacy against all species, except C. oncophora with a half maximal inhibitory concentration (IC50) that ranged from 0.56 to 1.41% for the coriander oil and 0.51 to 1.76% for linalool. The coriander oil and linalool combinations conferred a synergistic anthelmintic effect (combination index [CI] <1) on larval motility comparable to positive control (20 mg/mL levamisole) within 24 h (p < 0.05), reduced IC50 values to 0.11-0.49% and induced a considerable structural damage to L3s. Results of the combined treatment were validated by quantitative fluorometric microplate-based assays using Sytox green, propidium iodide and C12-resazurin, which successfully discriminated live/dead larvae. Only Sytox green staining achieved IC50 values comparable to that of the larval motility assay. The cytotoxicity of the combined coriander oil and linalool on Madin-Darby Canine Kidney cells was evaluated using sulforhodamine-B (SRB) assay and showed no significant cytotoxic effect at concentrations < 1%. These results indicate that testing essential oils and their main components may help to find new potential anthelmintic compounds, while at the same time reducing the reliance on synthetic anthelmintics.

Role of nutraceuticals during the transition period of dairy cows: a review

The transition period of dairy cattle is characterized by a number of metabolic, endocrine, physiologic, and immune adaptations, including the occurrence of negative energy balance, hypocalcemia, liver dysfunction, overt systemic inflammatory response, and oxidative stress status. The degree and length of time during which these systems remain out of balance could render cows more susceptible to disease, poor reproductive outcomes, and less efficient for milk production and quality. Studies on both monogastrics and ruminants have reported the health benefits of nutraceuticals (e.g. probiotics, prebiotics, dietary lipids, functional peptides, phytoextracts) beyond nutritional value, interacting at different levels of the animal’s physiology. From a physiological standpoint, it seems unrealistic to disregard any systemic inflammatory processes. However, an alternate approach is to modulate the inflammatory process per se and to resolve the systemic response as quickly as possible.

To this aim, a growing body of literature underscores the efficacy of nutraceuticals (active compounds) during the critical phase of the transition period. Supplementation of essential fatty acids throughout a 2-month period (i.e. a month before and a month after calving) successfully attenuates the inflammatory status with a quicker resolution of phenomenon. In this context, the inflammatory and immune response scenario has been recognized to be targeted by the beneficial effect of methyl donors, such as methionine and choline, directly and indirectly modulating such response with the increase of antioxidants GSH and taurine. Indirectly by the establishment of a healthy gastrointestinal tract, yeast and yeast-based products showed to modulate the immune response, mitigating negative effects associated with parturition stress and consequent disorders.

The use of phytoproducts has garnered high interest because of their wide range of actions on multiple tissue targets encompassing a series of antimicrobial, antiviral, antioxidant, immune-stimulating, rumen fermentation, and microbial modulation effects. In this review, we provide perspectives on investigations of regulating the immune responses and metabolism using several nutraceuticals in the periparturient cow.

Bioprospecting of Nitrogenous Heterocyclic Scaffolds with Potential Action for Neglected Parasitosis: A Review

Neglected parasitic diseases are a group of infections currently considered as a worldwide concern. This fact can be attributed to the migration of these diseases to developed and developing countries, associated with therapeutic insufficiency resulted from the low investment in the research and development of new drugs. In order to overcome this situation, bioprospecting supports medicinal chemistry in the identification of new scaffolds with therapeutically appropriate physicochemical and pharmacokinetic properties. Among them, we highlight the nitrogenous heterocyclic compounds, as they are secondary metabolites of many natural products with potential biological activity. The objective of this work was to review studies within a 10-year timeframe (2009- 2019), focusing on the pharmacological application of nitrogen bioprospectives (pyrrole, pyridine, indole, quinoline, acridine, and their respective derivatives) against neglected parasitic infections (malaria, leishmania, trypanosomiases, and schistosomiasis), and their application as a template for semi-synthesis or total synthesis of potential antiparasitic agents. In our studies, it was observed that among the selected articles, there was a higher focus on the attempt to identify and obtain novel antimalarial compounds, in a way that an extensive amount of studies involving all heterocyclic nitrogen nuclei were found. On the other hand, the parasites with the lowest number of publications up until the present date have been trypanosomiasis, especially those caused by Trypanosoma cruzi, and schistosomiasis, where some heterocyclics have not even been cited in recent years. Thus, we conclude that despite the great biodiversity on the planet, little attention has been given to certain neglected tropical diseases, especially those that reach countries with a high poverty rate.

Properties of Ginkgo biloba L.: Antioxidant Characterization, Antimicrobial Activities, and Genomic MicroRNA Based Marker Fingerprints

The aim of this study was to characterize extracts from the leaves of Ginkgo biloba L. from selected Slovakian localities in terms of the content of bioactive constituents, antioxidants and their antimicrobial properties. The results indicated that the content of antioxidants was sample-specific, and this specificity was statistically significant. Ginkgo biloba L. from the locality of Košice had the best activity determined by the free radical scavenging activity (DPPH) (1.545 mg Trolox equivalent antioxidant capacity (TEAC)/g fresh matter (FM)) as well as the molybdenum-reducing antioxidant power (35.485 mg TEAC/g FM) methods. The highest content of total polyphenols (2.803 mg gallic acid equivalent (GAE)/g FM) and flavonoids (4.649 μg quercetin equivalent (QE)/g FM) was also detected in this sample. All samples of G. biloba leaf extracts showed significant antimicrobial activity against one or more of the examined bacterial species, and Staphylococcus aureus subsp. aureus CCM 2461 was found to be the most susceptible (minimal inhibition concentration MIC50 and MIC90 values of 64.2 and 72.2 µg/mL, respectively). Based on the results it was concluded that Ginkgo biloba L. extracts can be used as antimicrobial and antioxidant additives. Selected miRNA-based molecular markers were used to examine the environmental adaptability of Ginkgo biloba L. An almost-complete genotype clustering pattern based on locality was determined in the analysis that involved a species-specific gb-miR5261 marker. Morphologically specific exemplar, cv. Ohatsuki, was excluded.

Antibiofilm, antiquorum sensing and antioxidant activity of secondary metabolites from seeds of Annona senegalensis, Persoon

The increasing resistance of bacteria to antibiotics has motivated the interest in potent natural compounds capable of disrupting bacterial cell-to-cell communication. Column chromatography of seed extract of Annona senegalensis afforded N-cerotoyltryptamine (1), asimicin (2) and ent-19-carbomethoxykauran-17-oic acid (3). The compounds were tested for their antimicrobial, antibiofilm, and anti-quorum sensing activities. The minimum inhibitory concentrations (MIC) values ranged from 50 μg/mL to 100 μg/mL for C. albicans ATCC 10239 and S. aureus ATCC 25923 E. coli ATCC 25922, C. violaceum CV026 and C. violaceum CV12472. All the compounds inhibited biofilm formations of all microorganisms tested in various percentages at MIC and MIC/2. Compound 2 also exhibited the highest antibiofilm activity against C. albicans (yeast) and E. coli with percentage inhibitions ranging from 6.3 ± 4.1 (MIC/4) to 37.9 ± 4.5 (MIC) for C. albicans and from 18.8 ± 1.1 (MIC/4) to 43.2 ± 0.5 (MIC) for E. coli. Compound 1, however, showed highest biofilm inhibition on S. aureus as the percentage inhibition varied from 26.7 ± 3.6 (MIC/4) to 43.8 ± 2.1 (MIC). Compound 2 showed highest percentage violacein inhibition on C. violaceum CV12472 ranging from 10.2 ± 0.5 (MIC/8), 65.76 ± 1.3 (MIC/2) and 100 (MIC). Compound 1 and 3 had percentage violacein formation inhibitions on C. violaceum CV12472 ranging from 9.66 ± 1.1 (MIC/4) to 100 (MIC), and from 17.4 ± 2.4 (MIC/4) to 100 (MIC), respectively. Swimming and swarming motility of P. aeruginosa PA01 strain was evaluated at three concentrations of 50, 75 and 100 μg/mL. The compounds inhibited the P. aeruginosa swimming and swarming motility at the three tested concentrations (50, 75 and 100 μg/ml) in a dose-dependent manner. The extents of inhibition of motility migration was relatively higher in the swimming model than in the swarming model for all compounds. Compound 1 exhibited the highest percentage inhibition of motility of 41.50 ± 3.5 and 39.73 ± 1.5 in swimming model and swarming model respectively at 100 μg/ml. Compound 3 showed the lowest percentage inhibition of 30.36 ± 2.0 and 23.50 ± 2.5 in swimming and swarming respectively at 100 μg/ml. At the lowest tested concentration of 50 μg/ml, it was compound 2 showing the highest inhibition of motility of 17.49 ± 0.5 and 14.29 ± 1.0 in swimming and swarming respectively. Compound 1 showed highest quorum sensing (QS) activity with QS inhibition zone of 20.0 ± 1.5 mm at MIC and 11.0 ± 1.0 mm at MIC/8 while compound 2 had the highest antimicrobial (AM) zone diameter amongst the compounds at MIC. Compound 3 was the QS inhibitory sample and did not show any QS inhibition at MIC/8 while showing its highest QS inhibition zone of 13.0 ± 1.6 mm at MIC. For antioxidant assays, no sample showed better activity than the standards. Compound 2 had highest activity with IC₅₀ values of 87.79 ± 2.70 and 42.77 ± 1.53 μg/mL in DPPH and β-carotene-linoleic acid assay respectively and was more active (IC₅₀ of 97.69 ± 1.40 μg/mL) than standard quercetin (IC₅₀ 250.09 ± 0.87 μg/mL) in metal chelation assay.

Methane production and estimation from livestock husbandry: A mechanistic understanding and emerging mitigation options

Globally, livestock is an important contributor to methane (CH₄) emissions. This paper reviewed the various CH₄ measurement and estimation techniques and mitigation approaches for the livestock sector. Two approaches for enteric livestock CH₄ emission estimation are the top-down and bottom-up. The combination of both could further improve our understanding of enteric CH₄ emission and possible mitigation measures. We discuss three mitigation approaches: reducing emissions, avoiding emissions, and enhancing the removal of emissions from livestock. Dietary management, livestock management, and breeding management are viable reducing emissions pathways. Dietary manipulation is easily applicable and can bring an immediate response. Economic incentive policies can help the livestock farmers to opt for diet, breeding, and livestock management mitigation approaches. Carbon pricing creates a better option to achieve reduction targets in a given period. A combination of carbon pricing, feeding management, breeding management, and livestock management is more feasible and sustainable CH₄ emissions mitigation strategy rather than a single approach.

Influence of dietary cardoon meal on volatile compounds and flavour in lamb meat

Cardoon meal is a by-product retained after oil extraction from the seeds of cultivated Cynara cardunculus var. altilis that has been proposed as a valuable resource for animal feeding. The study aimed to assess the influence of its dietary inclusion on volatile profile and flavour of meat and kidney fat from lambs. Fifteen Sarda × Comisana male lambs were randomly divided in two groups and fed for 75 days with a concentrate-based diet containing 15% cardoon meal (CMD, n = 7) or dehydrated alfalfa (CON, n = 8). Cardoon meal inclusion reduced the "barnyard/animal" odour perceived by a trained panel in kidney fat, which could be associated with the aromatic compound p-cresol (4-methylphenol), detected only in CON diet. Considering the other aroma volatiles regarded as the main contributors for the characteristic lamb flavour, both diets were characterized by moderate to low levels of 4-methyloctanoic acid, skatole and indole while 4-methylnonanoic acid and 4-ethyloctanoic acid were not detected.

Effects of oregano essential oil on in vitro ruminal fermentation, methane production, and ruminal microbial community

Different inclusion rates of oregano essential oil (OEO) were investigated for their effects on ruminal in vitro fermentation parameters, total gas, methane production, and bacterial communities. Treatments were (1) control, 0 mg/L of OEO (CON); 13 mg/L (OEO1); 52 mg/L (OEO2); 91 mg/L (OEO3); and 130 mg/L (OEO4), each incubated with 150 mL of buffered rumen fluid and 1,200 mg of substrate for 24 h using the Ankom in vitro gas production system (Ankom Technology Corp., Fairport, NY). Treatment responses were statistically analyzed using polynomial contrasts. Digestibility of DM, NDF, and ADF increased quadratically with increasing OEO inclusion rates. Digestibility of DM and NDF were highest for OEO2, whereas ADF digestibility was highest for OEO3, compared with CON, with the remaining treatments being intermediate and similar. Ammonia nitrogen concentrations decreased from CON at a quadratic rate with increasing OEO inclusion rates, and OEO2 had the lowest concentration compared with the other groups. Total VFA, acetate, propionate, butyrate, valerate, and isovalerate concentrations linearly decreased with increasing OEO inclusion rates. Total gas production levels by CON and OEO4 were greater than those of OEO1, OEO2, and OEO3 in a quadratic response, and methane production linearly decreased from CON, compared with OEO4, at a decreasing rate with OEO inclusion rates. As determined by 16S rRNA sequencing, the α biodiversity of ruminal bacteria was similar among OEO inclusion rates. Increasing OEO inclusion rates linearly increased the relative abundance of Prevotella and Dialister bacteria. Several bacteria demonstrated different polynomial responses, whereas several bacteria were similar among increasing OEO inclusion rates. These results suggested that OEO supplementation can modify ruminal fermentation to alter VFA concentrations and reduce methane emissions by extensively altering the ruminal bacterial community, suggesting an optimal feeding rate for future animal studies of approximately 52 mg/L for mature ruminants.

Inhibition of Bacteroidetes and Firmicutes by select phytochemicals

Current research indicates that changes in gut microbiota can impact the host, but it is not always clear how dietary and environmental factors alter gut microbiota. One potential factor is antimicrobial activity of compounds ingested by the host. The goal of this study was to determine the antimicrobial activity of common plant secondary metabolites against pure cultures of paired, structurally and phylogenetically distinct gastrointestinal bacteria of human or bovine origin: Prevotella bryantii B₁4, Bacteroides fragilis 25285, Acetoanaerobium (Clostridium) sticklandii SR and Clostridioides difficile 9689. When growth media were amended with individual phytochemicals (the alkaloids: berberine, capsaicin, nicotine, piperine and quinine and the phenolic: curcumin), growth of each species was inhibited to varying degrees at the three greatest concentrations tested (0.10-10.00 mg mL^-1). The viable cell numbers of all the cultures were reduced, ≥4-logs, by berberine at concentrations ≥1.00 mg mL^-1. Quinine performed similarly to berberine for B₁4, 25285, and SR at the same concentrations. The other phytochemicals were inhibitory, but not as much as quinine or berberine. Nicotine had activity against all four species (≥2-log reduction in viable cell number at 10.00 mg mL^-1), but had stronger activity against the Gram-positive bacteria, SR and 9689, (≥4-log reductions at 10.00 mg mL^-1). In conclusion, the phytochemicals had varying spectra of antimicrobial activity. These results are consistent with the hypothesis that ingested phytochemicals have the ability to differentially impact gut microbiota through antimicrobial activity.

Essential oil from halophyte Lobularia maritima: protective effects against CCl4-induced hepatic oxidative damage in rats and inhibition of the production of proinflammatory gene expression by lipopolysaccharide-stimulated RAW 264.7 macrophages

The present study evaluates the chemical profiling of the essential oil of a halophyte, L. maritima (LmEO), and its protective potential against CCl4-induced oxidative stress in rats. Forty compounds have been identified in LmEO. The major components are α-pinene (3.51%), benzyl alcohol (8.65%), linalool (22.43%), pulegone (3.33%), 1-phenyl butanone (7.33%), globulol (4.32%), γ-terpinene (6.15%), terpinen-4-ol (4.31%), α-terpineol (3.9%), ledol (3.59%), epi-α-cadinol (3.05%) and α-cadinol (4.91%). In comparison with the CCl4-intoxicated group, LmEO treatment resulted in decreased liver serum marker enzymes, decreased lipid peroxidation and increased antioxidant enzyme levels, with overall further amelioration of oxidative stress. The administration of LmEO to CCl4-treated rats at a dose of 250 mg kg-1 body weight significantly reduced the toxic effects and the oxidative stress on the liver, thus validating the traditional medicinal claim of this plant. Moreover, the anti-inflammatory activity of LmEO was evaluated in lipopolysaccharide-stimulated murine RAW 264.7 cells. Our oil could modulate the inflammatory mode of the macrophages by causing reduction in iNOS and COX2 enzymes as well as in IL-1β, IL-6, and TNF-α cytokine levels. These findings suggest that LmEO exerts anti-inflammatory effects by regulating the expression of inflammatory cytokines.

Comparative Drug Resistance Reversal Potential of Natural Glycosides: Potential of Synergy Niaziridin & Niazirin

Background:

Due to the limited availability of antibiotics, Gram-negative bacteria (GNB) acquire different levels of drug resistance. It raised an urgent need to identify such agents, which can reverse the phenomenon of drug resistance.

Objective:

To understand the mechanism of drug resistance reversal of glycosides; niaziridin and niazirin isolated from the pods of Moringa oleifera and ouabain (control) against the clinical isolates of multidrug-resistant Escherichia coli.

Methods:

The MICs were determined following the CLSI guidelines for broth micro-dilution. In-vitro combination studies were performed by broth checkerboard method followed by Time-Kill studies, the efflux pump inhibition assay, ATPase inhibitory activity, mutation prevention concentration and in-silico studies.

Results:

The results showed that both glycosides did not possess antibacterial activity of their own, but in combination, they reduced the MIC of tetracycline up to 16 folds. Both were found to inhibit efflux pumps, but niaziridin was the best. In real time expression pattern analysis, niaziridin was also found responsible for the down expression of the two important efflux pump acrB & yojI genes alone as well as in combination. Niaziridin was also able to over express the porin forming genes (ompA & ompX). These glycosides decreased the mutation prevention concentration of tetracycline.

Conclusion:

This is the first ever report on glycosides, niazirin and niaziridin acting as drug resistance reversal agent through efflux pump inhibition and modulation of expression pattern drug resistant genes. This study may be helpful in preparing an effective antibacterial combination against the drug-resistant GNB from a widely growing Moringa oleifera.

Influence of Plant Species, Tissue Type, and Temperature on the Capacity of Shiga-Toxigenic Escherichia coli To Colonize, Grow, and Be Internalized by Plants

Contamination of fresh produce with pathogenic Escherichia coli, including Shiga-toxigenic E. coli (STEC), represents a serious risk to human health. Colonization is governed by multiple bacterial and plant factors that can impact the probability and suitability of bacterial growth. Thus, we aimed to determine whether the growth potential of STEC for plants associated with foodborne outbreaks (two leafy vegetables and two sprouted seed species) is predictive of the colonization of living plants, as assessed from growth kinetics and biofilm formation in plant extracts. The fitness of STEC isolates was compared to that of environmental E. coli isolates at temperatures relevant to plant growth. Growth kinetics in plant extracts varied in a plant-dependent and isolate-dependent manner for all isolates, with spinach leaf lysates supporting the highest rates of growth. Spinach extracts also supported the highest levels of biofilm formation. Saccharides were identified to be the major driver of bacterial growth, although no single metabolite could be correlated with growth kinetics. The highest level of in planta colonization occurred on alfalfa sprouts, though internalization was 10 times more prevalent in the leafy vegetables than in sprouted seeds. Marked differences in in planta growth meant that the growth potential of STEC could be inferred only for sprouted seeds. In contrast, biofilm formation in extracts related to spinach colonization. Overall, the capacity of E. coli to colonize, grow, and be internalized within plants or plant-derived matrices was influenced by the isolate type, plant species, plant tissue type, and temperature, complicating any straightforward relationship between in vitro and in planta behaviors.IMPORTANCE Fresh produce is an important vehicle for STEC transmission, and experimental evidence shows that STEC can colonize plants as secondary hosts, but differences in the capacity to colonize occur between different plant species and tissues. Therefore, an understanding of the impact that these plant factors have on the ability of STEC to grow and establish is required for food safety considerations and risk assessment. Here, we determined whether growth and the ability of STEC to form biofilms in plant extracts could be related to specific plant metabolites or could predict the ability of the bacteria to colonize living plants. Growth rates for sprouted seeds (alfalfa and fenugreek) but not those for leafy vegetables (lettuce and spinach) exhibited a positive relationship between plant extracts and living plants. Therefore, the detailed variations at the level of the bacterial isolate, plant species, and tissue type all need to be considered in risk assessment.