Effects of Glycyrrhizic Acid on Productive and Immune Parameters of Broilers

The effect of intraperitoneal injection of Glycyrrhizin on central regulation of food intake in broilers injected with LPS

1. Poultry farming faces challenges regarding correct hygiene and nutrition. One of the challenges is gram-negative bacteria that stimulate pro-inflammatory reactions through lipopolysaccharide (LPS) and cause disease and anorexia. Liquorice, a medicinal plant containing glycyrrhizin (Glz; a saponin and emulsifier compound) as its main active ingredient, was injected into broilers to investigate any beneficial effects on feed intake in LPS-injected broilers.2. The study involved three experiments using 72 male broiler chickens in each, to examine the impact of Glz on feed intake, especially when challenged with lipopolysaccharide (LPS) by intra-peritoneal (IP) injection to cause inflammation (n = 24). Experiment 1 was conducted to examine the effects of intraperitoneal injection of Glz (12.5, 25 and 50 mg) on feed intake in chickens. In experiment 2, the effects of intracerebroventricular injections of LPS (6.25, 12.5 and 25 ng) were examined. The third experiment investigated the impact of IP injection of Glz on inflammation induced by LPS.3. Injection of Glz significantly increased feed intake in a dose-dependent manner. Whereas LPS significantly reduced the feed intake in feed-deprived chickens (p < 0.05).4. In conclusion, Glz can neutralise the feed intake reduction caused by inflammation in broilers, highlighting its potential role in modulating feed intake in broilers.

The efficacy of licorice root extract on meat amino acid, fatty acid, vitamin, and mineral composition and productivity of quail

Background and Aim

Poultry meat is an excellent animal protein source accessible to many low-income families in developing countries. It is also part of a balanced diet and contains valuable nutrients necessary for maintaining human health. The poultry sector implements improved processes to increase the quality and nutritional value of poultry meat. This study aimed to determine the influence of licorice root extract on the amino acid, fatty acid, vitamin, mineral composition, nutritional value, and productivity of quail meat.

Materials and Methods

Two groups were formed from Japanese quails: A control group and one experimental group, each consisting of 50 individuals. Quails from both the experimental and control groups received the same complete diet. Quails in the experimental group had licorice root extract added to their water at a dosage of 10 g/L, starting from the age of 3 days to 42 days of growth. At 42 days of age, 30 birds from each group were slaughtered to examine their meat productivity and chemical composition. The quail carcasses were analyzed for the following parameters: Live weight, carcass weight, nutritional value, mineral substances, vitamin content, fatty acid composition, amino acid composition, and amino acid score.

Results

This study demonstrated that quails in the experimental group receiving water with licorice extract exhibited higher indicators than those in the control group. Calcium (21.05%), magnesium (20.83%), and phosphorus (23.53%) were the most elevated mineral substances in the meat of the experimental birds. Vitamins E (22.22%) and C (20.0%) showed the greatest increase in vitamin content. The fatty acid composition parameters 17:0 margaric acid (8.16%), 18:3 linolenic acid (6.25%), and 20:4 arachidonic acid (4.49%) showed the highest increase. There was a clear increase in the amino acids valine (4.61%), lysine (4.32%), threonine (5.99%), tryptophan (4.87%), phenylalanine (5.87%), and cysteine (14.17%). The application of licorice root extract also positively impacted the amino acid score of quail meat, except for leucine, which remained within the range compared with the control group. Quails in the experimental group weighed 7.96% more live weight before slaughter than the controls. Moreover, the carcass weight was in favor of the experimental group (8.59%).

Conclusion

The use of licorice root extract positively influences the quality and biological value of quail meat. Data on amino acids, fatty acids, vitamins, trace elements, and other important components of quail meat will significantly expand our understanding of the biological value of licorice root extract. These findings can be used in the formulation of balanced diets for children and adults and highlight the importance of this issue.

Effects of Glycyrrhizin (GL) Supplementation on Survival, Growth Performance, Expression of Feeding-Related Genes, Activities of Digestive Enzymes, Antioxidant Capacity, and Expression of Inflammatory Factors in Large Yellow Croaker (Larimichthys crocea) Larvae

A 30-day feeding trial was conducted to determine the effects of dietary glycyrrhizin (GL) on survival, growth performance, expression of feeding-related genes, activities of digestive enzymes, antioxidant capacity, and expression of inflammatory factors of large yellow croaker larvae with an initial weight of 3.78 ± 0.27 mg. Four 53.80% crude protein and 16.40% crude lipid diets were formulated with supplementation of 0%, 0.005%, 0.01%, and 0.02% GL, respectively. Results indicated that larvae fed diets with GL had higher survival rate and specific growth rate than the control (P < 0.05). Compared with the control, the mRNA expression of orexigenic factor genes including neuropeptide Y (npy) and agouti-related protein (agrp) were significantly increased in larvae fed the diet with 0.005% GL, while the mRNA expression of anorexigenic factor genes including thyrotropin-releasing hormone (trh), cocaine and amphetamine regulated transcript (cart), and leptin receptor (lepr) were significantly decreased in larvae fed the diet with 0.005% GL (P < 0.05). The trypsin activity in larvae fed the diet with 0.005% GL was significantly higher than the control (P < 0.05). The alkaline phosphatase (AKP) activity in larvae fed the diet with 0.01% GL was significantly higher than the control (P < 0.05). A clear increase of total glutathione (T-GSH) content, activities of superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) was observed in larvae fed the diet with 0.01% GL compared with the control (P < 0.05). Moreover, the mRNA expression of interleukin-1β (il-1β) and interleukin-6 (il-6) (proinflammatory genes) in larvae fed the diet with 0.02% GL were significantly lower than the control (P < 0.05). In conclusion, the supplementation of 0.005% -0.01% GL could enhance the expression of orexigenic factor genes, activities of digestive enzymes and antioxidant capacity, ultimately improving the survival, and growth performance of large yellow croaker larvae.

Licorice Extract Supplementation Affects Antioxidant Activity, Growth-Related Genes, Lipid Metabolism, and Immune Markers in Broiler Chickens

The objective of this study was to evaluate the Glycyrrhiza glabra effect on growth performance, blood parameters, antioxidant and lysosomal activity, histology and immunohistochemistry of liver and intestine, and the gene expression profile of broiler chickens. A total of 180 Cobb500 broiler chicks (one-week-old) were used in this study. Chicks were distributed randomly into three treatment groups; the first group received drinking water without any supplementation (control group). In contrast, birds in groups 2 and 3 received licorice supplementation in drinking water with 0.4 and 0.8 g licorice/liter, respectively. Results revealed that licorice at a 0.4 g/L of water level improved body weight, weight gain, feed intake, and FCR. Licorice also exhibits a broad range of biological activities such as hypolipidemic, hypoglycemic, hepatoprotective, immunostimulant, and antioxidant effects. The morphometric analysis of different parameters of the intestine revealed a significant increase in the intestinal villi length, width, and villi length/crypt depth in the group supplemented with licorice 0.4 gm/L compared to other groups. The number of CD3 positive in both duodenum and ileum was increased in the licorice 0.4 gm/L group compared to other groups. The expression of growth-related genes was significantly increased with licorice supplementation and modulation of the lipid metabolism genes in the liver and upregulated to the mRNA expression of both superoxide dismutase (SOD1) and Catalase (CAT). Our results revealed that licorice supplementation increased the growth performance of broiler chickens and impacted the birds' antioxidant activity through modulation of the growth-related genes, lipid metabolic markers, and antioxidant-related pathways.

Recent advances in glycyrrhizin metabolism, health benefits, clinical effects and drug delivery systems for efficacy improvement; a comprehensive review

BACKGROUND

Glycyrrhizin (GL) is a major active constituent of licorice root (Glycyrrhiza glabra) that is considered one of the oldest and most frequently employed botanicals in Chinese medicine and worldwide, with most effects attributed to its rich GL content. Structurally, GL a triterpene saponin that is widely used as a flavoring agent in foodstuffs and cosmetics, and also proposed for various clinical applications with a myriad of health benefits. Pharmacological and biological activities of GL include antiviral, anti-inflammatory, antioxidant, and anticancer activities (in vitro and in vivo). Currently, there is no comprehensive review on GL biological effects and its action mechanisms.

PURPOSE

This review summarizes GL pharmacological actions from a molecular biology perception, presented on its metabolism and side effects based on in vitro, in vitro and clinical studies. Moreover, the potential of GL as a nanomedicine delivery system is also summarized. The progress in drug delivery research using GL presented herein is expected to provide a theoretical basis for developing other novel drugs formulations.

METHODS

A systematic review was carried out in several electronic databases (Science Direct, SpringerLink, CNKI, PubMed, Web of Science, Elsevier, and Scopus), using the following key words: glycyrrhizin "AND" bioactivity "OR" clinic "OR" therapeutic "OR" drug delivery. This search included manuscripts published between 1989 and 2021.

RESULTS

126 researches were selected and summarized in this review. The analysis of these studies indicated that GL has antiviral activity against different viruses. Further, GL efficiently suppressed the respiratory manifestations associated with COVID-19 by reducing the expression of angiotensin converting enzyme 2 (ACE2) that employed by the virus as an entry point. Otherwise, GL was found to induce antioxidant, anti-inflammatory, immune-modulatory, and anticancer activity. Besides, diminution the particle size of GL to nanometer size significantly augments their action and biodistribution.

CONCLUSION

This article summarizes the pharmacological actions of GL. The potential of GL as a nanomedicine delivery system is also presented. Nevertheless, most studies reported provide no deep insight of GL health effects warranting for more future studies to elucidate its action mechanism and potential therapeutic benefits through preclinical and clinical trials.

Effect of Acetic Acid and Sodium Bicarbonate Supplemented to Drinking Water on Water Quality, Growth Performance, Organ Weights, Cecal Traits and Hematological Parameters of Young Broilers

To evaluate the effect of acetic acid and sodium bicarbonate supplemented to drinking water on water quality, growth performance, relative organ weights, cecal traits and hematological parameters of broilers, a total of 456 one-day-old Cobb MV × Cobb 500 FF mixed broilers were randomly placed in three experimental treatments, with four replicates per treatment and 38 birds per replicate, for 10 days. The treatments consisted of the use of acetic acid (0.4%; T1) as acidifier, an apparently neutral pH (T2) and sodium bicarbonate (1%; T3) as alkalizer of the drinking water. T3 showed the highest values (p < 0.05) for total dissolved solids, electrical conductivity, salinity and pH. T1 and T2 showed the same productive response (p > 0.05); however, T3 decreased (p < 0.05) body weight, feed intake and the relative weight of the pancreas and immune organs and increased (p < 0.05) water intake, mortality and relative weight of the heart and liver. Likewise, T3 increased (p < 0.05) the cecal pH, although without changes for the cecal lactic cecal bacteria count and blood parameters (p > 0.05). The acid pH of the drinking water had no effect on the biological response of broilers compared to T2; however, the T3 provoked high mortality, ascites, low productivity and abnormal growth of some organs.

Atrazine-induced cell-mediated immunotoxicity in rabbits and the ameliorating role of glycyrrhizic acid

The present study aimed to explain the mechanisms involved in cell-mediated immunotoxicity of atrazine (ATR) in rabbits and to evaluate the ameliorative role of glycyrrhizic acid (GA) against such toxic effects. Forty rabbits were assigned into 4 equal groups: control, ATR, GA, and ATR + GA groups. ATR (2475 ppm) and GA (60 μg of GA/ml of water) were administrated via food and drinking water, respectively, for 60 consecutive days. The cell-mediated immunotoxicity of ATR was clarified by the induced thymus immunotoxicity through downregulation of interleukin (IL)-9 gene and interferon-γ (IFN-γ) gene expression, upregulation in caspase-3, and significant decrease in the total leukocytic and lymphocyte counts. Histopathological investigations demonstrated severe depletion of lymphoid follicles in the medulla of the thymus gland. On the other hand, co-administration of GA for group 4 improved most of the undesirable impacts of ATR. In conclusion, the alteration in IL-9/IFN-γ expression may involve ATR-induced thymocyte apoptosis which may explain the mechanisms of ATR-induced cell-mediated immunotoxicity with a possible amelioration influence of GA administration.

Dietary effect of licorice (Glycyrrhiza glabra) on quail performance, carcass, blood metabolites and intestinal microbiota

This study aimed to assess the impacts of licorice (Glycyrrhiza glabra) on the growth performance, carcass traits, intestinal microbiota, liver and kidney functions, immunity, oxidative status, and lipid profile of Japanese quails. A total of 200 one-week-old unsexed Japanese quails with an average initial body weight of 26.24 ± 0.2 g were randomly distributed into 5 equal groups of 40 birds and further subdivided into 5 replicates. The first (control) group was fed a diet without any licorice, while licorice powder was added at levels of 250, 500, 750, and 1000 mg per kg diet in the second, third, fourth, and fifth groups, respectively. At the age of 3 wk, the group of quail fed on a diet supplemented with 750 and 1000 mg licorice/kg of diet gained the highest body weight (BW) and daily body weight (DBW), while attaining the lowest feed conversion ratio (FCR) compared to other groups. Meanwhile, groups fed diets with licorice at levels of 0 and 250 mg/kg showed the highest feed intake. After the 5-wk feeding trial, the highest BW and DBW values, and the lowest FCR were recorded in the group fed with 750 mg licorice/kg diet. The different treatments produced no significant differences (P > 0.05) in quail carcass characteristics, including percentages of carcass, liver, gizzard, heart, giblets, and dressing. The blood of the group fed a 750 mg licorice diet had higher contents of total protein and GLOB, while its contents of A/G%, lactate dehydrogenase (LDH), total cholesterol, triglyceride (TG), and low density lipoprotein (LDL) were lower. Apart from the high level of licorice (1000 mg/kg), the MDA level was linearly and quadratically (P = 0.0413 and 0.001) decreased with different licorice groups, while superoxide dismutase (SOD), total antioxidant capacity (TAC), immunoglobulin G (IgG), and M (IgM) were quadratically increased when compared to the control group. Licorice supplementation resulted in marked reductions in the number of total bacteria, coliforms, E. coli, and Salmonella, compared to those in the control. In conclusion, the inclusion of licorice at levels of 750 and 1000 mg/kg into the diet of Japanese quail enhances the animal's performance, immunity, antioxidant capacity, and maintains a healthy gut microbiota.

Influence of Glycyrrhiza glabra Extract on Growth, Gene Expression of Gut Integrity, and Campylobacter jejuni Colonization in Broiler Chickens

Phytogenic feed additives have been gaining considerable interest due to their ability to improve gut health and thereby performance of broiler chickens. The impact of Glycyrrhiza glabra (licorice) extract (GE) on expression of genes coding for tight junction proteins and gut protection and Campylobacter jejuni colonization in broilers has not been discussed until now. Thus, the current study assessed the effective dose of GE for maximum growth in broiler chickens, clear-cut molecular mechanisms related to integrity and health of intestine, and controlling C. jejuni colonization. Over a 35-day feeding period, a total of 500 Ross broiler chicks were allocated to five groups; the first group was fed a control diet without GE and the second group to the fifth group were fed a control diet with GE (0.25, 0.5, 1, and 2 g/kg of diet); each group comprised 100 chicks with 10 replicates (10 birds/replicate). Birds fed GE had an improved body weight gain and feed conversion ratio. Furthermore, the highest body weight gain was observed in the group that received 1 g/kg of GE (P < 0.05). The expression of genes coding for tight junction proteins [occludin and junctional adhesion molecules (JAM)] was upregulated in all groups supplemented with GE. Moreover, birds fed 1 g/kg of GE exhibited the maximum gene expression of occludin and JAM [0.2 and 0.3 fold change, respectively (P < 0.05)]. In relation to enterocyte protective genes [glucagon-like peptide (GLP-2) and fatty acid-binding protein (FABP-6)], use of GE significantly upregulated expression of GLP-2 gene with 0.8 fold change in 2 g/kg of the GE supplemented group (P < 0.05) while the expression of FABP-6 gene was not affected by GE supplementation (P > 0.05). After challenge with C. jejuni, the expression of mucin (MUC-2) gene was upregulated and the inflammatory markers such as Toll-like receptors (TLR-4) and interleukin (IL-1β) were downregulated with increasing level of supplemented GE (P < 0.05). The mean log10 count of C. jejuni in cecal samples after 7 days post-infection by culture and real-time qPCR was decreased in groups fed GE in a dose-dependent manner (P < 0.05). In addition, the highest reduction of C. jejuni count in cecal samples by culture and real-time qPCR was observed in the group fed 2 g/kg of GE (2.58 and 2.28 log10 CFU/g, respectively). Results from this study suggested that G. glabra extract (1 g/kg) improved growth performance of broiler chickens, as well as influenced the maintenance of intestinal integrity and reduced C. jejuni shedding from infected birds.

Use of Licorice (Glycyrrhiza glabra) Herb as a Feed Additive in Poultry: Current Knowledge and Prospects

Simple Summary

The present review updates the current knowledge about the beneficial effect of licorice supplementation in poultry diets, particularly its positive effect on the treatment of high-prevalence diseases of the immune system, liver, and lungs.

Abstract

Supplementation of livestock and poultry diets with herbal plants containing bioactive components have shown promising reports as natural feed supplements. These additives are able to promote growth performance and improve feed efficiency, nutrient digestion, antioxidant status, immunological indices, and poultry health. Several studies have used complex herbal formulas with the partial inclusion of licorice. However, the individual use of licorice has been rarely reported. The major problem of the poultry industry is the epidemiological diseases, mainly confined to the respiratory, digestive, and immune systems. Licorice has certain bioactive components such as flavonoids and glycyrrhizin. The roots of this herb contain 1 to 9% glycyrrhizin, which has many pharmacological properties such as antioxidant, antiviral, anti-infective and anti-inflammatory properties. Licorice extracts (LE) have a positive effect on the treatment of high-prevalence diseases such as the immune system, liver, and lung diseases. Studies showed that adding LE to drinking water (0.1, 0.2, or 0.3 g/L) reduced serum total cholesterol (p < 0.05) of broiler chickens. Moreover, LE supplementation in poultry diets plays a significant role in their productive performance by enhancing organ development and stimulating digestion and appetite. Along with its growth-promoting effects, licorice has detoxifying, antioxidant, antimicrobial, anti-inflammatory, and other health benefits in poultry. This review describes the beneficial applications and recent aspects of the Glycyrrhiza glabra (licorice) herb, including its chemical composition and role in safeguarding poultry health.

Response of broiler chickens reared at high density to dietary supplementation with licorice extract and probiotic

This study evaluated the effects of licorice extract and probiotic on performance, excreta characteristics and welfare-related parameters of broiler chickens reared in high stocking density. Three hundred and thirty-six 1-day old broiler chicks (Ross 308) were used in a completely randomized design with five treatments and four replicates for 42 days. Treatments were as follows: (a) positive control (PC, 12 chicks/m² ); (b) negative control (NC, 18 chicks/m² ); (c) NC + 500 ppm licorice extract (LE); (d) NC + 200 ppm probiotic (P); (e) NC + ppm LE + ppm P. Body weight gain (BWG) was affected negatively by increased density in the growing period (p < 0.05). At high density, BWG was increased in the growing and whole period by adding LE and P separately and in combination (p < 0.01). Feed conversion ratio (FCR) was not affected by stocking density. Excreta weight (g/bird) and dry matter (DM, %) were reduced by increasing density (p < 0.01). Use of feed additives at high stocking density had no significant effect on excreta weight, but DM content of excreta was higher in NC + LE + P than NC. Gait problems and footpad and hock burns were increased by increased stocking density, but were not altered by feed additives. In conclusion, licorice extract and probiotic improved BWG of broilers reared at high stocking density; however, these birds had some disorders in footpad, hock and walking ability.