Scientific Opinion on the safety and efficacy of naringin when used as a sensory additive for all animal species

Natural Compounds for Bone Remodeling: A Computational and Experimental Approach Targeting Bone Metabolism-Related Proteins

Osteoporosis, characterized by reduced bone density and increased fracture risk, affects over 200 million people worldwide, predominantly older adults and postmenopausal women. The disruption of the balance between bone-forming osteoblasts and bone-resorbing osteoclasts underlies osteoporosis pathophysiology. Standard treatment includes lifestyle modifications, calcium and vitamin D supplementation and specific drugs that either inhibit osteoclasts or stimulate osteoblasts. However, these treatments have limitations, including side effects and compliance issues. Natural products have emerged as potential osteoporosis therapeutics, but their mechanisms of action remain poorly understood. In this study, we investigate the efficacy of natural compounds in modulating molecular targets relevant to osteoporosis, focusing on the Mitogen-Activated Protein Kinase (MAPK) pathway and the gut microbiome's influence on bone homeostasis. Using an in silico and in vitro methodology, we have identified quercetin as a promising candidate in modulating MAPK activity, offering a potential therapeutic perspective for osteoporosis treatment.

Naringin from Coffee Inhibits Foodborne Aspergillus fumigatus via the NDK Pathway: Evidence from an In Silico Study

In the tropics, coffee has been one of the most extensively cultivated economic crops, especially Arabica coffee (Coffea arabica L.). The coffee pulp, which includes phytochemicals with a proven antifungal action, is one of the most insufficiently utilized and neglected byproducts of coffee refining. In the current experiment, we carried out in silico screening of the isolated Arabica coffee phytochemicals for antifungal activity against Aspergillus fumigatus: a foodborne fungus of great public health importance. As determined by the molecular docking interactions of the library compounds indicated, the best interactions were found to occur between the nucleoside-diphosphate kinase protein 6XP7 and the test molecules Naringin (-6.771 kcal/mol), followed by Epigallocatechin gallate (-5.687 kcal/mol). Therefore, Naringin was opted for further validation with molecular dynamic simulations. The ligand-protein complex RMSD indicated a fairly stable Naringin-NDK ligand-protein complex throughout the simulation period (2-16 Å). In ADME and gastrointestinal absorbability testing, Naringin was observed to be orally bioavailable, with very low intestinal absorption and a bioavailability score of 0.17. This was further supported by the boiled egg analysis data, which clearly indicated that the GI absorption of the Naringin molecule was obscure. We found that naringin could be harmful only when swallowed at a median lethal dose between 2000 and 5000 mg/kg. In accordance with these findings, the toxicity prediction reports suggested that Naringin, found especially in citrus fruits and tomatoes, is safe for human consumption after further investigation. Overall, Naringin may be an ideal candidate for developing anti-A. fumigatus treatments and food packaging materials. Thus, this study addresses the simultaneous problems of discarded coffee waste management and antifungal resistance to available medications.

Naringenin potentiates anti-tumor immunity against oral cancer by inducing lymph node CD169-positive macrophage activation and cytotoxic T cell infiltration

The CD169⁺ macrophages in lymph nodes are implicated in cytotoxic T lymphocyte (CTL) activation and are associated with improved prognosis in several malignancies. Here, we investigated the significance of CD169⁺ macrophages in oral squamous cell carcinoma (OSCC). Further, we tested the anti-tumor effects of naringenin, which has been previously shown to activate CD169⁺ macrophages, in a murine OSCC model. Immunohistochemical analysis for CD169 and CD8 was performed on lymph node and primary tumor specimens from 89 patients with OSCC. We also evaluated the effects of naringenin on two murine OSCC models. Increased CD169⁺ macrophage counts in the regional lymph nodes correlated with favorable prognosis and CD8⁺ cell counts within tumor sites. Additionally, naringenin suppressed tumor growth in two murine OSCC models. The mRNA levels of CD169, interleukin (IL)-12, and C-X-C motif chemokine ligand 10 (CXCL10) in lymph nodes and CTL infiltration in tumors significantly increased following naringenin administration in tumor-bearing mice. These results suggest that CD169⁺ macrophages in lymph nodes are involved in T cell-mediated anti-tumor immunity and could be a prognostic marker for patients with OSCC. Moreover, naringenin is a new potential agent for CD169⁺ macrophage activation in OSCC treatment.

Assessment of the feed additive consisting of naringin for all animal species for the renewal of its authorisation (HealthTech Bio Actives, S.L.U. (HTBA))

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the assessment of the application for the renewal of authorisation of naringin as a sensory additive for all animal species. The applicant provided data demonstrating that the additive currently in the market complies with the conditions of authorisation. The FEEDAP Panel confirms that the use of naringin under the current authorised conditions of use is safe for the target species, the consumers and the environment. Naringin does not cause severe irritation or corrosion to eyes, is not irritant to the skin and is not classified as a dermal sensitiser. The FEEDAP Panel cannot conclude on the possible respiratory sensitisation of the additive, due to the lack of data. There was no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Safety and efficacy of a feed additive consisting of an aqueous extract of Citrus limon (L.) Osbeck (lemon extract) for use in all animal species (Nor-Feed SAS)

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of an aqueous extract of Citrus limon (L.) Osbeck (lemon extract) when used as a sensory additive in feed for all animal species. The FEEDAP Panel concluded that the additive under assessment is safe for all animal species up to the maximum proposed use levels of 1,000 mg/kg complete feed and 250 mg/kg water for drinking. No concerns for consumers were identified following the use of lemon extract up to the highest safe level in feed. The additive should be considered a skin and eye irritant, and a potential corrosive. The use of the extract in animal feed under the proposed conditions was not expected to pose a risk for the environment. Lemon extract was recognised to flavour food. Since its function in feed would be essentially the same as that in food, no further demonstration of efficacy was considered necessary.

Safety and efficacy of a feed additive consisting of a flavonoid-rich dried extract of Citrus × aurantium L. fruit (bitter orange extract) for use in all animal species (FEFANA asbl)

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of a dried flavonoid-rich extract of Citrus × aurantium L. fruit (bitter orange extract), when used as a sensory additive for all animal species. The use of the additive in feed was not expected to increase the exposure to furocoumarins of those target species that are already fed citrus by-products to a relevant extent (< 5%). For dog, cat and ornamental fish, not normally exposed to citrus by-products, no conclusion could be drawn. The FEEDAP Panel concluded that the additive under assessment is safe up to the maximum proposed use level of 400 mg/kg for veal calf (milk replacer), sheep, goat, horse and salmon. For the other species, the calculated maximum safe concentration in complete feed is 102 mg/kg for chicken for fattening, 151 mg/kg for laying hen, 136 mg/kg for turkey for fattening, 182 mg/kg for piglet, 217 mg/kg for pig for fattening, 268 mg/kg for sow, 259 mg/kg for dairy cow and 161 mg/kg for rabbit. The FEEDAP Panel considered that the use in water for drinking is safe provided that the total daily intake of the additive does not exceed the daily amount that is considered safe when consumed via feed, except dog, cat and ornamental fish. No concerns for consumer safety were identified following the use of the additive up to highest safe level in feed for the target animals. The extract under assessment should be considered as irritant to skin, eyes and the respiratory tract, and as a skin sensitiser. Since the additive contains 5-methoxypsoralen, it may cause phototoxicity. The use of the extract in animal feed under the proposed conditions was not expected to pose a risk for the environment. Bitter orange extract was recognised to flavour food. Since its function in feed would be essentially the same as that in food, no further demonstration of efficacy was considered necessary.

Naringin and naringenin as anticancer agents and adjuvants in cancer combination therapy: Efficacy and molecular mechanisms of action, a comprehensive narrative review

Although the rates of many cancers are controlled in Western countries, those of some cancers, such as lung, breast, and colorectal cancer are currently increasing in many low- and middle-income countries due to increases in risk factors caused by development and societal problems. Additionally, endogenous factors, such as inherited mutations, steroid hormones, insulin, and insulin-like growth factor systems, inflammation, oxidative stress, and exogenous factors (including tobacco, alcohol, infectious agents, and radiation), are believed to compromise cell functions and lead to carcinogenesis. Chemotherapy, surgery, radiation therapy, hormone therapy, and targeted therapies are some examples of the approaches used for cancer treatment. However, various short- and long-term side effects can also considerably impact patient prognosis based on clinical factors associated with treatments. Recently, increasing numbers of studies have been conducted to identify novel therapeutic agents from natural products, among which plant-derived bioactive compounds have been increasingly studied. Naringin (NG) and its aglycone naringenin (NGE) are abundantly present in citrus fruits, such as grapefruits and oranges. Their anti-carcinogenic activities have been shown to be exerted through several cell signal transduction pathways. Recently, different pharmacological strategies based on combination therapy, involving NG and NGE with the current anti-cancer agents have shown prodigious synergistic effects when compared to monotherapy. Besides, NG and NGE have been reported to overcome multidrug resistance, resulting from different defensive mechanisms in cancer, which is one of the major obstacles of clinical treatment. Thus, we comprehensively reviewed the inhibitory effects of NG and NGE on several types of cancers through different signal transduction pathways, the roles on sensitizing with the current anticancer medicines, and the efficacy of the cancer combination therapy.

Pharmacokinetic parameters of ifosfamide in mouse pre-administered with grapefruit juice or naringin

Grapefruit juice (GFJ) and naringin when consumed previously or together with medications may alter their bioavailavility and consequently the clinical effect. Ifosfamide (IF) is an antitumoral agent prescribed against various types of cancer. Nevertheless, there is no information regarding its interaction with the ingestion of GFJ or naringin. The aims of the present report were validating a method for the quantitation of IF in the plasma of mouse, and determine if mice pretreated with GFJ or naringin may modify the IF pharmacokinetics. Our HPLC results to quantify IF showed adequate intra and inter-day precision (RSD < 15%) and accuracy (RE < 15%) indicating reliability. Also, the administration of GFJ or naringin increased C_max of IF 22.9% and 17.8%, respectively, and decreased T_max of IF 19.2 and 53.8%, respectively. The concentration of IF was higher when GFJ (71.35 ± 3.5 µg/mL) was administered with respect to that obtained in the combination naringin with IF (64.12 ± µg/mL); however, the time required to reach such concentration was significantly lower when naringin was administered (p < 0.5). We concluded that pre-administering GFJ and naringin to mice increased the T_max and decreased the C_max of IF.

Elemental Metabolomics: Modulation of Egg Metallome with Flavonoids, an Exploratory Study

The basic principles of elemental metabolomics were applied to investigate whether alteration of egg metallome could be achieved after two flavonoids addition, namely hesperidin and naringin in diets of laying hens. A total of 72 hens were divided into six groups: Control (C) (basal diet), E1 (750 mg hesperidin/kg diet), E2 (1500 mg hesperidin/kg diet), N1 (750 mg naringin/kg diet), N2 (1500 mg naringin/kg diet), and VE (200 mg vitamin E/kg diet). The same diet was provided to birds of all treatments, with the exception of added supplements. The diets had the same vitamin and mineral premix; thus, all birds received the same number of elements because no differences on feed intake existed. The egg elemental profile consisted of As, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Sb, Se, Sr, V, Zn, and was determined using ICP-MS. Flavonoid supplementation altered the elemental profile. Most notably, in both albumen and yolk, hesperidin increased Ni, Pb, and Sr concentration while it decreased that of Co and Sb. Naringin increased Cd, Cr, Cu, Ni, and V and lowered the concentration of Co and Sb in both yolk and albumen. Vitamin E supplementation, in comparison to the control, decreased Co in both albumen and yolk and also raised Sb in albumen. Flavonoid presence led to the differences in deposition of certain trace minerals in egg compared to that of hens fed a basal diet or a diet with vitamin E supplementation.

Real-Time Intraoperative Assessment of Microcirculation in Living-Donor Small Bowel Transplant: A Case Report

Living-donor small bowel transplant has emerged as a modality to transplant patients with short bowel syndrome without prolonged wait time, albeit at the cost of technical challenges associated with vascular anastomosis due to the small size of vessels. Suboptimal perfusion in a transplanted bowel can lead to a devastating outcome, and clinical judgment alone is not completely reliable for assessment of bowel microcirculation. Here, we report a 55-year-old female patient who underwent flow cytometric cross-match-positive living-donor bowel transplant from her daughter. Initial suboptimal perfusion prompted a revision of the arterial anastomoses. Despite normal Doppler signals over the mesenteric vessels, the bowel had a variegated appearance. The microcirculation of the bowel wall was subsequently assessed in a real-time fashion by indocyanine green fluorescence angiography, which showed improved perfusion indices with time. Hence, this simple test helped us to avoid another unnecessary exploration and revision of the anastomoses. At present, the patient is thriving on an enteral diet. This case underpins the importance of real-time intraoperative assessment of bowel per-fusion and microcirculation in difficult cases. These assessments are needed to help surgeons identify tissues at risk for ischemia and necrosis, thereby allowing for maneuvers to improve intestinal viability.

In vitro effects of the citrus flavonoids diosmin, naringenin and naringin on the hepatic drug-metabolizing CYP3A enzyme in human, pig, mouse and fish

Flavonoids are known to have effects on cytochrome P450 enzymatic activity. However, little effort has been made to examine species differences and the relevance of studies on mammalian and fish microsomes so that extrapolations can be made to humans. Therefore, the effects of several naturally occurring flavonoids on the activity of CYP3A-dependent 7-benzyloxy-4-trifluoromethylcoumarin O-debenzylase (BFCOD) were evaluated in human, pig, mouse, and juvenile rainbow trout sources of hepatic microsomes. Each was exposed to three concentrations (1, 10, and 100μM) of diosmin, naringin, and naringenin. Naringenin competitively inhibited BFCOD activity (Ki values were 24.6μM in human, 15.6μM in pig, and 19.6μM in mouse microsomes). In fish, BFCOD activity was inhibited in a noncompetitive manner (Ki=7μM). Neither diosmin nor naringenin affected BFCOD activity in hepatic microsomes from the studied model organisms. These results suggest that dietary flavonoids potentially inhibit the metabolism of clinical drugs.

Six months chronic toxicological evaluation of naringin in Sprague-Dawley rats

Naringin is a flavonoid showing variable pharmacological properties and is distributed ubiquitously in plant foods. There is a paucity of reported data regarding its safety profile. In the present study, chronic toxicity studies of naringin was designed and conducted by oral gavage at doses of 0, 50, 250 and 1250 mg/kg in Sprague-Dawley (SD) rats for six months followed by 1-month recovery period. During the 6-month treatment period and one month recovery period, no mortality and toxicologically significant changes in clinical signs, opthalmoscopic examination, hematology, clinical biochemistry, serumsexhormone, macroscopic findings, organ weights and histopathological examination were noted and attributed to naringin administration. Although consecutive and/or isolated periods of significant body weights and food consumption decreases were relevant to naringin administration, they were not considered toxicologically significant. In addition, slight, non-pathological and reversible hair loss was noted during the 6-month treatment period and considered as a kind of change possibly relevant to naringin administration; however, it was not considered adverse change and to be of toxicological significance. Based on the results of this study, the no-observed-adverse-effect-level (NOAEL) of naringin in rats is greater than 1250 mg/kg/day when administered orally for 6 consecutive months.