Simulated Stomach Research Articles

Antioxidant Activities ofCentella asiaticaExtract-loaded Bovine Serum Albumin Nanoparticles in Simulated Gastrointestinal System Study

Bioavailability of active compounds extracted from herbs is generally limited to be adsorbed or expressed to target organisms due to several physical and chemical factors. Nanoparticle encapsulation techniques was developed to carry bioactive macromolecules ofCentella asiatica(Buabok) in the form ofC. asiaticaExtract-loaded Bovine Serum Albumin Nanoparticles (CBNPs) to improve bioavailability. In this study, the antioxidant activities of CBNPs andC. asiaticacrude extract were evaluated by using DPPH radical scavenging assay in the simulated gastrointestinal system, including mastication, stomach, duodenum, and ileum conditions to provide the environment which similar toin vivosystem in terms of chemical and physical parameters. CBNPs were prepared by mixing ofC. asiaticacrude extract and BSA at different ratio of 1:2, 1:3, and 1:4. The results showed that the highest antioxidant activity of CBNP was observed when the ratio of crude extract and BSA at 1:2 was used at pH 2.0 or in the simulated stomach condition. The denaturation or unfolding of BSA in the simulated stomach occurred when pH was low could lead to the release of active compounds at certain area in gastrointestinal system.

Construction of Slow Digestion Coconut Oil Emulsion System Series and Comparison of Their Microrheological Properties and in Vitro Digestive Properties

In this paper,coconut oil single-layer emulsion was prepared using coconut oil as the core material and whey protein isolate(WPI) as the wall material,respectively. And four types of double-layer emulsions were prepared using coconut oil single-layer emulsion as the core material and CMC,CNC,CNI,MCC as the wall material,respectively. The microrheological and in vitro digestive properties of all emulsion systems was studied. The results showed that WPI-CNC stabilized coconut oil emulsion systems had the highest macroscopic viscosity index and elasticity index(P<0.05),and the droplets in the emulsion were not free to move due to the droplets network interaction. The WPI-CNC emulsion had the lowest SLB value(P<0.05),and the rate of droplets movement in the emulsion was low. WPI-CNC emulsion had a lowest intestinal release rate and the slowest release rate. Following passage through the simulated stomach phase,extensive droplet flocculation was observed except coconut oil emulsion stabilized by WPI-CNC,and the degree of aggregation was increased following exposure to the simulated small intestinal stage. Following exposure to the simulated mouth,stomach and small intestinal stage,we observed an ordinal increase in the mean particle size of WPI,WPI-CNC and WPI-CMC emulsions,and the particle size distribution demonstrated that these emulsions exhibited multimodal distribution. Following exposure to the simulated small intestinal stage,increase in the negative charge of all emulsions was observed. It demonstrated that the microrheological property of coconut oil emulsion significantly affected their digestibility,and WPI-CNC stabilized coconut oil emulsion had the lowest and the slowest digestibility in vitro.

In Vitro Digestion of Apple Tissue Using a Dynamic Stomach Model: Grinding and Crushing Effects on Polyphenol Bioaccessibility.

Food structure is a key determinant for the release of phenolic compounds during gastric and intestinal digestion. We evaluated the bioaccessibility of polyphenols from apple tissue during gastric digestion in vitro from bio-mechanical perspectives including the effects of gastric juice and mucin on the apple tissue matrix under simulated stomach peristalsis. The gastric model system was effective in releasing polyphenols because of simultaneous compression and extrusion, with 3 times higher release from coarse than from fine particles. However, bioaccessibility of polyphenols was reduced up to 44% in the presence of both cell walls and gastric mucin. Most individual phenolic molecules were gradually released and were stable in the gastric environment, except for procyanidin B2. The study suggests that the bioaccessibility of polyphenols from apples in the upper digestive tract is dependent on mechanical disintegration and the residual matrix present in the swallowed bolus.

Anthocyanin-loaded double Pickering emulsion stabilized by octenylsuccinate quinoa starch: Preparation, stability and in vitro gastrointestinal digestion

In this study, anthocyanin-loaded water1-in-oil-in-water2 (W1/O/W2) double Pickering emulsions stabilized by octenylsuccinate quinoa starch (OSQS) were optimized, and their storage stability and in vitro gastrointestinal digestion were evaluated. Novel starch-based double emulsions as anthocyanin cargos were achieved at 2% (w/v of oil) of polyglycerol polyricinoleate concentration, the W1/O volume proportion of 3:7, 6% (w/v of total volume) of OSQS concentration, and the volume proportion of (W1/O): W2 = 6:4 and 5:5. CLSM results evidenced the formation of double Pickering emulsions, and the significant decreases in the encapsulation stability of anthocyanins were closely related to the increases in the droplet size induced by osmotic pressure. Less than 15% of anthocyanins in the double Pickering emulsions was released after incubated for 60 min under simulated stomach conditions; controlled-release of anthocyanins was observed during the 120 min of simulated intestinal digestion, consistent with starch hydrolysis data. These findings will be useful for designing starch-based double Pickering emulsion with intestinal-targeted delivery as a novel carrier of sensitive hydrophilic bioactive compounds.

Enumeration of Escherichia coli in Probiotic Products.

Probiotic products typically take the form of oral supplements or food-based products containing microorganisms, typically bacteria. The number of bacteria present in a dose of probiotic can be several orders of magnitude lower than the label claims, and in some cases, undetectable. The objective of this study was to assess probiotic products containing Escherichia coli to verify manufacturer claims, which have not yet been independently assessed, regarding the number of viable E. coli per suggested dose. It was found that the products tested contained E. coli in numbers several orders of magnitude less than claimed, and when subjected to simulated stomach conditions, the number of viable E. coli was significantly reduced.

Enrichment of zein nanofibre assemblies for therapeutic delivery of Barije (Ferula gummosa Boiss) essential oil

The present study intended to produce electrospun zein nanofibres containing concentrations varying from 1 to 4% w/w of Barije essential oil (BEO): BEO is said to have anti-diabetic and antioxidant properties. The BEO loaded nanofibres were characterised for chemical composition, morphology, chemical structure, thermal behaviour, α-amylase and α-glucosidase inhibitory action. Moreover, the kinetic release of BEO in simulated gastric and intestinal media was investigated. SEM and FT-IR results indicated that BEO was successfully entrapped in the ribbon-like zein fibres and that the nanofibres showed an encapsulation efficiency close to 95%. The fibre encapsulated BEO also retained its antioxidant capacity, although it had been exposed to high strength electric fields during manufacture. BEO-loaded zein nanofibres showed α-glucosidase and α-amylase inhibition activity with an IC50 value ranging of 0.78 ± 0.01 to 1.25 ± 0.03 and 1.09 ± 0.02 to 1.64 ± 0.01 mg/ml, respectively. Model fitting results showed that a first-order model is effective for describing the release of BEO into simulated stomach media, a Hixon-Crowell model relates BEO release to intestinal conditions and the Rigter-Peppas model describes time of release. The study indicates that combining BEO within zein fibres is a promising route for a novel BEO delivery vehicle for diabetes control.

PH-Dependent Site Specific Dissolution Improvement by Expansion Isolation Layers in Erythromycin Enteric Coated Tablets

The present research focuses on the formulation and optimization of enteric tablets of erythromycin (EM) based on expansion isolation layers with improved duodenum targeted delivery and dissolution. To achieve this aim, the core of the enteric tablets was formulated as a rapid release tablet. For the purpose of avoiding the enteric layer hindering drug release in the duodenum, cross-linked povidone (PVPP) was introduced as an expansion agent in the isolation layer to exert swelling focus on the enteric layer and fasten the shedding rate of the enteric coating. The influence of composition of the isolation layer (the fraction of PVPP) and also the coating weight gain of the isolation layer on the acid resistance as well as drug release profiles was investigated. Observation of the shedding state of the enteric coating was visually examined, and also was confirmed by theory. EM in the enteric tablet based on expansion isolation layer was successfully delivered both at pH6 and pH6.8 within 15 min after 1 h simulated stomach environment in vitro at an ascending release rate. The experimental results predict PVPP has a potential as an expansion agent in the isolation layer of enteric tablets to facilitate drug release.

Reactions of polyphenols in pomegranate peel with nitrite under simulated stomach conditions.

Punicalagin and ellagic acid are the major polyphenols present in pomegranate peels. The contents of α‐punicalagin, β‐punicalagin, and ellagic acid in the pomegranate peels were approximately 75, 72, and 20 µM, respectively. The reactions of polyphenols in pomegranate peels with sodium nitrite under simulated stomach conditions were studied. The reactions decreased the polyphenolic contents of the pomegranate peels and accompanied the formation of nitroso compounds. The oxidation rates followed the order ellagic acid ＜α‐punicalagin ≈ β‐punicalagin. The results suggested that the reactions can occur in the stomach after a meal, while the pH changes from 2 to 4.5.

Radioactive particles in the Yenisei River floodplain (Russia): Characterization, leaching and potential effects in the environment

The operation of the Mining-and-Chemical Combine (MCC), the largest producer of weapons-grade plutonium in Russia, has resulted in radioactive contamination of the Yenisei River floodplain. Investigations carried out in Novosibirsk and Krasnoyarsk institutes have shown that the floodplain of the Yenisei downstream of the MCC is contaminated by radioactive particles (RP) of various types and activities. Analytical characterization of the RP showed that most of them were fuel particles, which were carried into the Yenisei after incidents at the MCC reactors. The plutonium and caesium isotope ratios (238Pu/239,240Pu; 137Cs/134Cs) vary substantially between the particles, indicating different source terms and time intervals when the RP were formed. In addition to fuel RP, there were particles that contained activation radionuclides. The experiment on dissolution of RP using the model solution (the simulated stomach fluid) showed different cumulative extractions of radionuclides from the particles: 60Co and 137Cs extractions were the lowest, the extracted fractions of europium and americium isotopes were the largest, and plutonium occupied an intermediate position. High concentrations of radionuclides in RP are sources of exposure of organisms in aquatic and terrestrial ecosystems to low radiation doses. The plant bioassays of the effects of γ-radiation from RP showed the effect of low doses of γ-radiation on growth parameters of aquatic plant Elodea canadensis growing in the Yenisei River floodplain. The presence of RP from different sources in the Yenisei River floodplain makes this region a unique site for studying environmental effects of the particles.

Evaluation of Probiotic Potential of Lactic Acid Bacteria Isolated from Raphia Palm Wine (Raffia mambillensis)

Aim: The present study was undertaken to assess the probiotic potential of lactic acid bacteria strains isolated from raphia palm wine (Raffia mambillensis O.) of the South West region of Cameroon.&#x0D; Study Design: The study site and sample were randomly chosen and the responses assessed were submitted to analyses of variance.&#x0D; Place and Duration of Study: The study was carried out in Ekona in the South West region of Cameroon, between February 2017 and October 2018.&#x0D; Methodology: Physicochemical analyses were performed to characterize the Raphia palm wine samples. Lactic acid bacteria were isolated from these samples using pour plate method, and the isolates were tested for their antimicrobial activity, low pH and bile salts tolerance, antibiotic sensitivity, hemolytic activity and enzymes production. The active isolates were identified phenotypically using API 50 CHL.&#x0D; Results: The results revealed that among the nine isolates, only three were active against Escherichia coli BL21, Escherichia coli, Salmonella typhi, Salmonella enterica and Staphylococcus aureus with inhibition diameters ranging from 10 to 25 mm. The three isolates which exhibited antimicrobial activity were able to survive at simulated stomach pH (pH 3.0) with survival rate above 80% and in the presence of bile salts at 1% with survival rates above 50%. All three isolates gave negative results for hemolytic activity and were resistant to most antibiotic treatments. These three isolates produced β-galactosidase, which is beneficial for lactose intolerance. They also produced some non-carcinogenic enzymes including leucine arylamidase, crystine arylamidase, acid phosphatase, α-galactosidase, α-glucosidase, β-glucosidase, and N-acetyl-β-glucosamidase. Identification of these three isolates with API kit 50 CHL reveals that they are Lactobacillus lactis, Lactobacillus plantarum and Lactobacillus brevis.&#x0D; Conclusion: Our findings revealed that raphia palm wine can be an excellent source of probiotic lactic acid bacteria.

In situ monitoring of lipid droplet release from biopolymer microgels under simulated gastric conditions using magnetic resonance imaging and spectroscopy.

Functional foods are being designed to breakdown in the human gut in a controlled fashion so as to regulate blood nutrient profiles, hormone release, energy intake, and bioavailability. Biopolymer microgels, small spherical beads made from proteins and/or polysaccharides, are a promising tool that can be used to modulate the gastrointestinal behavior of food components. In this study, lipid droplets were loaded into microgels fabricated from either alginate or carrageenan using an injection-gelation method. The lipid-loaded microgels were then incubated in simulated gastric juices and the impact of biopolymer type on the release of the lipid droplets was observed. Optical microscopy and turbidity measurements showed that lipid droplet release occurred more rapidly for the carrageenan microgels, which was attributed to their partial disruption in the gastric fluids. In contrast, lipid droplet release was relatively slow from the alginate microgels because they remained intact. We also showed that magnetic resonance imaging (MRI) could be used for in situ monitoring of carrageenan microgel disruption and lipid droplet release under simulated stomach conditions. This method was based on quantifying the local lipid levels using T1 images and the magnetic resonance spectroscopy. A water-selected VIBE sequence was optimized for obtaining the T1 images and a stimulated echo acquisition mode (STEAM) sequence was selected for obtaining the MR spectra. The MRI method may be particularly useful for in vivo studies of the behavior of filled microgels.

FORMULATION AND EVALUATION OF BUOYANT TABLETS OF KETOCONAZOLE

Objective: The primary objective of the present work was to formulate the gastro-retentive delivery system of ketoconazole (ktz) for its extensive absorption in the stomach.&#x0D; Methods: The solubility and dissolution of antifungal ktz were reported to be higher in the stomach than in the intestinal pH conditions because of its dibasic pKa values 6.51 and 2.94. Thus the development of target buoyant tablets using Hydroxy Propyl Cellulose (HPC) and Xanthan gum (Xg) as polymers along with the effect of citric acid and sodium bicarbonate as an effervescent causing agent of floatation properties and drug release profile was investigated. The formulation optimization was carried out by using a central composite design using Design Expert software by taking HPC, Xanthan gum and sodium bicarbonate as independent variables and floating lag time, in vitro drug release profile as dependent variables respectively.&#x0D; Results: The optimized formulation of ktz buoyant tablets could be developed. The amount of HPC and Xg was found to significantly influence all in vitro response parameters. The results of pre-compression and post-compression parameters of all the formulations were found to be within the standard limits. The optimized formulation exhibited floating lag time of 160 secs with sustained drug release over a period of 12 h in simulated stomach pH condition.&#x0D; Conclusion: Buoyant tablets of ktz with sustained drug release over a period of 12 h in simulated stomach conditions for enhanced drug absorption could be successfully developed.

Improvement of bioavailability for resveratrol through encapsulation in zein using electrospraying technique

Abstract Resveratrol has proven antioxidant, anticancer, anti-inflammatory and cardioprotective effects. However, poor water solubility, low bioavailability and UV light sensitivity hinder its usage in food applications. Encapsulation of resveratrol can help to overcome these problems. In this work, encapsulation by electrospraying was adopted, owing to the possibility of obtaining spherical and nano-sized particles at room temperature. This study proved that resveratrol can be efficiently encapsulated with zein without modifying its native form. Size of nanoencapsulated particles obtained ranged from 230 to 330 nm. Nanoencapsulation through electrospraying process yielded 68.49% encapsulation efficiency at 1:50 resveratrol to zein w/w%. Further, nanoencapsulated resveratrol showed better stability and sustained release profiles as compared to the unencapsulated form. Nanoencapsulation with zein protected resveratrol in simulated stomach conditions and released resveratrol in the intestinal condition. Additionally, nanoencapsulated resveratrol showed increased permeability of 1.15 fold in ex-vivo dynamic engineered small intestinal system which in turn relates to improved bioavailability. Prepared nanoparticles can be used for oral administration by incorporation into food products or in tablet form.

Preparation and Evaluation of Release Formulation of γ-Oryzanol/Algae Oil Self-Emulsified with Alginate Beads.

Self-emulsion improves solubility and bioavailability for γ-oryzanol/algae oil, and alginate beads can be used as controlled release carriers. In this study, self-emulsified alginate beads (SEABs) were prepared with different weight ratios of self-emulsion treatment (5%, 10%, 15%, 20%, and 30%) with alginate. We found that the microstructure with a surfactant of SEABs had a different appearance with alginate-based beads. The encapsulation of γ-oryzanol corresponded with the self-emulsion/alginate ratio, which was 98.93~60.20% with a different formulation of SEABs. During in vitro release, SEABs had the gastric protection of γ-oryzanol/algae oil, because γ-oryzanol and emulsion were not released in the simulated stomach fluid. When the SEABs were transferred to a simulation of the small intestine, they quickly began to swell and dissolve, releasing a higher content of the emulsion. We observed that the emulsion that formed had a bimodal distribution in the simulated intestinal fluid as a result of the hydrogel and emulsion droplets, leading to the formation of large aggregates. These results suggested that γ-oryzanol encapsulation within alginate beads via emulsification combined with gelation can serve as an effective controlled delivery system.

Development and physico-chemical characterization of virgin coconut oil-in-water emulsion using polymerized whey protein as emulsifier for Vitamin A delivery

Emulsion systems have become an integral part of food manufacturing, mainly as delivery vehicles of sensitive lipophilic nutrients i.e. Vitamin A. Thus, it is crucial to develop emulsions stable enough to protect these nutrients. In this study, virgin coconut oil (VCO)-in-water emulsion was prepared with polymerized whey protein as emulsifier to encapsulate Vitamin A. The VCO droplets were dispersed in water phase, and Vitamin A was dissolved in oil phase. The study aimed at developing VCO-in-water emulsion to encapsulate and protect Vitamin A, in the form of retinyl acetate, and determining physico-chemical characteristics of the emulsion. In vitro analysis was conducted to determine the stability of the emulsion in encapsulating Vitamin A. Three emulsions were prepared at different homogenization speed: 720, 846.7 and 955.8 rpm. The emulsion made with speed setting of 846.7 rpm gave the best visual characteristics, comparable with dairy butter. Thermal analyses using differential scanning calorimeter showed that the emulsion increased the energy requirement to degrade Vitamin A at simulated stomach pH. Also, microscopy results show the emulsion has an average particle diameter of approximately 10 μm, which remained stable at acidic environment of simulated digestion. Therefore, the emulsion is thermodynamically stable and shows minimal coalescence.

Impact of plant extract on the gastrointestinal fate of nutraceutical-loaded nanoemulsions: phytic acid inhibits lipid digestion but enhances curcumin bioaccessibility.

The impact of phytic acid on lipid digestion and curcumin bioaccessibility in oil-in-water nanoemulsions was investigated using a simulated gastrointestinal tract (GIT). The size, charge, and structural organization of the colloidal particles in the system were measured as the curcumin-loaded emulsions (7 mg curcumin per g lipid) were passed through simulated mouth (pH 6.8, 2 min), stomach (pH 2.5, 2 hours), and small intestine (pH 7.0, 2 hours) stages. After the small intestine stage, the level of free fatty acids (FFAs) generated and the bioaccessibility of curcumin were measured. The total amount of FFAs released significantly decreased with increasing phytic acid level, from 105.7 ± 5.9% (control) to 78.4 ± 6.4% (0.5% phytic acid). Conversely, curcumin bioaccessibility significantly increased from 39.4 ± 3.5% (control) to 74.7 ± 2.6% (0.5% phytic acid). The inverse relationship between lipolysis and curcumin bioaccessibility was ascribed to the impact of phytic acid on droplet flocculation and the level of free calcium ions present, which affected the production of mixed micelles capable of solubilizing the nutraceutical. The knowledge obtained here might prove beneficial for the employment of phytic acid as a multifunctional ingredient that inhibits lipid digestion while boosting nutraceutical bioavailability.

Preparation and structural properties of amylose complexes with quercetin and their preliminary evaluation in delivery application

ABSTRACT In this study, amylose, known as the food-grade biopolymers has been proved as a feasible solution for the controlled delivery of quercetin. The effect of reaction variables including reaction temperature, time, pH and quercetin addition amount on the content and conversion rate of quercetin was analyzed. Meanwhile, fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) provided evidence of quercetin complexation with amylose. Then, the molecular, cluster, and fractal structures of the complexes were investigated using 13C cross-polarization/magic angle spinning nuclear magnetic resonance (13C CP/MAS NMR) and small-angle X-ray scattering (SAXS). Furthermore, laser scanning confocal microscopy (CLSM) identified the precise encapsulation structure from direct observation and scanning electron microscope (SEM) was conducted to show that complexes displayed a larger size granule with smooth and angular appearance. From the antioxidant study, amylose/quercetin complexes presented effective scavenging capacity toward DPPH•. Besides, complexes showed high retention of quercetin in simulated stomach conditions but gradual release in simulated small intestine conditions. It was therefore confirmed that the amylose/quercetin complexes could be served as suitable carriers for the controlled release of quercetin in the digestive tract. The present research expanded the application range of starch, meanwhile proved an alternative application prospect for the ameliorative bioactive quercetin products.

Linear and Hyperbranched Copolymers of PEG-Based Acrylates and Methacrylic Acid as pH-Responsive Hydrophobic Drug Carriers

The oral administration of pharmaceuticals is typically preferred over other methods due to its non-intrusiveness and convenience of administration. However, the varying chemical environments of the gastro-intestinal tract pose a challenge in ensuring the stability and inertness of a drug compound until it reaches its target. Polymers that are responsive to pH changes have potential as smart materials for the controlled oral administration of pharmaceuticals. In this study, linear and hyperbranched copolymers of methacrylic acid (MAA) and poly (ethylene glycol) methyl ether methacrylate (PEGMEMA) were synthesized by RAFT polymerization. High molecular weight polymers were produced with PDI values close to 1.0. These smart materials underwent phase changes at pH 5.15-5.6. This property enabled the amphiphilicity of the copolymers to be switched on or off. By doing so inin vitrodrug release studies with ibuprofen as the model hydrophobic drug, the copolymers were able to inhibit drug release in simulated stomach conditions to up to 13% while enhancing drug release in simulated intestinal conditions to up to 75% within 6 hours. These indicate that copolymers based on MAA and PEGMEMA have potential as smart materials for drug delivery applications.

Development of a standardized food model for studying the impact of food matrix effects on the gastrointestinal fate and toxicity of ingested nanomaterials

Food matrix effects impact the bioavailability and toxicity of pharmaceuticals, nutraceuticals, pesticides, and engineered nanomaterials (ENMs). However, there are currently no standardized food models to test the impact of food matrix effects using in vitro gastrointestinal models. The purpose of this study was to establish a standardized food model (SFM) for evaluating the toxicity and fate of ingested ENMs and then to assess its efficacy by examining the impact of food matrix effects on the toxicity of TiO2 nanoparticles. The formulation of the SFM was based on the average composition of the US diet: 3.4% protein (sodium caseinate); 4.6% sugar (sucrose); 5.2% digestible carbohydrates (modified corn starch); 0.7% dietary fiber (pectin); 3.4% fat (corn oil); and, 0.5% minerals (sodium chloride). The SFM consisted of an oil-in-water emulsion suitable for use in both wet and dried forms. The dried form was produced by spray drying the emulsion to improve its handling and extend its shelf-life. The particle size (D32 = 135 nm), surface charge (−37.8 mV), viscosity, color (L*, a,* b* = 82.1, −2.5, 1.3), and microstructure of the wet SFM were characterized. The hydration properties, flowability (repose angle ≈ 27.9°; slide angle ≈ 28.2o), and moisture sorption isotherms of the dry SFM were comparable to commercial food powders. The potential gastrointestinal fate of the SFM was determined using a simulated gastrointestinal tract, including mouth, stomach, and small intestine steps. Conversion of the SFM into a powdered form did not impact its gastrointestinal fate. A nanotoxicology case study with TiO2 nanoparticles exposed to a tri-culture epithelial cell model showed that food matrix effects reduced ENM cytotoxicity >5-fold. The SFM developed in the current study could facilitate studies of the impact of food matrix effects on the gastrointestinal fate and toxicity of various types of food NPs.

Toxicity of copper oxide and basic copper carbonate nanoparticles after short-term oral exposure in rats

Copper oxide (CuO) nanoparticles (NPs) and copper carbonate nanoparticles (Cu2CO3(OH)2 NPs have applications as antimicrobial agents and wood preservatives: an application that may lead to oral ingestion via hand to mouth transfer. Rats were exposed by oral gavage to CuO NPs and Cu2CO3(OH)2 NPs for five consecutive days with doses from 1 to 512 mg/kg and 4 to 128 mg/kg per day, respectively, and toxicity was evaluated at days 6 and 26. Both CuO NPs and Cu2CO3(OH)2 NPs induced changes in hematology parameters, as well as clinical chemistry markers (e.g. increased alanine aminotransferase, ALT) indicative of liver damage For CuO NPs histopathological alterations were observed in bone marrow, stomach and liver mainly consisting of an inflammatory response, ulceration, and degeneration. Cu2CO3(OH)2 NPs induced morphological alterations in the stomach, liver, intestines, spleen, thymus, kidneys, and bone marrow. In spleen and thymus lymphoid, depletion was noted that warrants further immunotoxicological evaluation. The NPs showed partial dissolution in artificial simulated stomach fluids, while in intestinal conditions, the primary particles simultaneously shrank and agglomerated into large structures. This means that both copper ions and the particulate nanoforms should be considered as potential causal agents for the observed toxicity. For risk assessment, the lowest bench mark dose (BMD) was similar for both NPs for the serum liver enzyme AST (an indication of liver toxicity), being 26.2 mg/kg for CuO NPs and 30.8 mg/kg for Cu2CO3(OH)2 NPs. This was surprising since the histopathology evidence demonstrates more severe organ damage for Cu2CO3(OH)2 NPs than for CuO NPs.