Long-term Oral Consumption Research Articles

Polar Phenol Detection in Plasma and Serum: Insights on Sample Pre-Treatment for LC/MS Analysis and Application on the Serum of Corinthian Currant-Fed Rats.

Analysis of plasma and serum provides valuable information on the amounts of polar phenols' circulating after ingestion. In the present study, protein precipitation (PPT), liquid-liquid extraction (LLE), solid phase extraction (SPE), enzymatic hydrolysis and their combinations were meticulously evaluated for the extraction of a variety of polar phenolic moieties from plasma and serum. The recovery values of the above methods were compared; satisfactory recoveries (>60%) were attained for most analytes. Polar phenol aglycones undergo degradation with enzymatic hydrolysis; however, their extended phase II metabolism makes enzymatic hydrolysis a mandated process for their analysis in such biofluids. Hence, enzymatic hydrolysis followed by LLE was used for the identification of polar phenols in rats' serum, after the long-term oral consumption of Corinthian Currant. Corinthian Currant is a Greek dried vine product rich in bioactive polar phenolics. Flavonoids and phenolic acids, detected as aglycones, ranged from 0.57 ± 0.08 to 181.66 ± 48.95 and 3.45 ± 1.20 to 897.81 ± 173.96 ng/mL, respectively. The majority of polar phenolics were present as phase II metabolites, representing their fasting state in the blood stream. This is the first study evaluating the presence of polar phenolics in the serum of rats following a long-term diet supplemented with Corinthian Currant as a whole food.

Subchronic toxicity study of the characterized hydroalcoholic extract of Paederia foetida (L.) leaves in swiss albino mice

• Chemical characterization of hydroalcoholic extract of paederia foetida (Linn.). • HPTLC fingerprinting profile of hydroalcoholic extract of P. foetida. • Sub chronic toxicity profile of hydroalcoholic extract of P. foetida. • In vivo safety assessment of hydroalcoholic extract of P. foetida according to OECD guideline 408. Paederia foetida Linn. have long been used as traditional medicines in subtropical countries for various diseases such as treatment of rheumatism, diarrhoea, inflammation, piles, snake bites, toothaches and a variety of other ailments. Phytochemical investigations of P. foetida leaves suggest the presence of glycosides, flavonoids, alkaloids, carbohydrates, amino acids and volatile oils. HPTLC fingerprint of hydroalcoholic extract of P. foetida leaves (HAPF) was developed for the quality control. Since the toxicity of a plant following repeated exposure is of higher clinical significance, the present investigation was conducted to establish the subchronic toxicity profile of the HAPF. Sub-chronic oral toxicity study of HAPF was done according to the Organization for Economic Cooperation and Development (OECD) guideline, HAPF was administered to swiss albino mice at doses of 1000, 300 and 100 mg/kg b. w. per day for 90 days. There was no significant ( p < 0.05) difference observed in the consumption of food and water, body weight and relative organ weights in different treatment groups comparison with vehicle treated mice. Changes in haematological and serum biochemical levels were not significant ( p < 0.05), which showed that long-term oral consumption of HAPF had no adverse effects. The histopathology examination did not show any differences in the organs that are critical to life. Based on what we found, HAPF is safe for long-term oral consumption at doses up to 1000 mg/kg body weight.

Subchronic oral toxicity evaluation of gold nanoparticles in male and female mice

Gold nanoparticles (AuNPs) are biocompatible nanomaterials with potential application in the food industry. The safety of AuNPs oral consumption remains inconclusive, and information on possible long-term toxicity is limited. The current study aimed to evaluate the subchronic oral toxicity of AuNPs in male and female Institute of Cancer Research (ICR) mice. Citrate-coated spherical AuNPs with 53 nm diameters were prepared and orally administered to the mice. No mortality or clinical abnormalities were observed following daily administration of AuNPs at the dosages of 0.2, 2, and 20 mg/kg for 90 days. There was no significant difference in body weight or the relative organs' weights between the control and AuNPs-treated mice. No gross abnormalities or histopathological changes were observed except that the male mice treated with high dose (20 mg/kg AuNPs) showed minor infiltration in the kidneys, and female mice showed a reduced A/G ratio and elevated platelet indices. Overall, the 90-day long-term oral consumption of AuNPs did not cause significant toxicity in mice.

Effect of different doses of 2,4-dichlorophenoxyacetic acid (2,4-D) on cardiac parameters in male Wistar rats.

The objective of this study was to evaluate the effects of different doses of 2,4-dichlorophenoxyacetic herbicide in rat hearts. Exposure was through rat food that was nebulized with the herbicide. Thirty adult male Wistar rats (200-300 g) were used. The diet was exposed to 2,4-D in two different doses (CG: control group 10 ml distilled water; LCG: low concentration group 3.71 × 10-3 g.ia/ha diluted in 10 ml saline at 0.9% and HCG: High concentration group 9.28 × 10-3 g.ia/ha diluted in 10 ml 0.9% saline). After 6 months of exposure, blood samples were collected for CKMB evaluation, and left ventricular fragments were analyzed by histological evaluation, fibrosis measurements, fractal dimension and immunohistochemistry (BAX, Bcl2, TNF-α and NF-kB). There were no significant changes in CK-MB concentration, histological parameters, fibrosis measurements and fractal dimension. Long-term oral consumption of food nebulized by the herbicide 2,4-D promoted an increase in BAX, Bcl-2/BAX, and cytoplasmic NF-kB in the nuclear area of the group that received the highest dose of the herbicide. This suggests that the herbicide induces cardiotoxicity.

Evaluation of skin absorption of the Citrullus colocynthis in treatment of type II diabetic patients.

Nowadays, among the herbal medicines utilized to treat diabetes, Citrullus colocynthis (CCT) is highly noticeable as it reduces blood glucose (BG) and stimulating insulin secretion. However, long-term oral consumption of this herbal medicine has often associated with digestive complications. In this study, skin absorption of CCT as a new therapeutic approach in the treatment of type II diabetic patients has been surveyed. 40 patients with type II diabetic (aged 45-65) were selected. Participants were asked for placing their metatarsus daily in a decoction containing 2% CCT solution for 40-60min each day and continuing that for 10days. Blood and urine samples of patients collected at the beginning and the end of the study. The samples were examined for the BG levels, serum insulin content, lipid profiles, hepatic enzymes, urea, creatinine, and microalbuminuria, The quantitative insulin sensitivity check index (QUICKI), Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), homeostasis model assessment of β-cell function (HOMA-β) and disposition index (DI) indicators were also calculated. Local treatment of CCT could significantly decrease BG levels, stimulate insulin secretion and improve the function of pancreatic beta cells. It also decreased serum urea levels comparing to pre-treatment levels (p < 0.05) but there was no significant change in creatinine levels, lipid profiles, hepatic enzymes, micro-albuminuria, and other insulin sensitivity indexes. This study demonstrated that the CCT plant can also have systemic therapeutic effects on type II diabetic patients through dermal absorption.

(-)-Epigallocatechin-3-gallate ameliorates memory impairment and rescues the abnormal synaptic protein levels in the frontal cortex and hippocampus in a mouse model of Alzheimer's disease.

(-)-Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenolic extract in green tea and it has attracted increasing attention for its multiple bioactive effects. However, the mechanisms by which EGCG exerts its neuroprotective actions in Alzheimer's disease (AD) are presently lacking. In the present study, a sporadic AD transgenic mouse model known as senescence-accelerated mouse prone 8 (SAMP8) was used to investigate whether oral administration of EGCG could improve recognition and memory function through reduction of amyloid β (Aβ) and tau hyperphosphorylation. We also investigated the effects of chronic EGCG treatment on the synaptic dysfunction in the frontal cortex (FC) and the hippocampus (Hip) of AD mice. The results showed that long-term oral consumption of EGCG at a relatively high dose (15 mg/kg) improved memory function in SAMP8 mice in the Y-maze and Morris water maze. The levels of Aβ1-42 and BACE-1 in FC and Hip were significantly reduced by EGCG treatment. EGCG treatment also prevented the hyperphosphorylation of tau and reversed the decreased synaptic protein marker synaptophysin and postsynaptic density protein 95 in FC and Hip of SAMP8 mice. The present study suggests that long-term oral consumption of EGCG ameliorates impairments in spatial learning and memory and rescues the reduction in synaptic proteins observed in an AD mouse model. Thus, EGCG may represent a novel candidate agent for the treatment of neurodegenerative diseases.

Acute and subacute toxicity profiles of thymoquinone-loaded nanostructured lipid carrier in BALB/c mice.

BackgroundThymoquinone (TQ), the predominant active lipophilic component in Nigella sativa seed oil, has a variety of pharmacological properties such as anticancer activities. However, translation of TQ to clinical phase is still not possible due to its hydrophobic properties. This problem can be solved by encapsulating it in nanoformulations to enhance its pharmacological properties. In our previous study, TQ has been successfully encapsulated in a nanostructured lipid carrier (hereinafter referred to as TQNLC) with excellent physiochemical properties such as high encapsulation efficiency, high drug-loading capacity, particle diameter less than 100 nm, and stability up to 2 years. In vitro studies also proved that TQNLC exhibited antiproliferative activity toward breast and cervical cancer cell lines. However, no toxicity profile related to this formulation has been reported. In this study, we determine and compare the in vivo toxicity of both TQNLC and TQ.Materials and methodsThe in vivo toxicity (acute and subacute toxicity) study was carried out by oral administration of TQNLC and TQ to BALB/c mice. Animal survival, body weight, organ weight-to-body weight ratio, hematological profile, biochemistry profile, and histopathological changes were analyzed.ResultsIn acute toxicity, TQ that is loaded in nanostructured lipid carrier (NLC) was found to be less toxic than pure TQ. It can be concluded that encapsulation of TQ in lipid carrier minimizes the toxicity of the compound. In the subacute toxicity study, oral administration of 100 mg/kg of TQNLC and TQ did not cause mortality to either male or female but resulted in toxicity to the liver. It is postulated that long-term consumption of TQNLC and TQ may cause toxicity to the liver but not to the extent of altering the functions of the organ. For both treatments, the no observed adverse effect level (NOAEL) was found to be 10 mg/kg/d for mice in both sexes.ConclusionFor long-term oral consumption, TQ and TQNLC at a dose of 10 mg/kg is safe in mice and does not exert any toxic effect. The results provide safety information of TQNLC, which would further help researchers in clinical use.

Agrimonia pilosa Ledeb., Cinnamomum cassia Blume, and Lonicera japonica Thunb. protect against cognitive dysfunction and energy and glucose dysregulation by reducing neuroinflammation and hippocampal insulin resistance in β-amyloid-infused rats

Objectives: The water extracts of Cinnamomum cassia Blume bark (CCB; Lauraceae), Lonicera japonica Thunb. flower (LJT; Caprifoliaceae), and Agrimonia pilosa Ledeb. leaves (APL; Rosaceae) prevented amyloid-β (25–35)-induced cell death in PC12 cells in our preliminary study. We evaluated whether long-term oral consumption of CCB, LJT, and APL improves cognitive dysfunction and glucose homeostasis in rats with experimentally induced AD-type dementia.Methods: Male rats received hippocampal CA1 infusions of amyloid-β (25–35, AD) or amyloid-β (35–25, non-plaque forming, normal-controls, Non-AD-CON), at a rate of 3.6 nmol/day for 14 days. AD rats were divided into four groups receiving either 2% lyophilized water extracts of CCB, LJT, or APL or 2% dextrin (AD-CON) in high-fat diets (43% energy as fat).Results: Hippocampal amyloid-β deposition, tau phosphorylation, and expressions of tumor necrosis factor (TNF)-α and inducible nitric oxide synthase (iNOS) (neruoinflammation markers) were increased, and insulin signaling decreased in AD-CON. CCB, LJT, and APL all prevented hippocampal amyloid-β accumulation and enhanced hippocampal insulin signaling. CCB, LJT, and APL decreased TNF-α and iNOS in the hippocampus and especially APL exhibited the greatest decrease. AD-CON exhibited cognitive dysfunction in passive avoidance and water maze tests, whereas CCB, LJT, and APL protected against cognitive dysfunction, and APL was most effective and was similar to Non-AD-CON. AD-CON had less fat oxidation as an energy fuel, but it was reversed by CCB, LJT, and especially APL. APL-treated rats had less visceral fat than AD-CON rats. AD-CON rats exhibited impaired insulin sensitivity and increased insulin secretion during oral glucose tolerance test compared with Non-AD-CON, but CCB and APL prevented the impairment.Discussion: These results supported that APL, LJT, and CCB effectively prevent the cognitive dysfunction and the impairment of energy and glucose homeostasis induced by amyloid-β deposition by reducing neuroinflammation and enhancing insulin signaling. APL exhibited the greatest effectiveness for improving cognitive function.

Methyl jasmolate treated buckwheat sprout powder enhances glucose metabolism by potentiating hepatic insulin signaling in estrogen-deficient rats

ObjectivesMethyl jasmolate (MeJA)-treated vegetables produce higher concentrations of various bioactive compounds. We investigated whether long-term oral consumption of MeJA-treated and untreated buckwheat sprout powder improves energy, glucose, lipid, and bone metabolism induced by estrogen deficiency in ovariectomized (OVX) rats fed high-fat diets, and explored the mechanisms involved. MethodsOVX rats were divided into four groups and fed high-fat diets supplemented with 3% dextrin (OVX-control), buckwheat sprout powder (BWS), or MeJA-treated buckwheat sprout powder (MJ-BWS) for 12 wk. Sham rats without estrogen deficiency had a control diet as a normal-control. ResultsMeJA-treatment increased total polyphenols and flavonoids by about 1.6 fold and isoorientin, orientin, rutin, and vitexin were elevated by about 18% in buckwheat. After 12 wk, OVX rats exhibited increased weight gain, fat mass, skin temperature, hyperglycemia, and decreased bone mineral density (BMD) compared to sham rats. BWS prevented the increase of skin temperature and decrease of femur BMD, but did not improve energy glucose homeostasis as much as MJ-BWS. MJ-BWS prevented increases in body weight and fat mass. Energy expenditure was lowest in OVX-control, followed by BWS, MJ-BWS, and normal-control. Furthermore, MJ-BWS exhibited greater improvements in glucose and insulin tolerance than OVX-control and BWS. Phosphorylation of hepatic Akt and AMPK was potentiated, in ascending order of OVX-control, BWS, MJ-BWS, and normal-control, whereas PEPCK expression was decreased. ConclusionsMJ-BWS prevented and ameliorated the disturbances in energy and glucose metabolism in estrogen-deficient animals better than BWS. Therefore, besides flavonoids in BWS, other components such as phytoalexins produced in MJ-BWS during MeJA-treatment might play a crucial role in the improvement.

Red peppers with moderate and severe pungency prevent the memory deficit and hepatic insulin resistance in diabetic rats with Alzheimer's disease.

BackgroundDementia induced by β-amyloid accumulation impairs peripheral glucose homeostasis, but red pepper extract improves glucose homeostasis. We therefore evaluated whether long-term oral consumption of different red pepper extracts improves cognitive dysfunction and glucose homeostasis in type 2 diabetic rats with β-amyloid-induced dementia.MethodsMale diabetic rats received hippocampal CA1 infusions of β-amyloid (25–35) (AD) or β-amyloid (35–25, non-plaque forming), at a rate of 3.6 nmol/day for 14 days (Non-AD). AD rats were divided into four dietary groups receiving either 1% lyophilized 70% ethanol extracts of either low, moderate and severe pungency red peppers (AD-LP, AD-MP, and AD-SP) or 1% dextrin (AD-CON) in Western diets (43% energy as fat).ResultsThe ascending order of control < LSP < MSP and SSP potentiated the phosphorylation of CREB and GSK and inhibited Tau phosphorylation in the hippocampus which in turn inhibited β-amyloid accumulation. The inhibition by MP and SP reduced the memory deficit measured by passive avoidance test and water maze test. Furthermore, the accumulation of β-amyloid induced glucose intolerance, although serum insulin levels were elevated during the late phase of oral glucose tolerance test (OGTT). All of the red pepper extracts prevented the glucose intolerance in AD rats. Consistent with OGTT results, during euglycemic hyperinulinemic clamp glucose infusion rates were lower in AD-CON than Non-AD-CON with no difference in whole body glucose uptake. Hepatic glucose output at the hyperinsulinemic state was increased in AD-CON. β-amyloid accumulation exacerbated hepatic insulin resistance, but all red pepper extract treatments reversed the insulin resistance in AD rats.ConclusionsThe extracts of moderate and severe red peppers were found to prevent the memory deficit and exacerbation of insulin resistance by blocking tau phosphorylation and β-amyloid accumulation in diabetic rats with experimentally induced Alzheimer’s-like dementia. These results suggest that red pepper consumption might be an effective intervention for preventing age-related memory deficit.

Yuzu Extract Prevents Cognitive Decline and Impaired Glucose Homeostasis in β-Amyloid–Infused Rats1–3

Our preliminary study revealed that dementia induced by β-amyloid accumulation impairs peripheral glucose homeostasis (unpublished). We therefore evaluated whether long-term oral consumption of yuzu (Citrus junos Tanaka) extract improves cognitive dysfunction and glucose homeostasis in β-amyloid–induced rats. Male rats received hippocampal CA1 infusions of β-amyloid (25-35) [plaque forming β-amyloid; Alzheimer disease (AD)] or β-amyloid (35–25) [non–plaque forming β-amyloid; C (non-Alzheimer disease control)] at a rate of 3.6 nmol/d for 14 d. AD rats were divided into 2 dietary groups that received either 3% lyophilized 70% ethanol extracts of yuzu (AD-Y) or 3% dextrin (AD-C) in high-fat diets (43% energy as fat). The AD-C group exhibited greater hippocampal β-amyloid deposition, which was not detected in the C group, and attenuated hippocampal insulin signaling. Yuzu treatment prevented β-amyloid accumulation, increased tau phosphorylation, and attenuated hippocampal insulin signaling observed in AD-C rats. Consistent with β-amyloid accumulation, the AD-C rats experienced cognitive dysfunction, which was prevented by yuzu. AD-C rats gained less weight than did C rats due to decreased feed consumption, and yuzu treatment prevented the decrease in feed consumption. Serum glucose concentrations were higher in AD-C than in C rats at 40–120 min after glucose loading during an oral-glucose-tolerance test, but not at 0–40 min. Serum insulin concentrations were highly elevated in AD-C rats but not enough to lower serum glucose to normal concentrations, indicating that rats in the AD-C group had insulin resistance and a borderline diabetic state. Although AD-C rats were profoundly insulin resistant, AD-Y rats exhibited normal first and second phases of glucose tolerance and insulin sensitivity and secretion. In conclusion, yuzu treatment prevented the cognitive dysfunction and impaired energy and glucose homeostasis induced by β-amyloid infusion.

Conditioned Activity and Instrumental Reinforcement Following Long-Term Oral Consumption of Cocaine by Rats.

Food-reinforced conditioned activity and instrumental responding were measured in rats after 50 weeks of continuous access to a cocaine-saccharin solution in their home cages. The elevation of conditioned activity produced by acute access to the cocaine-saccharin solution in the home cage during testing was abolished by long-term preexposure to the cocaine solution, an effect that was reversed by systemic administration of cocaine immediately prior to testing. By contrast, chronic cocaine preexposure enhanced instrumental responding for both cocaine-sucrose and pure sucrose solutions. These results support the idea that long-term cocaine exposure enhances subsequent reinforcement.