Showing papers on "Toxicity published in 2017"

The clinical efficacy of first-generation carcinoembryonic antigen (CEACAM5)-specific CAR T cells is limited by poor persistence and transient pre-conditioning-dependent respiratory toxicity.

Abstract: The primary aim of this clinical trial was to determine the feasibility of delivering first-generation CAR T cell therapy to patients with advanced, CEACAM5+ malignancy. Secondary aims were to assess clinical efficacy, immune effector function and optimal dose of CAR T cells. Three cohorts of patients received increasing doses of CEACAM5+-specific CAR T cells after fludarabine pre-conditioning plus systemic IL2 support post T cell infusion. Patients in cohort 4 received increased intensity pre-conditioning (cyclophosphamide and fludarabine), systemic IL2 support and CAR T cells. No objective clinical responses were observed. CAR T cell engraftment in patients within cohort 4 was significantly higher. However, engraftment was short-lived with a rapid decline of systemic CAR T cells within 14 days. Patients in cohort 4 had transient, acute respiratory toxicity which, in combination with lack of prolonged CAR T cell persistence, resulted in the premature closure of the trial. Elevated levels of systemic IFNγ and IL-6 implied that the CEACAM5-specific T cells had undergone immune activation in vivo but only in patients receiving high-intensity pre-conditioning. Expression of CEACAM5 on lung epithelium may have resulted in this transient toxicity. Raised levels of serum cytokines including IL-6 in these patients implicate cytokine release as one of several potential factors exacerbating the observed respiratory toxicity. Whilst improved CAR designs and T cell production methods could improve the systemic persistence and activity, methods to control CAR T ‘on-target, off-tissue’ toxicity are required to enable a clinical impact of this approach in solid malignancies.

Review of toxicity studies of carbon nanotubes.

Abstract: Objective We reviewed studies on pulmonary, reproductive, and developmental toxicity caused by carbon nanotubes (CNTs). In paricular, we analyzed how CNT exposure affects the several processes of pulmonary toxicity, including inflammation, injury, fibrosis, and pulmonary tumors. Methods In pulmonary toxicity, there are various processes, including inflammation, injury, fibrosis, respiratory tumor in the lungs, and biopersistence of CNTs and genotoxicity as tumor-related factors, to develop the respiratory tumor. We evaluated the evidence for the carcinogenicity of CNTs in each process. In the fields of reproductive and developmental toxicity, studies of CNTs have been conducted mainly with mice. We summarized the findings of reproductive and developmental toxicity studies of CNTs. Results In animal studies, exposure to CNTs induced sustained inflammation, fibrosis, lung cancer following long-term inhalation, and gene damage in the lung. CNTs also showed high biopersistence in animal studies. Fetal malformations after intravenous and intraperitoneal injections and intratracheal instillation, fetal loss after intravenous injection, behavioral changes in offsprings after intraperitoneal injection, and a delay in the delivery of the first litter after intratracheal instillation were reported in mice-administered multi-walled carbon nanotubes (MWCNTs). Single-walled carbon nanotubes (SWCNTs) appeared to be embryolethal and teratogenic in mice when given by intravenous injection; moreover, the tubes induced death and growth retardation in chicken embryos. Conclusion CNTs are considered to have carcinogenicity and can cause lung tumors. However, the carcinogenicity of CNTs may attenuate if the fiber length is shorter. The available data provide initial information on the potential reproductive and developmental toxicity of CNTs.

Faecal microbiota transplantation protects against radiation-induced toxicity.

Abstract: Severe radiation exposure may cause acute radiation syndrome, a possibly fatal condition requiring effective therapy. Gut microbiota can be manipulated to fight against many diseases. We explored whether intestinal microbe transplantation could alleviate radiation‐induced toxicity. High‐throughput sequencing showed that gastrointestinal bacterial community composition differed between male and female mice and was associated with susceptibility to radiation toxicity. Faecal microbiota transplantation (FMT) increased the survival rate of irradiated animals, elevated peripheral white blood cell counts and improved gastrointestinal tract function and intestinal epithelial integrity in irradiated male and female mice. FMT preserved the intestinal bacterial composition and retained mRNA and long non‐coding RNA expression profiles of host small intestines in a sex‐specific fashion. Despite promoting angiogenesis, sex‐matched FMT did not accelerate the proliferation of cancer cells in vivo . FMT might serve as a therapeutic to mitigate radiation‐induced toxicity and improve the prognosis of tumour patients after radiotherapy. ![][1] Faecal microbiota transplantation ameliorates radiation‐induced toxicity in irradiated mice by improving gastrointestinal tract function and epithelial integrity, preserving gut bacterial composition and maintaining the small intestine transcriptome. [1]: /embed/graphic-1.gif

Formation and control of disinfection byproducts and toxicity during reclaimed water chlorination: A review.

Abstract: Chlorination is essential to the safety of reclaimed water; however, this process leads to concern regarding the formation of disinfection byproducts (DBPs) and toxicity. This study reviewed the formation and control strategies for DBPs and toxicity in reclaimed water during chlorination. Both regulated and emerging DBPs have been frequently detected in reclaimed water during chlorination at a higher level than those in drinking water, indicating they pose a greater risk to humans. Luminescent bacteria and Daphnia magna acute toxicity, anti-estrogenic activity and cytotoxicity generally increased after chlorination because of the formation of DBPs. Genotoxicity by umu-test and estrogenic activity were decreased after chlorination because of destruction of toxic chemicals. During chlorination, water quality significantly impacted changes in toxicity. Ammonium tended to attenuate toxicity changes by reacting with chlorine to form chloramine, while bromide tended to aggravate toxicity changes by forming hypobromous acid. During pretreatment by ozonation and coagulation, disinfection byproduct formation potential (DBPFP) and toxicity formation potential (TFP) occasionally increase, which is accompanied by DOC removal; thus, the decrease of DOC was limited to indicate the decrease of DBPFP and TFP. It is more important to eliminate the key fraction of precursors such as hydrophobic acid and hydrophilic neutrals. During chlorination, toxicities can increase with the increasing chlorine dose and contact time. To control the excessive toxicity formation, a relatively low chlorine dose and short contact time were required. Quenching chlorine residual with reductive reagents also effectively abated the formation of toxic compounds.

Transgenerational toxicity of nanopolystyrene particles in the range of μg L−1 in the nematode Caenorhabditis elegans

Abstract: The potential toxicity of nanoplastics to environmental organisms has gradually received great attention recently. We employed the in vivo assay system of Caenorhabditis elegans to investigate the possible transgenerational toxicity of nanopolystyrene particles and the underlying cellular mechanisms. After prolonged exposure, we observed the toxicity of nanopolystyrene particles at concentrations higher than 10 μg L−1. The transgenerational toxicity was further detected in nematodes exposed to nanopolystyrene particles at concentrations higher than 100 μg L−1. This observed transgenerational toxicity of nanopolystyrene particles might be mainly due to the translocation of nanopolystyrene particles into reproductive organs such as the gonad, which potentially in turn led to the transfer of nanopolystyrene particles to the next generation. Leachates from nanopolystyrene particles at concentrations in the range of μg L−1 did not contribute to the development of this transgenerational toxicity. Enhancement of intestinal permeability and extension of defecation cycle length provide the explanation for the observed accumulation and translocation of nanopolystyrene particles in reproductive organs. Therefore, our results demonstrate the potential transgenerational toxicity of nanopolystyrene particles in the range of μg L−1 in environmental organisms.

Reversal of Autoimmune Toxicity and Loss of Tumor Response by Interleukin-17 Blockade

Abstract: In a patient with colon cancer and a history of autoimmunity, skin and gastrointestinal toxicity developed after the receipt of pembrolizumab Interleukin-17 blockade reversed the autoimmunity but led to tumor progression

Black Phosphorus Quantum Dot Induced Oxidative Stress and Toxicity in Living Cells and Mice

Abstract: Black phosphorus (BP), as an emerging successor to layered two-dimensional materials, has attracted extensive interest in cancer therapy Toxicological studies on BP are of great importance for potential biomedical applications, yet not systemically explored Herein, toxicity and oxidative stress of BP quantum dots (BPQDs) at cellular, tissue, and whole-body levels are evaluated by performing the systemic in vivo and in vitro experiments In vitro investigations show that BPQDs at high concentration (200 μg/mL) exhibit significant apoptotic effects on HeLa cells In vivo investigations indicate that oxidative stress, including lipid peroxidation, reduction of catalase activity, DNA breaks, and bone marrow nucleated cells (BMNC) damage, can be induced by BPQDs transiently but recovered gradually to healthy levels No apparent pathological damages are observed in all organs, especially in the spleen and kidneys, during the 30-day period This work clearly shows that BPQDs can cause acute toxicities by oxida

The Potential Liver, Brain, and Embryo Toxicity of Titanium Dioxide Nanoparticles on Mice

Abstract: Nanoscale titanium dioxide (nano-TiO2) has been widely used in industry and medicine. However, the safety of nano-TiO2 exposure remains unclear. In this study, we evaluated the liver, brain, and embryo toxicity and the underlying mechanism of nano-TiO2 using mice models. The results showed that titanium was distributed to and accumulated in the heart, brain, spleen, lung, and kidney of mice after intraperitoneal (i.p.) nano-TiO2 exposure, in a dose-dependent manner. The organ/body weight ratios of the heart, spleen, and kidney were significantly increased, and those of the brain and lung were decreased. High doses of nano-TiO2 significantly damaged the functions of liver and kidney and glucose and lipid metabolism, as showed in the blood biochemistry tests. Nano-TiO2 caused damages in mitochondria and apoptosis of hepatocytes, generation of reactive oxygen species, and expression disorders of protective genes in the liver of mice. We found ruptured and cracked nerve cells and inflammatory cell infiltration in the brain. We also found that the activities of constitutive nitric oxide synthases (cNOS), inducible NOS (iNOS), and acetylcholinesterase, and the levels of nitrous oxide and glutamic acid were changed in the brain after nano-TiO2 exposure. Ex vivo mouse embryo models exhibited developmental and genetic toxicity after high doses of nano-TiO2. The size of nano-TiO2 particles may affect toxicity, larger particles producing higher toxicity. In summary, nano-TiO2 exhibited toxicity in multiple organs in mice after exposure through i.p. injection and gavage. Our study may provide data for the assessment of the risk of nano-TiO2 exposure on human health.

Continuous in vitro exposure of intestinal epithelial cells to E171 food additive causes oxidative stress, inducing oxidation of DNA bases but no endoplasmic reticulum stress

Abstract: The whitening and opacifying properties of titanium dioxide (TiO2) are commonly exploited when it is used as a food additive (E171). However, the safety of this additive can be questioned as TiO2 nanoparticles (TiO2-NPs) have been classed at potentially toxic. This study aimed to shed some light on the mechanisms behind the potential toxicity of E171 on epithelial intestinal cells, using two in vitro models: (i) a monoculture of differentiated Caco-2 cells and (ii) a coculture of Caco-2 with HT29-MTX mucus-secreting cells. Cells were exposed to E171 and two different types of TiO2-NPs, either acutely (6–48 h) or repeatedly (three times a week for 3 weeks). Our results confirm that E171 damaged these cells, and that the main mechanism of toxicity was oxidation effects. Responses of the two models to E171 were similar, with a moderate, but significant, accumulation of reactive oxygen species, and concomitant downregulation of the expression of the antioxidant enzymes catalase, superoxide dismutase a...

Potential fluoride toxicity from oral medicaments: A review

Abstract: The beneficial effects of fluoride on human oral health are well studied. There are numerous studies demonstrating that a small amount of fluoride delivered to the oral cavity decreases the prevalence of dental decay and results in stronger teeth and bones. However, ingestion of fluoride more than the recommended limit leads to toxicity and adverse effects. In order to update our understanding of fluoride and its potential toxicity, we have described the mechanisms of fluoride metabolism, toxic effects, and management of fluoride toxicity. The main aim of this review is to highlight the potential adverse effects of fluoride overdose and poorly understood toxicity. In addition, the related clinical significance of fluoride overdose and toxicity has been discussed.

Chrysin Protects Rat Kidney from Paracetamol-Induced Oxidative Stress, Inflammation, Apoptosis, and Autophagy: A Multi-Biomarker Approach.

Abstract: Paracetamol (PC) is a safe analgesic and antipyretic drug at therapeutic doses, and it is widely used in clinics. However, at high doses, it can induce hepatotoxicity and nephrotoxicity. Chrysin (CR) is a natural flavonoid that has biological activities that include being an antioxidant, an anti-inflammatory, and an anti-cancer agent. The main objective of this study was to investigate the efficacy of CR against PC-induced nephrotoxicity in rats. CR was given orally via feeding needle to male Sprague Dawley rats as a single daily dose of 25 or 50 mg/kg for six days. PC was administered orally via feeding needle as a single dose on the sixth day. PC caused significant glutathione depletion, lipid peroxidation, increased serum toxicity markers (serum urea and creatinine), and reductions in activities of antioxidant enzymes (superoxide dismutase — SOD, catalase — CAT, and glutathione peroxidase — GPx). The renal protective effect of CR was associated with decreasing the regulation of serum renal toxicity markers and increasing the regulation of antioxidant enzyme activities. Additionally, PC led to significant increases in the levels of inflammatory markers including tumour necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β) and interleukin-33 (IL-33). Furthermore, PC induced apoptotic tissue damage by increasing cysteine aspartate-specific protease-3 (caspase-3) activity and autophagic tissue damage by increasing the expression of light chain 3B (LC3B). CR therapy significantly decreased these values in rats. This study demonstrated that CR has antioxidant, anti-apoptotic, anti-inflammatory and anti-autophagic effects on PC-induced kidney toxicity in rats.

Therapeutic effects of silymarin and naringin on methotrexate‐induced nephrotoxicity in rats: Biochemical evaluation of anti‐inflammatory, antiapoptotic, and antiautophagic properties

Abstract: Silymarin (SLY) and naringin (NRG) are natural flavonoids that have been reported to have many benefits and medicinal properties. The present study was designed to investigate the protective effect of SLY and NRG against methotrexate (MTX)-induced nephrotoxicity in experimental animals. Rats were subjected to oral pretreatment of SLY (25 and 50 mg/kg body weight (b.w.)/day) and NRG (50 and 100 mg/kg b.w./day) for 7 days against renal toxicity induced by single intraperitoneal administration of MTX (20 mg/kg b.w.). MTX resulted in an increase in serum toxicity markers, lipid peroxidation, and reduction in activities of antioxidant enzymes. Additionally, MTX provoked inflammatory responses by increasing the levels of TNF-α, IL-1β, IL-6, NF-κB, and activation of COX-2 and iNOS. Furthermore, MTX administration caused apoptosis and autophagy by increasing activity of Caspase-3 and light chain 3B level. Conversely, SLY and NRG therapy significantly decreased these values in rats. This study demonstrated that SLY and NRG protect against MTX-induced nephrotoxicity. Practical applications Chemotherapeutic drugs have been used for cancer treatment for many years. However, in the treatment process, they may damage organs such as liver and kidney, prolong the treatment process and negatively affects patient welfare. This study revealed that silymarin and naringin exhibited potent anti-inflammatory, antiapoptotic, and antiautophagic effect in renal injury caused by methotrexate, a chemotherapeutic drug. Therefore, treatment silymarin and naringin can be used for the beneficial effect against methotrexate-induced kidney damage in cancer chemotherapy.

Galleria mellonella (greater wax moth) larvae as a model for antibiotic susceptibility testing and acute toxicity trials

Abstract: Infectivity trials and toxicity testing in rodents are important prerequisites to the use of compounds in man. However, trials in rats and mice are expensive and there are ethical considerations. Galleria mellonella (greater wax moth) larvae are a potential alternative. We have assessed the use of these insects in infectivity trials and toxicity testing. Using four bacterial species (two Gram-negative and two Gram-positive) we have assessed the efficacy of four antibiotics against infections in Galleria and compared the antibiotic susceptibility with that in humans. In general, we find a good correlation. Similarly, we have assessed 11 compounds (initially tested blind) for their toxicity in Galleria and compared this with toxicity trials in mice and rats. Again we found a good correlation between toxicity in Galleria and that in rodents. We have found, in our hands, that G. mellonella larvae can be used in infectivity trials and toxicity testing, and that these assays represent an inexpensive and readily executable alternative to testing in rodents.

Melatonin protects rats from radiotherapy-induced small intestine toxicity.

Abstract: Radiotherapy-induced gut toxicity is among the most prevalent dose-limiting toxicities following radiotherapy. Prevention of radiation enteropathy requires protection of the small intestine. However, despite the prevalence and burden of this pathology, there are currently no effective treatments for radiotherapy-induced gut toxicity, and this pathology remains unclear. The present study aimed to investigate the changes induced in the rat small intestine after external irradiation of the tongue, and to explore the potential radio-protective effects of melatonin gel. Male Wistar rats were subjected to irradiation of their tongues with an X-Ray YXLON Y.Tu 320-D03 irradiator, receiving a dose of 7.5 Gy/day for 5 days. For 21 days post-irradiation, rats were treated with 45 mg/day melatonin gel or vehicle, by local application into their mouths. Our results showed that mitochondrial oxidative stress, bioenergetic impairment, and subsequent NLRP3 inflammasome activation were involved in the development of radiotherapy-induced gut toxicity. Oral treatment with melatonin gel had a protective effect in the small intestine, which was associated with mitochondrial protection and, consequently, with a reduced inflammatory response, blunting the NF-κB/NLRP3 inflammasome signaling activation. Thus, rats treated with melatonin gel showed reduced intestinal apoptosis, relieving mucosal dysfunction and facilitating intestinal mucosa recovery. Our findings suggest that oral treatment with melatonin gel may be a potential preventive therapy for radiotherapy-induced gut toxicity in cancer patients.

Pretreatment serum uracil concentration as a predictor of severe and fatal fluoropyrimidine-associated toxicity.

Abstract: We investigated the predictive value of dihydropyrimidine dehydrogenase (DPD) phenotype, measured as pretreatment serum uracil and dihydrouracil concentrations, for severe as well as fatal fluoropyrimidine-associated toxicity in 550 patients treated previously with fluoropyrimidines during a prospective multicenter study. Pretreatment serum concentrations of uracil and dihydrouracil were measured using a validated LC-MS/MS method. The primary endpoint of this analysis was global (any) severe fluoropyrimidine-associated toxicity, that is, grade ⩾3 toxicity according to the NCI CTC-AE v3.0, occurring during the first cycle of treatment. The predictive value of uracil and the uracil/dihydrouracil ratio for early severe fluoropyrimidine-associated toxicity were compared. Pharmacogenetic variants in DPYD (c.2846A>T, c.1679T>G, c.1129-5923C>G, and c.1601G>A) and TYMS (TYMS 5′-UTR VNTR and TYMS 3′-UTR 6-bp ins/del) were measured and tested for associations with severe fluoropyrimidine-associated toxicity to compare predictive value with DPD phenotype. The Benjamini-Hochberg false discovery rate method was used to control for type I errors at level q 16 ng ml−1) were strongly associated with global severe toxicity (OR 5.3, P=0.009), severe gastrointestinal toxicity (OR 33.7, P<0.0001), toxicity-related hospitalisation (OR 16.9, P<0.0001), as well as fatal treatment-related toxicity (OR 44.8, P=0.001). None of the DPYD variants alone, or TYMS variants alone, were associated with severe toxicity. High pretreatment uracil concentration was strongly predictive of severe, including fatal, fluoropyrimidine-associated toxicity, and is a highly promising phenotypic marker to identify patients at risk of severe fluoropyrimidine-associated toxicity.

The mechanisms of cyclophosphamide-induced testicular toxicity and the protective agents

Abstract: Introduction: Cyclophosphamide (CP) is an alkylating antineoplastic agent with known toxicity to the male reproductive system.Areas covered: This review summarizes the known mechanisms by which CP ...

Preclinical Mammalian Safety Studies of EPHARNA (DOPC Nanoliposomal EphA2-Targeted siRNA).

Abstract: To address the need for efficient and biocompatible delivery systems for systemic siRNA delivery, we developed 1,2-Dioleoyl-sn-Glycero-3-Phosphatidylcholine (DOPC) nanoliposomal EphA2-targeted therapeutic (EPHARNA). Here, we performed safety studies of EPHARNA in murine and primate models. Single dosing of EPHARNA was tested at 5 concentrations in mice (N = 15 per group) and groups were sacrificed on days 1, 14, and 28 for evaluation of clinical pathology and organ toxicity. Multiple dosing of EPHARNA was tested in mice and Rhesus macaques twice weekly at two dose levels in each model. Possible effects on hematologic parameters, serum chemistry, coagulation, and organ toxicity were assessed. Following single-dose EPHARNA administration to mice, no gross pathologic or dose-related microscopic findings were observed in either the acute (24 hours) or recovery (14 and 28 days) phases. The no-observed-adverse-effect level (NOAEL) for EPHARNA is considered >225 μg/kg when administered as a single injection intravenously in CD-1 mice. With twice weekly injection, EPHARNA appeared to stimulate a mild to moderate inflammatory response in a dose-related fashion. There appeared to be a mild hemolytic reaction in the female mice. In Rhesus macaques, minimal to moderate infiltration of mononuclear cells was found in some organs including the gastrointestinal tract, heart, and kidney. No differences attributed to EPHARNA were observed. These results demonstrate that EPHARNA is well tolerated at all doses tested. These data, combined with previously published in vivo validation studies, have led to an ongoing first-in-human phase I clinical trial (NCT01591356). Mol Cancer Ther; 16(6); 1114-23. ©2017 AACR.

Oxidative injury caused by individual and combined exposure of neonicotinoid, organophosphate and herbicide in zebrafish.

Abstract: The greatest challenge in environmental toxicology is to understand the effects of mixture toxicity as environmental pollutants co-exist and exhibit combined effects. Thus, it is necessary to evaluate the mixture toxicity associated with two or more co-existing compounds. Pesticides are widely used to control pest, they are ubiquitous in nature and present in all environmental components. Pesticide residue can be detected in almost all components of environment and food samples. Imidacloprid (IMD) (neonicotinoid), dichlorvos (DIC) (organophosphate) and atrazine (ATZ) are three widely used pesticides for commercial uses. Present work includes the assessment of effects of individual exposure of IMD (27.5 mg/L), DIC (15 mg/L), and ATZ (03 mg/L) and in combination of three (CMD) (13.75 + 7.5 + 1.5 mg/L IMD, DIC & ATZ, respectively) in terms of LPO, GSH content and antioxidant enzymes activities (superoxide dismutase, catalase and glutathione peroxidase) in zebrafish (Danio rerio), exposed for 24 h. CMD group exhibits highest lipid peroxidation than other individually exposed groups. Similarly, the activities of antioxidant enzymes were highest in CMD group with reduced GSH content. Results indicate that exposure to mixture of pesticides develops synergistic effects which were more toxic in compare to individual exposure and also produce toxicity in all examined tissues rather than selective organ toxicity.

Toxicology effects of Berberis vulgaris (barberry) and its active constituent, berberine: a review

Abstract: Berberis vulgaris and berberine, its main component, traditionally have been used for treatment of various disorders. The pharmacological properties of them have been investigated using different in vivo and in vitro models. In spite of beneficial effects of B. vulgaris on different cell lines, there are documents have revealed negative impacts of it on animal and human. In this regards, the determination of its toxicity in a scientific view is necessary. In current report, we provide classified information about the toxicity of B. vulgaris and berberine in different conditions consist of acute, sub-acute, sub-chronic and chronic state. Besides, it discusses the cytotoxicity, genotoxicity, mutagenicity, and carcinogenicity of B. vulgaris and berberine as well as developmental toxicity and clinical studies. Data from the present study indicate that their toxicity is depending on the route and duration of administration. According to present study, they could induce GI upset and ulceration, immunotoxicity, phototoxicity, neurotoxicity, cardiotoxicity and jaundice in a dose dependent manner. They should be used with caution in pregnancy, neonatal and G6PD deficiency. Besides, consideration should be taken in co-administration of berberine with drugs that are metabolized with CYP enzymes due their inhibitory effects on these enzymes. Furthermore, they evoke cytotoxicity on both normal and cancer cell line which is time and concentration dependent.

Evaluation of Acute and Subacute Oral Toxicity Induced by Ethanolic Extract of Marsdenia tenacissima Leaves in Experimental Rats.

Abstract: The objective of this study is to evaluate the acute and subacute toxicity of the ethanolic extract of Marsdenia tenacissima (MTE) leaves (family: Asclepiadaceae) in albino rats. The acute toxicity was performed where the limit dose of 5000 mg/kg body weight used. Observations were made and recorded for 24 h, and once daily further for a period of 14 days. The rats were weighed and various observations, like mortality, behavior, injury, or any signs of illness were conducted once daily during the period. For subacute study, four groups of 10 animals (female rats) received 10% Tween 20 in distilled water (control), and 250, 500, and 1000 mg/kg of freshly-prepared extracts, respectively, every 24 h orally for 28 days. At the end of each study, hematological analysis and biochemical parameters were evaluated. Histopathological examination of vital organs of the animals were taken for gross findings, compared to controls. There was no significant difference (p > 0.05) observed in the relative organs, body weights, hematological, biochemical parameters, and gross abnormalities, compared to the control. No mortality was recorded. Therefore, analysis of results may lead to the conclusion that the medium-term oral administration of the MTE leaves for 28 days does not cause toxicity.