Acute and sub-chronic (28days) oral toxicity evaluation of hydroethanolic extract of Bridelia ferruginea Benth root bark in male rodent animals

Bridelia ferruginea Benth.; An ethnomedicinal, phytochemical, pharmacological and toxicological review

Ethnopharmacological relevance

Bridelia ferruginea belonging to the family Euphorbiaceae, identified as an important commonly growing shrub, is used in traditional medicine for managing arthritis, dysentery, constipation, chronic diabetes, skin diseases, bladder and intestinal disorders, oral infections, thrush, bites and as an arrow poison antidote. This review aims at providing information on the traditional medicinal uses, pharmacological activities, phytochemistry and toxicity studies of Bridelia ferruginea to bridge the gap between traditional medicinal uses and preclinical studies on B. ferruginea and subsequently lead to the development of valued added medicines from B. ferruginea.

Materials and methods

Data in this review were compiled using databases such as Google Scholar, Science Direct, Scopus, PubMed, Springer link, Elsevier and Taylor and Francis, articles from peer reviewed journals and other grey literature (short notes, book chapters, short communications) to access all the relevant information available on B. ferruginea.

Results

B. ferruginea contains different phytochemicals including flavonoids, phenolics, phytosterols, triterpenes, saponins, alkaloids and cardiac glycosides. Gallocatechin-(4′-O-7)-epigallocatechin, 3,5-dicaffeoylquinic acid, 1,3,4,5-tetracaffeoylquinic acid and some derivatives of 3-methoxyflavone, such as quercetin-3-methyl ether, quercetin 3-,7,3′,4′-tetramethyl ether, myricetin 3′,4′,5′-trimethyl ether, myricetin 3,3′,4′,5′-tetramethyl ether, myricetin and quercetin 3-O-glucoside specific flavonoids and biflavonoids like apigenin, kaempferol and glycosides of both have been isolated and further characterized from B. ferruginea. B. ferruginea has several pharmacologically beneficial properties including anti-inflammatory, anti-diabetic, antioxidant, antimicrobial, anti-infective, antipyretic, analgesic, diuretic and natriuretic activities.

Conclusion

The wide distribution, traditional medicinal uses and wealth of phytochemicals present in B. ferruginea suggests that the plant can be useful in lead compound discovery. Although B. ferruginea has been widely studied, further studies on the mechanism of action, bioavailability, pharmacokinetics, toxicity and side effects in humans need to be investigated.

Antidepressant and Anxiolytic Effects and Subacute Toxicity of the Aerial Parts of Psychotria ankasensis J.B.Hall (Rubiaceae) in Murine Models

Background

The present study aimed at validating the traditional use and toxicity profile of a methanolic extract of the aerial parts of Psychotria ankasensis in alleviating depression and anxiety disorders.

Method

The antidepressant effect of methanolic extract of Psychotria ankasensis (PAE 30, 100, and 300 mg/kg, p.o.) was assessed in mice using the forced swim test (FST) and the tail suspension test (TST). The plant's anxiolytic potential was also evaluated in mice using the elevated plus-maze (EPM) and the open field tests (OFT). The subacute toxicity was assessed via oral administration of PAE at doses of 100, 300, and 1000 mg/kg in rats for 28 days.

Results

PAE 100 and 300 mg/kg showed antidepressant-like properties by significantly (at least p < 0.05) decreasing the frequency and duration of immobility in FST and TST. PAE (100 and 300 mg/kg) also showed a significant (at least p < 0.05) anxiolytic effect in both EPM and OFT. In the EPM test, E_max for PAE and diazepam were 92.52 ± 40.11% and 85.95 ± 45.92%, respectively, whereas E_max was approximately 100% for both test drugs in the OFT. Subacute administration of PAE did not reveal any toxic effects with respect to organ weight index, haematological, serum biochemical, and histopathological parameters.

Conclusions

Methanolic extract of P. ankasensis exhibited antidepressant-like and anxiolytic-like effects devoid of significant toxicity at the doses tested in murine models.

Pharmacological Potential and Chemical Characterization of Bridelia ferruginea Benth.-A Native Tropical African Medicinal Plant

To avail the possible pharmacological actions of Brideliaferruginea Benth., the present investigation was designed to quantitatively analyze the total flavonoid and phenolic contents and assess the various antioxidant and enzyme inhibition properties of leaf and stem bark extracts (ethyl acetate, water and methanolic) of B. ferruginea. Anti-proliferative effect was also investigated against human colon cancer cells (HCT116) as well as the antimicrobial potential against multiple bacterial and fungal (yeasts and dermatophytes) strains. The methanolic and water extracts of the stem bark demonstrated the highest phenolic content (193.58 ± 0.98 and 187.84 ± 1.88 mg/g, respectively), while the leaf extracts showed comparatively higher flavonoid contents (24.37-42.31 mg/g). Overall, the methanolic extracts were found to possess the most significant antioxidant potency. Compared to the other extracts, methanolic extracts of the B. ferruginea were revealed to be most potent inhibitors of acetyl- and butyryl-cholinesterases, tyrosinase α-amylase, except α-glucosidase. Only the ethyl acetate extracts were found to inhibit glucosidase. Additionally, the stem bark methanolic extract also showed potent inhibitory activity against E. coli and gram-positive bacteria (MIC (minimum inhibitory concentration): 2.48-62.99 µg/mL), as well as all the tested fungi (MIC: 4.96-62.99 µg/mL). In conclusion, B. ferruginea can be regarded as a promising source of bioactive compounds displaying multifunctional pharmacological activities and thus is a potential candidate for further investigations in the endeavor to develop botanical formulations for pharmaceutical and cosmeceutical industries.

In vitro and computational studies of the antioxidant and anti-diabetic properties of Bridelia ferruginea

The leaves, stem and root bark of Bridelia ferruginea were sequentially extracted with solvents of increasing polarity to yield the hexane, ethyl acetate, ethanol and aqueous extracts. In vitro analysis revealed the ability of the extracts to scavenge 1,1-diphenyl-2-picryl-hydrazyl (DPPH), nitric oxide (NO) and hydroxyl radical. They also inhibited the activities of α-glucosidase, α-amylase and lipase enzymes. Gas chromatography-mass spectroscopic (GC-MS) analysis of the extracts revealed the presence of sterols, aromatics, aliphatic acids and esters. The identified compounds were molecularly docked with α-glucosidase, α-amylase and lipase enzymes. All compounds showed good binding affinities with the enzymes studied. The strongest binding affinities were observed for β-amyrin, 4-phenylbenzophenone and lupenone for α-glucosidase, α-amylase and lipase enzymes, respectively. The data suggest antioxidant and antidiabetic potential of the different parts of B. ferruginea, with the leaves having the highest potential. These properties can be explored for development of novel anti-diabetic drugs.Communicated by Ramaswamy H. Sarma.

Non-clinical toxicity of (+)-limonene epoxide and its physio-pharmacological properties on neurological disorders

The compound (+)-limonene epoxide has antioxidant, anxiolytic, and antihelminthic properties. However, investigations to determine its long-term exposure were not performed. We investigated the systemic toxicological profile after chronic exposure as well as the antidepressant and antiepileptic potentialities of (+)-limonene epoxide on mice. Initially, we evaluated acute toxicity on Artemia salina nauplii and cytotoxicity on mice erythrocytes and peripheral blood mononuclear cells (PBMC). Aftterwards, mice were chronically treated for 120 days by gavage with (+)-limonene epoxide (25, 50, and 75 mg/kg/day) and this exposure was assessed by pathophysiological measurements. For antidepressant and anticonvulsivant analysis, we performed the forced swimming and tail suspension protocols and pentylenetetrazol- and picrotoxin-induced seizures, respectively. (+)-Limonene epoxide showed a LC50 value of 318.7 μg/mL on A. salina shrimps, caused lysis of red blood cells at higher concentrations only but did not show cytotoxicity on PMBC, which suggests pharmacological safety if plasma concentrations do not exceed 100 μg/mL. Macroscopic, hematological, clinical chemistry, and nutritional changes were not detected, though focal areas of hepatic necrosis, inflammatory infiltrate, and karyolysis have been detected at 75 mg/kg/day. The compound inhibited the developing of pentylenetetrazol- and picrotoxin-induced seizures, decreased deaths, and reduced immobility times, mainly at 75 mg/kg. So, it reversed reserpine effects, suggesting antidepressant effects should be linked to serotonergic and/or adrenergic transmission. It is feasible that (+)-limonene epoxide plays a benzodiazepine-like anticonvulsive action and may be also recommended as an antidote for poisonings caused by central depressants.

Alterations in histological, biochemical and hematological parameters in Plasmodium berghei NK-65 infected balb/c mice treated with Bridelia ferruginea stem bark extract

BACKGROUND

Recent ethnomedicinal studies on Bridelia ferruginea Benth (family Phyllanthaceae) as an antiplasmodial remedy have established its potency as a strong prophylactic and chemosuppressive agent. Human consumption of medicinal herbs without adequate evaluation of its efficacy and safety can result in grave physiological and pathological consequences. Therefore, this study assessed the antiplasmodial bioactivity, biochemical, hematological, histopathological and toxicity profile of the ethanolic stem bark extract of B. ferruginea in mice.

METHODS

Ethanolic stem bark extract of B. ferruginea (200, 400 and 800 mg/kg) were orally administered to Plasmodium berghei-infected mice in models and were subsequently observed for mortality, behavioral changes and signs of toxicity. Acute evaluation was experimented at 1,000 mg/kg for 28 days. Occult blood obtained from the euthanized mice were subjected to biochemical and hematological assays. A comprehensive assessment of the histology of the liver and kidney was also ascertained. The median lethal dose (LD₅₀) was determined and extrapolated using the regression equation obtained from the plot of the probits of mortalities (y) and the log of doses (log₁₀C).

RESULTS

Different concentrations of the phytochemical secondary metabolites were revealed. Antiplasmodial bioactivity was established at the 200, 400 and 800 mg/kg of the herbal extract with a dearth in parasitemia at different days post-treatment. The 800 mg/kg group responded by exhibiting a dose-dependent decrease in parasitemia comparable with the chloroquine bi-phosphate group. Significant alterations in the histology of the liver and kidney of the 1,000 mg/kg group was documented. There was a reduction in the titers of LDH, ALT, AST, and urea in the treated group when compared with the control (p < 0.05). Antioxidant profiles were also highly significant with elevation in SOD, GPx, and CAT, but a reduction in MDA. LD₅₀ was established at 424 mg/kg.

CONCLUSION

B. ferruginea Benth (family Phyllanthaceae) is a potent antiplasmodial, antioxidant, regenerative and ameliorative herbal remedy if administered in controlled dosage.

Acute and repeated dose 28-day oral toxicity of Chrysobalanusicaco L. leaf aqueous extract

Chrysobalanus icaco L. is a native plant of Brazil used as a food source and traditionally for the treatment of various diseases. The aim of study was performed the phytochemical analysis by UPLC-DAD-ESI-QTOF-MS/MS, and evaluated acute and repeated dose oral toxicities of the C. icaco L. leaf aqueous extract (AECi). The acute toxicity study was performed using a dose of AECi 2000 mg/kg, while the repeated dose toxicity study, the AECi was administered daily at doses of 100, 200 and 400 mg/kg, for 28 days. Behavior and mortality of animals were observed during the test period and body weight, as well water and eating consumption. Hematological, biochemical parameters and histopathological examinations were carried out. Phytochemical analysis of the AECi revealed the presence of flavonoids and tannins. Oral single dose of 2000 mg/kg of AECi resulted in no mortalities or abnormal clinical signs. Studies of repeated dose toxicity promoted a reduction in the body weight of treated animals and an increase of hepatic enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in both, males and females. Histopathological analyzes showed alterations in the livers of animals treated with AECi. Thus, this study recommends the population take care when using this species, especially during prolonged periods.

In vitro effects of tannin and extracts of Bridelia ferruginea and Mitragyna inermis on the exsheathment of infective larvae of Haemonchuscontortus

Bridelia ferruginea (Euphorbiaceae) and Mitragyna inermis (Rubiaceae) are two plants of the beninese pharmacopeia used in vivo for the control of gastrointestinal nematodes (GINs) in small ruminants. The objective of the present study is to explore the mechanism of bioactive compounds involved in the action of these two plants on the third-stage infective larvae (L3s) of Haemonchus contortus. Thus, sheathed L3s of H. contortus were incubated with acetone extracts of B. ferruginea and M. inermis at concentrations of 0, 150, 300, 600 and 1200 µg/mL for 3 h at 25°C. The L3s were then washed and artificially submitted to exsheathment in the presence of sodium hypochlorite solution. The role of tannins was verified by adding a tannin inhibitor, polyvinyl polypyrrolidone (PVPP), to the acetone extracts of these two plants for 2 h at 25°C. Acetone extracts from B. ferruginea and M. inermis inhibited the exsheathment of H. contortus larvae (p < 0.001) and this inhibitory effect was dose-dependent for M. inermis at the concentrations tested. Treatment of B. ferruginea and M. inermis extracts with PVPP was associated with a partial restoration of the exsheathment kinetics of H. contortus larvae (p < 0.001), confirming the predominant role of tannins but also the residual role of other secondary metabolites. These in vitro results suggest that these plants are endowed with anthelmintic (AHs) properties and therefore likely to be used as alternatives to synthetic molecules.

Effect of alcohol tincture of Aralia elata on the organism of rats and their gut microbiota against the background of excessive fat diet

Pharmacological effects of the medicinal plant Aralia elata (Miq.) Seem. 1868 (Araliaceae) are related to presence of over 150 secondary metabolites, including flavonoids, sterols, polysaccharides, terpenoid saponins and terpenoid acids, though the main biologically active substances of A. elata are saponins and flavonoids. Some clinical tests and experimental studies have proved the influence of A. elata on the organism through increase in physical work capacity, exerting an anti-stress effect against a broad range of harmful factors, including stress from cold, immobilization, ultraviolet radiation and low pressure. The literature also reports the anti-ulcer, anti-secretory, antifungal, anti-tumour, and antimicrobial activity of preparations from this plant. In our laboratory experiment, we determined that ethanolic tincture of A. elata has no effect on the intensity of growth of body weight of young rats against the background of excessive content of fat in their diet. Excessive fat-feeding of male rats leads mostly to disorders in the functioning of the liver and development of steatosis. This was accompanied by reduction in relative mass of the liver, increase in activity of hepatic enzymes, dysproteinemia, increase in the level of bilirubin and decrease in the level of urea. Additional use of 0.1% ethanol led to impaired functioning of the kidneys, reduction of their relative mass, signs of dehydration, increase in the level of creatinine and total calcium in the blood. Use of ethanolic tincture of A. elata mitigates negative excess of fat, is accompanied by normalization of indices of mass of the organs, less notable dysproteinemia, impairment in the level of creatinine, glucose, urea, cholesterol, bilirubin and total calcium. Ethanolic tincture of A. elata has a low immunosuppressive action, against the background of a high fat diet it leads to increase in the amount of typical Escherichia сoli, decrease in Еnterococcus spp. and Enterobacter spp., significant decrease and in high concentrations (0.1% ethanolic tincture of A. elata) elimination of bacteria of Clostridium and Klebsiella genera, and also various yeast fungi in the intestine. In the examined male rats, against the background of excess of fat in the diet, no serious changes in the composition of the normal gut microbiota (Bifidobacterium spp., Lactobacillus spp., Proteus spp., Staphylococcus spp., Candida spp.) was observed, nor were any lactose-negative enterobacteria (Citrobacter genus) found. Perspectives of further research include determining histological, histochemical and immune-histological changes in the organs of laboratory animals under the effect of ethanolic tincture of A. elata following excessive accumulation of fat.

Sexual stimulant effects of the mixture of Mondia whitei, Dracaena arborea, and Bridelia ferruginea in normal and prediabetic male Wistar rats

Background We investigated the effects of a polyherbal formulation prepared from the extracts of Mondia whitei (Periplocaceae), Dracaena arborea (Dracaenaceae), and Bridelia ferruginea (Euphorbiaceae) (MDB) on the sexual behavior of normal rats (NR) and prediabetic rats (PR). Methods Male Wistar rats were administered with drinking fructose solution (21%) or tap water for 16 weeks. After induction of prediabetic status, NR (n = 30) and PR (n = 30) were randomly distributed into 10 groups of six animals each and orally treated with distilled water (10 mL/kg), sildenafil citrate (5 mg/kg), or MDB (50, 100, or 500 mg/kg) for 21 days. Sexual behavior parameters per series (S) of ejaculation were evaluated on days 1, 7, 14, and 21. Results Drinking fructose solution (21%) induced prediabetic status in rats, characterized by a significant (p < 0.01) increase in glycemia by 43.41% compared with the control group. MDB improved sexual performances of NR and PR by increasing the mount frequency (MF) and the intromission frequency (IF) as well as the number of rats capable of ejaculating. For instance, the MF and the IF were significantly increased in animals administered with MDB for 7 (50 mg/kg, S1 and S2), 14 (100 mg/kg, S3), or 21 days (100 or 500 mg/kg, S2). This increase was more pronounced on days 7 and 14 in NR and PR treated with sildenafil citrate or MDB extracts, respectively. Conclusions The mixture of MDB improved sexual activity in NR and PR. This result may further justify the traditional use of these plants as sexual performance enhancers.

Curcumin-loaded self-nanomicellizing solid dispersion system: part II: in vivo safety and efficacy assessment against behavior deficit in Alzheimer disease

Curcumin (CUR), a natural polyphenolic compound, is considered as one of the most potential candidates against Alzheimer disease (AD) by targeting multiple pathologies such as amyloid-beta, tau phosphorylation, and oxidative stress. Poor physicochemical profile and oral bioavailability (BA) are the major contributors to its failure in clinical trials. Lack of success in numerous drug clinical trials for the treatment of AD urges the need of repositioning of CUR. To overcome its limitation and enhance oral BA, Novel CUR Formulation (NCF) was developed using self-nanomicellizing solid dispersion strategy which displayed 117-fold enhancement in oral BA of CUR. NCF was tested using SH-SY5Y695 APP human neuroblastoma cell line against the cytotoxicity induced by copper metal ion, H₂O₂, and Aβ42 oligomer and compared with CUR control. The safety and efficacy of NCF on mice AD-like behavioral deficits (open field, novel objective recognition, Y-maze, and Morris water maze tests) were assessed in transgenic AD (APPSwe/PS1deE9) mice model. In SH-SY5Y695 APP human neuroblastoma cell line, NCF showed better safety and efficacy against the cytotoxicity due to the significantly enhancement of cellular uptake. It not only prevents the deterioration of cognitive functions of the aged APPSwe/PS1deE9 mice during aging but also reverses the cognitive functions to their much younger age which is also better than the currently available approved options. Moreover, NCF was proved as well tolerated with no appearance of any significant toxicity via oral administration. The results of the study demonstrated the potential of NCF to improve the efficacy of CUR without compromising its safety profile, and pave the way for clinical development for AD.

Self-nanomicellizing solid dispersion of edaravone: part II: in vivo assessment of efficacy against behavior deficits and safety in Alzheimer's disease model

Background

Alzheimer’s disease (AD) is a devastating neurodegenerative disorder that lacks any disease-modifying drug for the prevention and treatment. Edaravone (EDR), an approved free radical scavenger, has proven to have potential against AD by targeting multiple key pathologies including amyloid-beta (Aβ), tau phosphorylation, oxidative stress, and neuroinflammation. To enable its oral use, novel edaravone formulation (NEF) was previously developed. The aim of the present investigation was to evaluate safety and efficacy of NEF by using in vitro/in vivo disease model.

Materials and methods

In vitro therapeutic potential of NEF over EDR was studied against the cytotoxicity induced by copper metal ion, H₂O₂ and Aβ42 oligomer, and cellular uptake on SH-SY5Y695 amyloid-β precursor protein (APP) human neuroblastoma cell line. For in vivo safety and efficacy assessment, totally seven groups of APP/PS1 (five treatment groups, one each as a basal and sham control) and one group of C57BL/6 mice as a positive control for behavior tests were used. Three groups were orally treated for 3 months with NEF at an equivalent dose of EDR 46, 138, and 414 µmol/kg, whereas one group was supplied with each Donepezil (5.27 µM/kg) and Soluplus (amount present in NEF of 414 µmol/kg dose of EDR). Behavior tests were conducted to assess motor function (open-field), anxiety-related behavior (open-field), and cognitive function (novel objective recognition test, Y-maze, and Morris water maze). For the safety assessment, general behavior, adverse effects, and mortality were recorded during the treatment period. Moreover, biochemical, hematological, and morphological parameters were determined.

Results

Compared to EDR, NEF showed superior cellular uptake and neuroprotective effect in SH-SY5Y695 APP cell line. Furthermore, it showed nontoxicity of NEF up to 414 µM/kg dose of EDR and its potential to reverse AD-like behavior deficits of APP/PS1 mice in a dose-dependent manner.

Conclusion

Our results indicate that oral delivery of NEF holds a promise as a safe and effective therapeutic agent for AD.

Toxicological evaluation of the aqueous stem bark extract of Bridelia ferruginea (Euphorbiaceae) in rodents

Bridelia ferruginea is a woody shrub that grows in the Savannah or rain forests of Africa and has traditionally been used to treat diabetes, arthritis and boils. Despite all these uses, extensive toxicological evaluation has not been carried out. The aim of the present investigation was to evaluate the sub-chronic toxicological effects of the stem bark aqueous extract of Bridelia ferruginea in rats. The lethal dose (LD₅₀) was determined using probit analysis and graded doses of the extract (250–4000 mg/kg) were administered to the animals via oral and intraperitoneal routes and observed for mortality, behavioral changes and signs of toxicity. Sub-chronic toxicity study was carried out at doses of 1 000, 2 000 and 4 000 mg/kg administered daily for 60 days. The animals were sacrificed after 60 days. Blood was collected for biochemical (renal and hepatic), hematological, oxidative stress, sperm and histopathological examinations, using standard methods. LD₅₀ of the extract was estimated as >4 000 mg/kg orally; neither significant visible signs of toxicity nor mortality were observed. There were no significant differences in the animals and organ weights, hematological and biochemical parameters in the treated groups compared to the control group. However, a significant increase (p<0.05) in the level of lipid peroxidation and a significant (p<0.05) decrease in sperm count were observed in the treated animals compared with the control group. The stem-bark aqueous extract of Bridelia ferruginea was found to be relatively safe, though it has the potential to cause lipid peroxidation and damage sperm quality and should thus be used with caution.

An ethnobotanical study of plants used to treat liver diseases in the Maritime region of Togo

ETHNOPHARMACOLOGICAL RELEVANCE

In Togo, many persons still rely on plants for healing, however very little is known about the medicinal practices of the indigenous people. The present study aimed to document the medicinal plant utilization for the management of liver diseases in the Maritime region of the country.

METHODOLOGY

This was an ethnobotanical survey conducted in the Maritime region of Togo from June to August 2015. The data were gathered from 104 traditional healers (TH) by direct interviews using a semi-structured questionnaire. The calculated use values (UV) were used to analyze the importance of the cited plants.

RESULTS

A total of 99 plant species belonging to 88 genera and 49 families were cited by the TH as curing the hepatic diseases. The most represented families were Caesalpiniaceae with 8 species, followed by Euphorbiaceae with 7 species, Apocynaceae and Asteraceae with 6 species each. The highest UV were recorded with Gomphrena celosioides (0.13), Xylopia ethiopica (0.12), Senna occidentalis (0.12), Bridelia ferruginea (0.12), Cymbopogon citratus (0.12), Kigellia Africana (0.09), Cassia sieberiana (0.08) and Sanseviera liberica (0.08), showing their importance in the management of liver dysfunction in the surveyed region. The main used parts were the leaves, followed by the roots, the whole plant, the rhizome and the bark, accounting for more than 10% each. The herbal medicines were mostly prepared in the form of decoction and administrated by oral route.

CONCLUSION

This study showed that Maritime region of Togo has an important plant biodiversity that is exploited by the indigenous TH. However, some plants cited by the TH have not been studied for their possible hepatoprotective effects. These plants are therefore a starting point for biological screenings.

Acute and sub-chronic toxicity study of the ethanol extract from leaves of Aralia elata in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Aralia elata Seem. (A. elata) is a well-known medicinal plant which has been used as a tonic, anti-arthritic and anti-diabetic agent in traditional Chinese medicine. This investigation aimed to evaluate the potential toxicological properties of the ethanol extract from leaves of A. elata, namely ethanol leaves extract (ELE), in rats by acute and sub-chronic toxicity studies.

MATERIALS AND METHODS

In the acute toxicity study, rats were orally administrated with ELE at doses of 1.00, 2.15, 4.64, and 10.00 g/kg to determine the oral medial lethal dose (LD50). Abnormal behavior, toxic symptom, and death were observed for 14 consecutive days. In the sub-chronic toxicity study, rats were orally administrated with ELE at doses of 0, 60, 180, and 540 mg/kg for 12 weeks and followed-up a 4-week recovery period. At the end of the treatment and recovery periods, the rats were sacrificed for hematological, biochemical, and histopathology analyses.

RESULTS

The acute toxicity study showed that oral administration of ELE induced the incidence of adverse effects. The death rate also increased in a dose-dependent manner. The LD50 value was 3.16 g/kg for female rats, and 5.84 g/kg for male rats, respectively. The sub-chronic toxicity study showed that daily oral administration of ELE induced no significant difference in food consumption. However, the body weight of male rats in high dose group increased slowly compared with the control group during the recovery period. The hematological and biochemical analysis showed that compared with the control group, HGB and MCV levels were significantly increased in ELE treatment groups at the end of the treatment period, while TP and GLB levels were significantly decreased at the end of the recovery period. The absolute and relative weight of thymus, brain and adrenal gland showed a significant difference in low or high dose group at the end of the treatment period, although no histological changes were observed in various organs.

CONCLUSION

The results of this study provided evidence that oral administration of ELE at dose of 540 mg/kg is safe in rats and may not exert severe toxic effects.

Toxicological evaluation of lactase derived from recombinant Pichia pastoris

A recombinant lactase was expressed in Pichia pastoris, resulting in enzymatic activity of 3600 U/mL in a 5 L fermenter. The lactase product was subjected to a series of toxicological tests to determine its safety for use as an enzyme preparation in the dairy industry. This recombinant lactase had the highest activity of all recombinant strains reported thus far. Acute oral toxicity, mutagenicity, genotoxic, and subchronic toxicity tests performed in rats and mice showed no death in any groups. The lethal dose 50% (LD₅₀) based on the acute oral toxicity study is greater than 30 mL/kg body weight, which is in accordance with the 1500 L milk consumption of a 50 kg human daily. The lactase showed no mutagenic activity in the Ames test or a mouse sperm abnormality test at levels of up to 5 mg/plate and 1250 mg/kg body weight, respectively. It also showed no genetic toxicology in a bone marrow cell micronucleus test at levels of up to 1250 mg/kg body weight. A 90-day subchronic repeated toxicity study via the diet with lactase levels up to 1646 mg/kg (1000-fold greater than the mean human exposure) did not show any treatment-related significant toxicological effects on body weight, food consumption, organ weights, hematological and clinical chemistry, or histopathology compared to the control groups. This toxicological evaluation system is comprehensive and can be used in the safety evaluation of other enzyme preparations. The lactase showed no acute, mutagenic, genetic, or subchronic toxicity under our evaluation system.

Effect of Bridelia ferruginea Benth (Euphorbiaceae) ethyl acetate and acetone fractions on insulin resistance in fructose drinking mice

ETHNOPHARMACOLOGICAL RELEVANCE

The root of Bridelia ferruginea is traditionally used as a treatment for type 2 diabetes. The present study was investigated to evaluate the effect of Bridelia ferruginea root bark fractions on some markers of type 2 diabetes on fructose drinking mice.

MATERIALS AND METHODS

Mice received a solution of fructose 15% during 42 days ad libitum; at the 15th day to the 42nd day, they received distilled water for fructose drinking control group, metformin 50 mg/kg per day or fractions 50 mg/kg per day for treatment groups. The normal control group received only distilled water during the experiment. After 6 weeks of experiment, OGTT, fasting blood glucose, plasma insulin, triglycerides (TG), total cholesterol, AST and ALT levels were measured.

RESULTS

Fructose drinking control group (F) showed significant (p<0.001) increase of glucose tolerance, plasma levels of total cholesterol, triglycerides and insulin index for insulin resistance (Homeostasis Model Assessment ratio HOMA-IR) as compared to normal control mice. In treated groups, there was a significant reduction of glucose intolerance respectively 74% (p<0.001), 25% (p<0.5) and 92% (p<0.001) for ethyl acetate fraction, acetone fraction and metformin at the same dose of 50 mg/kg per day during 4 weeks administration. In ethyl acetate fraction and metformin treated groups, biochemical parameters and insulin index were significantly (p<0.001) lower than that of fructose drinking control group.

CONCLUSIONS

This indicates that Bridelia ferruginea root bark ethyl acetate fraction improved insulin resistance as metformin significantly in type 2 diabetes.

Safety of red ginseng oil for single oral administration in Sprague-Dawley rats

The single oral administration of red ginseng oil (5000 mg/kg) to Sprague–Dawley rats induced no changes in behavioral patterns, clinical signs, and body weight, and hepatotoxicity parameters such as aspartate aminotransferase and alanine aminotransferase for 14 d. Therefore, these results suggest that the red ginseng oil is safe and nontoxic acutely.