Acute and sub-chronic toxicity of HPLC fingerprinted extract of Conyza sumatrensis (Retz.) E.H. Walker in rodents

Ethnopharmacological relevance

Conyza sumatrensis (CS) is an extensively used medicinal herb in the tropics for varied ailments related to pain, inflammation and malaria. Though in constant folkloric use, scientific validations are proving valuable.

Aim of the study

Evaluate the safety profile of methanol extract from CS in mice and rats through acute and sub-chronic toxicity studies respectively.

Material and methods

Acute toxicity study involved the single oral administration of CS at 1000, 2000 and 3000 mg/kg in mice, while the sub chronic toxicity was carried upon in rats at doses 250, 500 and 1000 mg/kg/day for 28 days. Besides body weight, general behaviour and mortality, serum biochemical parameters and liver histology were assessed after 7 and 28 days for acute and sub-chronic study respectively. The parameters were again checked on days 14 and 56 in order to assess the recovery from damage, if any. HPLC fingerprinting of the aqueous and methanol extract was performed through C18 column using water: acetonitrile as mobile phase with observations at 240 nm.

Results

In the acute toxicity test, single oral dose of 1000, 2000 and 3000 mg/kg of CS did not result in any behavioural changes or mortality, indicating non toxicity. In sub-chronic toxicity studies in rats, no mortality was observed at 250, 500 and 1000 mg/kg/day when administered orally for a period of 28 days. Except Serum Glutamate Pyruvate Transaminase (SGPT) level in acute study and Alkaline Phosphatase (ALP), SGPT and Serum Glutamate Oxaloacetate Transaminase (SGOT) level in sub-chronic study, all the observational, haematological and biochemical parameters studied showed non-significant changes. Histological examination of liver did not reveal any treatment-related effects in any of the studies. Moreover, haematological and biochemical changes orchestrated by CS got normalised after 14 and 56 days post-treatment in acute and sub-chronic toxicity respectively. The HPLC fingerprint could resolve 11 and 28 peaks from aqueous and methanol extracts respectively.

Conclusion

The experiments indicate the methanol extract to be safe even at high and repeated doses in pre-clinical studies even though the constituents are more than in aqueous extract.     

Effects of ethanolic dried leaf extract of Lecaniodiscus cupanioides on antioxidant enzymes and biochemical parameters in rats

Ethnopharmacological relevance

Lecaniodiscus cupanioides is widely used in West African folk medicine for the treatment of inflammatory conditions, fevers and bacterial infections.

Aim of the study

To evaluate the potential toxic effects of the ethanolic dried leaf extract of Lecaniodiscus cupanioides (LC) on antioxidant enzymes in selected organs and biochemical parameters.

Materials and Methods

Crude ethanolic extract of Lecaniodiscus cupanioides dried leaves was prepared. A 90-day sub-chronic toxicity study was conducted using albino rats. Reconstituted Lecaniodiscus cupanioides was administered at a dosage of 400, 800 and 1600 mg/kg (high dose) with a control group receiving 10 ml/kg orally. Histopathological studies of major organs and blood chemistry analysis were performed on blood obtained via cardiac puncture after euthanization. Selected organs (liver, kidney and brain) were harvested for antioxidant and histopathological assessments.

Results

The extract produced significant (p<0.05) increases in the weights of liver, kidney and brain at 800 mg/kg and 1600 mg/kg compared to the control. Biochemical analysis showed significant increase in Alanine transferase (ALT) at 800 mg/kg and 1600 mg/kg. Assay for antioxidant enzymes showed a reversible decrease in the activity of Catalase (CAT), Superoxide dismutase (SOD) and Glutathione (GSH) with an increase in Malondialdehyde (MDA) at 800 mg/kg and 1600 mg/kg Lecaniodiscus cupanioides. Histopathological study showed reversible congestion in the brain, liver, and kidney at 800 mg/kg and 1600 mg/kg.

Conclusion

Findings in this study reveal that the ethanolic dried leaf extract of Lecaniodiscus cupanioides has the potential for inhibiting in vivo antioxidant enzymes activity and causing hepatotoxicity after prolonged exposure.     

Acute and sub-chronic toxicity profile of methanol leaf extract of Gouania longipetala in rats

Ethnopharmacological relevance

Gouania longipetala leaves are commonly used in folkloric medicine in Africa and other parts of the world for treatment of edema, febrifuges, veneral diseases, lumbago, heart diseases, diabetes mellitus malaria, etc. This study therefore evaluated safety profile of the methanol leaf extract of the plant using acute and sub-chronic studies in rat model.

Materials and methods

Acute toxicity test of the plant lasted for 48 h with oral administration of graded doses (100–4000 mg/kg) of Gouania longipetala extract (GLE) in rats. The rats were observed for signs of toxicity and death. The sub-chronic toxicity was evaluated by administration of different doses (2.5, 5 and 10 mg/kg) of GLE daily in feed for 90 days. On days, 30, 60 and 90, blood samples collected from the retro-orbital plexus of the eye of the rats were used for evaluation of serum biochemistry, hematology, lipid peroxidation and in vivo antioxidant activities. Histopathological evaluations of the kidney, liver, lungs and heart were also done.

Results

The acute toxicity test revealed no observable signs of toxicity or morbidity. Sub-chronic study showed that GLE significantly (p<0.05) increased relative liver weight on day 90 at 10 mg/kg. There were no significant variations in the hematological parameters of both GLE treated and untreated rats. The extract significantly (p<0.05) reduced total cholesterol, triglycerides, very low density lipoproteins and increased high density lipoproteins which was more prominent on day 90 at the dose of 10 mg/kg. The extract significantly (p<0.05) increased liver enzyme markers at the doses used. GLE also significantly (p<0.05) increased serum urea at the dose of 10 mg/kg on day 90. The extract caused dose-dependent and significant (p<0.05) increase in superoxide dismutase and decrease in malondiadehyde. Histopathological studies revealed degenerative changes in the kidney and liver.

Conclusion

The results of the study suggest that Gouania longipetala is well tolerated in short term therapies, but may have long term toxic effects on the kidney and liver.     

Inhibitory effects of salvianolic acid B on CCl4-induced hepatic fibrosis through regulating NF-κB/IκBα signaling

Ethnopharmacological relevance

Hepatic fibrosis, a precursor of liver cirrhosis, is a consequence of severe liver damage that occurs in many patients with chronic liver diseases. Salvianolic acid B (SA-B) is one of water soluble compounds derived from Salvia miltiorrhiza Bunge (Danshen in Chinese) widely used for chronic liver diseases. In this study we investigated the protective effects of SA-B on CCl₄-induced hepatic fibrosis.

Materials and methods

Hepatic fibrosis in rats was induced by carbon tetrachloride (CCl₄). Rats were divided into four groups, including normal controls (N group), model (M group), low SA-B of 10 mg/kg body weight (L group), or high SA-B of 20 mg/kg body weight (H group). After 6 weeks, macroscopic features of the liver and weight ratio of liver to body were measured. Liver fibrosis of the rats was evaluated by HE and Massion staining. Activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBIL) were checked with automated biochemistry analyzer. Serum levels of hyaluronic acid (HA), type IV collagen (IV-C), Laminin (LN) and procollagen III peptide (PIIIP) were detected by radioimmunoassay (RIA). The expression of NF-κB and IκBα was detected by western blotting.

Results

SA-B was shown to reduce CCl₄-induced hepatic fibrosis in rats. The serum levels of ALT, AST, and TBIL were significantly lower in the SA-B treatment groups than in the M group. Compared the M group, the serum levels of HA, LN, IV-C and PIIIP were decreased markedly after treatment with SA-B, especially in the H group. Treatment with SA-B at 10–20 mg/kg (L and N groups, respectively) dose-dependently decreased the expression of NF-κB in the nucleolus and increased the expression levels of NF-κB and IκBα protein in the cytoplasm compared to that of the M group.

Conclusions

This study reveals that SA-B could prevent the progression of liver angiogenesis and alleviate liver fibrosis possibly by regulating the expression of NF-κB and IκBα.     

Subchronic toxicity study of Coptidis Rhizoma in rats

Ethnopharmacological relevance

Coptidis Rhizoma (CR) is a medical herb from the family Ranunculacease that has been used to treat gastroenteritis, dysentery, diabetes mellitus, and severe skin diseases.

Aim of the study

To evaluate the no-observed-adverse-effect level (NOAEL) and the toxicity of CR, following repeat oral administration to rats for 13 weeks.

Materials and methods

CR was administered by oral gavage to groups of rats (n=10/group, each sex) at dose levels of 0 (control), 25, 74, 222, 667 or 2000 mg/kg/day 5 times per week for 13 weeks. Mortality, clinical signs, body weights, food consumption, hematology, serum chemistry, urinalysis, vaginal cytology and sperm morphology, organ weights, gross and histopathological findings were compared between control and CR groups.

Results

Urinalysis showed a significant increase in N-acety1-β-glucosaminidase in males in the 2000 mg/kg/day group (P<0.01). However, no mortality or remarkable clinical signs were observed during this 13-week study. No adverse effects on body weight, food consumption, hematology, serum chemistry, organ weights, gross lesion, histopathology, vaginal cytology, sperm motility, or deformity were observed in the males or female rats treated with CR.

Conclusions

On the basis of these results, the NOAEL of CR is determined to be 667 mg/kg/day for males and 2000 mg/kg/day for females.     

Acute and sub-chronic toxicity of a lyophilised aqueous extract of Centaurium erythraea in rodents

Ethnopharmacological relevance

An aqueous concoction made from centaury (Centaurium erythraea (L.) Rafn., (Gentianaceae) whole plant is used in the Moroccan traditional medicine for the treatment of diabetes, as well as a number of other diseases. No systematic study of the potential toxicity of the plant has been described.

Aim of the study

The present investigation was carried out to evaluate the safety of an aqueous extract of Centaurium erythraea whole plant (CE-extract) by determining its potential toxicity after acute and sub-chronic administration in rats and mice.

Materials and methods

For the acute study, the lyophilised CE-extract was administered to adult IOPS OFA mice in single oral doses of 1-15 g/kg given by gavage, and single intraperitoneal (i.p.) doses of 1-14 g/kg. General behavioral adverse effects, mortality, and latency of mortality were determined for up to 14 days. In the sub-chronic dose study, the CE-extract was administered orally at doses of 100, 600 and 1200 mg/kg daily for 90 days to Wistar rats. Body weight and selected biochemical and hematological parameters were determined every 30 days and at the end of 90 days of daily administration; sections of liver and kidney were examined histologically for any signs of organ damage at the end of the treatment.

Results

In the acute study in mice, there were no deaths or any signs of toxicity observed after oral administration of single doses of the CE-extract at any dose level up to the highest dose tested (15 g/kg), which was the no-observed-adverse-effect level (NOAEL). However, the mortality rate as well as the acute toxicity of the i.p. administered CE-extract increased progressively with increasing dose. The NOAEL for the i.p. dose was 6 g/kg while the lowest-observed-adverse-effect level (LOAEL) was 8 g/kg; the calculated acute toxicity (LD₅₀) of i.p. administered CE-extract in mice was 12.13 g/kg.In sub-chronic studies in rats, the CE-extract (administered orally at daily doses of 100, 600 and 1200 mg/kg for 90 days), did not cause any changes in hematological and biochemical parameters, except a small reduction of mean corpuscular volume, and a decrease in serum glucose and triglyceride levels at the higher doses. Histopathological examination of the liver and kidneys at the end of the study showed normal architecture suggesting no morphological disturbances.

Conclusions

Because of the lack of toxicity of the CE-extract given by the oral route, and relatively high NOAEL values for the i.p. dose in the acute study in mice, as well as lack of mortality or clinically significant adverse changes in the biological and hematological parameters, and the morphology of liver and kidneys in rats after 90 days of daily dosing, it may be concluded that the CE-extract is relatively non-toxic. Also, in view of the doses consumed empirically in traditional medicine in Morocco, there is a wide margin of safety for the therapeutic use of Centaurium erythraea.     

Anti-diabetic effects of Panax notoginseng saponins and its major anti-hyperglycemic components

Ethnopharmacological relevance

Panax notoginseng (Burk) F.H. Chen (Araliaceae) is a well-known and commonly used traditional Chinese herb for treatment of various diseases, such as hemostasis, edema and odynolysis.

Aim of study

Our aim was to investigate the mechanisms of anti-hyperglycemic and anti-obese effects of Panax notoginseng saponins (PNS) in KK-Ay mice, and explore the components in PNS for such effects.

Materials and methods

KK-Ay mice received daily intraperitoneal injections of PNS 200 mg/kg or vehicle for 30 days while ginsenoside Re 14 mg/kg, Rd 15 mg/kg, Rg1 40 mg/kg, Rb1 60 mg/kg and notoginsenoside R1 6 mg/kg for 12 days. Fasting blood glucose levels (FBGL), glucose tolerance (GT), serum insulin, leptin levels, body weight changes, food intake, adipose tissues and blood fat levels were measured at different time points.

Results

The PNS group had significantly lower FBGL, improved GT and smaller body weight incremental percentage after the 30-day treatment. Additionally, Rb1 exhibited significant reduction of FBGL on day 12, and Re also exhibited a decreasing trend after the 12-day treatment.

Conclusions

PNS possess anti-hyperglycemic and anti-obese activities by improving insulin- and leptin sensitivity, and Rb1 is responsible for the anti-hyperglycemic effect among the five saponins in KK-Ay mice.     

Acute and subchronic oral toxicity assessment of the aqueous extract from the stem bark of Erythrina senegalensis DC (Fabaceae) in rodents

Aim of the study

The decoction of the stem bark of Erythrina senegalensis (EAES) is traditionally used in the Western region of Cameroon against liver disorders. The present study evaluated the potential toxicity of this decoction after acute and sub-chronic administration in rodents.

Materials and methods

In acute study, a single administration of EAES was given orally to mice at doses ranging from 1.25 to 12.5 g/kg. General behaviour, adverse effects and mortality were determined for up to 14 days post treatment. In the sub-chronic study, EAES was given orally as a single administration to Wistar rats at doses of 300, 600 and 1200 mg/kg/day for 28 days. Animal body weight was observed throughout the experimental period while haematological and biochemical parameters of blood and urine, as well as kidney and liver tissues histology were evaluated at the end of the experiment.

Results

In the acute study in mice, none of the doses used induced mortality or significant behavioural changes. In the sub-chronic study in rats, daily oral administration of EAES at the dose of 600 mg/kg resulted in a significant increase in the relative body weight at the last week of treatment. The relative weights of organs were not affected by the treatment. No haematological changes were observed a part of a significant increase in WBC count at the dose of 600 mg/kg. Serum AST, ALT, ALP, total protein, total cholesterol and triglycerides decreased significantly while total and conjugated bilirubin significantly increased. Renal function indices assay in blood showed significant modification in all the treated groups compared to control while, in urine, only urea excretion markedly reduced at a dose of 1200 mg/kg. Histological analysis did no show any liver or kidney alteration.

Conclusion

These results demonstrated that there is a wide margin of safety for the therapeutic use of EAES and further corroborated the traditional use of this extract as a hepatoprotective agent.     

Pharmacological evaluation of sedative–hypnotic activity and gastro-intestinal toxicity of Rhizoma Paridis saponins

Ethnopharmacological relevance

Rhizoma Paridis saponins (RPS) have been well studied for antimicrobial, anti-hemorrhagic, and anticancer effects. However, scientific information on RPS regarding the toxic and neuropharmacological effects is limited. In this study, the acute oral toxicity, sedative–hypnotic activity and gastro-intestinal toxicity of RPS were investigated.

Materials and methods

The acute toxicity was carried out by administering single doses (800–5000 mg/kg) of RPS to adult mice. Rotarod test and sodium pentobarbital-induced hypnosis activity were used to evaluate the neuropharmacological effects on mice. Gastric emptying and intestinal transit were used to investigate the gastric–intestinal system effects.

Results

A single oral administration of RPS dose-dependently caused adverse effects on the general behavior and mortality rate of mice. LD₅₀ value of oral acute toxicity was 2182.4 mg/kg, with 95% confidence limit of 1718.4–2807.8 mg/kg. In the test of sleeping mice, RPS acted in synergy with sodium pentobarbital at doses 250 and 500 mg/kg while motor coordination was not influenced within 120 min after treatment with RPS. Regarding the gastric–intestinal toxicity, RPS (100, 250, and 500 mg/kg) significantly inhibited gastric emptying but did not affect the intestinal transit.

Conclusions

RPS, which is a hypotoxic anticancer drug, possesses the sedative–hypnotic activity and gastric stimulus side effect.     

Subchronic exposure to mitragynine,the principal alkaloid of Mitragyna speciosa, in rats

Ethnopharmacological relevance

Mitragyna speciosa is a popular medicinal plant in Southeast Asia which is commonly used for its morphine-like effects. Although the analgesic properties of Mitragyna speciosa and its ability to ameliorate withdrawal signs after abrupt cessation of opioid abuse are well known, information about the long-term safety of the plant's active compounds is lacking. In this work, we evaluated the effects of sub-chronic exposure to mitragynine, the principal alkaloid of Mitragyna speciosa leaves in rats. Materials and methods: Male and female Sprague-Dawley rats received three doses of mitragynine (1, 10, 100 mg/kg, p.o) for 28 days respectively. Food intake and relative body weight were measured during the experiment. After completion of drug treatment biochemical, hematological, and histological analyses were performed.

Results

No mortality was observed in any of the treatment groups. The groups of rats treated with the lower and intermediate doses showed no toxic effects during the study. However, the relative body weight of the group of female rats treated with the 100 mg/kg dose was decreased significantly. Food intake also tended to decrease in the same group. Only relative liver weight increased after treatment with the high dose of mitragynine (100 mg/ kg) in both the male and female treatment groups of rats. Biochemical and hematological parameters were also altered especially in high dose treatment group which corresponds to the histopathological changes.

Conclusions

The study demonstrated that mitragynine is relatively safe at lower sub-chronic doses (1–10 mg/kg) but exhibited toxicity at a highest dose (sub-chronic 28 days: 100 mg/kg). This was confirmed by liver, kidney, and brain histopathological changes, as well as hematological and biochemical changes.     

Evaluation of reproductive and developmental toxicities of Pu-erh black tea (Camellia sinensis var. assamica) extract in Sprague Dawley rats

Ethnopharmacological relevance

Pu-erh black tea, which is obtained by first parching crude green tea leaves and followed by secondary fermentation with microorganisms, has been believed to be beneficial beverages for health in PR China. But its potential toxicity when administered at a high dose as concentrated extract has not been completely investigated.

Aim of the study

The present study was aimed at evaluating potential reproductive and developmental toxicities of Pu-erh black tea extract (BTE) in Sprague Dawley rats.

Materials and methods

Growing rats were given BTE by gavage at levels of 0, 200, 700 and 2500 mg/kg/day as the F₀ generation in reproductive toxicity study. Additionally, BTE was administered to mate female rats from gestation day 0.5 through 19.5 at the doses of 0, 200, 700 and 2500 mg/kg/day to evaluate the developmental toxicity.

Results

In the reproductive toxicity study, only 2500 mg/kg/day BTE reduced the body weight gain and altered the relative organ weights including testes, prostata and ovary both for F₀ parents and F₁ offspring compared to the controls. High dose of BTE (2500 mg/kg/day) administration caused developmental disturbances in embryo-to-foetus period including resorbed embryos, decreased embryo size and skeletal anomalies.

Conclusion

In conclusion, the no-observed-adverse-effect level of BTE is 700 mg/kg/day both for reproductive toxicity and developmental toxicities.     

Safety evaluation of main alkaloids from Rhizoma Coptidis

Ethnopharmacological relevance

Rhizoma Coptidis (RC), a widely used traditional Chinese medicine, has been used for the treatment of heat-clearing and detoxifying, but there is very little information on its safety.

Aim of the study

To provide information on the safety of RC, we evaluated the toxicity of the crude RC and RC alkaloids (berberine, coptisine, palmatine and epiberberine) including cytotoxicity, acute toxicity in mice and sub-chronic toxicity in rats.

Materials and methods

The cytotoxicity of RC alkaloids was tested in HepG2 and 3T3-L1 cells by the MTT assay. The acute toxicity of RC alkaloids was tested in mice and the mortality was calculated at the end of experiment. For sub-chronic toxicity study, the rats were treated with the RC alkaloids at a dose of 156 mg/kg/day and RC at a dose of 521 mg/kg/day for 90 days. Mortality, clinical signs, body weight changes, organ weights, urinalysis and hematological parameters, gross necropsy and histopathology were monitored during the study period.

Results

The cell assay indicates that the IC₅₀ values of berberine, coptisine, palmatine and epiberberine in HepG2 cells were 48.17, 64.81, 112.80 and 120.58 μg/mL, which in 3T3-L1 cells were 41.76, 56.48, 84.32 and 104.18 μg/mL, respectively. In the acute toxicity assay, the LD₅₀ values of four alkaloids were 713.57, 852.12, 1533.68 and 1360 mg/kg, respectively. However, in the sub-chronic toxicity study, no mortality and morbidity were observed which could be related to RC alkaloids and RC treatment. Besides, there was no abnormality in clinical signs, body weights, organ weights, urinalysis, hematological parameters, gross necropsy and histopathology in any of the animals after the oral administration of RC alkaloids and RC.

Conclusions

Taking these results together, we came to the conclusion that the toxicity of berberine is the maximum and palmatine is the minimal in four RC alkaloids. The currently recommended doses of RC alkaloids and RC consumed are relatively safe.     

The protective effect of Zizyphus jujube fruit on carbon tetrachloride-induced hepatic injury in mice by anti-oxidative activities

Aim of the study

The study was aimed to investigate the protective effect against hepatic injury induced by CCl₄ for the ethanolic extract of FZJ.

Materials and methods

The alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected as biomarker in blood of hepatic injury. Product of lipid peroxidation (MDA), activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px), and reduced glutathione (GSH) contents were evaluated for oxidative stress in hepatic injury. Moreover, histopathological observation was assayed at the degree of hepatic injury.

Results

After administrated the FZJ, the dose of 200 mg/kg significantly decreased ALT and AST, and attenuated histopathology of hepatic injury, and ameliorated the oxidative stress in hepatic tissue. Partly assayed indexes were ameliorated after administrated FZJ at the dose of 100 mg/kg.

Conclusion

These results indicated that hepatic protective effects of FZJ were very relevant to modulate the oxidative stress in hepatic injury.     

The protective effects of Acanthopanax senticosus Harms aqueous extracts against oxidative stress: Role of Nrf2 and antioxidant enzymes

Ethnopharmacological relevance

Acanthopanax senticosus (Rupr.et Maxim.) Harms, classified into the family of Araliaceae, is used in a variety of diseases in traditional Chinese system of medicine including hypertension, ischemic heart disease and hepatitis.

Materials and methods

Different doses (75 mg/kg, 150 mg/kg and 300 mg/kg) of aqueous extracts of Acanthopanax senticosus Harms were evaluated for the antioxidant activity against oxidative stress in mice induced by tert-butyl hydroperoxide (t-BHP) through observating histopathology of the liver and detecting antioxidant enzyme activity, concentration of antioxidant, and related gene and protein expression.

Results

Acanthopanax senticosus Harms aqueous extracts (ASE) attenuated the morphological injury of liver induced by t-BHP and increased the activity of antioxidant enzymes and the ratio of GSH/GSSG in serum and liver homogenates. Medium and high doses of ASE also elevated the gene expression of NF-E2-related factor-2 (Nrf2), but not CuZnSOD, MnSOD, catalase (CAT), glutathione peroxidase (GPx) and GCLC. Protein expression results showed that Nrf2 and the antioxidant enzymes were all increased significantly by medium and high doses of ASE.

Conclusion

The present results indicated that ASE protect against oxidative stress which may be generated via the induction of Nrf2 and related antioxidant enzymes.     

Evaluation of oral subchronic toxicity of Pu-erh green tea (camellia sinensis var. assamica) extract in Sprague Dawley rats

Ethnopharmacological relevance

Pu-erh green tea, originally produced in the Yunnan province of P.R. China for about 1700 years, is believed to be beneficial to health in Asian countries. The potential toxicity of Pu-erh green tea when administered at high doses via concentrated extract, however, has not been completely investigated.

The aim of the study

The present study was aimed to evaluate the potential toxicity of Pu-erh green tea extract (PGTE) of sub-chronic administration to Sprague Dawley (SD) rats.

Materials and methods

Growing SD rats were administrated orally by gavage with PGTE at doses of 0, 1250, 2500, and 5000 mg/kg/day for 91 consecutive days. Clinical observations, including survival, hematology, serum biochemistry, urinalysis and histopathological examination were measured to monitor treatment-related adverse effects in rats.

Results

The results showed that oral administration of high dose of PGTE led to body weight gain suppression, liver and calcium deposition dysfunctions.

Conclusions

In conclusion, the no-observed-adverse-effect level for Pu-erh green tea extract derived from the results of the present study was 2500 mg/kg/day for both genders.     

Toxicological evaluation of Grains of Paradise (Aframomum melegueta) [Roscoe] K. Schum.

Ethnopharmacological relevance

Grains of Paradise (Aframomum melegueta [Roscoe] K. Schum.) seeds are used in West Africa as a remedy for variety of ailments such as stomach ache, snakebite, diarrhea and they have reported anti-inflammatory properties. Additionally, the seeds contain gingerols and related compounds that may be useful against cardiovascular disease, diabetes, and inflammation.

Aim of study

A 28-day sub-chronic toxicity study in male and female Sprague–Dawley rats was conducted to evaluate the safety of a Grains of Paradise extract.

Materials and methods

An ethanolic extract of the seeds was evaluated for toxicological effect on rats.

Results

A dose-related increase in absolute and relative liver weights was observed in males and females dosed with 450 and 1500 mg/kg. There was a corresponding increase in alkaline phosphatase with no signs of steatosis or cirrhosis. At the same doses, there was a significant decrease in blood glucose in male rats.

Conclusions

This study shows that Grains of Paradise extract may be useful as a treatment for diabetes, however liver toxicity should be considered.     

Subchronic toxicity and plasma pharmacokinetic studies on wogonin,a natural flavonoid,in Beagle dogs

Aim of the study

To investigate subchronic toxicity and pharmacokinetic of wogonin using Beagle dog and to provide foundation for clinical applications of this promising anticancer agent.

Materials and methods

Wogonin was administered via intravenous infusion at dosages of 60, 30 and 15 mg/kg per day for 90 days followed by subchronic toxicity studies including general body parameters, hematological, plasma biochemical, histopathological, and viscera examinations. Dogs were given single intravenous injection of 20 mg/kg wogonin followed by pharmacokinetic parameters estimating.

Results

Dogs treated with wogonin showed no significant changes in organs compared with controls in the toxicological study. An innocuous dose was established to be 60 mg/kg, which was approximately 38.5 (body surface area) times higher than the dose (50 mg/60 kg) used for human trials. The area under concentration–time curve (AUC_∞) was estimated to be 2137.9 ± 231.4 ng h/ml, while the elimination half-life (t_1/2) was 1.51 ± 0.43 h in dogs treated with 20 mg/kg wogonin.

Conclusions

Wogonin offered a wide margin of safety and had no organ toxicity for a long time intravenous administration in dogs.     

Subchronic oral toxicity of evodia fruit powder in rats

Ethnopharmacological relevance

Evodia, a fruit from Evodia rutaecarpa, has been used in oriental medicine, and since its various pharmaceutical actions, including anti-cancer activity, have become known, evodia has been widely used as a dietary supplement. However, information regarding its toxicity is limited.

Materials and methods

Evodia fruit from Evodia rutaecarpa (Juss.) Benth. var. officinalis (Dode) Huang (0, 25, 74, 222, 667, and 2000 mg/kg) was administered orally five times per week for 13 weeks. Clinical signs, body weight, food consumption, hematology, serum chemistry, urinalysis, vaginal cytology, sperm morphology, organ weight, and gross and histopathological findings were evaluated.

Results

Urinary ketone body excretion was detected in males at 667 and 2000 mg/kg and in females at 2000 mg/kg. An increase in absolute/relative liver weight was observed in both sexes at 2000 mg/kg. Although levels of serum alanine aminotransferase, glucose, total cholesterol, and triglycerides were significantly reduced in males and/or females at 200 and/or 667 and 2000 mg/kg, all values were within normal ranges and were considered non-adverse. In addition, no treatment-related differences in body weight, food consumption, hematology, vaginal cytology, sperm morphology, or gross and histopathological examination were detected.

Conclusions

The subchronic no-observable-adverse-effect level for evodia fruit powder following oral administration in rats is greater than 2000 mg/kg.     

Antihyperglycemic,hypolipidemic and antioxidant activities of total saponins extracted from Aralia taibaiensis in experimental type 2 diabetic rats

Ethnopharmacological relevance

As a well-known traditional Chinese medicine the root bark of Aralia taibaiensis has multiple pharmacological activities, including relieving rheumatism, promoting blood circulation to arrest pain, inducing diuresis to reduce edema, and antidiabetic action. It has long been used as a folk medicine for the treatment of traumatic injury, rheumatic arthralgia, nephritis, edema, hepatitis and diabetes mellitus in China.

Aim of study

To evaluate the antihyperglycemic, hypolipidemic and antioxidant activities of total saponins extracted from Aralia taibaiensis (SAT) in experimental type 2 diabetic mellitus (T2DM) rats.

Materials and methods

Acute toxicity was studied in rats to determine the safe oral dose of SAT. Then, SAT was given orally to normal and streptozotocin–nicotinamide induced T2DM rats at 80, 160 and 320 mg/kg doses for a series of 28 days to determine the antihyperglycemic activity. Glibenclamide (600 μg/kg), a standard antidiabetic drug, was used as a positive control drug. At the end of treatment, biochemical parameters and antioxidant levels were measured to evaluate the hypolipidemic and antioxidant activities of SAT.

Results

Oral administration of SAT did not exhibit toxicity and death at a dose not more than 2000 mg/kg. SAT dose-dependently improved the symptoms of polydipsia, polyuria, polyphagia and weight loss in diabetic rats. Compared with diabetic control group, administration of 320 mg/kg SAT resulted in significant (P<0.05) fall in the levels of fasting blood glucose, glycosylated hemoglobin, creatinine, urea, alanine transarninase, aspartate aminotransferase, total cholesterol, triglycerides, low density lipoprotein cholesterol and malondialdehyde, but significant (P<0.05) increase in the levels of serum insulin, superoxide dismutase and reduced glutathione. However, SAT did not have any effect on the normal rats.

Conclusions

SAT had excellent antihyperglycemic, hypolipidemic and antioxidant activities in T2DM rats and might be a promising drug in the therapy of diabetes mellitus and its complications.     

Toxicity evaluation of standardized extract of Gynostemma pentaphyllum Makino

Ethnopharmacological relevance

To evaluate the safety of standardized extract of Gynostemma pentaphyllum in rats.

Materials and methods

The water extract of Gynostemma pentaphyllum was prepared and standardized, the dry powder yielded 6% gypenosides. In the acute oral toxicity test, the single oral dose of 5000 mg/kg of Gynostemma pentaphyllum extract was given to female Sprague–Dawley rats. In subchronic toxicity test, the oral dose of 1000 mg/kg/day of the extract was given to rats in treatment and satellite groups for 90 days. Satellite groups of both sexes were kept for additional 28 days after 90-day treatment. Control rats received distilled water.

Results

Standardized extract of Gynostemma pentaphyllum did not cause death or any toxic signs in rats. The daily administration of the extract for 90 days did not produce lethal or harmful effects. Although certain hematological and blood chemistry values (i.e., neutrophil, monocyte, glucose, and serum alkaline phosphatase levels) were found to be statistically different from the control group, however; these values were within the ranges of normal rats.

Conclusion

Standardized extract of Gynostemma pentaphyllum did not produce mortality or any abnormality in rats.