Improved up-and-down procedure for acute toxicity measurement with reliable LD50 verified by typical toxic alkaloids and modified Karber method

Background Up-and-down procedure (UDP) was recommended to replace traditional acute toxicity methods. However, it was limited due to the long experimental period (20–42 days). To improve UDP, an improved UDP method (iUDP) was developed by shortening observation time between sequence dosages. The aim of this study was to test the reliability of iUDP to provide a reliable method for the acute toxicity measurement of valuable or minor amount compounds. Methods Oral median lethal dose (LD50) of nicotine, sinomenine hydrochloride and berberine hydrochloride were measured both by iUDP and modified Karber method (mKM). Results LD50 of the three alkaloids measured by iUDP with 23 mice were 32.71 ± 7.46, 453.54 ± 104.59, 2954.93 ± 794.88 mg/kg, respectively. LD50 of the three alkaloids measured by mKM with 240 mice were 22.99 ± 3.01, 456.56 ± 53.38, 2825.53 ± 1212.92 mg/kg, respectively. The average time consumed by the two methods were 22 days and 14 days respectively. Total grams of the alkaloids used by the two methods were 0.0082 and 0.0673 (nicotine), 0.114 and 1.24 (sinomenine hydrochloride), 1.9 and 12.7 (berberine hydrochloride). Conclusion iUDP could replace mKM to detect acute toxicity of substances with comparable and reliable result. And it is suitable for valuable or minor amount substances.

An Overview on Chemical Constituents, Medicinal Applications, Pharmacological Activity, Toxicology, Metabolism and Pharmacokinetics of Strobilus lupuli

Strobilus lupuli is the dried strobiles (inflorescences) of Humulus lupulus L. (Cannabaceae). Other names of Strobilus lupuli include European hops, hoblon, hop vine, hopfen, and hops. Humulus lupulus L. is an important plant that contains metabolites used in the brewing and pharmaceutical fields. Strobilus lupuli is cultivated in Europe, Asia, and North America, occurring in the world's temperate areas. The analysis of Strobilus lupuli through chromatography analysis showed the presence of bitter substances and xanthohumol. The bitter substances in the resins are the major constituents of Strobilus lupuli, where these substances represent 15-25% of Strobilus lupuli constituents. Strobilus lupuli is applied as a sedative agent for the treatment of nervous tension and insomnia. Strobilus lupuli is applied in the treatment of dyspepsia and lack of appetite. Strobilus lupuli is applied to treat anemia, bacterial infections, abdominal cramps, dysmenorrhoea, leukorrhoea, dermatitis, diarrhea, migraine, and edema. The pharmacology activity of Strobilus lupuli includes experimental and clinical pharmacology. Experimental pharmacology includes antimicrobial, anti-inflammatory, antioxidant, central nervous system depressant, estrogenic and miscellaneous activities. The oral median lethal dose of ethanol extract of Strobilus lupuli in mice was found to be 500 mg/kg, while the oral median lethal dose of Strobilus lupuli in rats was 2700 mg/kg. No information is available on general precautions or on precautions concerning drug and laboratory test interactions. There is no teratogenic effect in pregnancy, or nursing mothers, or pediatric use of Strobilus lupuli. Strobilus lupuli powder dose = one dose of 0.5 g. Infusion or decoction dose = 0.5 g/ 150 ml water. Strobilus lupuli extract dose = 0.06-0.08g.

Acute Toxicity, Immunotoxicity and Allergenicity of Protease Complex Obtained from Micromycete Sarocladium strictum

The different effects on animals of the thrombolytic protease complex of the new producer S. strictum 203 were studied. The tests of acute toxicity, immunotoxicity and allergenicity should conclude that the studied proteolytic complex is safe for medical usage. For the intravenous and the intraperitoneal routes of administration, the maximum tolerated dose and the median lethal dose were not determined.

Sensitivity of The Stripe-Faced Dunnart, Sminthopsis Macroura (Gould 1845), To The Phenyl Pyrazole Insecticide, Fipronil, Toxicological Signs And Implications For Pesticide Risk Assessments In Australia

A lack of toxicity data quantifying responses of Australian native mammals to agricultural pesticides prompted an investigation into the sensitivity of the stripe-faced dunnart, Sminthopsis macroura (Gould 1845) to the insecticide, fipronil (5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinyl pyrazole, CAS No. 120068-37-3). Using the Up-And-Down method for determining acute oral toxicity in mammals, derived by the Organisation for Economic Cooperation and Development (OECD), median lethal dose estimates of 990 mg kg− 1 (95% confidence interval (CI) = 580.7–4770.0 mg kg− 1) and 270.4 mg kg− 1 (95% CI = 0.0 - >20000.0 mg kg− 1) were resolved for male and female S. macroura respectively. The difference between median lethal dose estimates for males and females may have been influenced by the increased age of two female dunnarts. Further modelling of female responses to fipronil doses used the following assumptions: (a) death at 2000 mg kg− 1, (b) survival at 500 mg kg− 1 and (c) a differential response (both survival and death) at 990 mg kg− 1. This modelling revealed median lethal dose estimates for female S. macroura of 669.1 mg kg− 1 (95% CI = 550–990 mg kg− 1; assuming death at 990 mg kg− 1) and 990 mg kg− 1 (95% CI = 544.7–1470 mg kg− 1; assuming survival at 990 mg kg− 1). These median lethal dose estimates are 3–10-fold higher than the only available LD50 value for a similarly sized eutherian mammal, Mus musculus (L. 1758; 94 mg kg− 1) and that available for Rattus norvegicus (Birkenhout 1769; 97 mg kg− 1). Implications for pesticide risk assessments in Australia are discussed.

Calculation of the Median Lethal Dose and Low Lethal Dose Using the CombiStats Biometric Software

The median lethal dose (LD50) and low lethal dose (LD10) are calculated in acute toxicity studies, as well as during specific activity assessment of some medicines. The aim of the study was to develop a procedure for using CombiStats to calculate LD50 and LD10. The authors proposed a step-by-step algorithm for processing bioassay results using the CombiStats biometric software (median effective dose determination model, probit analysis) with conversion of doses to simple fractions (fractions of the maximum dose) to calculate LD50 and LD10. They compared LD50 and LD10 calculation results obtained using CombiStats with those obtained using electronic spreadsheets according to the Bliss–Miller–Tainter–Prozorovsky method described in the State Pharmacopoeia of the Russian Federation (General Monograph 1.1.0014.15). It has been demonstrated that the use of CombiStats sometimes has advantages over the use of the pharmacoepoeial method.

Lethal Dose of Calcium Bentonite in Wistar Rats

Background: Calcium bentonite is a type of clay produced by a devitrification of volcanic ash which is often used as a traditional medicine to absorb toxins and waste products of metabolism. The aim of this study was to determine the lethal dose of calcium bentonite in Wistar rats to explore its toxicity level and safe use.Methods: Fifty male and female Wistar rats were randomly divided into five groups for each sex. The control group was given 5 cc aquadest whereas the other four groups received calcium bentonite solution of 50 mg/kgBW, 300 mg/kgBW, 2,000 mg/kgBW, and 5,000 mg/kgBW, respectively, at a single dose. The weight was observed for up to 7 days and analyzed using the unpaired t-test and Mann-Whitney test. The death rate was calculated using the probit analysis. Median lethal dose results were then classified according to Loomis Criteria. Results: No deaths occurred at the highest dose, suggesting that the median lethal dose value of calcium bentonite was >5,000 mg/kgBW. No weight loss occurred due to the administration of calcium bentonite and a significant increase in the body weight was even observed in the male rat group. Interestingly, a significant decrease was found in the female rats group when compared to the control group.Conclusions: Calcium bentonite is classified as a practically non-toxic material with a median lethal dose of over 5,000 mg/kgBW.

Median lethal dose and sub-chronic toxicity profile of Azadirachta indica A. Juss. leaf hexane and ethyl acetate fractionated extracts on albino rats

Azadirachta indica A. Juss. (Neem) is a multipurpose medicinal plant, traditionally used in the treatment of various human ailments. This plant is tagged as having high toxicity profile, and the toxicity might be related to the polarity nature of the solvent used for extraction. Hence, this research was aimed at screening the toxicity profile of Azadirachta indica leaf fractionated extracts using Albino rats. A. indica leaf was collected, authenticated and extracted using 95 % methanol then fractionated with hexane and ethyl acetate. Median lethal dose (LD50) of each fraction was determined using single oral dose of 5,000 mg/kg body weight (b. wt.) to five (5) rats. For the sub-chronic toxicity screening, the fractions were administered to groups of rats at different concentrations. Group 1 served as control, groups 2-5 received 900, 1800, 2700 and 3600 mg/kg b. wt. respectively. After 28 days, biochemical indices of hepatic and renal functions as well as haematological and histopathological parameters were analyzed. LD50 of each of the fractions was greater-than 5000 mg/kg b. wt. All the extract fractions at the administered doses, significantly (P<0.05) altered the serum levels of some biochemical indices of the hepatic and renal functions, as well as the levels of some haematological parameters. For the histopathology, hepatic congestion, periportal inflammation, distortion, infiltration and haemorrhage were observed at 1800-3600 mg/kg b. wt. Hence, these results indicated that using hexane or ethyl acetate as solvent of extraction, A. indica leaf extracts might not be considered safe at the administered sub-chronic doses.