Presence Of Liver S9 Fraction Research Articles

Anticarcinogenic and antimutagenic activity of Alstonia scholaris on the albino mice bone marrow cells and peripheral human lymphocyte culture against methyl methane sulfonate induced genotoxicity.

Background:The use of medicinal plants in modern medicine for the prevention and treatment of cancer is an important aspect. For this reason, it is important to identify antitumor promoting agents present in medicinal plants commonly used by the human population.Materials and Methods:We used in vivo and in vitro methods using chromosomal aberrations (CAs), sister chromatid exchange (SCE) and replication index (RI) as markers, exposed by methyl methanesulfonate (MMS) as well as alcoholic extract of Alstonia scholaris in five increasing concentrations (200, 250, 300, 350 and 400 mg/kg body weight for in vivo and 150, 200, 250 and 300 μg/ml of culture) and of three different durations of 24, 48 and 72 h in the presence as well absence of S9 mix.Results:Extracts of Alstonia reduces the total aberrant cells ranges from 10.0% to 41.84% and frequencies of aberration in the aberrant cells ranges from 220 to 124 against 290 aberrations causes due to MMS in vivo. Similarly in the in vitro, it reduces CAs (39.62%, 32.83%, and 38.48%) and (45.31%, 44.46%, and 38.34%) at 24, 48, and 72 h of exposure respectively; in the absence as well as presence of liver S9 fraction. It also reduces SCE from 7.70 to 4.20 per cell and enhances RI from 1.45 to 1.64.Conclusion:Extracts of Alstonia significantly reduces the number of aberrant cells and frequency of aberration per cell at each concentration and duration of exposure in vivo; and CAs and SCE in vitro and enhances RI.

Antigenotoxic and anticlastogenic potential of Agaricus bisporus against MMS induced toxicity in human lymphocyte cultures and in bone marrow cells of mice

The aim of the present study is to evaluate, for the first time, antigenotoxic potential of Agaricus bisporus against methyl methanesulphonate induced toxicity in human lymphocyte culture in vitro and in bone marrow cells of albino mice in vivo. The parameters studied included total aberrant cells and the frequencies of aberrations in the bone marrow cells at three exposure durations viz., 16, 24 and 32h, and for the in vitro method using chromosomal aberrations, sister chromatid exchanges and replication indices as markers. The alcoholic extract of A. bisporus was taken in five increasing concentrations of 200, 250, 300, 350 and 400mg/kg body weight for three in vivo exposure durations viz., 16, 24 and 32h. Similarly, four doses of extracts viz., 150, 200, 250 and 300μg/ml of culture were taken for in vitro durations of 24, 48 and 72h in the presence as well as the absence of S9-mix. The treatment reduced the total number of aberrant cells ranging from 10.0% to 46.15% and it reduced the total frequencies of aberrations ranging from 198 to 96 against very high aberrations i.e., 227 caused due to methyl methanesulphonate in vivo. The same trends were observed in the in vitro experiments i.e., it reduced chromosomal aberrations from (42.00%, 71.25%, and 83.00% to 20.00%, 39.50%, and 43.00%) at 24, 48, and 72h of exposure respectively. However when experiments were carried out in the presence of liver S9 fraction, these values were respectively 52.38, 44.56, and 48.34% significant at <0.05 level, likewise it also reduced sister chromatid exchanges from 14.86±1.44 down to 8.84±0.75 per cell, whereas the replication index got enhanced from 1.45 to 1.64.

Mutagenic activity and polycyclic aromatic hydrocarbon levels in urine of humans exposed to therapeutical coal tar.

The urinary mutagenicity and the excretion of polycyclic aromatic hydrocarbons (PAH) in three non-smoking male patients, treated for psoriasis with cutaneous applications of crude coal tar, were analysed. Mutagenicity of the urinary extracts was measured by the plate incorporation assay using Salmonella typhimurium strains TA 98 and TA 100 in the presence of liver S9 fraction from Aroclor-induced rats with or without beta-glucuronidase. After concentration, hydrolysis and reduction of the urine sample, PAH levels were measured by high resolution gas chromatography/mass spectrometry. Following cutaneous treatment with coal tar, the urine of all three subjects showed noticeable levels of PAH and/or metabolites and marked mutagenicity both on strain TA 98 and TA 100 in the presence of S9 fraction. The addition of beta-glucuronidase increased the mutagenicity of the urinary extracts, the maximum values being attained on strain TA 100 in the presence of both microsomal fraction and deconjugating enzymes. The mutagenicity of urinary extracts from subjects treated therapeutically with crude coal tar was correlated (r = 0.788, P less than 0.01) with the total PAH levels in their urine. The PAH excreted in urine were mainly low molecular weight compounds, while benzo[a]anthracene was present in scarce amounts and the excretion of benzo[a]pyrene did not increase following the cutaneous exposure to the crude coal tar.

Effect of glutathione and uridine-5′-diphosphoglucuronic acid on the mutagenicity of tryptophan pyrolysis products (Trp-P-1 and Trp-P-2) by rat-liver and -intestine S9 fraction

In the Ames test, after the addition of glutathione (GSH) or uridine-5′ diphosphoglucuronic acid (UD-PGA), we observed for Trp-P-1 an unchanged or a reduced mutagenicity by both the liver and intestine S9 fraction. For Trp-P-2, the same was true when we used the intestine S9 fraction. In the presence of liver S9 fraction, Trp-P-2 mutagenicity was also decreased by the addition of UDPGA but was increased by the addition of GSH. These results show that cofactors for glucuronide and GSH conjugation may alter the metabolic activation of Trp-P-1 and Trp-P-2 and consequently their mutagenicity.

Absence ofin vitrogenotoxicity of pyrvinium pamoate in sister‐chromatid exchange, chromosome aberration, and HGPRT‐locus mutation bioassays

A single preparation of U.S.P. pyrvinium pamoate that exhibited promutagen activity in Salmonella/mammalian microsome reverse mutation assays was subjected to in vitro mammalian cell bioassays. Cytotoxicity limiting doses of dimethyl sulfoxide-solubilized drug were without effect in the absence and/or presence of liver S9 fraction from Aroclor-1254-induced rats in an in vitro Chinese hamster ovary (CHO) cell assay for chromosome aberration and sister-chromatid exchange induction at concentrations of 0.025-0.78 microgram/ml. Forward gene mutation at the hypoxanthine-guanine phosphoribosyl-transferase (HGPRT) locus in Chinese hamster (V-79) cells was studied with and without exogenous metabolic activation at concentrations ranging from 0.3 to 10 micrograms/ml. In concurrent promutagen controls, dimethylnitrosamine, benzo[a]pyrene, and cyclophosphamide caused significant (p less than 0.05) increases over controls in each respective assay endpoint under the metabolic activations used. These results suggest that intrinsic mutagenic activity manifested in lower microbial systems does not have a corresponding effect in mammalian cells. Coupled with the lack of solubility and poor absorption in vivo, we concluded that the drug, when used In the single oral dose mode of administration, possesses a negligible somatic and germinal genotoxicity risk.