Enhanced production of glutaminase-free L-asparaginase by marine Bacillus velezensis and cytotoxic activity against breast cancer cell lines

Background: The increasing rate of breast cancer globally requires extraordinary efforts to discover new effective sources of chemotherapy with fewer side effects. Glutaminase-free L-asparaginase is a vital chemotherapeutic agent for various tumor malignancies. Microorganisms from extreme sources, such as marine bacteria, might have high L-asparaginase productivity and efficiency with exceptional antitumor action toward breast cancer cell lines. Results: L-Asparaginase-producing bacteria, Bacillus velezensis isolated from marine sediments, were identified by 16S rRNA sequencing. L-Asparaginase production by immobilized cells was 61.04% higher than that by free cells fermentation. The significant productivity of enzyme occurred at 72 h, pH 6.5, 37°C, 100 rpm. Optimum carbon and nitrogen sources for enzyme production were glucose and NH4Cl, respectively. L-Asparaginase was free from glutaminase activity, which was crucial medically in terms of their severe side effects. The molecular weight of the purified enzyme is 39.7 KDa by SDS-PAGE analysis and was ideally active at pH 7.5 and 37°C. Notwithstanding, the highest stability of the enzyme was found at pH 8.5 and 70°C for 1 h. The enzyme kinetic parameters displayed Vmax at 41.49 µmol/mL/min and a Km of 3.6 × 10−5 M, which serve as a proof of the affinity to its substrate. The anticancer activity of the enzyme against breast adenocarcinoma cell lines demonstrated significant activity toward MDA-MB-231 cells when compared with MCF-7 cells with IC50 values of 12.6 ± 1.2 µg/mL and 17.3 ± 2.8 µg/mL, respectively. Conclusion: This study provides the first potential of glutaminase-free L-asparaginase production from the marine bacterium Bacillus velezensis as a prospect anticancer pharmaceutical agent for two different breast cancer cell lines.

Effects of antioxidants [antox] on the liver of adult male albino rat exposed to herbicides [paraquat]

Paraquat [PQ] is widely used as a herbicide. Although it is very toxic for humans and animals, it is still used in about 130 countries of the world to control harmful weeds in growing corn, fruit trees and vegetables. The aim of the present study was to elucidate histological changes of the possible protective role of antioxidant [Antox] on the adult male albino rat liver when given with the PQ. 21 male adult albino rats were used and were classified into three groups; Control group [G1], PQ given group [G2] and Antox with PQ-given group [G3]. Paraffin sections of liver parenchyma were prepared and stained with H and E. Others were prepared for electron microscope examination. The histological examination of the liver of PQ-given rats eith H and E revealed remarkable changes versus control animals. The liver parenchyma showed marked congestion with dilated blood sinusoid and congested central vein. Hepatocytes showed contracted, pyknotic nuclei and vacuolated cytoplasm. There was markedly congested central vein invaded with inflammatory cells indicationg that there was severe hepatocyte necrosis. The histological examination of the livers of G3 given animals revealed that antox ameliorated the PQ induced liver injuries and improved the histological liver appearance. The electron microscopic examination of sections of G2 livers showed that the degenerated hepatocytes. The cytoplasm of the hepatocytes contained dilated rough endoplasmic reticulum cisternae, bizarre-shaped mitochondaria, and lysosomes. Nuclei of degenerating hepatocytes were irregular or small shrunken and the parenchyma was infiltrated with a neutrophil with an indented nucleus. The electron microscopic examinations of sections of the livers of G3 showed apparently normal hepatocytes. There were some hepatocytes having euchromatic euchromatic nuclei. Other hepatocytes were having dark elongated nuclei. The cytoplasm contained a variable shaped mitochondria, rough endoplasmic reticulum, lysosomes, a few lipid droplets and the cells canalicular border were facing relatively dilated bile canaliculi. The parenchyma was infiltrated with a neutrophil having fine granules. The present study demonstrated the effectiveness of the combination antioxidants [Antox] in reducing the paraquat-related degenerative histological changes in the liver parenchyma. It also demonstrated that the antox plays major role in ameliorating these delirious changes. It is recommended to investigate the other possible factors which may be involved in the PQ- associated liver damage [e.g. heavy metals]

light microscopic study on the effects of the eletromagnetic waves arising from the mobile phone onthe rat cerebellum

This work was performed to study the effects of the electromagnetic waves emitted from the mobile phone on the cerebellum cortex of adult albino rats. A total number of 48 rats was used in this study. The animals were divided into three groups [control, sham-exposed and exposed]. Mobile phones were switched on for 20 minutes daily for two months. The animals of each group were sacrificed at the end of the experiment. Intra-cardiac perfusion with a fixative was performed. The cerebellum of each animal was extracted and processed for examination. For examination by light microscope, gallocyanine stain, toluidine blue stain and Golgi impregnation technique were used. Gallocyanine stain was performed for the evaluation of the layering pattern and cellular constituents of each layer. Toluidine blue stain was used for the examination of semithin sections. Golgi impregnation technique was limited for evaluating the cerebellar granular and Golgi neurons. In the control group, there was a complete and mature layering pattern of the cerebellar cortex. The cerebellar cortex consists of an outer molecular layer, middle Purkinje cell layer and an inner granular cell layer. There were no observable changes in either the layering pattern or the cell constituents in all layers of the cerebellar cortex in the sham-exposed group. In the exposed group, there were no observable changes in the layering pattern of the cerebellar cortex. However, there were darkly stained neurons and empty spaces in the granular cell layer denoting a suggested neuronal loss