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Nov 2024 DOI 10.14302/issn.2690-4829.jen-24-5291
Wang XiaotangCorresponding author
The perpendicular orientation of the proximal alpha helix to the heme plane in chloroperoxidase (CPO) maximizes the influence of its intrinsic helix dipole that has been shown to reduce the “push-effect”, thereby increasing the heme redox potential and fine-tuning the catalytic capabilities of CPO. We investigated the effects of a disruption of the hydrogen bonding network between R26-N37 and A27-N33, formed by the proximal alpha helix, on the CPO structural stability and catalytic profile using site-directed mutagenesis and spectroscopy. The mutant CPO (R26A, N33A, and R26A/N33A) exhibited significant tertiary structural changes and distinct heme coordination, likely, due to destabilization of the proximal helix as a result of the disruption of the proximal hydrogen bonding network. In line with these observations, biochemical characterizations showed that all mutants displayed dramatically different activity profiles relative to that of the WT CPO. Mutant epoxidation and peroxidation activities were markedly enhanced, especially in the R26A/N33A CPO mutant. Moreover, all mutant CPO enzymes exhibited broader pH profiles in both epoxidation and peroxidation activities, including a shift in the optimal peroxidation activity towards pH 3.5 as opposed to pH 2.75. Conversely, the dismutation activity (pH 3.0-5.5) was almost completely lost while chlorination activity (pH 2.75-5.0) was virtually non-existent in all CPO mutants. Our results demonstrate the important role the R26-N37 and A27-N33 hydrogen bond pairs play in the heme coordination and tertiary structure of CPO defining its catalytic capabilities, and also suggest the importance of the proximal helix stability and orientation.
Jul 2021 DOI 10.14302/issn.2577-2279.ijha-21-3869
Jain JuliCorresponding author
Neuroscience Research Lab, Department of Zoology, School of Biological Sciences, Dr. Harisingh Gour Vishwavidyalaya (A Central University), Sagar – 470003 (MP), India.
Rotenone is well known environmental neurotoxin used to induce Parkinson’s disease (PD) model. Numerous studies are investigated its toxicity on the brain but few studies are available that examined its toxicity on the liver and kidney. Therefore, the main aim of the present work was to explore the toxicity of rotenone on the liver and kidney and its protection through quercetin. Administration of rotenone orally at the dose of (5mg/kg b.w daily for 60 days) caused a significant increase in the levels of liver function and renal function biomarkers as compared to controls. A significant increase in the level of lipid peroxidation, nitric oxide, and decrease in the levels of reduced glutathione, reduction in the activities of catalase and superoxide dismutase were observed in the liver and kidney as compared to control. The histopathological and SEM study in rotenone-treated mice showed alteration and signs of inflammation in the liver and kidney. While co-treatment of quercetin orally (30 mg/kg b.w for 60 days) together with rotenone, reversed the above parameters. In conclusion, rotenone significantly damages the liver and kidney, and the administration of quercetin along with rotenone shown a protective role. This study provides a new insight into where rotenone-induced liver and kidney dysfunction could be successfully protected by quercetin.
Mar 2021 DOI 10.14302/issn.2471-2140.jaa-21-3747
Jana SnehasisCorresponding author
Trivedi Science Research Laboratory Pvt. Ltd., Thane (W), Maharashtra, India.
A proprietary formulation was designed that consisted minerals (zinc, magnesium, iron, calcium, selenium, and copper), vitamins (pyridoxine HCl, cyanocobalamin, ascorbic acid, and cholecalciferol), Panax ginseng extract, and cannabidiol isolate. The study was aimed to assess the potential of the novel test formulation (blessed) and per se to the animals with the Trivedi Effect® in male Sprague Dawley (SD) rats, fed with vitamin D3 deficiency diet (VDD). The test formulation consisted above mentioned ingredients was divided into two parts. One part was left aside as the untreated test formulation without any Biofield Treatment, while the other part was defined as the Biofield Energy Treated sample, which received the Biofield Treatment by renowned Biofield Energy Healer, Mr. Mahendra Kumar Trivedi. The level of lipid peroxidation end product malondialdehyde (MDA) in liver tissues was significantly reduced by 34.59%, 34.91%, and 65.81% (p≤0.001) in test formulation treated with Biofield Energy (G5), Biofield Treated test formulation from day -15 (G7), Biofield Treatment per se with Biofield Treated test formulation from day -15 (G8) groups, respectively as compared to the disease control group (G2). Moreover, level of catalase enzyme in liver tissues was also increased by 8.64% in the G7 group as compared to the G2 group. Besides, in brain homogenate the level of glutathione peroxidase (GPx) was significantly increased by 433.94%, 266.97%, 133.94%, 467.89%, and 489.86% in the G5, Biofield Energy Treatment per se to animals from day -15 (G6), G7, G8, and Biofield Treatment per se animals plus untreated test formulation (G9) groups, respectively than G2. Antioxidant enzyme like superoxide dismutase (SOD) was significantly (p≤0.001) increased by 14.16% in the G9 group as compared to the G2 group. Allover, results signified that the Biofield Treated test formulation significantly increased antioxidative parameters, could be able to give support against oxidative stress induced by free radical and to maintain a good human health.
Feb 2021 DOI 10.14302/issn.2471-2140.jaa-21-3704
Jana SnehasisCorresponding author
Trivedi Science Research Laboratory Pvt. Ltd., Thane (W), Maharashtra, India.
The aim of the study was to evaluate the antioxidant potential of Biofield Energy Healing (the Trivedi Effect®) based test formulation using TNBS-induced colitis animal model. Each ingredient of the test formulation was divided into two parts. One part was denoted as the control without any Biofield Energy Treatment, while the other part was treated with Biofield Energy Treatment by Mr. Mahendra Kumar Trivedi and defined as the Biofield Energy Treated test formulation. The colon tissue was used for the estimation of anti-oxidation activity for catalase (CAT), glutathione (GSH), lipid peroxidation (LPO) product, myeloperoxidase (MPO), superoxide dismutase (SOD), and glutathione peroxidase (GPx) using standard procedure. The antioxidant results showed that the CAT level was significantly increased by 95.4% (p≤0.001), 72.3%, 47.6%, and 13.9% in the Biofield Energy Treated test formulation (G5), Biofield treatment per se to animals (-15 days)(G6), Biofield Energy Treatment per se to animals plus Biofield Energy Treated test formulation (-15 day) (G8), and Biofield Energy Treatment per se to animals plus untreated test formulation (G9) groups, respectively as compared to the untreated test formulation group (G4). Further, colon GSH activity was found to be significantly increased by 23.2% (p≤0.05) 15.4%, and 15.5%, in G5, G6, and G9 groups, respectively with respect to G2 group. In addition, colon LPO activity data suggested that it was decreased by 12%, 17%, 18%, and 19.1% in G5, G6, Biofield Energy Treated test formulation (-15 day) (G7), and G8 groups, respectively, as compared with the G2 group. The level of MPO showed a significant (p≤0.001) reduced level by 27.9%, 22%, 14.5%, 16.6%, and 25.3% in G5, G6, G7, G8, and G9 groups, respectively as compared with the G2 group. The level of colon SOD was increased by 16.7% and 14.2% in the G5 and G9 groups, respectively as compared with the untreated test formulation, G4 group. Colon GPx level was increased by 177.6%, 71.4%, 71.4%, 161.2%, and 114.3% in G5, G6, G7, G8, and G9 groups, respectively as compared with the G2 group. Thus, it can be concluded that the Trivedi Effect®-Consciousness Energy Healing based test formulation and Biofield Energy per se has significant colon anti-oxidation profile, which can be used to improve many autoimmune and inflammatory diseases, stress management and prevention, and anti-aging by improving overall health.
Dec 2020 DOI 10.14302/issn.2835-513X.ijl-20-3247
Z A Soliman GhadaCorresponding author
Prof Biochem, NNI, Cairo, ARE
Hypercholesterolemia plays an important role in atherosclerosis and cardiovascular diseases (CVD) that represent one of the greatest worldwide medical problems nowadays. Recently, an increased attention/ interest for natural antioxidant/ hypercholesterolemia as WG/WGO is increasing. Wheat germ/ Wheat germ oil (WG/WGO) is an excellent source of essential and polyunsaturated fatty acids and vitamin E. It is one of the richest natural sources of tocopherol. This work aims to evaluate the effect of administration of wheat germ (WG) /wheat germ oil (WGO) for 6 weeks on serum lipid profile, lipid peroxidation (liver malondialdehyde) in hypercholesterolemic rats. One hundred and twenty maleSprague Dawelyrats weighing 180-192 gm were used in this study. They were randomly distributed into six groups (20 rats/ group) as follow: g1: normal control, G2: hypercholesterolemic rats; G3: Normal rats treated with WG; G4: hypercholesterolemic rats treated with WG; G5: Normal rats treated with WGO; G6: hypercholesterolemic rats treated with WGO for 6 weeks. Also WG was analysed for its nutritive value, while WGO was analysed for fatty acid profile, and studied for its physico-chemical properties. The results showed significant elevation of liver malondialdehyde (MDA) and serum lipid profile in untreated rats fed on hypercholesterolemic diet. Hypercholesterolemic rats treated with WG/WGO showed an improvement in the biochemical assay of their lipid profile compared with untreated hypercholesterolemic rats. WG/WGO may be able to protect against atherosclerosis and CVD. The administration of WG /WGO to diets of rats caused a marked reduction in TC, LDL-C, VLDL-C, TG and MDA. This improvement effect may be mediated via enhancement of the antioxidant defence system and other factors. However, further clinical studies on human beings are required to assess the efficacy and safety of the WG/WGO.
Jun 2020 DOI 10.14302/issn.2691-8862.jvat-20-3417
Teto GeorgesCorresponding author
Chantal BIYA International Reference Centre for research on HIV/AIDS prevention and management, Yaoundé, Cameroon
Background Decreased antioxidant ability is one of the worsening conditions in AIDS.We aimed to evaluate total antioxidant ability among others, and their variation in HIV infected patients following their CD4+T cells count and viral load, in a context of new ART scarcity in most LMICs. Material and Methods We conducted a cross sectional study on 167 individuals (76 controls, 33 treatments naïve and 58 HIV-1 infected patients on ART). We assessed their plasma total antioxidant ability (FRAP), malondialdehyde (MDA) and thiol (SH) groups using standard spectrophotometric methods, then we calculated lipid peroxidation index (LPI). Statistical analysis was performed using GraphPad Prism 6. Data were analyzed by two-tailed unpaired t-test for two groups’ comparison and ANOVA for more than two groups. Pearson correlation between CD4+T cells count, viral load and the above markers was determined; P ≤ 0.05 was considered statistically significant. Results The following controls/naïve/treated subjects’ values for FRAP(mM) (1.907±0.074/1.77±0.05/1.695±0.03); MDA(μΜ) (0.781±0.081/1.115±0.118/ 1.342±0.109); SH (μΜ) (2.747±0.130/1.582±0.197/1.498 ±0.140)and LPI (0.43±0.61/ 0.61±0.7/2.59±0.83) were all obtained with P ≤ 0.05. The FRAP increased only with 3TC+TDF+EFV and 3TC+ABC+NVP cART while MDA decrease significantly with the later(p=0.027). MDA and LPI significantly increased in heavily treated patients with p<0.0014 and p=0.0001 respectively. overall, the patients showed an increase of viral loads following a decrease of CD4+T cells (r= -0.803, p=0.016) but 3TC+TDF+EFV seem to better manage the both. The only significant correlation was established between SH groups and CD4+Tcells count (r=0.447; p=0.0006); Conclusion Our study showed that thiol groups may be protective againstCD4+Tcells count depletion and that the cART 3TC+TDF+EFV, 3TC+ABC+NVP may be helpful in fighting against free radical generation and particularly 3TC+TDF+EFV as controlling CD4+Tcells count and viral load in long term treated patients. The study particularly showed the implication of cART in increasing lipid peroxidation index following the treatment duration in heavily treated patients, which aggravated their conditions in an area where drug options are limited, calling for new drugs availability and personalized medicine.
Jan 2020 DOI 10.14302/issn.2690-4829.jen-19-3127
P.A.GhazaryanCorresponding author
Hematology center after prof. R.H.Yeolyan MH RA
The antioxidant and membrane resistant peculiarities of a new derivative (2-cyan-3,4,4-trymethil-2-buten-4-olyd - CTBO) of cyan containing unsaturated lactones have been studied in membranes of hepatocytes with Sarcoma-45 1. The results of our previous research 123 showed significant changes of phospholipid (PL) exchange in hepatocytes of microsomal membranes at experimental animals vaccinated with Sarcoma-45 tumor strain. It is manifested in significant changes of quantitative and qualitative contents of membrane phospholipids separate fractions, increase of cytotoxic lysophospholipids (LPCs), phosphatidylinositol (PI) and phosphatidic acid (PA) levels, significant decrease of phosphatitylcholines (PC) and sphingomyeline (SP) contents, statistically significant changes of PL/PL ratio, peroxidation ratio intensity, dramatic increase of phospholipase A2 (PLA2)activity, quantitative and qualitative changes of adenyl nucleotides, as well as disorders of adenosine triphosphatase (ATPase) system activity 34567.
Oct 2019 DOI 10.14302/issn.2574-450X.jom-19-2852
Radwan EHCorresponding author
Department of Zoology, Faculty of Science, Damanhour University, Egypt.
Obesity can be defined as a condition of abnormal or excess fat accumulation in adipose tissue, to the extent that health may be impaired. Fennel is one of the oldest spice plants which widely grows in arid and semi-arid and due to its economic importance and pharmaceutical industry usage. This plant has anti-inflammatory and analgesic effect and is effective in gastrointestinal disorder treatment. The aim of the present study was to evaluate the phytochemical characteristics and therapeutic properties of this medicinal plant. The current study demonstrates that the alteration induced by high fat diet causing changes in blood parameters. These changes are exhibited through a decrease in RBCs, Ht, Hb and platelet and these changes could be due to oxidative stress, which lead to lipid peroxidation in RBCs membranes, auto oxidation of hemoglobin. As regards the total WBCs, lymphocytes and monocytes showed marked decrease. While a distinct increase in the percentage of neutrophils and eosinophil. The present, demonstrates that rats treated with (fennel), (ator) and (fennel with ator) exposure provided significant protection to the altered hematological variables. The effect of the treatment with fennel and ator more effect than fennel only and ator only. The finding of this study indicates that the concentration of Malondialdehyde (MDA) and Myeloperoxidase (MPO) in liver homogenates of the fennel and ator group significant decrease than group (3) and group (4) and the obese group. There is a growing awareness that obesity is a prime risk factor for the development of dyslipidemia profile and that oxidative stress may play a role in various adverse effects of obesity.
Mar 2019 DOI 10.14302/issn.2379-7835.ijn-19-2677
Grootveld MartinCorresponding author
Leicester School of Pharmacy, De Montfort University, The Gateway, Leicester LE1 9BH, United Kingdom
Objectives: Sunflower oil (SFO) is regularly employed for cosmetic, emollient and food frying purposes, the latter representing its foremost use globally. Therefore, full investigations of the molecular composition and quality of SFO products are a major requirement. In this study high-field 1H NMR analysis was employed to explore the molecular composition and authenticities of East African virgin (EAV) SFO products, particularly their acylglycerol fatty acid contents, together with those of selected minor constituents. Results acquired were statistically compared to those obtained on commercially-available, EU-approved refined SFO products via NMR-linked multivariate chemometrics strategies. Methodology: High-field 1H NMR spectra of EAV and refined SFOs (n = 55 and 4 respectively) were acquired at an operating frequency of 400 MHz. Their triacylglycerol fatty acid, triacylglycerol hydrolysis product, and sterol and stanol contents were determined via intelligent frequency bucketing and electronic integration of selected resonances. Univariate analysis-of-variance, and multivariate ROC curve evaluations were conducted to determine the magnitude and statistical significance of analyte concentration differences between these two sample classifications. Further multivariate NMR-linked chemometrics analyses such as principal component, random forest and support vector machine classification analyses were also utilised for this purpose. Key Results: Multicomponent 1H NMR analysis demonstrated that EAV SFOs had significantly higher and lower contents of monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs), respectively, than those of refined SFOs. Furthermore, significantly higher concentrations of ‘health-friendly’, cholesterol-blocking sterols and stanols were also found in these virgin SFO products. Major Conclusions: 1H NMR analysis provides much valuable molecular information regarding the composition and virginal status of SFOs.The high [MUFA]:[PUFA] content ratio of unrefined EAV SFO products renders them more suitable and safer for commercial or domestic deep-frying episodes than refined SFOs (MUFAs are much more resistant to thermally-induced peroxidation than PUFAs). These products also potentially offer valuable health benefits in view of their high natural sterol and stanol contents.
Mar 2018 DOI 10.14302/issn.2575-1212.jvhc-18-2013
A Halawa AmalCorresponding author
Department of Forensic Medicine and Toxicology, Faulty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
Lipopolysaccharide (LPS) is a component of the outer membrane of gram negative bacteria. LPS challenging allows switching transcription of proinflammatory cytokines on via over stimulation of Toll-like receptors (TLRs) signaling pathway with subsequent pathogenic inflammatory response. We investigated the possible reproductive toxicity of LPS in male Wister albino rats. Oxidative stress markers, antioxidant status and caspase-3 activity were analyzed in testicular tissues of rats exposed to either saline or LPS (4 mg/kg BW, ip; 0.18 of the LD50). The samples were collected at 6 h and 72 h after injection of LPS. A significant reduction in testicular reduced glutathione (GSH), glutathione-S-transferase (GST) and superoxide dismutase (SOD) was observed at 72 h compared to control group. Total antioxidant capacity was decreased at 6 h with additional significant reduction at 72 h. Catalase activity was reduced significantly at both 6 and 72 h. Malondialdehyde (MDA) was increased (P ≤ 0.05) in LPS injected rats without variation between 6 and 72 h. A significant increase in nitric oxide (NO) was observed at 72 h after injection. A time-dependent increase in LPS-treated groups was observed in the concentration of caspase-3.Histopathological analysis revealed degenerative changes and necrosis of seminiferous tubules after 6 h with further accumulation of eosinophilic edematous transudate in its lumen after 72 h. In conclusion, by increasing time of exposure, LPS induced lipid peroxidation, oxidative stress, reduced testicular antioxidant capacity and encouraged testicular apoptosis which could be possible mechanisms for impairment of testicular function.
Dec 2017 DOI 10.14302/issn.2641-7669.ject-17-1789
M.E.Abdel-Salam OmarCorresponding author
Departments of Toxicology and Narcotics
We aimed to study the effect of buspirone, an anxiolytic drug and 5-HT1A agonist on liver injury induced by carbon tetrachloride (CCl4) in rats. Rats were orally treated with CCl4 (2.8 mL/kg in olive oil) along with buspirone at 10, 20 or 30 mg/kg once daily starting with CCl4 and for one week thereafter. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) as well as alkaline phosphatase (ALP) activities were determined in the serum. Markers of oxidative stress: lipid peroxidation (malondialdehyde; MDA), reduced glutathione (GSH), nitric oxide (nitrite/nitrate) levels were measured in the liver. Moreover, paraoxonase 1 activity was determined in the liver and serum. The administration of CCl4 led to significant increases in serum ALT, AST, and ALP activities. Results showed that there were significantly increased hepatic MDA, nitrite and decreased GSH levels. PON1 activity decreased both in the liver and serum, respectively. The immunohistochemical investigations using anti-caspase-3 antibody revealed that CCl4 caused apoptosis to many hepatocytes. DNA studies showed that CCl4 caused hypoploidy in hepatocytes. Rats treated with 20-30 mg/kg buspirone showed significant decrease in serum ALT and AST by 19.5-34.3% and 24.2-31.4%, respectively. Serum ALP decreased by 21.7% after 30 mg/kg buspirone. In the liver, the higher dose of the drug resulted in decreased MDA (by 15.8%), decreased nitric oxide (17.4%) and increased GSH (by 20.1%). Significantly increased serum PON1 activity by 43.9-53.5% was observed after treatment with 20-30 mg/kg buspirone. On histopathologic examination of liver sections, there was mild protective effect for the drug at 30 mg/kg. Sections stained with anti- caspase- 3 confirmed the results obtained from histopathological examination. Moreover, buspirone given at 30 mg/kg resulted in an increase in % of cells containing normal values of DNA. These results indicate that buspirone decreases liver oxidative stress and exerts protective effect against CCl4- toxicity. The study thus indicates more beneficial effects of buspirone as an anxiolytic drug and that the drug could be used safely in patients with liver disease.
Oct 2017 DOI 10.14302/issn.2576-6694.jbbs-17-1742
A.Sakr SaberCorresponding author
Department of Zoology, Faculty of Science, Menoufia University, Shebin El-kom, Egypt.
Introduction: Cyclophosphamide (CPA) is an anticancer drug .Fennel (Foeniculum vulgare Mill) essential oil is a traditional medicine used against many diseases. Aim. The present work studied the effect of fennel oil against testicular damage and oxidative stress induced by the anticancer drug, cyclophosphamide (CPA) in albino rats. Methods. Animals were divided into 4 groups: group1, control, group2, orally given fennel oil, group3 treated with CPA and group4 treated with CPA and fennel oil. The testes were removed for histological and immune histochemical preparation. Blood was collected and sera were prepared for hormonal and biochemical analysis. Results. The results revealed that CPA caused histological alterations in the testis including decrease in diameter and germinal epithelial height of the seminiferous tubules, degeneration of germ cells, cytoplasmic vacuolation and congestion of blood vessels. Cell proliferation marker was decreased and apoptotic marker caspase-3 was decreased. Biochemical results revealed decrease in the hormones LH and testosterone. Moreover, the serum activity of the antioxidant enzymes, SOD, CAT was decreased and the lipid peroxidation marker, DMA was increased. Treating rats with CPA and fennel oil caused an improvement in the histological structure of the testis. There was an increase in LH ,testosterone,SOD and CAT, while MDA level decreased. Conclusion. It is concluded that administration of fennel oil exhibited protective effects against CPA-induced reproductive toxicity in male rats. The protective effect of fennel oil might be due to induction of antioxidant defense systems by one or more of its constituents.
Aug 2017 DOI 10.14302/issn.2471-2140.jaa-17-1541
Yu ZhiCorresponding author
College of Horticulture and Forestry Science, Huazhong Agricultural University, Key Laboratory of Horticultural Plant Biology, Ministry of Education, No. 1 Shizishan Street, Hongshan District, Wuhan City, Hubei Province, China 430070
In the present study, we investigated the chemical compositions, in vitro antioxidant and in vivo hepatoprotective activities of two tea polysaccharides (TPS), which were extracted from two different tea cultivars, Yingshuang (Camellia Senesis, T01) and Yunnan Dayezhong (Camellia Senesis, T09). Compared with T09-TPS, T01-TPS had lower contents of neutral sugar, protein, uronic acid and polyphenol. However, T01-TPS showed stronger scavenging abilities for transient free radicals of hydroxyl radical and superoxide anion radicals and lipid peroxidation inhibition effect, but weaker scavenging ability for stable free radical of DPPH. For hepatoprotective activity in vivo, the results demonstrated that both T01-TPS and T09-TPS could significantly prevent the increase of serum alanine aminotransferase and, aspartate aminotransferase levels, decrease the liver index, reduce the formation of malonydialdehyde and enhance the activities of superoxide dismutase, glutathione peroxidase and peroxidase in carbon tetrachloride-induced liver injury mice. These results suggest that T01-TPS and T09-TPS have potent antioxidant and hepatoprotective activities.
Jul 2017 DOI 10.14302/issn.2639-1716.jn-17-1495
J Gonzalez MichaelCorresponding author
University of Puerto Rico Medical Sciences Campus, Schools of Public Health and Pharmacy, San Juan PR.
Diets high in unsaturated fatty acids, especially those containing high levels of linoleic acid, e.g., corn oil, enhance mammary gland tumorigenesis in experimental animals. In contrast, diets high in long-chain polyunsaturated fatty acids such as eicosapentaenoic (EPA) and docosahexaenoic (DHA), e.g. menhaden oil, appear to have a suppressive effect on this tumorigenic process. Many mechanisms have been proposed to explain the tumor inhibitory action exerted by menhaden oil and other fish oils, e.g., differences in prostaglandin metabolism, energy efficiency, alterations of the immune system, changes in lipid peroxidation, etc. Fundamental to a mechanistic understanding of this phenomenon, however, is an understanding as to whether or not the tumor inhibitory activities of dietary fish oil is mediated via an inhibition of tumor cell proliferation or mediated via an enhancement of tumor cell loss. Whether the amount of dietary fat or the type of fat effects mammary tumorigenic processes, via an effect on tumor cell proliferation or tumor cell loss, has not been clearly established. In the studies described in this communication, three methods were utilized to study tumor cell proliferation, i.e., H3-thymidine autoradiographic analysis, 5-bromo 2'-deoxyuridine (Brdu) flow cytometric analysis, and proliferative cell nuclear antigen (PCNA) flow cytometric analysis. Two methods were used to study tumor cell loss, i.e., a determination of the I125Urd tumor emission rate and a determination of a cell loss factor from the formulas of Steel and Begg. The tumor examined was the human breast carcinoma cell line MDA- MB231 maintained in athymic nude mouse. No significant difference in cell proliferation between carcinomas of mice fed a high corn oil diet (20% w/w) and a diet high in fish oil (19% menhaden oil, 1% corn oil). In contrast, a significant (p<0.05) increase in the rate of I125Urd emission rate and cell loss factor from the carcinomas in the fish oil fed mice compared to the corn oil fed mice was observed. In summary, the decreased tumor volume in the human breast carcinomas maintained in athymic nude mice fed a fish oil diet as compared to those fed a corn oil diet, appears to be due, at least in part, to an increased rate of carcinoma cell loss rather than a decreased rate of carcinoma cell proliferation.