Gallotannin and Annonamuricata extract inhibit polyphenol oxidase activity and mitigate browning in Malusdomestica

Background: The prevention of browning in fruits remains a great concern in the food industry.Objective: In the present study, we evaluated the anti-browning potentials of gallotannin and Annona muricata extract in red apple (Malus domestica).Materials and Methods: Apple slices were made and dipped in the different solutions; distilled water (control), 1 % gallotannin, 1 % Annona muricataextract or 1 % ascorbic acid. The treated apple slices were stored at 4 oC for 0, 7 and 14 days and used for the determination of the browning index, polyphenolic content, total protein, polyphenol oxidase and peroxidase activities. Results: The treatment with gallotannin, A. muricata and ascorbic acid reduced browning of apple for storage days 7 and 14. However, only gallotannin treatment preserved the polyphenolic content of the apple slices when compared to the control as well as the other treatment groups. Furthermore, all treatments reduced the activity of the polyphenol oxidase for days 0 and 7 storage, relative to the control. In contrast, the treatments had no effect on the peroxidase activity when compared to the control.Conclusion: Data support the anti-browning potential of gallotannin, A. muricata and ascorbic acid. Further, anti-browning potential of these naturally derived materials may be linked with their inhibitory actions against polyphenol oxidase

POLLUTANTS IN WASTEWATER EFFLUENTS: IMPACTS AND REMEDIATION PROCESSES

Due to extensive industrialization and increase in population density and urbanized societies, the world is faced with problems related to the management of wastewater. On a daily basis, the effluents generated from domestic and industrial activities constitute a main cause of pollution of receiving water bodies, which is a great burden on water quality management. Some of these pollutants are pathogenic microorganisms, phosphorus and nitrogen, hydrocarbons, heavy metals, endocrine disruptors and organic matter. The majority of water related infections, such as cholera, typhoid fever, diarrheoa and others are caused by the presence of pathogenic microorganisms in water. The diseases caused by bacteria, viruses and protozoa are the most common health hazards associated with untreated waters. The main sources of these microbial contaminants in wastewater are human and animal wastes Also, the presence of these phosphorus and nitrogen in excess amounts could lead to the eutrophication of water sources, which may also create environmental conditions that favour the growth of toxin-producing cyanobacteria. Chronic exposure to some of such toxins produced by these organisms can cause a host of other diseases. In addition, the danger of nonbiodegradable and recalcitrant pollutants in water is their ability to persist in natural ecosystems for an extended period and have their ability to accumulate in successive levels of the biological food chain. As a result of these negative effects, a number of processes are in place for the treatment of wastewater effluents before discharge into receiving water bodies. This review was therefore aimed at providing an insight into the major pollutants in wastewater effluents and the various treatment processes

Cellular apoptosis of HFF cells by inorganic nanoparticles not susceptible to modulation by Toxoplasma gondii infection in vitro

The interaction of nanoparticles with living cells is becoming one of the urgent areas of collaborative research in materials science and biology. Previously, we showed that nanoparticles have promising anti-Toxoplasma gondii properties. Meanwhile, Toxoplasma gondii has been shown to avert apoptosis in host cells whereas nanoparticles have been implicated for apoptotic tendency. Therefore, in the present study, we assessed the in vitro apoptotic properties of inorganic nanoparticles in the absence or presence of Toxoplasma infection and/or small molecules used as metabolic modulators. Results showed that inorganic nanoparticles dose-dependently caused cellular apoptosis. However, in the presence of infection by Toxoplasma gondii, nanoparticles-induced cellular apoptosis was not mitigated. Likewise, use of several small molecules (anti-metabolites) as metabolic modulators either mildly or nearly failed to abate cellular apoptosis by nanoparticles. Taken together, our findings do not only confirm the apoptotic potential of inorganic nanoparticles but show evidence that cellular apoptosis by inorganic nanoparticles of gold and silver might not be susceptible to modulation by Toxoplasma gondii infection. The findings are new and contribute to deepen our understanding of the cellular interaction of nanoparticle

Modulation of rat plasma kynurenine level by platinum nanoparticles and likely association with oxidative stres

In this study, we investigated whether oxidative stress contributes to activation of kynurenine pathway by platinum nanoparticles (PtNPs). Thirty male Wistar rats with an average weight between 126 – 130 g were randomly assigned into six groups. The negative control group was orally administered distilled water while the other treatment groups respectively received oral administration of either PtNPs (25 and 50 mg/kg bw) singly or in combination with ascorbic acid (100 mg/kg bw). Results revealed that oral administration of PtNPs did not cause lipid peroxidation in rat brain and plasma relative to negative control. In contrast, PtNPs elevated protein carbonyl levels in rat plasma relative to negative control. In the meantime, the level of reduced glutathione (GSH) in rat tissues was maintained when compared with negative control and PtNPs alone. However, plasma GSH was significantly (p<0.05) increased by PtNPs at both doses used and co-treatment with ascorbic acid. Oral exposure to PtNPs and ascorbic acid elevated kynurenine level in rat plasma. Taken together, data indicated that PtNPs given alone at the doses investigated might not have caused oxidative stress in rat tissues and plasma but co-treatment with ascorbic acid appeared to potentiate capacity to elevate oxidative stress markers. Further, elevation of kynurenine level in rat plasma by PtNPs might be connected with oxidative stress since PtNPs did elevate protein carbonyl level and co-treatment with ascorbic acid modulated the kynurenine level

Gallotannin and Annonamuricata extract inhibit polyphenol oxidase activity and mitigate browning in Malusdomestica

Background: The prevention of browning in fruits remains a great concern in the food industry.Objective: In the present study, we evaluated the anti-browning potentials of gallotannin and Annona muricata extract in red apple (Malus domestica).Materials and Methods: Apple slices were made and dipped in the different solutions; distilled water (control), 1 % gallotannin, 1 % Annona muricataextract or 1 % ascorbic acid. The treated apple slices were stored at 4 oC for 0, 7 and 14 days and used for the determination of the browning index, polyphenolic content, total protein, polyphenol oxidase and peroxidase activities. Results: The treatment with gallotannin, A. muricata and ascorbic acid reduced browning of apple for storage days 7 and 14. However, only gallotannin treatment preserved the polyphenolic content of the apple slices when compared to the control as well as the other treatment groups. Furthermore, all treatments reduced the activity of the polyphenol oxidase for days 0 and 7 storage, relative to the control. In contrast, the treatments had no effect on the peroxidase activity when compared to the control.Conclusion: Data support the anti-browning potential of gallotannin, A. muricata and ascorbic acid. Further, anti-browning potential of these naturally derived materials may be linked with their inhibitory actions against polyphenol oxidase

The oral administration of silver nanoparticles activates the kynurenine pathway in rat brain independently of oxidative stress

In this work, we determined whether oxidative stress contributed to the activation of the kynurenine pathway by AgNPs. Male Wistar rats weighing between 130 and 146 g were randomly assigned into six groups. Animals in the negative control group were orally administered distilled water while, the other treatment groups were respectively given AgNPs (25 and 50 mg/kg bw) alone or in combination with Trolox (100 mg/kg bw). Results showed that treatments with AgNPs signi fi cantly raised protein carbonyl level in rat liver, but the co-treatment with Trolox attenuated the elevation. Conversely, AgNPs raised the level of reduced glutathione (GSH) in rat plasma and tissues compared to the negative control. Further, oral exposure to AgNPs (50 mg/kg bw) sig- ni fi cantly elevated rat plasma and brain kynurenine levels compared to the negative control. Meantime, the co- treatment with Trolox appreciably restored kynurenine level in rat plasma, but not in the rat brain. Taken together, findings indicate that the oral administration of AgNPs alone at the doses used in this study, might not have caused oxidative stress. However, the co-treatment with Trolox appears to potentiate oxidative stress in rats following exposure to AgNPs. Furthermore, data support that the activation of the kynurenine pathway in the rat brain by AgNPs might be independent of oxidative stress. The fi ndings are new and contribute to deepen our understanding of the cellular interaction by nanoparticle

In Vitro Screening to Identify Anti-Toxoplasma Compounds and In Silico Modeling for Bioactivities and Toxicity

Toxoplasmosis, which affects more than a billion people worldwide, is a common parasitic infection caused by the obligate intracellular parasite, Toxoplasma gondii. Current treatment strategies have several limitations, including unwanted side effects and poor efficacy. Therefore, newer therapies are needed for toxoplasmosis. Drug repurposing and screening of a vast array of natural and/or synthetic compounds is a viable option for antiparasitic drug discovery. In this study, we screened 62 compounds comprising natural products (NPs†) and FDA-approved (FDA) drugs, to identify the hit compounds that suppress the growth of T. gondii. To determine the parasite inhibitory potential of the compounds, host mammalian cells were infected with a transgenic T. gondii strain, and the viability of the parasite was evaluated by luminescence. Of the 62 compounds, tubericidin, sulfuretin, peruvoside, resveratrol, narasin and diacetoxyscirpenol of the natural product isolates, as well as bortezonib, 10-Hydroxycamtothecin, mebendazole, niflumic acid, clindamycin HCl, mecamylamine, chloroquine, mitomycin C, fenbendazole, daunorubicin, atropine, and cerivastatin of FDA molecules were identified as “hits” with ≥ 40 percent anti-parasite action. Additionally, mitomycin C, radicicol, naringenin, gitoxigenin, menadione, botulin, genistin, homobutein, and gelsemin HCl of the natural product isolates, as well as lomofungin, cyclocytidine, prazosin HCl, cerivastatin, camptothecin, flufenamic acid, atropine, daunorubicin, and fenbendazole of the FDA compounds exhibited cytotoxic activity, reducing the host viability by ≥ 30 percent. Our findings not only support the prospects of drug repurposing, but also indicate that screening a vast array of molecules may provide viable sources of alternative therapies for parasitic infection

Cypermethrin and chlorpyrifos raises serum urea level and causes abnormal sperm morphology in Wistar rats

Chlorpyrifos (organophosphate) and cypermethrin (pyrethroid) are insecticides, which are widely used for agricultural as well as for domestic purposes. This study investigated the toxicological effect of chlorpyrifos and cypermethrin on selected organs and tissues of male Wistar rats. Nine (9) male Wistar rats were randomly grouped into three and were orally given chlorpyrifos or cypermethrin, while the control group was given distilled water for 28 days. The results revealed a significant increase (p<0.05) in rat serum AST activity for the chlorpyrifos and cypermethrin groups. Also, there was significant elevation in serum urea following oral exposure to either chlorpyrifos or cypermethrin. Conversely, a reduction in the rat liver ALP activity for treatment with cypermethrin or chlorpyrifos was recorded. Thehistology results revealed that the administration of chlorpyrifos but not cypermethrin for 28 days has no significant effecton the biochemical properties and sperm morphology of the rats. Taken together, findings indicate that cypermethrin and chlorpyrifos exposure in rats predisposes to renal injury, while altering sperm morpholog