99 research outputs found
Heme oxygenase-1 attenuates cadmium-induced mitochondrial-caspase 3- dependent apoptosis in human hepatoma cell line
Background: Cadmium (Cd) is a well known environmental and industrial toxicant causing damaging effects in numerous organs. In this study, we examined the role of heme oxygenase-1 (HO-1) in modulating the Cd-induced apoptosis in human hepatoma (HepG2) cells after 24 h exposure. Methods: HepG2 cells were exposed to 5 and 10 μM Cd as CdCl2 for 24 h while other sets of cells were pre-treated with either 10 μM Cobalt protoporphyrin (CoPPIX) or 10 μM Tin protoporphyrin (SnPPIX) for 24 h, or 50 μM Z-DEVD-FMK for 1 h before exposure to 5 and 10 μM CdCl2 for 24 h. Expressions of caspase 3, cytosolic cytochrome c, mitochondrial Bax and anti-apoptotic BCL-xl proteins were assessed by western blot. Intracellular reactive oxygen species (ROS) production was determined using the dihydrofluorescein diacetate (H2DFA) method. Cell viability was assessed by MTT assay, while a flow cytometry method was used to assess the level of apoptosis in the cell populations. Results: Our results show that there were a significant increase in the expression of cytosolic cytochrome c, mitochondrial Bax protein, and caspase 3 at 5 and 10 μM compared to the control, but these increases were attenuated by the presence of CoPPIX. The presence of SnPPIX significantly enhanced Cd-induced caspase 3 activities. CoPPIX significantly decreased the level of ROS production by 24.6 and 22.2 % in 5 and 10 μM CdCl2, respectively, but SnPPIX caused a significant increase in ROS production in the presence of CdCl2. HepG2 cell viability was also significantly impaired by 13.89 and 32.53 % in the presence of 5 and 10 μM CdCl2, respectively, but the presence of CoPPIX and Z-DEVD-FMK significantly enhanced cell survival, while SnPPIX enhanced Cd-impaired cell viability. The presence of CoPPIX and Z-DEVD-FMK also significantly decreased the population of apoptotic and necrotic cells compared with Cd. Conclusion: In summary, the present study showed that HO-1 attenuates the Cd-induced caspase 3 dependent pathway of apoptosis in HepG2 cells, probably by modulating Cd-induced oxidative stress
Factors affecting the performance of a manufacturing supply chain, and the organization
Abstract: Due to constant failure in delivering the products to customers on time the defence manufacturing organization introduced the supply chain phenomenon into its operations in an attempt to improve its performance (on-time delivery). This research aims to identify if supply chain performance is affected mainly by social or technical factors and also outline which of these factors have the highest effect on the performance of supply chain. The importance of this research is that it will determine if the performance of supply chain is affected by technical or social factors and also how the organization is affected by these factors. This research employed a case study and made use of both qualitative and quantitative data to allow for data triangulation in order to minimize biasness and increase the credibility of the results. The findings indicate that supply chain performance is affected by both social factors and technical factors, however the impact of these factors on both supply chain and the organization is different. In summary, this research will provide insight to the factors that affect the performance of supply chain and accordingly provide methods to minimize or eliminate these factors and therefore reducing their effect on supply chain and the organization
Rooibos (Aspalathus linearis) and its Major Flavonoids — Potential Against Oxidative Stress-Induced Conditions
Reactive species are products of normal cellular metabolism and may be deleterious or beneficial. At low/moderate concentrations, reactive species are involved in physiological roles including cell signalling, defense against infectious agents and mitogenic responses. However, unbalanced defense mechanism of antioxidants, overproduction of reactive species or incorporation of free radicals into the living system from the environment may result in oxidative stress, a deleterious process that can lead to damage of important cell structures, including lipids and membranes, proteins and nucleic acids. The role of oxidative stress as a contributing factor in the pathophysiology of various diseases is increasingly being recognized, and augmenting the oxidative defense capacity of the cell through the intake of antioxidants as a way of preventing free radical-mediated cellular injuries is becoming a popular strategy. Much attention is being focused on the health beneficial role of phenolic phytochemicals derived from plants. They are considered to play an important role as physiologically functional foods and for the prevention of clinical conditions related to oxidative stress, even though their modes of action may still not be fully understood. Rooibos (Aspalathus linearis) is a popular South African tisane enjoyed for its taste and aroma. Rooibos has been made in the Cederberg mountain region of South Africa for generations and has been used medicinally for alleviation of allergies, asthma, infantile colic and skin problems. The potential antioxidative, immune-modulating, chemopreventive and chemotherapeutic actions of rooibos have been reported in several studies. This review provides a comprehensive data on the current knowledge of the biological and chemotherapeutic activity of rooibos and its major flavonoids. Most recent in vitro and in vivo (animal and human) studies were conducted with special attention paid to clinical conditions in which oxidative stress has been implicated. The conclusion described directions for future rooibos research to establish its activity and utility as a human chemopreventive and therapeutic agent
Determinants of attitudes to carnivores : implications for mitigating human-carnivore conflict on South African farmland
Human–wildlife conflict is increasingly prevalent,
particularly in relation to carnivores in non-protected areas
of Africa. Quantifying the attitudes of land owners towards
carnivores and understanding the factors that influence these
attitudes are instrumental in conservation planning and
reducing persecution-related threats to carnivores.However,
information about attitudes to carnivores in Africa, and
South Africa in particular, is scarce. To obtain such data we
interviewed 170 commercial game and livestock farmers in
two ecologically important rural areas of northern South
Africa. Responses to statements about carnivore management,
stock protection and predationwere generally positive.
However, 62% of respondents believed carnivores to be
financially damaging and 35% thought them overly abundant.
Many respondents (41%) were unwilling to tolerate
even low levels of predation and considered persecution of
carnivores to be the cheapest form of stock protection (31%).
Attitudes were significantly more positive among respondents
who did not kill carnivores than among those who did.
Generalized linear regression coupled with informationtheoretic
analysis showed that attitudes to carnivores were
determined by a combination of cultural and land-use
attributes more than by economic factors such as stock
holdings or predation losses. The results elucidate potential
targets for mitigation activities and facilitate the development
of communication, education and extension activities
specifically designed to appeal to intended recipients and
address prevalent motives for persecuting carnivores.Endangered Wildlife Trust, Knowsley Safari Park, the Rufford Small Grants Foundation, the University of Brighton, and the Leverhulme Trust.http://journals.cambridge.org/action/displayJournal?jid=ORXhb201
Fumonisin-induced hepatocarcinogenesis: mechanisms related to cancer initiation and promotion.
We review the hepatocarcinogenic effects of fungal cultures of Fusarium verticillioides(= Fusarium moniliforme) strain MRC 826 in male BD IX rats. Subsequent chemical analyses of the fumonisin B (FB) mycotoxin content in the culture material used and long-term carcinogenesis studies with purified FB1 provide information about dose-response effects, relevance of hepatotoxicity during FB1-induced carcinogenesis, and the existence of a no-effect threshold. Fumonisin intake levels of between 0.08 and 0.16 mg FB/100 g body weight (bw)/day over approximately 2 years produce liver cancer in male BD IX rats. Exposure levels < 0.08 mg FB/100 g bw/day fail to induce cancer, although mild toxic and preneoplastic lesions are induced. The nutritional status of the diets used in the long-term experiments was marginally deficient in lipotropes and vitamins and could have played an important modulating role in fumonisin-induced hepatocarcinogenesis. Short-term studies in a cancer initiation/promotion model in rat liver provided important information about the possible mechanisms involved during the initial stages of cancer development by this apparently nongenotoxic mycotoxin. These studies supported the findings of long-term investigations indicating that a cytotoxic/proliferative response is required for cancer induction and that a no-effect threshold exists for cancer induction. The mechanisms proposed for cancer induction are highlighted and include the possible role of oxidative damage during initiation and the disruption of lipid metabolism, integrity of cellular membranes, and altered growth-regulatory responses as important events during promotion
Attitudes and tolerance of private landowners shape the African wild dog conservation landscape in the greater Kruger National Park
The survival of wildlife ultimately relies on its acceptability to humans. The African
wild dog Lycaon pictus is an endangered species that often comes into conflict with humans. Currently,
the only viable population in South Africa resides in the Kruger National Park (KNP). To
begin to understand the acceptability of wild dogs outside this important wild dog stronghold, we
interviewed private landowners (n = 186) along the KNP western and southern boundaries.
Respondents generally held positive attitudes towards wild dogs and had a good knowledge of
them. Attitudes were also more positive when the property was part of a conservancy, indicating
that the conservation landscape for wild dogs on private land outside the KNP is promising. However,
the impact of edge effects such as disease transmission should not be ignored in future
research, and creative solutions for mitigating these effects must be sought to ensure the future
conservation of wild dogs.Jaguar Land Rover South Africa,
Vaughan de la Harpe and his Climb for Kruger Wild Dogs
Expedition, Richard Bosman and GCCL2 Management Services,
and Rhodes University for the Henderson Prestigious
Masters Postgraduate Scholarship.http://www.int-res.com/journals/esr/esr-homeam2018Mammal Research InstituteZoology and Entomolog
Why humans kill animals and why we cannot avoid it
Killing animals has been a ubiquitous human behaviour throughout history, yet it is becoming increasingly controversial and criticised in some parts of contemporary human society. Here we review 10 primary reasons why humans kill animals, discuss the necessity (or not) of these forms of killing, and describe the global ecological context for human killing of animals. Humans historically and currently kill animals either directly or indirectly for the following reasons: (1) wild harvest or food acquisition, (2) human health and safety, (3) agriculture and aquaculture, (4) urbanisation and industrialisation, (5) invasive, overabundant or nuisance wildlife control, (6) threatened species conservation, (7) recreation, sport or entertainment, (8) mercy or compassion, (9) cultural and religious practice, and (10) research,education and testing. While the necessity of some forms of animal killing is debatable and further depends on individual values, we emphasise that several of these forms of animal killing are a necessary component of our inescapable involvement in a single, functioning, finite, global food web. We conclude that humans (and all other animals) cannot live in a way that does not require animal killing either directly or indirectly, but humans can modify some of these killing behaviours in ways that improve the welfare of animals while they are alive, or to reduce animal suffering whenever they must be killed. We encourage a constructive dialogue that (1) accepts and permits human participation in one enormous global food web dependent on animal killing and (2) focuses on animal welfare and environmental sustainability. Doing so will improve the lives of both wild and domestic animals to a greater extent than efforts to avoid, prohibit or vilify human animal-killing behaviour. Animal ethics Conservation biology Culling Factory farmingpublishedVersio
The prevalence, characteristics and effectiveness of Aichi Target 11's "other effective area‐based conservation measures" (OECMs) in key biodiversity areas
Aichi Target 11 of the CBD Strategic Plan for Biodiversity commits countries to the effective conservation of areas of importance for biodiversity, through protected areas and "other effective area-based conservation measures" (OECMs). However, the prevalence and characteristics of OECMs are poorly known, particularly in sites of importance for biodiversity. We assess the prevalence of potential OECMs in 740 terrestrial Key Biodiversity Areas (KBAs) outside known or mapped protected areas across ten countries. A majority of unprotected KBAs (76.5%) were at least partly covered by one or more potential OECMs. The conservation of ecosystem services or biodiversity was a stated management aim in 73% of these OECMs. Local or central government bodies managed the highest number of potential OECMs, followed by local and indigenous communities and private landowners. There was no difference between unprotected KBAs with or without OECMs in forest loss or in a number of state-pressure-response metrics
Why humans kill animals and why we cannot avoid it
Killing animals has been a ubiquitous human behaviour throughout history, yet it is becoming increasingly controversial and criticised in some parts of contemporary human society. Here we review 10 primary reasons why humans kill animals, discuss the necessity (or not) of these forms of killing, and describe the global ecological context for human killing of animals. Humans historically and currently kill animals either directly or indirectly for the following reasons: (1) wild harvest or food acquisition, (2) human health and safety, (3) agriculture and aquaculture, (4) urbanisation and industrialisation, (5) invasive, overabundant or nuisance wildlife control, (6) threatened species conservation, (7) recreation, sport or entertainment, (8) mercy or compassion, (9) cultural and religious practice, and (10) research,education and testing. While the necessity of some forms of animal killing is debatable and further depends on individual values, we emphasise that several of these forms of animal killing are a necessary component of our inescapable involvement in a single, functioning, finite, global food web. We conclude that humans (and all other animals) cannot live in a way that does not require animal killing either directly or indirectly, but humans can modify some of these killing behaviours in ways that improve the welfare of animals while they are alive, or to reduce animal suffering whenever they must be killed. We encourage a constructive dialogue that (1) accepts and permits human participation in one enormous global food web dependent on animal killing and (2) focuses on animal welfare and environmental sustainability. Doing so will improve the lives of both wild and domestic animals to a greater extent than efforts to avoid, prohibit or vilify human animal-killing behaviour. Animal ethics Conservation biology Culling Factory farmingpublishedVersio
Biosynthesis, Characterization, and Biological Activities of Procyanidin Capped Silver Nanoparticles
In this study, procyanidin dimers and Leucosidea sericea total extract (LSTE) were employed in the synthesis of silver nanoparticles (AgNPs) and characterized by ultraviolet-visible (UV-Visible) spectroscopy, high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), and dynamic light scattering (DLS) techniques. AgNPs of about 2-7 nm were obtained. DLS and stability evaluations confirmed that the AgNPs/procyanidins conjugates were stable. The formed nanoparticles exhibited good inhibitory activities against the two enzymes studied. The IC50 values against the amylase enzyme were 14.92 ± 1.0, 13.24 ± 0.2, and 19.13 ± 0.8 µg/mL for AgNPs coordinated with LSTE, F1, and F2, respectively. The corresponding values for the glucosidase enzyme were 21.48 ± 0.9, 18.76 ± 1.0, and 8.75 ± 0.7 µg/mL. The antioxidant activities were comparable to those of the intact fractions. The AgNPs also demonstrated bacterial inhibitory activities against six bacterial species. While the minimum inhibitory concentrations (MIC) of F1-AgNPs against Pseudomonas aeruginosa and Staphylococcus aureus were 31.25 and 15.63 µg/mL respectively, those of LSTE-AgNPs and F2-AgNPs against these organisms were both 62.50 µg/mL. The F1-AgNPs demonstrated a better bactericidal effect and may be useful in food packaging. This research also showed the involvement of the procyanidins as reducing and capping agents in the formation of stable AgNPs with potential biological applications.IBB University, Lapai, Nigeria: TETFund
National Research Foundation of South Africa: Grant number 10605
- …