Muscle fiber type and metabolic profiles of four muscles from the African black ostrich

Muscle fiber type, fiber cross-sectional area (CSA), enzyme activities (citrate synthase (CS), 3-hydroxyacetyl Co A dehydrogenase (3HAD), lactate dehydrogenase (LDH) and phosphofructokinase (PFK)) and glycogen content were analyzed in the M. iliotibialis cranialis (ITC), M. iliotibialis lateralis, M. gastrocnemius (G) and M. fibularis longus (FL) muscles from 24 ostriches. Type I and II fiber proportions were similar across the 4 muscles, but the ITC had overall the smallest fibers. CS activity was the highest in the ITC, but similar between the remainder of the muscles. 3HAD activities were very low in all muscles, ranging between 1.9 and 2.7 μmol/min/g protein, indicating poor β-oxidation. The ITC also had the lowest PFK activity. Glycogen content averaged ∼85 mmol/kg dry weight across the muscles with large intramuscular variations. The 4 ostrich muscles present with low fat oxidation capacity and low glycogen content, which could have significant implications on meat quality attributes

Selected Derivatives of Erythromycin B- In Silico and Anti-Malarial Studies

From MDPI via Jisc Publications RouterHistory: accepted 2021-11-12, pub-electronic 2021-11-18Publication status: PublishedFunder: Ministry of Education, Science and Technological Development of Republic of Serbia; Grant(s): 451-03-9/2021-14/200124Funder: National Research Foundation; Grant(s): 107881Erythromycin A is an established anti-bacterial agent against Gram-positive bacteria, but it is unstable to acid. This led to an evaluation of erythromycin B and its derivatives because these have improved acid stability. These compounds were investigated for their anti-malarial activities, by their in silico molecular docking into segments of the exit tunnel of the apicoplast ribosome from Plasmodium falciparum. This is believed to be the target of the erythromycin A derivative, azithromycin, which has mild anti-malarial activity. The erythromycin B derivatives were evaluated on the multi-drug (chloroquine, pyrimethamine, and sulfadoxine)-resistant strain K1 of P. falciparum for asexual growth inhibition on asynchronous culture. The erythromycin B derivatives were identified as active in vitro inhibitors of asexual growth of P. falciparum with low micro-molar IC50 values after a 72 h cycle. 5-Desosaminyl erythronolide B ethyl succinate showed low IC50 of 68.6 µM, d-erythromycin B 86.8 µM, and erythromycin B 9-oxime 146.0 µM on the multi-drug-resistant K1 of P. falciparum. Based on the molecular docking, it seems that a small number of favourable interactions or the presence of unfavourable interactions of investigated derivatives of erythromycin B with in silico constructed segment from the exit tunnel from the apicoplast of P. falciparum is the reason for their weak in vitro anti-malarial activities

Investigating the effect of yeast on the anaerobic digestion of cow dung

Abstract: The aim of this paper was to investigate the effect of yeast on the biomethane yield of an anaerobic digester with cow dung feedstock. The biochemical methane potential (BMP) test was conducted on three different substrates for the production of biomethane. The BMP test was carried out using batch digesters at a temperature of 37 ℃. The substrates were divided into three parts: cow dung alone, yeast alone and the last involved the digestion of the mixture of cow dung and yeast. The maximum volume of the biomethane produced was observed from the samples containing yeast alone with a volume of 675.97 Nml Biogas/g VS. The lowest volume of biogas occurred on the samples containing the mixture of cow dung and yeast with 15 g of yeast and had a volume of 266.0 Nml Biogas/g VS. The sample containing cow dung alone produced a volume of 364.29 Nml Biogas/g VS. The results obtained for the digestion of yeast alone indicated that the higher yield of biogas was obtained when little amount of yeast was added on the substrate and that the addition of yeast on the anaerobic digestion of cow dung improves the yield of biogas; with the optimum biogas yield occurring at the ratio of 1:2 (yeast: cow dung)

Evaluation of the antidiabetic, antiobesity and antioxidant potential of Anthophycus longifolius ((Turner) Kützing)

Obesity is a major public health problem that is associated with many metabolic disorders including diabetes, hypertension, and cardiovascular diseases. Anthophycus longifolius is a brown seaweed that have been shown to possess antioxidant, antibacterial and anti-inflammatory activities. The present study investigated the anti-diabetic, anti-obesity and oxidative stress ameliorating properties of cold water (CW) and ethanolic (EtOH) extracts of A. longifolius using in vitro and ex vivo experimental models. The extracts significantly inhibited the activities of carbohydrate and lipid digestive enzymes α - glucosidase (IC50 = CW: 176.9±2.1 µg/ml; EtOH: 179.8±1.9 µg/ml); α-amylase (IC50 = CW: 86.1±1.7 µg/ml; EtOH: 77.8±1.9 µg/ml); and pancreatic lipase (IC50 = CW: 184.3±1.7 µg/ml; EtOH: 534.1±2.3 µg/ml), and stimulated adipose glucose uptake (CW: 10- 50.5 mg/g adipose tissue; EtOH: 9 - 79 mg/g adipose tissue). Incubation of adipose tissues with FeSO4 significantly depleted reduced glutathione (GSH) level, super oxide dismutase (SOD) and catalase activities, while concomitantly elevated malondialdehyde (MDA) level. These changes were significantly reversed following the treatment of A. longifolius extracts. Liquid chromatography-mass spectrometry (LC-MS) analysis of the extracts revealed the presence of rhodomycinone, salsolinol, 5-hydroxyconiferyl alcohol, 2-caffeoylisocitrate and demethylalangiside in the cold water extract, while petromyzonol 24-sulfate, atractyloside, abyssinone VI and podecdysone B in the ethanolic extract. Molecular docking analysis revealed potent interactions of the phytochemicals with GLUT4 and leptin. These results indicate the possible antidiabetic, antiobesity and oxidative stress ameliorating potentials of A. longifolius extracts at in vitro and ex vivo experimental models. The identified compounds may be responsible for the observed biological activities

Evaluation of 4-Aminoquinoline Hydrazone Analogues as Potential Leads for Drug-Resistant Malaria

The emergence of resistance to first-line antimalarial drugs calls for the development of new therapies for drug-resistant malaria. The efficacy of quinoline-based antimalarial drugs has prompted the development of novel quinolines. A panel of 4-aminoquinoline hydrazone analogues were tested on the multidrug-resistant K1 strain of Plasmodium falciparum: IC50 values after a 48 h cycle ranged from 0.60 to 49 µM, while the 72 h cycle ranged from 0.026 to 0.219 μM. Time-course assays were carried out to define the activity of the lead compounds, which inhibited over 50% growth in 24 h and 90% growth in 72 h. Cytotoxicity assays with HepG2 cells showed IC50 values of 0.87–11.1 μM, whereas in MDBK cells, IC50 values ranged from 1.66 to 11.7 μM. High selectivity indices were observed for the lead compounds screened at 72 h on P. falciparum. Analyses of stage specificity revealed that the ring stages of the parasite life cycle were most affected. Based on antimalarial efficacy and in vitro safety profiles, lead compound 4-(2-benzylidenehydrazinyl)-6-methoxy-2-methylquinoline 2 was progressed to drug combination studies for the detection of synergism, with a combinatory index of 0.599 at IC90 for the combination with artemether, indicating a synergistic antimalarial activity. Compound 2 was screened on different strains of P. falciparum (3D7, Dd2), which maintained similar activity to K1, suggesting no cross-resistance between multidrug resistance and sensitive parasite strains. In vivo analysis with 2 showed the suppression of parasitaemia with P. yoelii NL (non-lethal)-treated mice (20 mg/kg and 5 mg/kg)

Discovery of potent 4-aminoquinoline hydrazone inhibitors of NRH:quinoneoxidoreductase-2 (NQO2)

(NRH):quinone oxidoreductase 2 (NQO2) is associated with various processes involved in cancer initiation and progression probably via the production of ROS during quinone metabolism. Thus, there is a need to develop inhibitors of NQO2 that are active in vitro and in vivo. As part of a strategy to achieve this we have used the 4-aminoquinoline backbone as a starting point and synthesized 21 novel analogues. The syntheses utilised p-anisidine with Meldrum's acid and trimethyl orthoacetate or trimethyl orthobenzoate to give the 4-hydrazin-quinoline scaffold, which was derivatised with aldehydes or acid chlorides to give hydrazone or hydrazide analogues, respectively. The hydrazones were the most potent inhibitors of NQO2 in cell free systems, some with low nano-molar IC50 values. Structure-activity analysis highlighted the importance of a small substituent at the 2-position of the 4-aminoquinoline ring, to reduce steric hindrance and improve engagement of the scaffold within the NQO2 active site. Cytotoxicity and NQO2–inhibitory activity in vitro was evaluated using ovarian cancer SKOV-3 and TOV-112 cells (expressing high and low levels of NQO2, respectively). Generally, the hydrazones were more toxic than hydrazide analogues and further, toxicity is unrelated to cellular NQO2 activity. Pharmacological inhibition of NQO2 in cells was measured using the toxicity of CB1954 as a surrogate end-point. Both the hydrazone and hydrazide derivatives are functionally active as inhibitors of NQO2 in the cells, but at different inhibitory potency levels. In particular, 4-((2-(6-methoxy-2-methylquinolin-4-yl)hydrazono)methyl)phenol has the greatest potency of any compound yet evaluated (53 nM), which is 50-fold lower than its toxicity IC50. This compound and some of its analogues could serve as useful pharmacological probes to determine the functional role of NQO2 in cancer development and response to therapy

The Call for Relevance: South African Psychology Ten Years into Democracy

Published when Prof de la Rey was Deputy Vice-Chancellor (Research and Innovation), University of Cape Town.A number of scholars during the 1980s and early 1990s questioned the relevance of psychology in South Africa. In this paper we characterise the nature of what became known as the ‘relevance debate’, and then investigate whether South African psychology has become more relevant during the nation’s first ten years of democracy. Themes which are identified with respect to this issue include the apparent increasing representation of marginalised groups within South African psychology, the conscious responsiveness of psychologists to post-apartheid policy imperatives and issues, their alignment with international theoretical trends, and finally, an increasing recognition of the political nature of South African psychology. The authors conclude that a more productive approach within future debates regarding relevance in psychology would be to examine the nature of knowledge production within the discipline