Effects of Breaking Up Prolonged Sitting on Cardiovascular Parameters: A systematic Review

The aim of this systematic review was to analyze the acute and chronic effects of sitting breaks on cardiovascular parameters. PubMed and Web of Science databases were searched by two independent researchers for relevant studies published until February 2020. Acute or chronic studies reporting the effects of sitting breaks or reduction in sitting time on cardiovascular parameters were examined. The eligibility criteria followed PICOS: Population - Humans ≥ 18 years old; Interventions – Sitting break strategies; Comparisons – Uninterrupted sitting; Outcomes – Cardiovascular parameters (blood pressure, heart rate, ambulatory blood pressure, vascular function, pulse-wave velocity, cerebral blood flow and biomarkers); Study design – Randomized controlled trials, non-randomized non-controlled trials and randomized crossover trials. Forty-five studies were included, where 35 investigated the acute and 10 the chronic effects of sitting breaks or reductions in sitting time. Walking was the main acute study strategy, used in different volumes (1 min 30 s to 30 min), intensities (light to vigorous) and frequencies (every 20 min to every 2 h). Acute studies found improvements on cardiovascular parameters, especially blood pressure, flow-mediated dilation, and biomarkers, whereas chronic studies found improvements mostly on blood pressure. Breaking up or reducing sitting time improves cardiovascular parameters, especially with walking.

Evaluation of the Sub Acute Toxicity of the Stem Bark of Andira inermis

The aqueous methanolic Andira inermis stem bark extract was screened in evaluation of its potential for its toxic effect in a 28 days study using the oral route only. The sub acute study was carried out in Wistar rats divided into 4 groups of 5 rats each; control group (a) received distilled water while the aqueous methanolic Andira inermis stem bark extract treatment groups (b), (c), and (d), received 100, 200, and 400 mg/kg of the extract respectively, for a period of 28 days, with their intake of feeds, water and signs of abnormality observed. At the end of the sub acute study, the rats were anaesthetized with chloroform and blood collected by cardiac puncture for biochemical and haematological evaluation. And the visceral organs (liver, kidneys, lungs, heart and spleen) excised for weighing and patho-morphological examination. The aqueous methanolic Andira inermis stem bark extract was found to; reduce the intake of water weekly, drop intake of feeds; significantly increased the red blood cell count (RBC), the haemoglobin concentration (HB), as well as the pack cell volume (PCV). The renal indices, showed the electrolytes sodium and chloride of the treatment groups (b, c and d) to be significantly different from the control. Urea was noticed to have reduce significantly and creatinine insignificantly. The organs weights across the Andira inermis treatment groups were noticed to be insignificantly (P › 0.05) different from the control for all the organs sampled (Lungs, Liver, Heart and Spleen) except for the kidney (organ weight which was noticed to have increased significantly). The patho-morphologies of the organs showed the heart to be normal, the kidney was normal in the control and the other treatment groups 100 mg 400 mg and 200 mg but a rat (an outlier) in one of the 200 mg group was noticed with tubular necrosis; the liver indicated a non concentration-dependent hepatitis while the lungs and the spleen presented an infective process. It was concluded that, the aqueous methanolic extract of Andira inermis is a safe medicinal plant with the capacity to; raise red blood cell count (RBC), haemoglobin concentration (HB) as well as the pack cell volume (PCV); proffers a nephro- protective property; shrunken spleen; have a hepato-protective property and as well was non toxic to the heart and lungs. These findings warrants further pharmacognostic efficacy experimental research to harness the array of benefits of Andira inermis as discovered in this study.

Acute, sub-acute, sub-chronic and chronic toxicity studies of four important Nigerian ethnomedicinal plants in rats

Background Azadirachta indica, Khaya senegalensis, Anogeissus leiocarpus and Tamarindus indica are important ethnomedicinal plants used for health mitigation since the history of mankind. They are used discretionarily in folkloric medicine on the premise that they are natural products devoid of synthetic preservatives. However, nature endows plants with metabolites for warding off potential attacks from animals and the environment. Some of these metabolites are responsible for toxicity of some plants. Furthermore, drug-induced liver injuries and nephrotoxicity are the leading causes of pharmaceutical attrition of promising drug candidates in clinical trials. Thus, we aimed to evaluate the safety of four ethnomedicinal plants in short-, medium- and long-term usage. Methods Rats dosed once with 5000 mg/kg extracts of each of these plants served as acute study (AS) while rats dosed daily with 2000 mg/kg for 2, 12 and 14 weeks served as sub-acute (SAS), sub-chronic (SCS) and chronic (CS) studies, respectively. Rats administered distilled water served as the negative control (NC). Results A. leiocarpus and T. indica significantly reduced percentage weight gain in the SCS compared to the NC. A. leiocarpus significantly (P< 0.05) increased transaminases and alkaline phosphatase in the AS only; and total protein (TP) in the AS, SAS, SCS and CS compared to the NC. K. senegalensis significantly (P< 0.05) increased alanine aminotransferase but significantly (P< 0.05) decreased TP in the AS only compared to the NC. However, A. indica and T. indica significantly (P< 0.05) increased globulin and aspartate transaminase in the CS only. Whereas A. leiocarpus and K. senegalensis significantly (P< 0.05) increased urea and creatinine in the AS than SAS, SCS and CS; Na+ and K+ were significantly higher in the SCS and CS studies compared to the NC. The histological lesions seen ranged from cellular degeneration, congestion, fibrosis to necrosis. Conclusion Thus, nonlethal, reversible toxic insults occur in short-term usage (AS); while, insidious lethal toxic effects occur in medium-term (SAS) and long-term usage (SCS and CS). The ability of these plant to maintain adequate hematological parameters, bodyweight and absence of mortality may explain free usage of preparations made from these plants in folkloric medicine.

Dietary flavanols improve cerebral cortical oxygenation and cognition in healthy adults

Cocoa flavanols protect humans against vascular disease, as evidenced by improvements in peripheral endothelial function, likely through nitric oxide signalling. Emerging evidence also suggests that flavanol-rich diets protect against cognitive aging, but mechanisms remain elusive. In a randomized double-blind within-subject acute study in healthy young adults, we link these two lines of research by showing, for the first time, that flavanol intake leads to faster and greater brain oxygenation responses to hypercapnia, as well as higher performance only when cognitive demand is high. Individual difference analyses further show that participants who benefit from flavanols intake during hypercapnia are also those who do so in the cognitive challenge. These data support the hypothesis that similar vascular mechanisms underlie both the peripheral and cerebral effects of flavanols. They further show the importance of studies combining physiological and graded cognitive challenges in young adults to investigate the actions of dietary flavanols on brain function.

Acute and chronic effects of Rhaponticum carthamoides and Rhodiola rosea extracts supplementation coupled to resistance exercise on muscle protein synthesis and mechanical power in rats

Background Owing to its strength-building and adaptogenic properties, Rhaponticum carthamoides (Rha) has been commonly used by elite Soviet and Russian athletes. Rhodiola rosea (Rho) is known to reduce physical and mental fatigue and improve endurance performance. However, the association of these two nutritional supplements with resistance exercise performance has never been tested. Resistance exercise is still the best way to stimulate protein synthesis and induce chronic muscle adaptations. The aim of this study was to investigate the acute and chronic effects of resistance exercise coupled with Rha and Rho supplementation on protein synthesis, muscle phenotype, and physical performance. Methods For the acute study, fifty-six rats were assigned to either a trained control group or one of the groups treated with specific doses of Rha and/or Rho. Each rats performed a single bout of climbing resistance exercise. The supplements were administered immediately after exercise by oral gavage. Protein synthesis was measured via puromycin incorporation. For the chronic study, forty rats were assigned to either the control group or one of the groups treated with doses adjusted from the acute study results. The rats were trained five times per week for 4 weeks with the same bout of climbing resistance exercise with additionals loads. Rha + Rho supplement was administered immediately after each training by oral gavage. Results The findings of the acute study indicated that Rha and Rha + Rho supplementation after resistance exercise stimulated protein synthesis more than resistance exercise alone (p < 0.05). After 4 weeks of training, the mean power performance was increased in the Rha + Rho and Rha-alone groups (p < 0.05) without any significant supplementation effect on muscle weight or fiber cross-sectional area. A tendency towards an increase in type I/ type II fiber ratio was observed in Rha/Rho-treated groups compared to that in the trained control group. Conclusion Rhodiola and Rhaponticum supplementation after resistance exercise could synergistically improve protein synthesis, muscle phenotype and physical performance.

Evaluation of Acute and Sub-Acute Toxicity of Aqueous Extracts of Artemisia afra Leaves on Brain, Heart and Suprarenal Glands in Swiss Albino Mice

BACKGROUND፡ The majority of population rely on traditional medicine as a source of healthcare. Artemisia afra is a plant traditionally used for its medicinal values, including treatment of malaria in many parts of the world. Currently, it is also attracting attention because of a claim that a related species, Artemisia annua, is a remedy for the COVD-19 pandemic. The aim of the present study was to investigate toxic effects of A. afra on brain, heart and suprarenal glands in mice aged 8-12 weeks and weighing 25-30g.METHODS: Leaves of A.afra were collected from Bale National Park, dried under shade, crushed into powder and soaked in distilled water to yield aqueous extract for oral administration. For acute toxicity study, seven treated and one control groups, with 3 female mice each, were used. They were given a single dose of 200mg/kg, 700mg/kg, 1200mg/kg, 2200mg/kg, 3200mg/kg, 4200mg/kg or 5000mg/kg b/wt of the extract. For the sub-acute toxicity study, two treated and one control groups, with 5 female and 5 male mice each, were used. They were daily treated with 600mg/kg or 1800mg/kg b/wt of extract.RESULTS: LD50 was found to be greater than 5000mg/kg indicating that the plant is relatively safe. In the sub-acute study, no signs of toxicity were observed in all treatment groups. On microscopic examination of the brain, heart and suprarenal glands no sign of cellular injury was observed.CONCLUSION: The findings of this study suggest that the leaves extract of A. afra is relatively safe in mice.

An Absorption and Plasma Kinetics Study of Monoterpenes Present in Mastiha Oil in Humans

Monoterpenes are bioactive compounds, however studies on their metabolic fate in humans are scarce. The present work aimed to identify and quantify the bioactive monoterpenes myrcene, α- and β-pinene of the Mediterranean product Mastiha Oil, in human plasma after acute consumption of a single dose. This was an open-label, single-arm acute study. After overnight fasting, healthy males were administered with Mastiha Oil. Blood samples were collected on different time-points before and after consumption. A novel GC-MS-MS application was performed to detect and quantify terpenes in MO and in plasma. Serum lipid resistance to oxidation was also determined. Alpha-Pinene, β-pinene and myrcene were identified and quantified in plasma. Alpha-pinene concentration significantly increased after 0.5 h of Mastiha Oil consumption, remaining significantly increased at 1 h, 2 h, 4 h, 6 h and 24 h. Beta-pinene and myrcene followed similar patterns. The increase in serum lipid resistance to oxidation was significant at 1 h, reached its peak at 2 h and remained significant until 4 h. Conclusively, α-pinene, β-pinene and myrcene that are present in Mastiha Oil are absorbed by humans. (ClinicalTrials.gov Identifier: NCT04290312).

Evaluation of Protective Properties of Elaeis oleifera Fruit Extract on Renal Parameters of Dichlorvos-Induced Nephrotoxocity in Albino Rats

Aim: Evaluate the protective effects of palm oil on renal parameters after dichlorvos toxicity in albino rats. Study Design and Methodology: The study consisted of 3 phases: The acute study which lasted for 24 hours, the sub-acute study which lasted for 14 days and the sub chronic study which lasted for 30 days. The design and treatment pattern is shown below. Phase 1: Acute Study. Group 1: No DDVP, No palm oil for 24 hours (Negative control), Group 2: 30 mg/kg of DDVP without palm oil (positive control), Group 3: 30 mg/kg of DDVP and 100 mg/kg palm oil for 24 hours (treatment group). Phase 2: Sub-Acute (14 days) Study. Group 4: No DDVP, No palm oil for 14 days (Negative control), Group 5: 10 mg/kg of DDVP without palm oil daily for 14 days (positive control), Group 6: 10 mg/kg of DDVP and 100 mg/kg of palm oil daily for 14 days (positive control). Phase 3: Sub-Chronic (30 days) Study. Group 7: No DDVP, No palm oil for 30 days (Negative control), Group 8: 10 mg/kg of DDVP without palm oil daily for 30 days (positive control), Group 9: 10 mg/kg of DDVP and 100 mg/kg palm oil daily for 30 days (treatment group). All administration was done orally. After the period of treatments, the rats were sacrificed after 18 hours of fast. Whole blood samples (5 mls) were collected into lithium heparin bottle and spun at 3500 rpm for 5 minutes to obtain plasma samples. Samples obtained were used for the determination of Na+, K+, HCO3, urea, and creatinine while renal tissues obtained were used for histopathological examinations. Results: Significantly higher values were seen in urea in the dichlorvos treated rats over a period of 24 hours, 14 days, and 30 days as compared to rats co-treated with palm oil and the control. Creatinine indicated significantly higher over a period of 24 hours while non-significant increases were observed in the dichlorvos treated rats over a period of 14 days and 30 days. More so, significantly higher values were seen in potassium in the dichlorvos treated rats over a period of 24 hours and 14 days, while significantly higher values in potassium were seen after period of 30 days as compared to rats co-treated with palm oil and the control. Sodium and chloride did not indicate significant difference over the period of 24 hours, 14 days, and 30 days. Histological examination of the renal tissue indicated structural distortions dichlorvos treated rats over a period of 24 hours, 14 days and 30 days while significant improvements in the structural integrity of the kidney were observed in rats co-treated with palm oil. Conclusion: Results obtained indicated that palm oil showed a protective effect in ameliorating the nephrotoxicity induced by dichlorvos as shown by the histological examination and decreased values of creatinine and urea as well as potassium in palm oil treated rats.

Resistance Exercise Does Not Up-Regulate YAP Expression in Aged Human Skeletal Muscle

Objectives Yes-Associated Protein (YAP) is implicated as a regulator of the post-exercise skeletal muscle response through mechanical transduction. We recently observed that resistance exercise (RE) increased both total (t) and phosphorylated (p) muscle YAP content, which correlated with extracellular signal-regulated kinase 1/2 (Erk1/2). Other anabolic signaling pathways (i.e., mTORC1) are known to be potentiated by the combined stimuli of RE and protein ingestion during post-exercise recovery. However, the impact of protein ingestion on t- and p-muscle YAP content during recovery from RE is unknown. Therefore, we aimed to determine the nutrient sensitivity of YAP in both an acute and chronic exercise setting in aging skeletal muscle. Methods Acute study: 13 untrained older women (59.8 ± 0.5 y) were randomized to perform an acute bout of unilateral RE (3 sets × 12 repetitions at 65% of one repetition maximum) followed by the ingestion of whey protein (0.3 g/kg lean body mass) or water. Muscle biopsies of both the rested and exercised legs were collected before and during the postprandial period. Chronic study: 20 untrained middle-aged men and women (47.5 ± 0.3 y) performed 3 weeks of whole body RE (3 d/wk) with moderate or high protein intake set at 1.2 g/kg/d or 1.6 g/kg/d, respectively. Muscle biopsies were taken weekly in the rested state. Total and phosphorylated YAPSer127 and Erk1/2Thr202/Tyr204 were examined by western blotting. Results Acute study: Protein ingestion decreased t- and p-YAP compared to the water condition in the non-exercised leg (main effect: P &lt; 0.04). There was no change in t- or p-YAP, regardless of condition, in the exercised-leg throughout recovery (P = 0.88). There was no change in p/t ratio of Erk1/2 in the exercised or non-exercised leg. Chronic study: There was no change in either p- or t-YAP in moderate and high protein conditions throughout training (both, P &gt; 0.05). There was a decrease in t-Erk1/2 irrespective of condition (P = 0.04). There was no change in p/t ratio of Erk1/2 throughout training. There was a significant correlation between t-Erk1/2 and t-YAP (r = 0.741 and P &lt; 0.001). Conclusions Protein ingestion mediated an acute down-regulation of YAP in the postprandial-state. However, resistance training did not modulate YAP content in aged skeletal muscle tissue. Funding Sources Funded by Beef Checkoff. AFS is supported by CAPES-Brazil.