The effect of commonly used techniques and solvents in the antioxidant activities of pink-flesh guava fruit were studied. The extraction techniques compared were homogenization, shaking, sonication, magnetic stirring, and maceration for 1, 2, and 3 days. The solvent systems used were methanol, ethanol, and acetone at three different concentrations (50%, 70%, and 100%) and with 100% distilled water. The antioxidant activity of the fruit was evaluated using Folin-Ciocalteu index, ferric-reducing antioxidant power assay, and 1,1-diphenyl-2-picrylhydrazyl free radical-scavenging capacity. Ultrasonic and homogenization were the best techniques to extract the antioxidant from guava fruit. Homogenization technique was found to be the most convenient exhaustive and time-saving extraction technique. Results showed that the extracting solvent significantly (P<0.05) altered the antioxidant property estimations of pink-flesh guava fruit. Pure solvents were inefficient extraction media for antioxidant. Enhanced extraction yields were obtained from solvent containing higher water concentrations and 50% acetone is a recommended solvent for extracting antioxidants compounds from pink-flesh guava fruit. High correlations between phenolic compositions and antioxidant activities of pinkflesh guava extracts were observed. High levels of antioxidant activities were detected in pink-flesh guava, indicating that the fruit may serve as an excellent dietary source of natural antioxidants.

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There is a need to synthesize eco-friendly nanoparticles with more effective and potent antibacterial activities. A green and cost-effective method for the synthesis of silver nanoparticles (AgNPs) using Thymus vulgaris, Mentha piperita, and Zingiber officinale extracts was developed. The analytical instrumentation, namely, UV/Vis, absorption spectroscopy, FTIR, and scanning electron microscopy (SEM), was used to determine the developed AgNPs, confirming the functional groups involved in their reduction. Acidic molybdate, DPPH, and FRAP regents were reacted with AgNPs extract to evaluate their antioxidant, scavenging, and oxidative activities. The agar well diffusion method was used to determine the antibacterial potential of AgNPs extracts using clinical isolates. The developed AgNPs showed peaks at 25 cum\Diff, 50 cum\Diff, and 75 cum\Diff, respectively, of 16.59 ± 0.78, 45.94 ± 1.07, and 81.04 ± 0.98 nm, for Thymus vulgaris, Mentha piperita, and Zingiber officinale. SEM revealed uniform prepared and encapsulated AgNPs by plant extracts matrix. The FTIR shows the involvement of amide (-CO-NH2), carbonyl (-CO), and hydroxyl (-OH), which resulted in the reduction of AgNPs. The AgNPs extract showed significantly higher TAA, DPPH, and FRAP values than free AgNPs and plant extract ( p < 0.05 ). Antibacterial of AgNPs extracts revealed various degrees of inhibition zones against Escherichia coli, Acinetobacter baumannii, and Staphylococcus aureus. The developed AgNPs extract showed acceptable antioxidant activities and noticeable antibacterial potential. The prepared green synthesized AgNPs showed a promising antibacterial activity against four multidrug-resistant clinical isolates, Escherichia coli, Acinetobacter baumannii, and Staphylococcus aureus. Further, fractionated extracts other than crude extracts will be utilized in the preparation of AgNPs to get more efficient antibacterial activities for future work.

Gum arabic (GA) is the main product of acacia trees. As a raw and commercial samples, GA was extracted with methanol and analysed to measure the antioxidant activity using five methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH), Folin-Ciocalteu indexes (FCI), which indicate total phenolic compounds (TPC), oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC). This study used antioxidant assays to detect TPC and selected appropriate and inexpensive methods to determine the antioxidant capacity of GA samples. The results reveal that the FCI, ORAC, and CUPRAC are correlated highly with FRAP. Person's correlation coefficient (r) values are 0.98, 0.93, and 0.99, respectively, based on the sample size of (n = 8). This means that the TPC of GA is highly correlated with their antioxidant activities that are measured by these three methods. Hence the FCI, ORAC, and the CUPRAC methods are more effective and simpler. They had similar predictive power to the FRAP of GA antioxidant activity. Consequently, GA is generally recognized as being slightly acidic which may have been obtained from appropriate methods of the antioxidant capacity detection. This acidity is due to the electronic transfer mechanism based on the selection of the working pH.

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The nutritional value of the rhizomes of Kaempferia angustifolia was measured through the antioxidant properties of various extracts and the determination of the bioactive compounds. The chloroform and methanol extracts of the rhizomes of Kaempferia angustifolia showed strong free radical scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) with values of 615.92 mg Trolox equivalent (TE)/g each. The methanol extract also exhibited the strongest antioxidant properties in the azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) assay with a value of 38.87 mg TE/g. The hexane extract gave the strongest reducing ability in cupric reducing antioxidant capacity (CUPRAC) assay with a value of 901.76 mg TE/ g, whilst the ethyl acetate extract exhibited the strongest reducing ability against ferric reducing antioxidant power (FRAP) with a value of 342.23 mg TE/g. Column chromatographic separation on the rhizomes of Kaempferia angustifolia afforded boesenboxide (1), crotepoxide (2), 2ˊ-hydroxy-4,4ˊ,6ˊ-trimethoxychalcone (3), kaempfolienol (4), and zeylenol (5), which were elucidated by spectroscopic methods. Kaempfolienol (4) was the strongest free radical agent against DPPH with a value of 443.92 mg TE/g, whilst 2ˊ-hydroxy-4,4ˊ,6ˊ-trimethoxychalcone (3) exhibited the strongest antioxidant properties with values of 42.23, 1497.22, and 781.53 mg TE/g against ABTS, CUPRAC, and FRAP assays, respectively. ARTICLE HISTORY

Patients with acute myocardial infarction (AMI) or ischaemic heart disease are at risk of developing anxiety and depression. This systematic review aims to identify the various risk factors and the role of cardiac rehabilitation in reducing the risk of depression in patients after AMI. In this review, we included data on the prevalence of depression in patients post-AMI for the years 2016-2017 from a cardiac rehabilitation unit at Morriston Hospital, Swansea, a primary coronary angioplasty centre. Results from our meta-analysis were compared with the findings of previous studies. Our data showed the prevalence of depression to be 14% pre-cardiac rehabilitation and 3% post-cardiac rehabilitation. A meta-analysis of seven studies showed the prevalence to be approximately 20-35% depending on the type of questionnaire or screening method used. Gender, marital status, age, and sedentary lifestyle were found to be risk factors for depression post-acute coronary syndrome (ACS). Females, patients aged >65 years, and those who were single, lived alone, or widowed were at a higher risk of depression, and patients with sedentary lifestyles were more likely to have post-ACS depression. Depression in patients post-myocardial infarction was also associated with increased mortality and morbidity risk as well as higher hospital re-admission and future cardiac events.The meta-analysis showed significant publication bias, studies with negative results were less likely to be published, and the study data were heterogeneous. The pooled estimate for depression estimated using the random-effects model was 1.78 (95% confidence interval = 1.58-2.01).