Free radicals are generated in our body by several systems. A balance among free radicals and antioxidants is an important matter for appropriate physiological function. If free radicals become greater than the ability of the body to control them, a case known as oxidative stress appears, as a result of that, a number of human diseases spread in the body. Antioxidants can contribute to facingthis oxidative stress. The present review provides a brief overview of free radicals, oxidative stress, some natural antioxidants and the relationship between them.

A Review on Free Radicals and Antioxidants.

The current research study is to develop an easy and eco-friendly method for the synthesis of AgNPs using aqueous leaf extract of Calophyllum tomentosum (CtAgNPs) and evaluated the extract to know the effects of anti-bacterial, antioxidant, anti-diabetic, anti-inflammatory and anti-tyrosinase activity. Using UV–vis spectrophotometer, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) characterized the Calophyllum tomentosum mediated silver nanoparticles. The leaf extract of C. tomentosum yielded flavonoids, saponins, tannins, alkaloids, glycosides, phenols, terpenoids and coumarins. AgNPs formation was confirmed by UV–vis spectra at 438 nm. Crystalline structure with a face centered cubic (fcc) of AgNPs was observed in XRD. FTIR had shown that the phytochemicals were responsible for the reduction and capping material of silver nanoparticles. The size and shape of the AgNPs were determined using SEM. From EDX study analysed the strong absorption property of AgNPs. The CtAgNPs have showed significant antibacterial activity on multi drug resistance bacteria. The CtAgNPs had shown strong antioxidant (DPPH, H2O2 scavenging, nitric oxide scavenging power, reducing power) activities. The CtAgNPs had strongly inhibited the α-glucosidase and DPPIV compared to α-amylase. The CtAgNPs exhibited strong anti-inflammatory activity (albumin denaturation, membrane stabilization, heat haemolytic, protein inhibitory, lipoxygenase, xanthine oxidase) and tyrosinase inhibitory activity. To our best knowledge, this is the first attempt on the synthesis of silver nanoparticles using Calophyllum tomentosum leaves extract. Hence, to validate our results the in vivo studies at molecular level are needed to develop an antioxidant, anti-diabetic and anti-inflammatory agent.

Characterization, antibacterial, antioxidant, antidiabetic, anti-inflammatory and antityrosinase activity of green synthesized silver nanoparticles using Calophyllum tomentosum leaves extract

Diabetes mellitus (DM) is recognized as a serious global health problem that is characterized by high blood sugar levels. Type 2 DM is more common in diabetic populations. In this type of DM, inhibition of 𝛼-glucosidase is a useful treatment to delay the absorption of glucose after meals. As a megabiodiversity country, Indonesia still has a lot of potential unexploited forests to be developed as a medicine source, including as the 𝛼-glucosidase inhibitor. In this study, we determine the 𝛼-glucosidase inhibitory activity of 80% ethanol extracts of leaves and twigs of some plants from the Apocynaceae, Clusiaceae, Euphorbiaceae, and Rubiaceae. Inhibitory activity test of the 𝛼-glucosidase was performed in vitro using spectrophotometric methods. Compared with the control acarbose (IC50 117.20 μg/mL), thirty-seven samples of forty-five were shown to be more potent 𝛼-glucosidase inhibitors with IC50 values in the range 2.33–112.02 μg/mL.

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Screening of α-glucosidase inhibitory activity from some plants of Apocynaceae, Clusiaceae, Euphorbiaceae, and Rubiaceae.

This research study is to develop an easy and eco-friendly method for the synthesis of AgNPs using aqueous extract of endophytic fungi, Cladosporium species (CsAgNPs) and investigated the effects o...

Endophyte fungi, Cladosporium species-mediated synthesis of silver nanoparticles possessing in vitro antioxidant, anti-diabetic and anti-Alzheimer activity

Depression is a serious disorder that affects hundreds of millions of people around the world and causes poor quality of life, problem behaviors, and limitations in activities of daily living. Therefore, the search for new therapeutic options is of high interest and growth. Research on the relationship between depression and oxidative stress has shown important biochemical aspects in the development of this disease. Flavonoids are a class of natural products that exhibit several pharmacological properties, including antidepressant-like activity, and affects various physiological and biochemical functions in the body. Studies show the clinical potential of antioxidant flavonoids in treating depressive disorders and strongly suggest that these natural products are interesting prototype compounds in the study of new antidepressant drugs. So, this review will summarize the chemical and pharmacological perspectives related to the discovery of flavonoids with antidepressant activity. The mechanisms of action of these compounds are also discussed, including their actions on oxidative stress relating to depression.

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Antidepressant Flavonoids and Their Relationship with Oxidative Stress

Flavonoids represent a remarkable group of plant secondary metabolites and have long been used as traditional medicines with scientifically proven pharmacological benefits. They serve vast-ranging medicinal activities that may lead drug discovery with novel and potential therapeutic evidence. Latest research magnifies primarily functional activity of flavonoids as antioxidant against oxidative stress. This review enlightens the prospective role of flavonoids as antioxidant.

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Antioxidant properties of flavonoids

The compounds that could inhibit the activity of a-glucosidase are potentially used for antidiabetic by suppressing postprandial hyperglycemia. This research aimed to investigate the hypoglycemic activity in A. terreus koji extracted by ethyl acetate. The extracts was dissolved in methanol: water (1:4), followed by fractionations with n-hexane, methylene chloride and ethyl acetate. Each fraction was assayed for its activity against a-glucosidase. The active fraction was purified by column chromatography using silica gel and resin as adsorbent. The kopi extract showed potential as alpha-glucosidase inhibition with IC50 <10 microg mL(-1) and showed combination of non-competitive and uncompetitive inhibition mode against a-glucosidase. Ethyl acetate fraction showed potential as inhibitor alpha-glucosidase with IC50 = 8.6 microg mL(-1). In animal experiment, active fraction (F10-4) of ethyl acetate fraction suppressed the increase of postprandial blood glucosidase level compare to the control. Thus it showed potential as alpha-glucosidase inhibitor and demonstrated depressed postprandial blood glucose level and may have potential use in the management of type 2 diabetes.

Inhibitory effect of koji Aspergillus terreus on alpha-glucosidase activity and postprandial hyperglycemia.

L-arginine and its derivatives, asymmetric and symmetric dimethylarginine (ADMA and SDMA) and L-homoarginine, have emerged as cardiovascular biomarkers linked to cardiovascular outcomes and various metabolic and functional pathways such as NO-mediated endothelial function. Cellular uptake and efflux of L-arginine and its derivatives are facilitated by transport proteins. In this respect the cationic amino acid transporters CAT1 and CAT2 (SLC7A1 and SLC7A2) and the system y+L amino acid transporters (SLC7A6 and SLC7A7) have been most extensively investigated, so far, but the number of transporters shown to mediate the transport of L-arginine and its derivatives is constantly increasing. In the present review we assess the growing body of evidence regarding the function, expression, and clinical relevance of these transporters and their possible relation to cardiovascular diseases.

Transport of L-Arginine Related Cardiovascular Risk Markers.

Exploration of Mekongga national park resulted in novel finding of anticancer property from Tetrameles nudiflora. The investigation of toxic features of T. nudiflora is vital for further studies of its pharmacological activities. Acute toxicity test was done on methanolic extracts of T. nudiflora in DDY mice. Animals were divided into 5 groups: Group 1 was given 1 ml solution of 2.5% Tween 80 in a single oral dose; Group 2, 3, 4 and 5 were orally administrated a single dose of 1, 2, 4 and 8 g/kg body weight T. nudiflora, respectively. Toxic effects of the extract were evaluated on the basis of behavioral observations in the form of locomotor activity; curiosity; defecation; urination and also animal mortality. Observations were carried out for 14 days. No significant changes on body weight, and behavioural activities were recorded. Mortality was recorded up to 22% of the male group, and 11% within the female group. The T.nudiflora extracts tested for toxicity against brine shrimp had 50% lethal concentration (LC50) values of 46.67 μg/ml. It can be concluded that methanol extracts of T. nudiflora are potential to be explored as anticancer (LC50=46.67 μg/ml). The extract is slightly toxic in male mice with Lethal Dose 50 (LD50) 12.6 g/kg body weight, and practically non toxic for female (LD50>15 g/kg body weight). Key words : Tetrameles nudiflora , brine shrimp lethality test, acute oral toxicity, LD 50.

https://www.jtrolis.ub.ac.id/index.php/jtrolis/article/download/224/pdf_5

Sofna D.S. Banjarnahor

Papers

Antioxidant properties of flavonoids

Inhibitory effect of koji Aspergillus terreus on alpha-glucosidase activity and postprandial hyperglycemia.

Transport of L-Arginine Related Cardiovascular Risk Markers.

Toxicological Evaluation of Tetrameles nudiflora Methanolic Extract

PENENTUAN LD50 DAUN CINCO (Cyclea barbata Miers.) PADA MENCIT