Antioxidant activity, phenol and flavonoid contents of some selected Iranian medicinal plants

In present study, we carried out a systematic record of the relative antioxidant activity in selected Iranian medicinal plant species' extracts. The total phenol varied from 24.1 ± 1 to 289.5 ± 5 mg g -1 in the extracts. Flavonoid contents were between 25.15 ± 0.8 and 78.3 ± 4.5 mg g-1. 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging effect of the extracts was determined spectrophotometrically. The highest radical scavenging effect was observed in Mellilotus officinalis with IC50 = 0.018 mg ml –1. The potency of radical scavenging effect of M. officinalis extract was about 4 times greater than synthetic antioxidant butylated hydroxy toluene (BHT). The greater amount of phenolic compounds leads to morepotent radical scavenging effect as shown by M. officinalis extrac

Nitric oxide radical scavenging potential of some Elburz medicinal plants

Some plants scavenge nitric oxide (NO) with high affinity. For this purpose, forty extracts from 26 medicinal plants, growing extensively in Elburz mountains, were evaluated for their NO scavenging activity. Total phenolic and flavonoid contents of these extracts were also measured by Folin Ciocalteu and AlCl3 colorimetric assays, respectively. Sambucus ebulus fruit aqueous extract and Pterocarya fraxinifolia leaf methanol extract showed better activity than others with IC50 equal to 29 and 65 g ml-1, respectively. NO is also implicated in inflammation and other pathological conditions, therefore very powerful scavenging activity of S. ebulus fruit extract may explain its very good anti-inflammatory activity. Phenolic and flavonoids contents of the extracts varied between 10.2 - 200.4 and 2.1 - 90.9 mg g-1 of extract, respectively. Good correlations could be found between total phenolic contents and NO scavenging activity through linear regression analysis (R2 = 0.63). There was also a better correlation between total flavonoids and NO scavenging activity (R2 = 0.73). High NO scavenging activity in plants can candidate them for testing their anti-inflammatory property.Key words: Antiinflammatory, flavonoid contents, medicinal plants, nitric oxide scavenging activity, phenolic contents, Sambucus ebulus, Pterocarya fraxinifolia

In vitro antioxidant analysis of Achillea tenuifolia

Achillea tenuifolia (AT) is one of the most herbs are being used by people as a traditional medicinal remedy. Antioxidant activity of AT different extracts and total flavonoid and phenol levels in the extracts were investigated in this study. Plant extracts were prepared by maceration method using ethyl acetate, methanol and methanol-water (1:1). Folin Ciocalteu reagent in terms of gallic acid equivalent achieved the total phenol's content. AlCl3 was used as a reagent for flavonoid determination. Flavonoid content of the plant extracts obtained in terms of quercetin equivalent. DPPH radical scavenging effect of the extracts was determined by UV spectroscopy. Also in order to determine lipid peroxidation inhibition of the extracts of A. tenuifolia, ferric thiocyanate method with BHT, a synthetic reference standard, was carried out in this study. Phenol contents were 43.97 ± 0.034, 74.16 ± 0.55 and 106 ± 0.693 mg g-1 in theethyl acetate, methanol and methanol-water extracts, respectively. Flavonoid amount obtained in the ethyl acetate, methanol and methanol-water extracts were 10.6 ± 1.85, 23.1 ± 0.5 and 190 ± 1.3 mg g-1, respectively. The percentage of DPPH radical scavenged by the most active extract (methanol-water) of A. tenuifolia was 92% at a concentration of 1 mgml-1 greater than 94% of BHT at 2 mgml-1. IC50 of methanol-water extract and BHT were 0.015 and 0.053 mgml-1, respectively. Lipid peroxidation inhibition was observed by the most polar extract of AT about 91.84%. Phenol and flavonoids content confirm theexistence of more polar hydroxyl containing chemical structures in the plant. The potency of radical scavenging effect of methanol-water extract was about 3.5 times greater than synthetic antioxidant BHT. The inhibitory activity of the extracts on the lipid peroxidation of linoleic acid in ferric thiocyanate test was also significant (> 90%). In this study we concluded that there is a direct relation between phenol and flavonoid content of plant extracts and the antioxidant activity. So that the greater amountof phenolic compounds leads to more potent radical scavenging and lipid peroxidation inhibition activities as it was observed in A. tenuifolia polar extract in the present study

Evaluation of free-radical quenching properties of standard Ayurvedic formulation Vayasthapana Rasayana

<p>Abstract</p> <p>Background</p> <p>Cellular damage induced by free-radicals like Reactive Oxygen and Nitrogen Species (ROS and RNS) has been implicated in several disorders and diseases, including ageing. Hence naturally occurring anti-oxidant rich-herbs play a vital role in combating these conditions. The present study was carried out to investigate the <it>in vitro </it>free-radical quenching capacity of a known <it>Ayurvedic </it>poly-herbal formulation called <it>Vayasthapana Rasayana.</it></p> <p>Methods</p> <p>Methanol extracts of <it>Vayasthapana Rasayana </it>formulation (VRF) were studied for <it>in vitro </it>total antioxidant activity along with phenolic content and reducing power. <it>In vitro </it>assays like DPPH, FRAP, ABTS scavenging to evaluate radical quenching potential were performed.</p> <p>Results</p> <p>The formulation has shown 94% at 0.1 mg/ml DPPH free-radical scavenging activity as against 84% at 0.1 mg/ml for standard ascorbic acid (IC₅₀value 5.51 μg/ml for VRF and 39 μg/ml for standard). It has a significant higher ferric reducing potential also (OD 0.87 at 700 nm & 0.21 at 0.1 mg/ml for VRF and standard, respectively). The total phenolic content (gallic acid equivalent) of the VRF is 8.3 mg per g of dry mass. Total antioxidant capacity of the formulation, estimated by FRAP was 1150 ± 5 μM Fe(II)/g dry mass. ABTS radical scavenging activity of VRF was 69.55 ± 0.21% at 100 μg/ml concentration with a IC₅₀value of 69.87 μg/ml as against 9% and 95% by ascorbic acid and Trolox (at 70.452 μg/ml and 0.250 μg/ml concentrations, respectively).</p> <p>Conclusion</p> <p>In Indian traditional <it>Ayurvedic </it>system, use of VRF is in regular practice for mainly combating age-related disorders and diseases as many of the components of the <it>Rasayana </it>are known for their free-radical scavenging activity. This study has validated the potential use of VRF as an anti-oxidant to fight age-related problems.</p

Screening of anti-dengue activity in methanolic extracts of medicinal plants

<p>Abstract</p> <p>Background</p> <p>Dengue fever regardless of its serotypes has been the most prevalent arthropod-borne viral diseases among the world population. The development of a dengue vaccine is complicated by the antibody-dependent enhancement effect. Thus, the development of a plant-based antiviral preparation promises a more potential alternative in combating dengue disease.</p> <p>Methods</p> <p>Present studies investigated the antiviral effects of standardised methanolic extracts of <it>Andrographis paniculata, Citrus limon, Cymbopogon citratus, Momordica charantia, Ocimum sanctum </it>and <it>Pelargonium citrosum </it>on dengue virus serotype 1 (DENV-1).</p> <p>Results</p> <p><it>O. sanctum </it>contained 88.6% of total flavonoids content, an amount that was the highest among all the six plants tested while the least was detected in <it>M. charantia</it>. In this study, the maximum non-toxic dose (MNTD) of the six medicinal plants was determined by testing the methanolic extracts against Vero E6 cells <it>in vitro</it>. Studies also determined that the MNTD of methanolic extract was in the decreasing order of <it>M. charantia </it>><it>C. limon </it>><it>P. citrosum, O. sanctum </it>><it>A. paniculata </it>><it>C. citratus</it>. Antiviral assay based on cytopathic effects (CPE) denoted by degree of inhibition upon treating DENV1-infected Vero E6 cells with MNTD of six medicinal plants showed that <it>A. paniculata </it>has the most antiviral inhibitory effects followed by <it>M. charantia</it>. These results were further verified with an <it>in vitro </it>inhibition assay using MTT, in which 113.0% and 98.0% of cell viability were recorded as opposed to 44.6% in DENV-1 infected cells. Although methanolic extracts of <it>O. sanctum </it>and <it>C. citratus </it>showed slight inhibition effect based on CPE, a significant inhibition was not reflected in MTT assay. Methanolic extracts of <it>C. limon </it>and <it>P. citrosum </it>did not prevent cytopathic effects or cell death from DENV-1.</p> <p>Conclusions</p> <p>The methanol extracts of <it>A. paniculata </it>and <it>M. charantia </it>possess the ability of inhibiting the activity of DENV-1 in <it>in vitro </it>assays. Both of these plants are worth to be further investigated and might be advantageous as an alternative for dengue treatment.</p

Iron chelating activity, phenol and flavonoid content of some medicinal plants from Iran

Thalassemia major is characterized by anemia, iron overload, further potentiation of reactive oxygen species (ROS) and damage to major organs, especially the cardiovascular system. Antioxidant andother supportive therapies protect red blood cells (RBC) against antioxidant damage. Chelation therapy reduces iron-related complications and thereby improves quality of life and overall survival. The poor oral bioavailability, short plasma half-life and severe side effects of available chelators are still not optimal. In this study, iron chelating activity of some medicinal plants was determined to findalternative sources with lower side effects in thalassemic patients. Extracts were prepared by soaking dry material of the selected plant in appropriate solvent. Phenol and flavonoid content of the extractwere measured by folin ciocalteu and AlCl3 assays. Phenol content of the extracts varied between 9 -290 mg/g. The largest amount of phenolic compounds and highest chelating activity were found inMellilotus arvensis. All extracts contained various amount of flavonoids from 10 to 60 mg/g. Extracts with high phytochemicals and chelating activity can be observed as a good source of new agents forthalassemic patients

An experimental investigation of mechanical properties, forming limit curves, and bending behavior of aluminum-polymer sandwich composites

This study aimed to investigate the forming limit diagrams (FLDs), mechanical properties, and bending behavior of the three kinds of sandwich composites. The core layer in all sandwich sheets consisted of polyethylene, and just the skin layers were chosen to be AA5754 or AA3105. The results showed that the sandwich sheets are an appropriate choice to be used instead of the monometallic sheets. According to the 3-point bending test results, the flexural strength of the AL 3105/Polyethylene/AL 3105 sandwich composite is about 30 percent less than the AA3105 monometallic layer. Also, the formability of the metallic sandwich composites with non-identical skin layers was studied. The results demonstrated that using one layer AA 3105 and one layer AA5754 instead of AA5754 for both skin layers, although formability decreased about 11% in the plane strain region, the cost of fabricating the composite was decreased sheet reduces almost 75%. As a result, using skin layers with the different grades of aluminum is an appropriate way to reduce the cost of fabricating the aluminum-polymer sandwich composites, in which the formability does not decrease significantly