scholarly journals Bioactivity of Rumex obtusifolius (Polygonaceae)

2010 ◽  
Vol 62 (2) ◽  
pp. 387-392 ◽  
Author(s):  
Diane Harshaw ◽  
Lutfun Nahar ◽  
Brahmachari Vadla ◽  
Gadria Saif-E-Naser ◽  
Satyajit Sarker
Keyword(s):  
Free Radical ◽  
Solid Phase ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Bacterial Strains ◽  
Meoh Extract ◽  
Rumex Obtusifolius ◽  
Brine Shrimp Lethality Assay ◽  
Ethnobotanical Uses

Rumex obtusifolius L. (Polygonaceae), commonly known as 'broad-leaf dock', is one of the most common Irish wayside weeds, and it also occurs in silage fields, on river banks, in ditches and on waste grounds. The ethnobotanical uses of this species include its use as an antidote to nettle, depurative, astringent, laxative, and tonic, and in the treatment of sores, blisters, burns, cancer and tumors. The bioactivities of n-hexane, dichloromethane (DCM) and methanol (MeOH) extracts of the leaves of R. obtusifolius were assessed using the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay, the newly developed micro-titer-based antimicrobial assay incorporating resazurin as an indicator of cell growth, and the brine shrimp lethality assay. The most potent free radical scavenging activity was displayed by the MeOH extract with a RC50 value of 7.80 x 10-2 mg/mL. Among the fractions obtained from solid-phase extraction (SPE) of the MeOH extract, the 50% aqueous methanolic SPE fraction exhibited the highest levels of free radical scavenging property (RC50 = 1.05 x 10-2 mg/mL). While the n-hexane extract did not show any antibacterial activity at test concentrations, the DCM extract was active only against Escherichia coli. However, the MeOH extract as well as the 50% and 80% SPE fractions of the MeOH extract showed significant antibacterial property against all bacterial strains tested. None of the extracts or fractions exhibited any significant toxicity towards brine shrimps.

scholarly journals Bioactivity of extracts of Centaurea polyclada dc. (Asteraceae)

2009 ◽  
Vol 61 (3) ◽  
pp. 447-452 ◽  
Author(s):  
Melanie Granger ◽  
Emilie Samson ◽  
Severine Sauvage ◽  
Anisha Majumdar ◽  
Poonam Nigam ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Free Radical ◽  
Solid Phase Extraction ◽  
Brine Shrimp ◽  
Solid Phase ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Phase Extraction ◽  
Brine Shrimp Lethality Assay

The free radical-scavenging property, antibacterial activity, and brine shrimp toxicity of n-hexane, dichloromethane (DCM), and methanol (MeOH) extracts of Centaurea polyclada, an endemic Turkish species, were assessed using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, the resazurin microtiter plate-based assay, and the brine shrimp lethality assay, respectively. The DCM and MeOH extracts of C. polyclada exhibited free radical-scavenging ability with RC50 values 1.17 and 0.015 mg/mL, respectively. Among solid-phase extraction fractions of the MeOH extract, the fraction eluted with 60% MeOH in water demonstrated the highest level of free radical-scavenging activity (RC50 = 0.016 mg/mL). Only the DCM extract showed considerable antibacterial activity against all nine test strains except Escherichia coli, with MIC ranging from 1.25 to 2.50 mg/mL. This antibacterial activity pattern was also observed with solid-phase extraction fractions of the DCM extract with varied potencies. None of the extracts showed any significant toxicity towards brine shrimps (LD50 = >1.00 mg/mL).

Composition of Dithyrea wislizenii fruit extract and free-radical scavenging activity of its constituents

2012 ◽  
Vol 90 (8) ◽  
pp. 652-659 ◽  
Author(s):  
Sabine Montaut ◽  
Julie Grandbois ◽  
Laura S. Rossi ◽  
Sonia Kamal ◽  
James Khouri ◽  
...  
Keyword(s):  
Free Radical ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Positive Control ◽  
Free Radical Scavenging ◽  
Free Radical Scavenging Activity ◽  
Scavenging Activity ◽  
Activity Assay ◽  
Fruit Extract ◽  
Brine Shrimp Lethality Assay

Glucolesquerellin (2), glucohesperin (3), quercetin 3-O-sophoroside (4), and quercetin 3-O-sophoroside-7-O-glucoside (5), isolated from the fruit of Dithyrea wislizenii , were quantified by HPLC. The fruit extract and flavonoids were not found to be toxic by using a brine shrimp lethality assay. The fruit extract and the flavonoids and glucosinolates were submitted to a free-radical scavenging activity assay with the diphenylpicrylhydrazyl radical (DPPH•). The concentration of quercetin (6) (a positive control for the flavonoids) able to scavenge 50% of DPPH• (SC50) was 32 ± 2 µmol/L (or 4 ± 1 µg/mL), which was about 27 times more potent than the crude extract. Compounds 4 and 5 had a SC50, the concentration of the compound required to scavenge 50% of the DPPH•, of 78 ± 1 µmol/L and 113 ± 10 µmol/L, respectively. The positive control for the glucosinolates, glucoraphasatin, (1) had a SC50 of 1768 ± 60 µmol/L. The glucosinolates 2 and 3 had a SC50 of 7819 ± 1968 and 970 ± 63 µmol/L, respectively.

scholarly journals Bioactivity of Centaurea persica boiss. (Asteraceae)

2012 ◽  
Vol 64 (2) ◽  
pp. 517-523 ◽  
Author(s):  
Satyajit Sarker ◽  
Lutfun Nahar ◽  
Srikanth Gujja ◽  
Shazi Begum ◽  
Sezgin Celik
Keyword(s):  
Antibacterial Activity ◽  
Free Radical ◽  
Solid Phase ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Disc Diffusion ◽  
Dpph Assay ◽  
Meoh Extract ◽  
E Coli ◽  
Diffusion Assay

The free-radical-scavenging property, antibacterial activity and brine shrimp toxicity of petroleum ether (PE), dichloromethane (DCM) and methanol (MeOH) extracts of Centaurea persica, a Turkish medicinal plant, were assessed using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, the resazurin microtiter plate based assay, and the brine shrimp lethality assay, respectively. Additionally, the disc diffusion assay was also used to assess antibacterial activity. Only the MeOH extract of C. persica exhibited a significant free-radical-scavenging property in the DPPH assay, with an RC50 value of 0.025 mg/mL. However, in the TLC-based qualitative assay, petroleum ether and DCM extracts showed an extremely low level of free-radical-scavenging property. Among the solid-phase extraction fractions of the MeOH extract, the fractions eluted with 60% and 80% MeOH in water exhibited the highest level of free-radicalscavenging activity (RC50 = 0.010 and 0.015 mg/mL, respectively). While DCM extract showed reasonable antibacterial activity against five out of the nine test strains both in the disc diffusion assay and in the resazurin assay, the MeOH extract was highly active against both Escherichia coli and ampicillin-resistant E. coli strains. Among the solid-phase extraction fractions of the MeOH extract, fractions eluted with 80% MeOH in water and 100% MeOH displayed significant antibacterial potencies against both E. coli species. None of the extracts showed any significant toxicity towards brine shrimps (LD50 = >1.00 mg/mL).

scholarly journals Antibacterial and free-radical-scavenging properties of Stachys schtschegleevii (Lamiaceae)

2010 ◽  
Vol 62 (4) ◽  
pp. 941-945 ◽  
Author(s):  
Malvika Abichandani ◽  
Lutfun Nahar ◽  
Poonam Singh ◽  
Rohit Chitnis ◽  
H. Nazemiyeh ◽  
...  
Keyword(s):  
Free Radical ◽  
Bacterial Infections ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Positive Control ◽  
Free Radical Scavenging ◽  
Meoh Extract ◽  
Inflammatory Conditions ◽  
Iranian Traditional Medicine ◽  
Radical Scavenging Properties

Stachys schtschegleevii Sosn. (Lamiaceae alt. Labiatae) is one of 34 Stachys species found in Iran, and is morphologically similar to Stachys inflata. This plant has been used in the Iranian traditional medicine as a remedy for bacterial infections, rheumatic fever and other inflammatory conditions. The n-hexane, dichloromethane (DCM) and methanol (MeOH) extracts of the non-flowering aerial parts of this plant were assessed for their antibacterial and freeradical- scavenging activities using the micro-titer-based antimicrobial assay incorporating resazurin as an indicator of cell growth and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, respectively. While the n-hexane extract did not show any free-radical-scavenging activity, the MeOH extract showed the highest level of activity with a RC50 value of 2.94 x 10-2 mg/mL, which was about ten-fold less active than the positive control Trolox? (RC50 = 2.60 x 10-3 mg/mL). None of the extracts showed any antibacterial property against Bacillus cereus and B. subtilis at test concentrations. However, all extracts were active against ampicillin-resistant Escherichia coli and Staphylococcus aureus. The MeOH extract was the most potent (MIC range 1.56-6.25 mg/mL) among the extracts and was most active against ampicillin-resistant E. coli (MIC = 1.56 mg/mL).

scholarly journals Utilization of tomato waste as a source of polyphenolic antioxidants

2010 ◽  
pp. 187-194 ◽  
Author(s):  
Sladjana Savatovic ◽  
Gordana Cetkovic ◽  
Jasna Canadanovic-Brunet ◽  
Sonja Djilas
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Solid Phase ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Free Radical Scavenging ◽  
Ultrasonic Bath ◽  
Tomato Waste ◽  
Flavonoid Fraction

This study is concerned with the effects of two extraction procedures (using ultrasonic bath and high performance homogenizer) on the extraction efficiency of polyphenolics present in the tomato waste. The isolation of flavonoid fraction of obtained extracts was performed by solid-phase extraction. The antioxidant activity of flavonoid fractions was determined using different spectrophotometric tests, including reducing power and 2,2- diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assays. The content of total polyphenolics and flavonoids in extract obtained employing homogenizer (E2) was higher than in the extract obtained employing ultrasonic bath (E1), and it was 14.33 mg/g and 7.70 mg/g, respectively. The flavonoid fraction (EF2) of extract E2 showed higher antioxidant activity than flavonoid fraction (EF1) of extract E1. The DPPH free radical scavenging activity of fractions EF1 and EF2, expressed as EC50 value, were 0.78 mg/ml and 0.45 mg/ml, respectively. The obtained results show that tomato wastes can be used as an easily accessible source of antioxidant polyphenolics.

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