Antioxidant activity of stem and root extracts of Rhubarb (Rheum ribes): An edible medicinal plant

The antioxidant activity of chloroform and methanol extract of roots and stems of Rhubarb (Rheum ribes L.), which are used for medicinal purposes and also its fresh stems and petioles are consumed as vegetable, was studied. The antioxidant potential of both extracts of roots and stems were evaluated using different antioxidant tests, namely total antioxidant (lipid peroxidation inhibition activity), DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging, superoxide anion radical scavenging, ferric reducing power, and cupric reducing power (CUPRAC), and metal chelating activities. Total antioxidant activity was also measured according to the beta-carotene bleaching method, and all four extracts exhibited stronger activity than known standards, namely butylated hydroxytoluene (BHT) and alpha-tocopherol. Particularly, higher activity was exhibited by roots with 93.1% and 84.1% inhibitions of chloroform and methanol extracts, while 82.2% and 82.0% inhibitions by stem extracts, respectively. However, both methanol extracts exhibited higher DPPH radical scavenging activity than the corresponding chloroform extracts, moreover, methanol extract of the stems showed better activity than BHT. In addition, both root extracts showed more potent superoxide anion radical scavenging activity than BHT, and comparable with well known radical scavenger L-ascorbic acid. Except chloroform extract of the roots, the other three extracts exhibited better metal chelating activity than quercetin. Also, total phenolic and flavonoid contents in both extracts of the roots and stems of R. ribes were determined as pyrocatechol and quercetin equivalents, respectively. (c) 2006 Elsevier Ltd. All rights reserved

Evaluation of fruit extracts of six Turkish Juniperus species for their antioxidant, anticholinesterase and antimicrobial activities

BACKGROUND: Juniperus L. (Cupressaceae) species are mostly spread out in the Northern Hemisphere of the world, and some of them are used as folkloric medicines. The fruits of some species are eaten. Since oxidative stress is one of the reasons for neurodegeneration and is associated with the Alzheimer's disease (AD), the extracts prepared from the fruits of six Juniperus species were screened for their antioxidant activity. Therefore, the extracts were also evaluated against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), which are chief enzymes in the pathogenesis of AD. In addition, antimicrobial activity was also evaluated

Preclinical study of the medicinal plants for the treatment of malignant melanoma

Melanoma is the most aggressive type of skin cancer and originates from pigment-containing cells called melanocytes. The incidence of melanoma has been increasing worldwide. In the current study, the cytotoxic and photo-cytotoxic activities of different medicinal plants from Lamiaceae (Salvia cedronella,Salvia chionantha, andSalvia adenophylla), Asteraceae (Klasea kurdica,Klasea bornmuelleri, andAchillea millefolium), Apiaceae (Cuminum cyminum,andAnethum graveolens), and Polygonaceae (Rumex crispus) families were studied against HT 144 (Human malignant melanoma) cancer cell lines. The activities were performed by employing the MTT assay. Moreover, the apoptotic effects of the plant extracts were investigated by flow cytometry with annexin V/PI dual staining technique. The production of intracellular ROS by DCFH-DA technique and the effects of TNF-alpha secretion on apoptosis were also investigated. All plant extracts exhibited cytotoxic, and photo-cytotoxic effects against HT 144 cancer cells.Salviaspecies andKlaseaspecies induced apoptosis via intracellular ROS generation secreted by TNF-alpha.On the other hand,A. millefolium,C. cyminum,A. graveolens, andR. crispusextracts induced apoptosis due to the intracellular generation of ROS, but, via the different pathway. In conclusion, this study indicates that the tested medicinal plant extracts have the potential in the treatment of melanoma

Effect of Sideritis leptoclada against HT-144 human malignant melanoma

Sideritis leptoclada O. Schwarz et P.H. Davis extracts were evaluated for its singlet oxygen production capacity using spectrophotometric method. The extracts producing singlet oxygen were then evaluated for cytotoxicity against malignant melanoma cancer (HT-144) and fibroblast (3T3) cell lines using the 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay. The photocytotoxicity against the HT-144 human melanoma cell line in the presence of illumination (similar to >= 400 nm) was also evaluated. In the standard MTT assay, the ethanol extract of S. leptoclada (100 mu g/ml) showed 83.49 +/- 3.33% inhibition of HT-144 cancer cells, whereas in the illuminated MTT assay, it showed 77.46 +/- 1.97% inhibition of HT-144 cancer cells. The effects of ethanol extract on reactive oxygen species production, apoptosis, and tumor necrosis factor-alpha secretion were also evaluated on HT-144 cell lines. The extract triggered an increase in intracellular reactive oxygen species production and tumor necrosis factor-alpha secretion compared with the respective controls. Thus, the ethanol extract may cause apoptosis. The LC-MS/MS analyses of S. leptoclada ethanolic extract showed that it has quinic acid (137213 +/- 11.25 mu g/g extract), malic acid (1468 +/- 0.16 mu g/g extract), chlorogenic acid (881.7 +/- 0.06 mu g/g extract), and apigetrin (223.2 +/- 0.13 mu g/g extract) as major constituents. The ethanolic extract of S. leptoclada should be further investigated as a potential treatment for malignant melanoma cancer. (C) 2018 Wolters Kluwer Health, Inc. All rights reserved