• Korean Journal of Weed Science
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• v.10 no.4
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• pp.305-311
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• 1990

Effects of light on germination of major weeds in upland fields were examined. Most weeds showed light positive response to germination at above 25$^{\circ}C$, but germination percentage was very low at lower temperatures. Red light promoted germination of Amaranthus lividus, Portulaca oleracea, and A. retroflexus, but far-red light inhibited germination. Germination resposnse of A. retroflexus, A. lividus, and P. oleracea showed reversible reaction to red/far-red light, and thus it seemed that phytochrome was involoved in seed germination, Echinochloa crusgali and Eleusine indica showed higher germination percentage under the conditions of continuous illumination of red, white, and bule lights, and thus it was estimated that blue light pigment (HIR, high irradiation reaction) related to long time illumination was involved in germination in addition to phytochrome.

• Journal of Life Science
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• v.28 no.8
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• pp.892-899
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• 2018

Portulaca oleracea L. is an edible plant widely consumed in daily diet throughout Europe, Asia and America. In this study, protective effects of P. oleracea L. extracts against oxidative stress and matrix metalloproteinase (MMP) activity induced by ultraviolet B (UVB) radiation were investigated using HaCaT immortal human keratinocytes. In this context, the mRNA and protein productions of MMPs (MMP-1, -2, and -9) and type I procollagen, which are major markers of photoaging induced by UVB radiation in HaCaT keratinocytes, were evaluated. Furthermore, UVB-induced reactive oxygen species (ROS) generation and mRNA and protein expression levels of superoxide dismutase-1 (SOD-1), oxygenase-1 (OH-1), and nuclear factor-erythroid 2-related factor-2 (Nrf-2), all of which are associated with the antioxidant balance, were investigated. As shown by the results, UVB radiation induced ROS formation and led to increased production of MMPs and decreased collagen production in human keratinocytes, which resulted in skin photoaging or photodamage. The treatment with P. oleracea L. extracts downregulated MMP (MMP-1, -2, and -9) production and upregulated type I procollagen expression in UVB-induced HaCaT cells. Furthermore, treatment with the extracts decreased UVB-induced ROS generation and increased the expression of antioxidant enzymes, such as SOD-1 and OH-1, through the Nrf-2 pathway. Taken together, these results suggest that P. oleracea L. extracts could be a potential cosmeceutical agent for the prevention of skin photoaging or photodamage.

• KSBB Journal
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• v.18 no.3
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• pp.165-169
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• 2003

The antioxidative activity of Portulaca oleracea was tested using in vitro experimental models. Antioxidative activities were determined by measuring DPPH radical scavenging activity and lipid peroxide using 2-thiobarbituric and (TBA). The crude extract was sequentially partitioned with n-hexane, 15% aq. MeOH, EtOAc, n-BuOH, $H_2O$. A remarkable antioxidative effect was observed in the EtOAc and n-BuOH fractions. The DPPH radical scavenging effect ($IC_{50}$=17.90 $\mu\textrm{g}$/ml) of the n-BuOH soluble fraction was comparable with that of the natural antioxidant, $\alpha$-tocopherol ($IC_{50}$=6.99 $\mu\textrm{g}$/ml) and the inhibition effect of lipid peroxidation in mouse liver homogenate was similar to that of the natural antioxidant, L-ascorbic acid at a concentration of 1.0 mg/ml to 5 mg/ml.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.4
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• pp.538-543
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• 2011

This study was conducted for the antihyperlipidemic effect of ethanol extract from Portulaca oleracea in high fat diet-induced obese mice after having injected the ethanol extract from Portulaca oleracea to the obese mice with high fat diet. The 30 six-week-old male C57BL/6J mice were divided into 3 groups of 10 and fed for 5 weeks to be obese with high fat diet. Thereafter, for 4 weeks, ethanol extract from Portulaca oleracea was provided through oral injection to the 3 groups: control group (HFD), group injected with 75 mg/kg of ethanol extract from Portulaca oleracea (HFD+POE 75) and the group injected with 125 mg/kg of ethanol extract from Portulaca oleracea (HFD+POE 125). The serum and liver lipid and the alanine transaminase (ALT) and aspartate transaminase (AST) activity were measured. The result showed that there was no significant difference in weight gain and feed intake, and the feed efficiency ratio was significantly low in the group provided with ethanol extract from Portulaca oleracea. Serum total cholesterol was significantly low in the group of ethanol extract from Portulaca oleracea (HFD+POE 125). It appeared that all the groups provided with ethanol extract from Portulaca loeracea reduced plasma triglyceride significantly according to the ethanol extract from Portulaca oleracea dose. There was no dose dependency of HDL-cholesterol to the dose of ethanol extract of Portulaca oleracea. LDL-cholesterol was low in the group dosed with high ethanol extract from Portulaca oleracea (HFD+POE 125). There was difference of total cholesterol, triglyceride and total lipid contents in liver. AI (atherogenic index) and CRF (cardiac risk factor) were significantly low in the group with high dose of ethanol extract from Portulaca oleracea (HFD+POE 125). There was no difference of serum AST activity, however, serum ALT activity was significantly low in the group with high dose of ethanol extract from Portulaca oleracea (HFD+POE 125).

• Herbal Formula Science
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• v.9 no.1
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• pp.367-374
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• 2001

This study was performed to investigate the effects of purslane extracts on growth inhibition of Escherichia coli KCTC 2441. The purslane extract is effective on retarding growth of Escherichia coli KCTC 2441 and effect of its extract was founded from 1% concentration. At 7% the growth of Escherichia coli KCTC 2441 was suddenly retarded. The stem of purslane in a sunny place on June is more effective than its leaf. Leaves with a red violet color has high effect on retarding growth of Escherichia coli KCTC 2441. These results suggest that purslane extract is effective in growth inhibition of Escherichia coli KCTC 2441.

• Korean Journal of Plant Resources
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• v.10 no.2
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• pp.169-174
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• 1997

This study was conducted to obtain basic information needed to develop the effective weed control method by using thermal weeder which uses LPG as fuel. For survey of weed distribution in herb field, weed species were investigated at two kinds of herb field of Codonopsis lanveolata and Aster scaber located in Hoengseongkun and Hwacheonkun, Kangwondo. In Codonopsis lanveolata field, Digitaria sanguinalis and Persicaria viridis L were dominated. In Aster scaber field, Digitaria sanguinalis and Erigeron canadensis were dominated. In general, Grasses weeds in herb were more dominated than other broadleaf and Cyperaceae weeds. The treatments of $H_2SO_4$ in weed seeds were more effective for germination of several weeds, compared with that nontreated weed seeds. However, the rate of germination differed depending on weed species and tereatment time of $H_2SO_4. Also, viability of weed seeds was significantly affected by irradiation time and temperature. As the temterature and treatment time of irradiation increased, the rate of germination was decreased.

• Journal of Life Science
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• v.27 no.12
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• pp.1430-1436
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• 2017

This study assessed the effects of treatment with sap extract from onion residues postharvest and purslane on the quality and quantity of organic onions. At the bending stage, onions treated with the sap extract showed vigorous growth, with higher plant heights, more leaves, and longer sheath lengths than untreated onions. The onion yield was significantly increased when the plant was treated with extracted sap as compared with that of untreated plants (p<0.05). The bulb weight distribution of onions in the mixed onion and purslane treatment was also significantly increased (~300 g) as compared with that of the other treatment (p<0.05). Except for CaO and S, the mineral content of the onions produced from plants treated with the onion and purslane extract mixture was higher than those of onions in the other treatment. The hardness of onions produced from plants treated with the onion and purslane extract was significantly increased (8% and 20%, respectively) as compared with that of onions produced from plants treated with the onion extract only or no treatment (p<0.05). However, there was no significant difference in the sugar contents of the onions produced from extract-treated and nonextract-treated plants. Postharvest, the content of inorganic components (phosphate, calcium, sulfuric acid, and manganese) was higher in soil treated with the onion extract than in soil treated with the onion and purslane extract and non-treated soil. It can be concluded that residues left after onion harvests and purslane extract can be used as natural and environmentally friendly materials for the cultivation of organic onions.

• Agrochemical news magazine
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• v.14 no.6 s.117
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• pp.25-29
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• 1993

• Agrochemical news magazine
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• v.22 no.5 s.168
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• pp.45-47
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• 2001

• Journal of Life Science
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• v.28 no.4
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• pp.421-428
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• 2018

Postprandial hyperglycemia plays an important role in the development of Type 2 Diabetes and diabetic complications. Controlling postprandial hyperglycemia is the most important factor for reducing the risks of diabetic complications in Type 2 diabetic patients. This study was designed to determine whether Portulaca oleracea L. extract suppresses the activation of carbohydrate-digesting enzymes, and lowers postprandial hyperglycemia in diabetic mice through streptozotocin. P. oleracea was extracted with either 80% ethanol (PEE) or water (PWE), and the extract solutions were concentrated. The ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibition assays were performed using the chromogenic method. Normal mice and STZ-induced diabetic mice were orally treated with PEE, PWE (300 mg/kg of body weight) or acarbose (100 mg/kg of body weight), with soluble starch (2 g/kg of body weight). The ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibitory effectiveness by PEE were markedly more effective than PWE, and both extracts indicated a higher effectiveness than the acarbose (positive control). The rise in postprandial blood glucose due to starch loading was markedly inhibited in the PEE group when compared to the control group in diabetic and normal mice. Furthermore, the area under the concentration-time curve values were markedly declined by the PEE injection in the diabetic group when compared to that exerted for the control group. These results demonstrate that P. oleracea extracts lower postprandial hyperglycemia by inhibiting carbohydrate-digesting enzymes, and that the ethanol extract is more efficacious than the water extract.