• Korean Journal of Food Science and Technology
• /
• v.15 no.3
• /
• pp.209-214
• /
• 1983

Analytical methods on Stevia sweeteners are compared for their reproducibilities and recoveries. It is possible to separate stevioside, rebaudioside A, rebaudioside C, and dulcoside A through HPLC analysis. Steviolbioside, in addition to above 4 Stevia sweeteners, is detected through TLC scanner and TLC-FID assays. C.V.s on stevioside and rebaudioside A in HPLC analysis are 1.39 and 4.89%, which shows outstanding reproducibilities of this method. The recoveries of stevioside in HPLC, TLC scanner, and TLC-FID analyses are 97.7 89.4, and 97.3%. The recoveries of rebaudioside A in HPLC, TLC scanner, and TLC-FID assays are 90.8, 90.1, and 75.8%. Total content of Stevia sweeteners in 8 strains tested, ranges from 5 to 17% as dry weight basis.

• Journal of Applied Biological Chemistry
• /
• v.61 no.2
• /
• pp.205-211
• /
• 2018

Rebaudioside A is a natural sweetener isolated from Stevia rebaudiana Bertoni, one of the glycosides based on steviol. Recent studies have shown that rebaudioside A inhibits the inflammatory response by inhibiting cytokines secretion such as interleukin-$1{\alpha}/1{\beta}$ in activated RAW264.7 mouse macrophage cells by LPS. However, the inhibitory mechanism of inflammation by rebaudioside A in the presence of LPS has not been fully elucidated. Therefore, in this study, we tried to investigate the anti-inflammatory activity of rebaudioside A at the protein level when RAW264.7 cells were stimulated by LPS. The inducible nitric oxide synthase protein expression level was reduced in the group treated with $250{\mu}M$ rebaudioside A compared to the LPS-treated group. In addition, the mRNA expression level of $NF-{\kappa}B$, which is a representative nuclear transcription factor by inflammatory signal, was also decreased as compared with that of LPS-treated group. In addition, $NF-{\kappa}B$ and inhibitor-${\kappa}B$ ($I-{\kappa}B$) complexes that are known to be dissociated by $I-{\kappa}B$ phosphorylation and ubiquitination were less phosphorylated than LPS treated group in the presence rebaudioside A. Finally, we could find that rebaudioside A was involved in the $NF-{\kappa}B$ pathway through reducing extracellular signal-regulated kinase1/2 phosphorylation in a concentration-dependent manner. These results suggest that rebaudioside A might suppress inflammatory reaction through MAPK and $NF-{\kappa}B$ regulation in LPS-stimulated RAW264.7.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.43 no.2
• /
• pp.157-164
• /
• 2017

Stevia (Stevia rebaudiana) is a perennial plant of the genus Stevia, originated in South America. It stores many forms of glycosides, mainly stevioside and rebaudioside A, in which steviol is the basic structure. Steviol glycosides, widely used as sweeteners, are superior to sugar in sweetness. Recently, it has been reported that steviol glycosides are involved not only in the skin whitening and anti-inflammatory effect but also in enhancing skin barrier function through tight junction regulation. Thus, we examined anti-inflammatory effect of rebaudioside A and tried to identify its potential for improving atopic dermatitis as cosmetic ingredients. To investigate the anti-inflammatory effect, cell viability and mRNA expression level of inflammation-related cytokines were measured using mouse macrophage RAW264.7 cells. Cell counting kit 8 (CCK-8) assay was carried out to measure cell viability and the maximum concentration without cytotoxicity was set to $250{\mu}M$. A quantitative real-time RT-PCR method was used for the study of the inflammatory suppression of rebaudioside A. Rebaudioside A inhibited expression of inducible nitric oxide synthase (iNOS) up to 47% and COX-2 up to 41% compared to LPS treated condition. NO synthesis was decreased by rebaudioside A. Also, mRNA expression of interleukin (IL)-$1{\alpha}$, IL-$1{\beta}$ and IL-6 in LPS-stimulated RAW264.7 cells was decreased to 40%, 45% and 59%, respectively, as a concentration-dependent manner. In conclusion, rebaudioside A inhibited the inflammatory response by regulation of cytokine gene expression. From these results, we expect that steviol glycoside, such as rebaudioside A, can be used as a material for improving atopic dermatitis in the future.

• Korean Journal of Breeding Science
• /
• v.43 no.5
• /
• pp.442-447
• /
• 2011

This study was carried out to assess the potential of hypocotyl explants for multiple-propagation by intensive sweetener variety with high yielding in stevia of self-fertilization. Agronomical character of self-fertilization shown a height range 72.0~120.7 cm, branch's 4.9~56.6 in stevia. Selection of high content of Rebaudioside A (RA) from segregating population in mixing variety have a variety, 'DA1' (55.2%) from HPLC analysis. On a developing of multiple-propagation in stevia, hypocotyl explants used to select for reasonable medium under the influence of each plant growth regulators concentrations. In a Mix treatment of plant growth regulators, as Murashige and Skoog medium with 1.5 mg/L BA and 0.5 mg/L Kinetin showed the most favorable. We got the multiple-propagation of 30 shoots from one inoculated hypocotyl explants as the result of these bases. Rooting induced superbly on MS medium with 0.1 mg/L IBA with inoculated shoots. All of the rooting plants were adapted to a normal seedling. This method of multi-propagation is used effectively in Rebaudioside A productivity elevation.

• Food Science and Preservation
• /
• v.11 no.4
• /
• pp.491-495
• /
• 2004

Consumers were tend to purchase more natural sweeting materials then atificial sweeting materials because of safety and the consumed amount of natural sweeting material was increased sharply with consumers concern to health. The proper harvest time with changes of sweeting material contents was investigated in the purpose of cultivation and utilization on functional foodstuff, Soluble solid content and extraction yield were increased with growth priod, but pH was decreased. Color value, transmittance and browning color showed little. L, a, b values was changed a little. Stevioside ratio($68.97\%$) in sweetness components was decreased to $61.09\%$. Rebaudioside A ratio was increased from $20.83\%\;to\;27.52\%$ stevioside contents was maximized to $12.80\%$ of August. The highest sweetening potencies of stevia leaves was 2530times to sugar. The stevia leaves harvested at May showed the best deliciousness.

• Archives of Pharmacal Research
• /
• v.25 no.6
• /
• pp.725-746
• /
• 2002

The demand for new alternative "low calorie" sweeteners for dietetic and diabetic purposes has increased worldwide. Although the currently developed and commercially used highly sweet sucrose substitutes are mostly synthetic compounds, the search for such compounds from natural sources is continuing. As of mid-2002, over 100 plant-derived sweet compounds of 20 major structural types had been reported, and were isolated from more than 25 different families of green plants. Several of these highly sweet natural products are marketed as sweeteners or flavoring agents in some countries as pure compounds, compound mixtures, or refined extracts. These highly sweet natural substances are reviewed herein.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.26 no.1
• /
• pp.69-89
• /
• 1981

Stevia (Stevia rebaudiana Bertoni) is a perennial herb widely distributed in the mountainous area of Paraguay. It belongs to the family Compositae and contains 6 to 12 percent stevioside in the leaves. Stevioside is a glucoside having similar sweetening character to surgar and the degree of sweetness is approximately 300 times of sugar. Since Korea does not produce any sugar crops, and the synthetic sweetenings are potentially hazardous for health, it is rather urgent to develop an economical new sweetener. Consequently, the current experiments are conducted to establish cultural practices of stevia, a new sweetening herbs, introduced into Korea in 1973 and the results are summarized as followings: 1. Days from transplanting of cuttings to the flower bud formation of 6 stevia lines were similar among daylengths of 8, 10 and 12 hours, but it was much greater at daylengths of 14 or 24 hour and varietal differences were noticable. All lines were photosensitive, but a line, 77013, was the most sensitive and 77067 and Suweon 2 were less sensitive to daylength. 2. Critical daylength of all lines seemed to be approximately 12 hours. Growth of plants was severely retarded at daylengths less than 12 hours. 3. Cutting were responded to short daylength before rooting. Number of days from transplanting to flower bud formation of 40-day old cuttings in the nursery bed was 20 days and it was delayed as duration of nursery were shorter. 4. Number of days from emergence to flower bud formation was shortest at short day treatment from 20 days after emergence. It was became longer as initiation of short day treatment was earlier or later than 20 days. 5. Plant height, number of branches, and top dry weight of stevia were reduced as cutting date was delayed from March 20 to May 20. The highest yield of dry leaf was obtained at nursery duration of 40-50 days in march 20 cutting, 30-40 days in April 20 cutting, and 30 days in May 20 cutting. 6. An asymptotic relationship was observed between plant population and leaf dry weight. Yield of dry leaf increased rapidly as plant population increased from 5,000 to 10,000 plants/10a with a reduced increasing rate from 10,000 to 20,000 plants/l0a, and levelled off at the plant population higher than 20,000 plants/l0a. 7. Stevia was adaptable in Suweon, Chengju, Mokpo and Jeju and drought was one of the main factors reducing yield of dry leaf. Yield of dry leaf was reduced significantly (approximately 30%) at June 20 transplanting compared to optimum transplanting. 8. Yield of dry leaf was higher in a vinyl house compared to unprotected control at long daylength or natural daylength except at short day treatment at March 20. Higher temperature ill a vinyl house does not have benefital effects at April 20 transplanting. 9. The highest content of stevioside was noted at the upper leaves of the plant but the lowest was measured at the plant parts of 20cm above ground. Leaf dry weight and stevioside yield was mainly contributed by the plant parts of 60 to 120cm above ground but the varietal differences were also significant. 10. Delayed harvest by the time of flower bud formation increased leaf dry weight remarkably. However, there were insignificant changes of yield as harvests were made at any time after flower bud formation. Content of stevioside was highest at the time of flower bud formation and earlier or later harvest than this time was low in its content. The optimum harvesting time determined by leaf dry weight and stevioside content was the periods from flower bud formation to right before flowering that would be the period from September 10 to September 15 in Suweon area. 11. Stevioside and rebaudioside content in the leaves of Stevia varieties were ranged from 5.4% to 14.3% and 1.5% to 8.3% respectively. However, no definit relationships between stevioside and rebaudioside were observed in these particular experiments.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.42 no.4
• /
• pp.403-412
• /
• 2016

The tight junction, one of Intercellular junctions, performs a variety of biological functions by bonding adjacent cells, including the barrier function to control the movement of the electrolyte and water. Recent studies have revealed that unusual expression of tight junction-related genes have been shown to be related in cancer development and progression. Recently, there are many reports that control of tight junction proteins expression is closely related to the skin moisture. In this study, we are focusing on the regulating mechanism of tight junction-associated genes by the steviol and its derivatives. Steviol, used as a sweetner, is known to chemical compound isolated from stevia plant. The MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) assay was carried out in HaCaT cells (human keratinocyte cell line) in order to determine the cytotoxicity. As a result, while steviol showing cytotoxicity from $250{\mu}M$, steviol derivatives are not cytotoxic more than $250{\mu}M$ concentration. We have observed a change in the tight junction protein via quantitative real-time PCR. Claudin 8 among tight junction proteins is only significantly reduced up to 30% in the presence of steviol. In addition, cell migration was inhibited by steviol, not by stevioside and rebaudioside. Finally, we could observe that steviol, not stevioside and rebaudioside, is able to increase the skin barrier permeability through the transepithelial electric resistance (TEER) measurements. These results suggest that the steviol and its derivatives are specifically acts on the tight junction related gene expression, but steviol derivatives are more suitable as a cosmetic material.

• Korean Journal of Food Science and Technology
• /
• v.29 no.2
• /
• pp.249-254
• /
• 1997

Stevioside was transglucosylated to improve its sweetness. Eighteen conditions were tested using the tables of orthogonal arrays of $L_{18}\;(2^{1}{\times}3^{7})$. Statistical analysis showed that the transglucosylation rate was significantly affected by temperature, the ratio of co-substrate (maltodextrin) to stevioside, pH, DE of maltodextrin and concentration of stevioside, in their order. Optimum conditions selected for temperature, ratio of co-substrate to stevioside, pH and DE of maltodextrin were $80^{\circ}C$, 1.0, 6.0 and 15, respectively. Glycosyl-stevioside with 68% yield of transglucosylation was produced at the optimum condition and found to have better quality in sweetness than stevioside and rebaudioside A.

• Journal of Sericultural and Entomological Science
• /
• v.23 no.2
• /
• pp.37-49
• /
• 1982

Larvae of the silkworm (Bombyx mori L.) were reared during the 5th instar on the four kinds of artificial diets on the basis of the different amounts of soybean meal used as the protein source. In this experiment it was shown that the various levels of protein in the diet affected not only the growth and silk production but the digestibility of the diet. haemolymph protein and uric acid excretion. The results obtained are summarized as follows; 1. By an increase of the level of protein in the diet the apparant digestibility was increased. but the protein digestibility was comparatively decreased. 2. Larval body weight increment was not observed by the 3rd day of the 5th instar, but was increased from the 4th day as the level of protein was increased in the diet. 3. After the 3rd day of the 5th instar, protein content in the hemolymph was increased steeply by an increase of the protein content in the diet. However, the percentage of hemolymph protein to the ingested protein was decreased from the 2nd day of the 5th instar and increased more or less after the 4th day. 4. An increase of the uric acid excretion was observed as the content of protein in the diet was increased but the pattern of the uric acid excretion was different between high and low-protein diet. However, the percentage of the uric acid excretion to the ingested protein and to the hemolymph protein were both decreased steeply after the 2nd day of the 5th instar. 5. It was also evident that the high-protein diet increased the cocoon productivity. 6. It showed that the feed efficiency for body weight increment and silk formation was high by an increase of the level of protein in the diet, but the protein efficiency was not.