Ringgoldianum Research Articles

Hypoglycemic Effect of Sargassum ringgoldianum Extract in STZ-induced Diabetic Mice

This study was designed to investigate whether Sargassum ringgoldianum extract may inhibit α-glucosidase and α-amylase activities, and alleviate postprandial hyperglycemia in streptozotocin-induced diabetic mice. The IC50 values of Sargassum ringgoldianum extract against α-glucosidase and α-amylase were 0.12 mg/mL and 0.18 mg/mL, respectively, which evidenced higher activities than those of acarbose. The blood glucose levels of the Sargassum ringgoldianum extract administered group were significantly lower compared to the control group in the streptozotocin-induced diabetic mice. Moreover, the area under the two-hour blood glucose response curve was significantly reduced and the absorption of dietary carbohydrates was delayed after administration of Sargassum ringgoldianum extract in the diabetic mice. Therefore, these results indicated that Sargassum ringgoldianum extract may help decrease the postprandial blood glucose level via inhibiting α-glucosidase.

Antioxidant activity and cell protective effect of loliolide isolated from Sargassum ringgoldianum subsp. coreanum

A monoterpene lactone, loliolide was successively isolated from brown seaweed, Sargassum ringgoldianum subsp. coreanum using column chromatography and high-performance liquid chromatography. The structure of the isolated compound was determined by comparison of EIMS and NMR spectral data with the previously published data. The antioxidant activities of loliolide were also evaluated by DPPH and H 2 O 2 radical and intracellular reactive oxygen species scavenging assays, and it showed moderate activities in all antioxidant assays. Furthermore, loliolide was found to exert positive dose-dependent effects in the protective effects against H 2 O 2 -induced cell damage which were determined via MTT, Hoechst staining assays and cell cycle analysis. This is the first study on chemical constituent of this seaweed according to our best knowledge. These results clearly indicated that loliolide isolated from Sargassum ringgoldianum subsp. coreanum can protect the cells against H 2 O 2 -induced cell damage or apoptosis.

Growth and Maturation of Sargassum ringgoldianum in Odawa Bay, Miura Peninsula, Kanagawa Prefecture

Growth and Maturation of Sargassum ringgoldianum in Odawa Bay, Miura Peninsula, Kanagawa Prefecture

Minerals, polysaccharides and antioxidant properties of aqueous solutions obtained from macroalgal beach-casts in the Noto Peninsula, Ishikawa, Japan

To clarify the useful properties of the macroalgal beach-casts for food, we determined mineral, water-soluble polysaccharide and total phenolic compound contents and antioxidant properties of aqueous solutions obtained from frond of eight brown and four green algae. These algae were washed ashore from the East Sea (the Sea of Japan) to the northeast beaches of the Noto Peninsula in autumn. There were fresh and large amounts of Ecklonia stolonifera (Es), Ecklonia kurome (Ek), Sargassum ringgoldianum subsp. coreanum (Sr) and Sargassum macrocarpum on the beaches. Potassium, magnesium and calcium ions were high in Sr-solution. High molecular weight water-soluble polysaccharide, mainly alginates, and relative viscosity were also high in Sr-solution. Both Es and Ek solutions showed high contents of total phenolic compounds and high antioxidant activities, including DPPH radical- and hydroxyl radical-scavenging and ferrous reducing power. On the other hand, the highest superoxide anion radical-scavenging activity was in the Sr solution. In the case of Sr, the same antioxidant properties were also found in the aqueous solution obtained from stem. These results suggest that some macroalgal beach-casts, especially Sr, can be utilised as new natural resources for functional foods, cosmetics, medical applications and fertilizer instead of being processed to landfill or incineration.

Ecological studies on the community of drifting seaweeds in the south-eastern coastal waters of Izu Peninsula, central Japan. II: Seasonal changes in plants showing maximum stipe length in drifting seaweed communities

SUMMARY The authors examined seasonal patterns in 20 sargassaceous species (maximum stipe length of ≥ 45 cm) from 902 patches of drifting seaweeds in the southeastern coastal waters of the Izu Peninsula, central Japan, between spring and autumn, 1991‐1993. The first analysis, dealing with plants occurring for three consecutive years, examined the top three ranked species determined from monthly pooled means of frequency of appearance in these 3 years. The second analysis examined not only the top-ranked species in monthly means in each year, but also the continuity of appearance of species among years. The third analysis was made from dendrogram analysis based on monthly samples from each year. The first and second analyses revealed three seasonally discernible changes. From April to June, dominance shifted from Sargassum horneri (Turner) C. Agardh to Sargassum yamamotoi Yoshida with a stable transition; in July, S . yamamotoi , Sargassum macrocarpum C. Agardh, Sargassum crispifolium Yamada and Sargassum piluliferum (Turner) C. Agardh appeared consistently in an unstable domination with low frequency of appearance by Sargassum nipponicum Yendo, Sargassum fulvellum (Turner) C. Agardh, S . macrocarpum or S. crispifolium ; in August to October, there was a stable shift from S . macrocarpum to Sargassum micracanthum (Kutzing) Endlicher and Sargassum ringgoldianum Harvey. In the third analysis, monthly samples from each year were divided into four groups, characterized using the top five ranks. This characterization indicated that the topranked species shifted from S. horneri to S. yamamotoi , to S . macrocarpum and to S . micracanthum with the change of seasons. Because of an overlap in the characteristic species in these three analyses, seven species ( S. horneri , S . micracanthum , S. yamamotoi , S . macrocarpum , S . ringgoldianum , S . nipponicum and S . crispifolium ) were regarded as dominant species. Results are compared to our previous study and it is suggested that the similarity in the pattern of plant community during seasonal changes over the period from April to June and in July resulted from both stable and unstable changes, respectively, but discrepancies in the pattern of plant community during seasonal change from August to October were the result of differences in the frequency of appearance of S . ringgoldianum and S . macrocarpum in August 1991. These results indicated that the seasonal changes of dominant species in the plant community from April to October in this study area were periodic except in July.

Inhibition of HIV-1 reverse transcriptase and HIV-1 integrase and antiviral activity of Korean seaweed extracts

Forty-seven species of marine macroalgae from the coast of Korea havebeen screened for the presence of inhibitory compounds against humanimmunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) and HIV-1integrase (IN). One of 4 Chlorophyta, 8 of 17 Phaeophyta and 6 of 26 Rhodophytashowed inhibitory activity against HIV-1 reverse transcriptase. Five species(Ecklonia cava, Ishige okamurae,Sargassum confusum, Sargassumhemiphyllum, Sargassum ringgoldianum) belongingto Phaeophyta showed to inhibit the 3′-processing activity of HIV-1integrase. In cell-based assays, the methanol extracts ofBossiella sp. and Chondriacrassicaulis inhibited cytopathogenecity of HIV-1 at a concentrationbelow that cytotoxic for MT4 cells.

Ecological studies on the community of drifting seaweeds in the south-eastern coastal waters of Izu Peninsula, central Japan. I: Seasonal changes of plants in species composition, appearance, number of species and size

SUMMARY Seasonal patterns of drifting seaweeds in the southeastern coastal waters of Izu Peninsula of central Japan were examined by sampling 966 patches from spring to autumn 1991–1993. In total, 57 plant species appeared, including 10 epiphytic algal species. Monthly totals of the number of species, excluding epiphytic aigae, were highest in May (33) and August (27), though 19–21 species of sargassaceous algae were found from May to August, The number of species, excluding epiphytic algae, in one patch of drifting seaweeds was 1 to 11 (x= 2.93 ± 2.06) with high richness in May a result of almost entirely sargassaceous species. The wet weight of each patch and maximum stipe length of plants varied from 5 to 6970 g and from 20 to 840 cm (x= 536.1 ± 782,3 g and 110.6 ± 76.8 cm), respectively, with highs in April and May. Out of 18 species common to all years, 10 species dominated the top or second rank in monthly pooled frequency of appearance. Seasonal changes of these 10 major species were examined, Sargassum horneri (Turner) C. Agardh and Hizikia fusiformis (Harvey) Okamura were abundant in April, but were replaced partly by Sargassum muticum (Yendo) Fensholt in May and largely by Sargassum yamamotoi Yoshida in June. In July, Sargassum nipponicum Yendo and Sargassum piluliferum (Turner) C. Agardh dominated. Subsequently, the major species shifted to Sargassum ringgoldianum Harvey and S. yamamotoi in August, Sargassum micracanthum (Kutzing) Endlicher, Sargassum macrocarpum C. Agardh and Zostera marina Linnaeus in September, and S. ringgoldianum and S. micracanthum in October. However, the occurrence of S. yamamotoi, S. nipponicum and S. piluliferum in June or July were particularly heterogeneous compared with other areas of Japan. Dendrogram analysis was done based on frequency of appearance. Pooled monthly samples were divided into three groups characterized from the dominant species, degree of domination, weight, length and number of species of drifting seaweeds as well as the degree of diversity or evenness in appearance. This characterization indicated that the diversity and abundance of drifting seaweeds were higher from April to June than in later months.

Effects of Salinity and Light Intensity on the Growth of Brown Algae, Sargassum ringgoldianum

Effects of Salinity and Light Intensity on the Growth of Brown Algae, Sargassum ringgoldianum

Studies on the antitumour activity of marine algae.

Screening of antitumour activities were performed by using 56 species of marine algae (4 green, 24 brown, and 28 red algae) from the viewpoint of possible utilization for tumour preventing material. After the preoral administration of powdered 57 species of marine plants for 14 days, mice were inoculated with Ehrlich carcinoma, and breeding was continued for further 14 days. It was found that 3 green, 8 brown, 5 red algae and Z. marina show appreciable antitumour activity. Of the marine algae Scytosiphon lomentaria (Phaeophyta) showed the higherst inhibition rate (69.8%), followed by Lessonia nigrescens (60.0%, Phaeophyta), Laminaria japonica (57.6%, Phaeophyta), Porphyra yezoensis (53.2%, Rhodophyta), Eucheum gelatinae (52.1%, Rhodophyta), Enteromorpha prolifera (51.7%, Chlorophyta) and Sargassum ringgoldianum (46.5%, Phaeophyta).When 24 kinds of seaweed powder samples (2 green, 13 brown, and 9 red algae) were administered intraperitoneally 7 times during 21 days to mice inoculated with Meth A fibrosarcoma, 5 brown and 4 red algae showed appreciable antitumour activities. The inhibition rates were the highest in Sargassum patens (55.5%, Phaeophyta) followed by Eucheuma cottonii (39.8%, Rhodophyta), S. ringgoldianum (39.1%, Phyaeophyta), Laminaria angustata (36.6%, Phaeophyta), Ecklonia cava (35.9%, Phaeophyta) and Chondrus ocellatus (34.7%, Rhodophyta). Among the seaweed, only S. ringgoldianum and P. yezoensis were effective against both Ehrlich carcinoma and Meth A fibrosarcoma.

Positional distribution of fatty acids in galactolipids of algae

Fatty acid composition of both total lipids and galactolipids were determined for thalli from Gloiopeltis complanata, Grateloupia filicina, Gymnogongrus flabelliformis, (Rhodophyta), Ishige okamurai, Padina arborescens, Sargassum ringgoldianum (Phaeophyta) and Monostroma nitidum (Chlorophyta); the positional distribution of fatty acids in galactolipids of these algae was further analysed. C 16 fatty acids were distributed at both the sn-1 and sn-2 positions of galactolipids from the red and brown algae, but mainly located at the sn-2 position of those from the green alga. In C 18 fatty acids from brown algae, 18:1 and 18:2 were distributed only at the sn-2 position, with 18:3 and 18:4 at both the sn-1 and sn-2 positions. In the green alga, all C 18 fatty acids were predominantly located at the sn-1 position of galactolipids. In red and brown algae, C 20 fatty acids were exclusively located at the sn-1 position of galactolipids, but exceptionally at both the sn-1 and sn-2 positions in monogalactosyl diacylglycerols from red algae, C 20 fatty acids being found more at the sn-1 than the sn-2 position.

A comparative investigation on the water-soluble and the alkali-soluble alginates from various Japanese brown algae.

The yields and the M/G ratios of water-soluble alginates (WSA) from various brown algal sources in Japan were investigated and were compared with those of alginates extracted with alkali in the routine procedures(ASA). The yields on a dry weight basis of WSA from most brown algae varied widely from 0.01% (Sargassum thunergii) to 9.23% (Laminaria religiosa) while those of ASA varied to lesser extentsuch as from 2.20% (Hizikia fusiformis) to 31.80% (Sargassum kjellmanianum)in most samples. The M/G ratios of these alginates measured by high performance liquidc hromatography fluctuated between O.66 (Sargassum kjellmanianum) and 5.28 (Sargassum patens)with WSA while they were O.26 (Sargassum ringgoldianum) to 1.78 (Laminaria religiosa) with ASA. However, higher M/G ratios were found for WSA than those for ASA in any individual brown alga tested.

Ecological studies of Sargassum ringgoldianum Harv. subsp. coreanum (J.Ag.) Yoshida in Obama Bay, Japan Sea. I. Growth of the stem in Sargassum ringgoldianum HARV. subsp. coreanum (J.AG.) YOSHIDA in Obama Bay, Japan Sea.

The growth of length and weight of the stem and the relationship between the branching pattern of the stem and annual rings of the holdfast in Sargassum ringgoldianum HARV. subsp. coreanum (J. AG.) YOSHIDA (Sargassaceae, Phaeophyceae) growing in Obama Bay, a branch bay of Wakasa Bay located in the middle part of Honshu facing the Japan Sea were studied. The stem is dichoto-mously branched several times, thus the lowest axis and the dichotomies above the axis were named as stemsI, II, III, IV, and V in the order of branching from base to apex. Among the branches, stem I is the longest and heaviest and becomes longer and heavier with the age of the plant. The mean length and weight of stem I were 10.19cm (S. D. 4.09cm) and 1.54 g (S. D. 1.07g), respec-tively. Statistically, a total length of all branches of stem V plants measures 109.1 cm and its corresponding weight is 5.1g. Annual rings of the holdfast showed a direct relationship to the number of dichotomies. Stem I1 plants are one year old; stem I2 plants two years old; stem H plants three years old; and stem III plants four years old. This relationship was obscured in stem IV and stem V plants, because they were in various stages of growth and their ages varies from four to six years old. From these data it is shown that it is possible to determine the plant age of S. ringgoldianum from the branching of the stem without cutting the holdfast.

Sugar constituents of sulfated polysaccharides from the fronds of Sargassum ringgoldianum.

Sulfated polysaccharides (fucoidans) were extracted from methanol-treated fronds of Sargassum ringgoldianum (Oobamoku) with dilute hydrochloric acid and fractionated by DEAE-Sephadex column chromatography into three components: Fr-A, -B, and -C. Fr-B and -C each behaved as a single component on electrophoresis, but Fr-A was comtaminated with alginic acid. It was difficult to remove this alginic acid in the present work. All three comtained ester sulfate, and IR analusis suggested this was at ab equatorial. Fucose was largest largest in amount among the neutral sugar constituents. In addition, galactose, manmose, xylose and glucuronic acid were detected in various proportions. The molar ratios of Fuc, Gal, Man, Xyl, GlcUA and and SO42- were 1:0.37:0.35:0.42:0.69:2.26 and 1:0.44:0.11:0.12:0.28:2.03 for Fr-B and -C, respectively. Thoes of the same constituents in Fr-A (except uronic acid) were 1:0.36:0.82:0.78:2.32, respectively.

海藻油及びそのステロールに關する研究(第I報)1.おほばもく脂質の季節的變化に就て

We studied the seasonal variation of crude oil, unsaponifiable matter and sterol of Sargassum Ringgoldianum Harv. (Brown algae.) The results obtained were as the following. (1) As we show in Table 1 and Fig. 2, the younger algae has more crude oil than old algae. (2) But just before its sheding, the content of oil and its unsaponifiable matter and sterol increases a little, and decreases after sheding.