Suppressive effect of the hot-water extract of Ficus pseudopalma Blanco leaves on the postprandial increase in blood glucose level in mice.

The use of medicinal plants with anti-diabetic properties continues because of the high cost of diabetes mellitus treatment. In the Bicol region of the Philippines, one local source is the leaves of Ficus pseudopalma Blanco (Philippine fig), which is utilized as an ingredient of their cuisine, and the decoction of its leaves is believed to have a blood-glucose lowering effect. The aim of this study was to evaluate the blood-glucose lowering effect of F. pseudoplama using sugar/carbohydrate-loaded and normoglycemic mice. The results showed that the hot-water extract of the leaves significantly suppressed the increase of blood glucose levels after glucose, maltose and starch loading. On the other hand, the extract did not show any hypoglycemic activity in either fasted or non-fasted mice as compared to the positive control drugs. These results suggest that F. pseudopalma is potentially useful for the management of blood glucose levels in the postprandial condition, as believed in the Bicol region of the Philippines.

Rosmarinic acid in Argusia argentea inhibits snake venom-induced hemorrhage.

A methanolic extract of Argusia (or Messerschmidia or Tournefortia) argentea (Boraginaceae) significantly inhibited hemorrhage induced by crude venom of Trimeresurus flavoviridis. The extract was then separated according to antivenom activity by using silica gel column chromatography and HPLC equipped with an octadecylsilanized silica gel (ODS) column to afford rosmarinic acid (RA) (1) as an active principle. RA (1) significantly inhibited the hemorrhagic effect of crude venoms of T. flavoviridis, Crotalus atrox, Gloydius blomhoffii, Bitis arietans as well as snake venom metalloproteinases, HT-b (C. atrox), bilitoxin 2 (Agkistrodon bilineatus), HF (B. arietans), and Ac1-proteinase (Deinagkistrodon acutus). This is the first report of the antihemorrhage activity of RA (1), and RA (1) greatly contributes to the antihemorrhagic efficiency of A. argentea against crude snake venoms and hemorrhagic toxins.

Biological and pathological studies of rosmarinic acid as an inhibitor of hemorrhagic Trimeresurus flavoviridis (habu) venom.

In our previous report, rosmarinic acid (RA) was revealed to be an antidote active compound in Argusia argentea (family: Boraginaceae). The plant is locally used in Okinawa in Japan as an antidote for poisoning from snake venom, Trimeresurus flavoviridis (habu). This article presents mechanistic evidence of RA's neutralization of the hemorrhagic effects of snake venom. Anti-hemorrhagic activity was assayed by using several kinds of snake venom. Inhibition against fibrinogen hydrolytic and collagen hydrolytic activities of T. flavoviridis venom were examined by SDS-PAGE. A histopathological study was done by microscopy after administration of venom in the presence or absence of RA. RA was found to markedly neutralize venom-induced hemorrhage, fibrinogenolysis, cytotoxicity and digestion of type IV collagen activity. Moreover, RA inhibited both hemorrhage and neutrophil infiltrations caused by T. flavoviridis venom in pathology sections. These results demonstrate that RA inhibited most of the hemorrhage effects of venom. These findings indicate that rosmarinic acid can be expected to provide therapeutic benefits in neutralization of snake venom accompanied by heat stability.

Three new pentasaccharide resin glycosides from the roots of sweet potato (Ipomoea batatas).

Three new pentasaccharide resin glycosides, batatosides III-V (1-3), were isolated from the roots of Sweet potato (Ipomoea batatas). Saponification of the crude resin glycoside mixture yielded substituents and simonic acid B. The structures of the isolated compounds (1-3) were established through spectroscopic analyses, including high field NMR spectroscopy and HR-ESI-MS, and chemical correlation. The major characteristics of 3 are the presence of three different substituents, especially the substituent of cinnamic acid was seldom. The monosaccharides of 1-3 were proved by GC-MS and the absolute configuration of aglycone was further established as S by Mosher's method with R-methyloxyphenylacetic acid (MPA) and S-MPA.

Diterpenes from Coleus forskohlii (WILLD.) BRIQ. (Labiatae).

Three new minor labdane diterpene glycosides, forskoditerpenoside C, D, and E (1-3), and a novel labdane diterpene forskoditerpene A (4) were isolated from the ethanol extract of the whole plant of Coleus forskohlii. Their structures and relative stereochemistry were elucidated on the basis of extensive spectroscopic analyses including 1D-, 2D-NMR, and HR-ESI-MS experiments. Compounds 1-3 showed an unusual 8,13-epoxy-labd-14-en-11-one glycoside pattern. They showed relaxative effects on isolated guinea pig tracheal spirals in vitro. Compound 4 with a cyclopropyl, confirmed by a single-crystal X-ray diffraction determination, is the first known labdane derivative with a spiro element.

Two new monodesmosidic triterpene saponins from Gypsophila oldhamiana.

Two new monodesmosidic triterpene saponins were isolated from the roots of Gypsophila oldhamiana (Caryophyllaceae). Their structures were elucidated on the basis of spectral data to be quillaic acid, alpha-L-arabinopyranosyl-(1-->4)-alpha-L-arabinopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranosyl ester (1), and vaccaric acid, beta-D-glucopyranosyl-(1-->3)-[beta-D-xylopyranosyl-(1-->4)]-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranosyl ester (2). Compound 1 showed a significant enhancement of granulocyte phagocytosis in vitro.

Antioxidant constituents of radish sprout (Kaiware-daikon), Raphanus sativus L.

Methanol extracts of 11 kinds of commonly available vegetables were examined for hydroxyl radical scavenging potency using the bleomycin-Fe method. In this method, the iron ion and bleomycin in water form hydroxyl radicals, and the scavenging activity is monitored by the modified thiobarbituric acid method. All extracts showed scavenging capacity, even though the activity of some of them was lower than that of l-ascorbic acid. Those vegetables were classified into three groups according to their activity, groups showing strong activity, moderate activity, and weak activity, as compared to the activity of l-ascorbic acid at the same concentration. Among them, the methanol extract of radish sprout (Japanese name "kaiware-daikon") exhibited the highest potency (1.8 times as l-ascorbic acid). Then, we investigated the constituents of the methanol extract of radish sprout and the contribution to the overall activity of each compound by examining their activity. As the result, several kinds of sinapinic acid esters and flavonoids were isolated with high radical scavenging potency, which must contribute substantially to the activity.

Oxidation of ferulic acid by Momordica charantia peroxidase and related anti-inflammation activity changes.

Plant peroxidases were found to play an important role in plant physiology such as the metabolism and transformation of small complexes. In the present research, a novel Momordica charantia peroxidase (MCP) from fruits was purified to electrophoretic homogeneity by combining consecutive treatment of ammonium sulfate fractionation, ion exchange chromatography on DEAE-Sepharose FF, affinity chromatography on concanavalin A (Con A) Sepharose and gel filtration on Sephadex G-150. The physical and chemical characters of MCP were also investigated. MCP catalyzed the oxidation of ferulic acid (FA) to dehydrodimer (FA-2) in aqueous acetone system at pH 5.0. Its structure was identified by spectral analyses including IR, 1H-, 13C-NMR and electrospray ionization mass spectroscopy (ESI-MS). The anti-inflammatory activities of FA, FA-2 and other derivatives were examined. FA-2 significantly inhibited the release of proinflammatory factors such as TNF-alpha, NO and proliferation of spleen cells induced by phytohemagglutinin (PHA) and Con A and promoted a greater DNA fragmentation of spleen cells than that of other complexes. These results suggested that MCP as a tool enzyme transformed some complexes such as FA to more active derivatives, and that FA-2 was a potential inhibitor on inflammation through interference with immune response in the process of inflammation, which maybe was associated with apoptosis of immune related cells induced by FA-2.

Antibacterial polyphenol from Erodium glaucophyllum.

Geraniin and gallic acid were isolated from the alcohol extract of the aerial parts of Erodium glaucophyllum (Geraniaceae). The identity of the compounds was verified through different physical and spectrometric methods. The antibacterial and antifungal activity of geraniin is presented.

New cytotoxic bis-labdanic diterpenoids from Alpinia calcarata.

Two novel bis-labdanic diterpenoids named calcaratarin D and calcaratarin E were isolated from the rhizomes of Alpinia calcarata. Their structures were elucidated as a pair of stereoisomers on the basis of the spectral evidence. 2D NMR techniques including (1)H- (1)H COSY, HMQC, HMBC, NOESY spectra and HRFABMS were extensively applied to establish the structures. The two bis-labdanic diterpenoids showed cytotoxic activity against human KB cells in vitro.

A new triterpene saponin from Chenopodium ficifolium.

The new triterpene saponin 3-O-beta-D-glucopyranoside, 28-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosiduronic acid oleanolate was isolated from the roots of Chenopodium ficifolium. The known compounds stigmasterol-3-O-glucoside and 3-O-beta-D-glucopyranosiduronic acid, 28-beta-D-glucopyranosyl oleanolate were also isolated. The latter compound, oleanolic acid, beta-sitosterol and its glucoside were isolated from the aerial parts. The identity of these compounds was verified through different chemical and physico-chemical evidences including different 1D and 2D NMR experiments.