A new flavan from Elephantorrhiza goetzei

A new compound, 3,3′,4′,5,6,7,8-heptahydroxyflavan (1), was isolated from the roots of Elephantorrhiza goetzei. The crude extract, and its n-butanol and residual water fractions showed antimicrobial activity. Semi-purified extracts showed higher activity and of the purified compounds only methyl gallate gave activity below 100 μg of sample.     

Antibacterial activity of Cotula cinerea extracts

The antibacterial activity of ethyl ether, ethyl acetate and n-butanol extracts of Cotula cinerea was investigated. The n-butanol extract was highly effective against pathogens at concentrations ranging from 12 to 200 μg/ml.     

Identification and evaluation of antioxidant activities of bamboo extracts

The antioxidant activity of solvent extracts from two main bamboo species, moso bamboo (Phyllostachys pubescens) and madake bamboo (P bambusoides) in Japan, was first evaluated by scavenging free radical of 1,1-diphenyl-2-picrylhydrazyl (DPPH), the inhibition activity for peroxidation of linoleic acid, and the reduction power. The methanol-extracts of moso bamboo culms and madake bamboo leaves presented stronger antioxidant activity compared with DPPH scavenging activity. Methanol-extract of moso bamboo culms was further fractionated by different solvents and n-butanol soluble fraction exhibited the most significant activity in the DPPH scavenging assay. The fractionation of n-butanol soluble extract was isolated by silica gel column with gradient mixture solvent of chloroform and methanol. The isolated fractions were directed by the antioxidant activity measured by scavenging the stable DPPH free radical. It was observed that most of the eluted fractions showed the antioxidative activity. Fractions acquired from elution with the mixture solvent of chloroform and methanol (10:1-5:1) showed stronger antioxidant activity than the other fractions.     

Antioxidant properties and polyphenol contents of trembling aspen bark extracts

Trembling aspen (Populus tremuloides Michx) bark was extracted with water and the crude extract fractionated with tert-butyl-methyl ether (TBME), ethyl acetate (EtOAc) and n-butanol (BuOH) to obtain four different fractions. The antioxidant properties of the bark hot water extracts and its fractions were determined by three in vitro experiments: DPPH assay, phosphomolybdenum assay and canola oil thermoxidation assay by DSC analysis. Most of the results of the reported tests showed that the crude hot water extract and its fractions exhibited a strong antioxidant activity, higher than the synthetic antioxidant BHT. The results of this study confirm that antioxidant activity is a property that strongly depends on the oxidation conditions used in the particular oxidation test. Among the fractions separated from the aqueous extracts of bark, BuOH, TBME and EtOAc soluble fractions exhibited the best antioxidant efficiency, in phosphomolybdenum assay, DPPH assay and canola oil thermoxidation, respectively. Total phenol, flavonoid and flavanol contents were also evaluated and the results confirmed that the polyphenols contained in the hot water extract of this bark are mainly composed of non-flavonoid compounds.     

Cytotoxicity and antihyperglycemic effect of minor constituents from Rhizoma Coptis in HepG2 cells

Generally, berberine, coptisine, palmatine, and jatrorrhizine were considered as the main bio-active compounds in Rhizoma Coptis (RC). Little attention was paid to investigate the pharmacological activity of minor constituents in RC. The present study was designed to separate the minor compounds, and the cytotoxicity and antihyperglycemic effect of these compounds in HepG2 cells were also studied. Palmatine (1), berberine (2), coptisine (3), epiberberine (4), columbamine (5), and jatrorrhizine (6) from RC ethanol extract were isolated by high speed counter current chromatography (HSCCC) in one run. The remaining fraction (about 50% of extract in HSCCC) was further isolated by traditional column chromatography methods to yield magnoflorine (7), ferulic acid (8), and choline (9). Another four alkaloids, namely groenlandicine (10), berberrubine (11), oxyberberine (12), 8-oxo-coptisine (13), also were obtained from CHCl₃ extracts. Especially, choline was first isolated from RC. Cell assay indicated that the minor fractions excluding compounds 1-6 showed obvious glucose lowering activity. In addition, the minor monomers also exhibited moderate glucose lowering activity. The combination of berberine and ferulic acid showed synergistic effect on antihyperglycemic. The combination of alkaloids 1-6 was same so. All compounds had different cytotoxicity in HepG2 cells within the test concentration. Of them, berberrubine showed the strongest cytotoxicity. The results suggested that combined action of variety constituents contributed to the antihyperglycemic effets and low cytotoxicity of RC extract in HepG2 cells.     

Antifeedant activities of secondary metabolites from <Emphasis Type="Italic">Ajuga nipponensis</Emphasis> against adult of striped flea beetles, <Emphasis Type="Italic">Phyllotreta striolata</Emphasis>

Antifeedant activities of the isolated chemical compounds from Ajuga nipponensis, were studied against adult of striped leaf beetles. The methanol, petroleum ether, ethyl acetate and n-butanol extracts at 1.0 mg/ml, were used in this study. All four extracts exhibited more than 65 antifeedant index at 24 h and ethyl acetate extract showed significant activity against striped leaf beetles with 83.12 antifeedant index. Six compounds and one fraction were isolated by chromatography and their structures were identified by NMR, MS and FTIR spectra. At 2.0 mg/ml for 24 h the three compounds 20-hydroxyecdysone, acacetin and apigenin showed considerable activities with antifeedant indexes 59.29, 51.22 and 61.55, respectively. In contrast to this the antifeedant indexes of acacetin and apigenin, were sharply reduced as the time extended and that of 20-hydroxyecdysone remained unchanged. In addition, the synergistic effects of two mixtures of secondary metabolites, were studied and no sharp difference was observed.     

Antifungal agents from heartwood extract of <Emphasis Type="Italic">Taiwania cryptomerioides</Emphasis> against brown root rot fungus <Emphasis Type="Italic">Phellinus noxius</Emphasis>

Taiwania (Taiwania cryptomerioides Hayata) is a native and plantation species in Taiwan, and its heartwood has demonstrated excellent decay resistance. Brown root rot fungus Phellinus noxius has caused severe damage to more than 100 tree species in Taiwan. The aims of this study were to investigate the antifungal activities of Taiwania heartwood extracts against P. noxius and to identify the antifungal compounds. Antifungal activities were examined using the agar dilution method (a direct contact assay) and the inverted lid method (a vapor contact assay). Active compounds were purified using liquid–liquid partition, open-column chromatography and HPLC. Among four soluble fractions (n-hexane, ethyl acetate, n-butanol and water soluble fractions), results showed that n-hexane soluble fraction (HSF) can significantly inhibit the growth of P. noxius via the agar dilution method. Moreover, active compounds present in HSF were obtained using antifungal assay-guided fractionation. Results showed that ferruginol, T-cadinol, α-cadinol and T-muurolol were found to exhibit excellent antifungal activities against P. noxius, and their IC₅₀ values were 16.9, 25.8, 33.8 and 50.6 μg/mL, respectively. According to the current findings, phytochemicals (ferruginol, T-cadinol, α-cadinol and T-muurolol) of Taiwania heartwood had the potential to be used as environmentally benign antifungal agents against P. noxius in place of synthetic or inorganic fungicides.     

Antimicrobial activity of heartwood components of sugi (Cryptomeria japonica) against several fungi and bacteria

Methanol extract of sawdust of sugi (Cryptomeria japonica) heartwood was fractionated with toluene and n-hexane to give solvent-soluble and solvent-insoluble fractions. The n-hexane-soluble fraction showed the most inhibition activity among the fractions against phytopathogenic microorganisms, namely Fusarium oxysporum, Phytophthora capsici, Pythium splendens, and Ralstonia solanacearum. Sandaracopimarinol and ferruginol, isolated from the n-hexane-soluble fraction, showed moderate antifungal activity against the three fungi and strong antibacterial activity against R. solanacearum. The content of sandaracopimarinol (7.07 g/kg based on the dried sawdust) in the heartwood was about twice that of ferruginol. Sandaracopimarinol and ferruginol strongly inhibited the growth of Gram-positive bacteria but did not show inhibitory action against Gram-negative bacteria except for R. solanacearum. The antibacterial effect of sandaracopimarinol was first found in the present study and was stronger than that of ferruginol.     

Antihyperglycemic effect of Cucurbita ficifolia fruit extract in streptozotocin-induced diabetic rats

In the present study, the antihyperglycemic effects of Cucurbita ficifolia fruit extract were investigated on streptozotocin-induced experimental diabetes in rats. Oral administration of the extract (300 and 600 mg/kg body weight, day) for 30 days resulted in a significant reduction in blood glucose, glycosylated haemoglobin, and an increase in plasma insulin and total haemoglobin. The effect was compared with 150 mg/kg b.w. tolbutamide.     

Simple and effective large-scale preparation of geniposide from fruit of Gardenia jasminoides Ellis using a liquid–liquid two-phase extraction

Geniposide was prepared on a large-scale using a selective two-phase liquid–liquid extraction. The aqueous residue from the fruit of Gardenia jasminoides Ellis was treated with sodium carbonate and extracted with n-butanol several times. The n-butanol extracts were treated with activated granular charcoal to remove pigments and were then concentrated to produce a residue with a high solid content. The residue was crystallized to obtain geniposide with 98% purity. For large-scale synthesis, the residue (solid content 45%, geniposide 5.5%) was extracted to generate 70 g of geniposide with 98% purity and 84.8% recovery using 1500 g residue.     

Anti-hyperglycemic action of apigenin-6-C-β-fucopyranoside from Averrhoa carambola

A stimulatory effect of apigenin-6-C-β-fucopyranoside (1) on glucose uptake was observed when rat soleus muscle was incubated with 1, 10 and 100μM of this flavonoid glycoside. The presence of specific insulin signaling inhibitors, such as wortmannin, an inhibitor of phosphoinositide 3-kinase (PI3K), RO318220, an inhibitor of protein kinase C (PKC), PD98059, an inhibitor of mitogen-activated protein kinase (MEK), and HNMPA(AM)(3), an insulin receptor tyrosine kinase activity inhibitor showed that apigenin-6-C-β-fucopyranoside triggers different metabolic pathways in skeletal muscle. The oral administration of crude extract, fractions and isolated flavonoids (apigenin-6-C-β-fucopyranoside (1) and apigenin-6-C-(2″-O-α-rhamnopyranosyl)-β-fucopyranoside (2)) from Averrhoa carambola leaves exhibited a potential hypoglycemic activity in hyperglycemic normal rats. Additionally, both flavonoids significantly increased the muscle and liver glycogen content after an acute treatment. The results indicate that A. carambola can be regarded as a potent antihyperglycemic agent with insulin secretagogue and insulin mimetic properties.     

Isolation of xanthone and benzophenone derivatives from Cyclopia genistoides (L.) Vent. (honeybush) and their pro-apoptotic activity on synoviocytes from patients with rheumatoid arthritis

A fast and efficient method for the isolation of the C-glucosidated xanthones mangiferin and isomangiferin from the South-African plant Cyclopia genistoides was developed for the first time. The procedure involved extraction, liquid–liquid partitioning with ethyl acetate and subsequent precipitation of mangiferin and isomangiferin from methanol and acetonitrile–water fractions, respectively. Additionally, two benzophenone derivatives: 3-C-β-glucosides of maclurin and iriflophenone, were isolated from C. genistoides extracts using semi-preparative HPLC. Apart from the above, the isolation procedure also yielded hesperidin and small amounts of luteolin. The structures of the compounds were determined by 1D and 2D NMR experiments and/or LC-DAD-ESI–MS. The selected Cyclopia constituents were screened for pro-apoptotic activity on TNF-α-stimulated synovial cells isolated from rheumatoid arthritis patients. The strongest effect, measured as percent of apoptotic cells, was recorded for isomangiferin (75%), followed by iriflophenone 3-C-β-glucoside (71%), hesperidin (67%) and mangiferin (65%). The results are encouraging for further studies on the use of the above compounds in the treatment of rheumatoid arthritis.     

Antidiabetic activity of Caesalpinia bonducella seed extracts in rats

The seed extracts of Caesalpinia bonducella were subjected to screening of antidiabetic activity in alloxan induced hyperglycemia. The oral administration of the extracts (300 mg/kg) produced significant antihyperglycemic action as well as it lowered the BUN levels significantly. In the same study the action of the extracts on diabetes induced hyperlipidemia was analyzed where the extracts significantly lowered the elevated cholesterol as well as LDL level. The antihyperglycemic action of the extracts may be due to the blocking of glucose absorption. The drug has the potential to act as antidiabetic as well as antihyperlipidemic.     

Antihyperglycemic effects of Japanese maple Acer amoenum leaf extract and its constituent corilagin

The antihyperglycemic effects of the leaves of Acer amoenum and purification and identification of an active compound were investigated. In screening experiments for α-glucosidase inhibitory activity, methanolic extracts of A. amoenum leaves showed potent inhibitory action. This extract showed antihyperglycemic effects in sucrose-loaded mice. Fractionation of the crude extract gave the active compound corilagin [β-1-O-galloyl-3,6-(R)-hexahydroxydiphenoyl-d-glucose] by spectroscopic analysis. This is the first report about the possibility of novel utilization of the Japanese maple tree as a source of compounds for prevention or treatment of diabetes mellitus.     

Antidiabetic activity of hydro-ethanolic extract of Cyperus rotundus in alloxan induced diabetes in rats

In light of the traditional claim of Cyperus rotundus in the treatment of diabetes, investigations were carried out to evaluate its effect on alloxan induced hyperglycemia in rats. Oral daily administration of 500 mg/kg of the extract (once a day for seven consecutive days) significantly lowered the blood glucose levels. This antihyperglycemic activity can be attributed to its antioxidant activity as it showed the strong DPPH radical scavenging action in vitro.     

Effect of Helicteres isora root extracts on glucose tolerance in glucose-induced hyperglycemic rats

The ethanol, ethyl acetate and butanol extracts of Helicteres isora root showed significant oral hypoglycemic activity on glucose loaded rats at a dose of 250 mg/kg. The butanol extract showed maximum antihyperglycemic activity and effect being comparable to that of glibenclamide.     

Antioxidant activity and constituents of extracts from the root of Garcinia multiflora

The methanolic extract of the root of Garcinia multiflora and its derived soluble fractions, namely those soluble in ethyl acetate (EtOAc), n-butanol, and water, were screened for their antioxidant activities. Among them, the EtOAc-soluble fraction exhibited the highest scavenging activity against the 1,1-dipheny1,2-picrylhydrazyl radical, the highest superoxide radical scavenging activity, and the strongest reducing power. In addition, according to the bioactivity-guided isolation, 26 specific phytocompounds, including 3 aromatics, 3 benzophenones, 3 flavonoids, 3 isocoumarins, 1 phloroglucinol, 6 steroids, and 7 xanthones, were isolated from the EtOAc-soluble fraction and identified. Of these, 2,4,3′,4′-tetrahydroxy-6-methoxybenzophenone and 1,3,6,7-tetrahydroxyxanthone were found to be the major bioactive constituents, present in the crude extract in concentrations of 3.9 and 15.6 mg/g, respectively. These two compounds had similar antioxidant activities to (+)-catechin, a well-known antioxidant.     

Inhibition of Helicobacter pylori adhesion to human gastric adenocarcinoma epithelial cells by aqueous extracts and pectic polysaccharides from the roots of Cochlospermum tinctorium A. Rich. and Vernonia kotschyana Sch. Bip. ex Walp

In Malian traditional medicine infusions of the roots of Vernonia kotschyana or Cochlospermum tinctorium in water are used for treating gastric ulcer. Helicobacter pylori is known to play a major role in gastric ulcer development, and it was of interest to evaluate a potential anti-adhesive activity towards H. pylori by crude water extracts and isolated polysaccharide fractions from the roots of V. kotschyana and C. tinctorium. The inhibitory effects were examined by an in vitro flow cytometric assay using human gastric adenocarcinoma epithelial cells, where fluorescent-labeled H. pylori were pre-treated with the test fractions. The crude extract Ctw50 from C. tinctorium, containing a mixture of inulin, pectic polysaccharides, phenols and protein, led to a 43% reduction of bacterial attachment. The isolated pectic type fractions CtwA1 and CtwA2 from C. tinctorium, and Vko-I from V. kotschyana resulted in approximately 30% inhibition of H. pylori adhesion. These fractions consist of rhamnogalacturonan backbones with side chains of arabinogalactans and/or arabinans. The low degree of uronic acids in the fractions compared to anti-adhesive polysaccharides reported previously, suggests that the neutral side chains might play a role in the binding of bacterial adhesins. The fraction Vko-III.1 from V. kotschyana consisting mainly of galacturonic acid resulted only in a 19% inhibition of H. pylori adhesion. The anti-adhesive properties shown by the crude water extracts and isolated polysaccharide fractions in the present study might partly explain the anti-ulcer activities by the roots of V. kotschyana and C. tinctorium.     

Pharmacological effects of Ganoderma lucidum collected from ume (Japanese apricot) trees

We performed functional evaluation of the fruiting bodies of Ganoderma lucidum growing on ume trees (Japanese apricot, Prunus mume), and determined the suitability of pruned ume branches as a basic component of culture medium for this mushroom. We observed that all tested functional activities of the fruiting bodies of G. lucidum collected from ume trees were higher than those collected from other broadleaf trees or cultured artificially; the functional tests were angiotensin I-converting enzyme inhibitory activity, a platelet aggregation inhibition test, and an interleukin-8 (IL-8) gene expression inhibition test. When extracts from fruiting bodies of G. lucidum were orally administered to spontaneous hypertensive rats, hypotensive effects were found. Freeze drying was the most suitable procedure for preservation of the extracts, and the activities of 30% ethanol extracts and 30% methanol extracts were higher than those of hot-water extracts. The highest functional activities for extracts from G. lucidum mycelia cultured on sawdust media were for sawdusts based on ume wood. Part of this study was presented at the 56th Annual Meeting of the Japan Wood Research Society, Akita, Japan, August 2006     

Antiobesity and lipid lowering effects of Murraya koenigii (L.) Spreng leaves extracts and mahanimbine on high fat diet induced obese rats

The dichloromethane (MKD) and ethyl acetate (MKE) extracts of Murraya koenigii leaves significantly reduced the body weight gain, plasma total cholesterol (TC) and triglyceride (TG) levels significantly when given orally at a dose of 300 mg/kg/day to the high fat diet (HFD) induced obese rats for 2 weeks. The observed antiobesity and antihyperlipidemic activities of these extract are correlated with the carbazole alkaloids present in them. Mahanimbine (1) when given orally (30 mg/kg/day) also significantly lowered the body weight gain as well as plasma TC and TG levels. These findings demonstrate the excellent pharmacological potential of mahanimbine to prevent obesity.