Cytotoxic, antitumour-promoting and inhibition of protein denaturation effects of flavonoids, isolated from <i>Potentilla evestita</i> Th. Wolf

<div><p>This study was designed to evaluate the isolated flavonoids (chrysin <b>1</b>, and umbelliferone <b>2</b>) from <i>Potentilla evestita</i> for cytotoxic, antitumour-promoting and inhibition of protein denaturation activities. The results showed marked cytotoxic effect of compounds <b>1</b> and <b>2</b> in brine shrimp cytotoxic assay at various concentrations with LD₅₀ of 34.5 and 31.8 mg/mL, respectively. In Epstein–Barr-virus early antigen activation assay, both compounds <b>1</b> and <b>2</b> illustrated significant antitumour-promoting effect with IC₅₀ values of 462 and 308 mol ratio/32 pmol TPA, respectively. The cytotoxic and antitumour-promoting effects of compounds were strongly supported by inhibition of protein denaturation activity with IC₅₀ of 119 and 112 μg/mL, respectively. In conclusion, both compounds possess strong cytotoxic, antitumour-promoting and inhibition of protein denaturation activities.</p></div

Inhibition of thermal induced protein denaturation of extract/fractions of <i>Withania somnifera</i> and isolated withanolides

<div><p>This study describes the <i>in vitro</i> inhibition of protein denaturation of extract/fractions of <i>Withania somnifera</i> and isolated withanolides including 20β hydroxy-1-oxo(22<i>R</i>)-witha-2,5,24 trienolide (<b>1</b>), (20<i>R</i>,22<i>R</i>-14α,20α)-dihydroxy-1-oxowitha-2,5,16,24 tetraenolide (<b>2</b>). The results showed that the extract/fractions of the plant evoked profound inhibitory effect on thermal-induced protein denaturation. The chloroform fraction caused the most dominant attenuation of 68% at 500 μg/mL. The bioactivity-guided isolation from chloroform fraction led to the isolation of compounds <b>1</b> and <b>2</b> that showed profound protein inhibition with 78.05% and 80.43% effect at 500 μg/mL and thus strongly complimented the activity of extract/fractions. In conclusion, extract/fractions of <i>W. somnifera</i> possessed strong inhibition of protein denaturation that can be attributed to these isolated withanolides.</p></div

<i>In vivo</i> antinociceptive and anti-inflammatory activities of umbelliferone isolated from <i>Potentilla evestita</i>

<div><p>This study was designed to evaluate the antinociceptive and anti-inflammatory activities of a compound, umbelliferone, isolated from the chloroform fraction of <i>Potentilla evestita</i> in animal models. When tested against acetic acid-induced noxious stimulus, it significantly prolonged pain threshold and provided 38.38% and 60.95% reduction in abdominal constriction at 5 and 10 mg/kg i.p., respectively. Post-umbelliferone injection evoked significant dose-dependent reduction in noxious stimulation with 33.65% and 58.89% pain attenuation at 5 and 10 mg/kg i.p., respectively, in the initial phase. In the late phase, it illustrated more dominant effect with 37.65% and 63.79% blockade of painful sensation. Similarly, it exhibited significant anti-inflammatory activity during various assessment times (1–5 h) with 46.28% and 66.13% amelioration after 4th of administration against induced oedema. In conclusion, umbelliferone possessed strong antinociceptive and anti-inflammatory activities by inhibiting both peripheral and centrally acting pain mediators.</p></div

Antimicrobial and inhibition on heat-induced protein denaturation of constituents isolated from <i>Polygonatum</i><i>verticillatum</i> rhizomes

<div><p>This study was designed to assess the susceptibility of various microorganisms and inhibition on heat-induced protein denaturation against diosgenin and santonin, isolated from <i>Polygonatum verticillatum</i> rhizomes. Both diosgenin and santonin showed significant zone of inhibition when studied against various Gram-positive (<i>Bacillus subtilis</i>, <i>Bacillus cereus</i>, <i>Staphylococcus aureus</i> and <i>Staphylococcus epidermidis</i>) and Gram-negative bacteria (<i>Escherichia coli</i> and <i>Salmonella typhi</i>). In antifungal assay, only santonin exhibited profound sensitivity against various fungi (<i>Aspergillus flavus</i>, <i>Aspergillus niger</i>, <i>Trichoderma harzianum</i> and <i>Fusarium oxysporum</i>) used in the test. Both diosgenin and santonin also exhibited marked attenuation on heat-induced protein denaturation in a concentration-dependent manner with EC₅₀ values of 375 and 310 μg/mL, respectively. In conclusion, both the isolated compounds have antimicrobial potential supported by strong inhibition on protein denaturation and thus support the antimicrobial uses of plant in traditional system of treatment.</p></div

Bioassay-guided isolation of antibacterial constituents from <i>Diospyros lotus</i> roots

<div><p>The aim of this study was to explore the extract/fractions and compounds of <i>Diospyros lotus</i> against various Gram-positive and Gram-negative bacteria strain. The results showed marked susceptibility of extract and its fractions against test pathogens. Among them, chloroform fraction was most dominant and effective against all tested bacteria. The chloroform fraction was subjected to column chromatography which led to the isolation of lupeol (<b>1</b>), 7-methyljuglone (<b>2</b>), β-sitosterol (<b>3</b>), stigmasterol (<b>4</b>), betulinic acid (<b>5</b>), diospyrin (<b>6</b>) and 8-hydroxyisodiospyrin (<b>7</b>). Among the isolated compounds, betulinic acid (<b>5</b>) showed significant activity against most of the tested pathogen. In conclusion, our study validated the traditional uses of the plant in the treatment of infectious diseases which was also strongly supported by the isolated compound, betulinic acid (<b>5</b>).</p></div

Anti-hyperalgesic activity of crude extract and 7-methyljuglone of <i>Diospyros lotus</i> roots

<div><p>This study was designed to evaluate the antihyperalgesic effect of crude extract of <i>Diospyros lotus</i> followed by the isolation and characterisation of 7-methyljuglone in acetic acid and formalin tests. The pretreatment of crude extract evoked dose-dependent inhibition of noxious stimulation with maximum effect of 56.78% in acetic acid-induced writhing test, which were 51.89% and 60.69% in first and second phases, respectively, at 100 mg/kg i.p. The structure of 7-methyljuglone was confirmed by spectroscopic analysis. 7-Methyljuglone evoked profound increase in pain threshhold dose dependently; when it was studied in acetic acid-induced writhing test with 63.73% pain attenuation while 51.22% and 65.44% pain amelioration in first and second phases, respectively, at 100 mg/kg i.p. In conclusion, crude extract and 7-methyljuglone of <i>D. lotus</i> roots possessed both peripheral and central antinociceptive potential and thus could be a useful new therapeutic agent.</p></div

Biofunctional properties of <i>Eruca sativa</i> Miller (rocket salad) hydroalcoholic extract

<p><i>Eruca sativa</i> Miller is a worldwide common alimentary plant (rocket leaves). The aim of this study was to correlate the potential <i>in vitro</i> scavenging activity of the <i>E. sativa</i> hydroalcoholic extract (HAE) with its <i>in vivo</i> hypoglycaemic effect. In DDPH free radical (DFR) and ferric-reducing antioxidant power assays, HAE in a concentration dependent manner (25–100 μg/mL) displayed a strong scavenging activity with maximum effect of 88% and 75% at 100 μg/mL, respectively. Daily administration of HAE (50 mg/kg; p.o.) in the <i>in vivo</i> model of alloxan-induced diabetic rabbits for 28 days showed significant reduction in glycaemia, also supported by recovery of body weight. In conclusion, our results give preliminary information on the potential use of this plant as a nutraceutical, useful to control and/or prevent a hyperglycaemic status.</p

Antimicrobial and antioxidant activities of a new metabolite from <i>Quercus incana</i>

<p>Phytochemical investigations of <i>Quercus incana</i> led to the isolation of a new catechin derivative quercuschin (<b>1</b>), along with six known compounds: quercetin <b>(2</b>), methyl gallate (<b>3</b>), gallic acid (<b>4</b>), betulinic acid (<b>5</b>), (<i>Z</i>)-9-octadecenoic acid methyl ester (<b>6</b>) and β-sitosterol glucoside (<b>7</b>) from the ethyl acetate fraction of methanolic extract of the bark. Compound <b>1</b> was screened for its antibacterial, antifungal and antioxidant potential. Antibacterial and antifungal activities of the compound were tested against different bacterial and fungal strains, employing the agar well diffusion methods. The antibacterial activity was the highest against <i>Streptococcus pyogenes</i> with 80.0% inhibition, while the antifungal activity of the compound was the highest against <i>Candida glabrata</i> with 80.5% inhibition. The results of the antioxidant activity indicated that the compound exhibited antioxidant activity comparable to that of standard, butylated hydroxyanisole (51.2 μg/10 μl versus 45.9 μg/10 μl).</p