Identification Of Phytochemicals Research Articles

Plumbagin, a novel Nrf2/ARE activator, protects against cerebral ischemia

Many phytochemicals function as noxious agents that protect plants against insects and other damaging organisms. However, at subtoxic doses, the same phytochemicals may activate adaptive cellular stress response pathways that can protect cells against a variety of adverse conditions. We screened a panel of botanical pesticides using cultured human and rodent neuronal cell models, and identified plumbagin as a novel potent activator of the nuclear factor E2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway. In vitro, plumbagin increases nuclear localization and transcriptional activity of Nrf2, and induces the expression of the Nrf2/ARE-dependent genes, such as heme oxygenase 1 in human neuroblastoma cells. Plumbagin specifically activates the Nrf2/ARE pathway in primary mixed cultures from ARE-human placental alkaline phosphatase reporter mice. Exposure of neuroblastoma cells and primary cortical neurons to plumbagin provides protection against subsequent oxidative and metabolic insults. The neuroprotective effects of plumbagin are abolished by RNA interference-mediated knockdown of Nrf2 expression. In vivo, administration of plumbagin significantly reduces the amount of brain damage and ameliorates-associated neurological deficits in a mouse model of focal ischemic stroke. Our findings establish precedence for the identification and characterization of neuroprotective phytochemicals based upon their ability to activate adaptive cellular stress response pathways.

EFFECTS OF STRAWBERRY CONSUMPTION ON PLASMA ANTIOXIDANT STATUS AND PARAMETERS OF RESISTANCE TO OXIDATIVE STRESS: PRELIMINARY EVIDENCE FROM HUMAN SUBJECTS

Strawberry is a relevant source of dietary antioxidants, such as vitamin C and phenolic compounds, which are widely reported to have biological properties ranging from antioxidant to anticancer and antiatherosclerotic properties. However, the fine identification of the health-promoting phytochemicals in strawberry, and the mechanisms of action for their in vivo absorption, bioavailability and bioefficacy are still poorly understood. In our work, a preliminary evaluation of the beneficial effects of strawberry consumption started from the observation of two groups of human volunteers, involved in a short-term and a medium-term feeding studies, respectively. In keeping with previous findings, the plasma antioxidant capacity and the ascorbate serum concentration of the participants significantly increased during both the studies, whereas the serum urate maintained unmodified. Relevant variations in the serum lipophilic antioxidants were also observed, and an improvement in the erythrocyte responsiveness to oxidative stress seemed to be related to the strawberry intake. Future additional in vivo studies are strongly hoped.

In vitro immunomodulatory activity of various extracts of Maltese plants from the Asteraceae family

Various extracts of ten plants from the Asteraceae family were studied for their effects of on human peripheral T-lymphocytes in vitro. Five solvent systems were used to extract constituents from these plants. Phytochemical identification of the most prevalent phytochemical classes was carried out, followed by screening for pharmacological activity using the Brine Shrimp Lethality test (BST). One BST-negative and five BST-positive extracts were tested on human lymphocytes. Marked effects were observed in treated lymphocytes with all six extracts. However only two extracts caused lymphocyte activation and pronounced blastogenesis similar to that of phytohaemagglutinin (PHA). The results obtained indicate that in particular the petroleum ether extract of Calendula arvensis is relatively nontoxic to peripheral lymphocytes suggesting its potential use as an immune booster.

KARAKTERISASI EKSTRAK ETANOLIK DAUN ASAM JAWA (TAMARINDUS INDICA L.)

Leaves of tamarind (Tamarindus indica L.) has been traditionally used to treat some diseases such as: constipation, dyspepsia, flatulence and urinary tract infection. The leaves extract also reported has antibacterial and antidiabetic activities. It is essential to determine its specific and non specific parameters in assesing the quality and safety. The samples collected from three different perferctures. Grounded samples were macerated with ethanol. The extracts were subjected to determine its characteristic parameters. Parameter of quality for the extracts consisted of water content, ethanol-extractive, water-extractive, loss on drying, total ash, acid-insoluble ash, solvent residue and heavy metal content. Phytochemical identification showed that the ex-tract contains flanovoid, tannin, glycosides, and saponin. TLC chromatogram using chloroform-methanol-water (80:12:2) as mobile phase, exhibited 4 spots after sprayed with iron(III) chloride. Total phenolic was determined spectrophotometrically using Folin Ciocalteu reagent, gave 0.35-8.24% total phenolic as gallic acid. Key words: Folin Ciocalteu, phenolic compounds, TLC chromatogram, standard-ization, Tamaridus indica.

Assessment of antiradical potential of Calluna vulgaris (L.) Hull and its major flavonoid

AbstractBACKGROUND: Antioxidant capacity of the chloroform, ethyl acetate, n‐butanol and water fractions of the aerial parts of Calluna vulgaris (L.) Hull (Ericaceae) has been assessed in this study. Antioxidant capacity of the plant was screened by assays of 2,2‐diphenyl‐β‐picrylhydrazyl, superoxide anion and hydrogen peroxide scavenging, metal‐chelating activity and reducing power. Butylated hydroxyanisole was used as reference in all assays; ethylene diamine tetraacetic acid was also used as reference in the assay of metal‐chelating activity. Total phenolic contents of the fractions were determined by the Folin–Ciocalteu method.RESULTS: Liquid chromatography/diode array detection/mass spectrometry was used for phytochemical identification of the fractions. Kaempferol‐3‐O‐β‐D‐galactoside was found to be the major constituent in the ethyl acetate fraction (37.1 ± 0.9%), followed by the n‐butanol fraction (4.6 ± 0.1%). High occurrence of antioxidant capacity, with the exception of metal‐chelating activity, was observed in the ethyl acetate and chloroform fractions as well as in kaempferol‐3‐O‐β‐D‐galactoside.CONCLUSION: Calluna vulgaris and its major flavonoid, kaempferol‐3‐O‐β‐D‐galactoside, show high antioxidant capacity in various assays. As far as is known, this is the first report on antioxidant capacity of C. vulgaris and its major flavonoid. Copyright © 2009 Society of Chemical Industry

Potent antioxidant biophenols from olive mill waste

Olive mill waste (OMW) is rich in biophenols that can be extracted and applied as natural antioxidants for the food and pharmaceutical industries. Bioactivity-guided fractionation combines the use of bioassay and chromatographic separation for isolation of potent bioactive compounds from highly complex plant extracts, such as OMW, and avoids tedious purification and identification of inactive phytochemicals. Antioxidant activity-guided fractionation and sub-fractionation of Correggiola variety OMW extract, using semi-preparative HPLC and multidimensional antioxidant screening, followed by isolation of the screening hits are described. Activity-guided fractionation using four different bioscreens revealed verbascoside and 3,4-dihydroxyphenylethyl alcohol–deacetoxyelenolic acid dialdehyde (3,4-DHPEA–DEDA) as the most potent antioxidants in Correggiola OMW extracts.

Isosilybin B causes androgen receptor degradation in human prostate carcinoma cells via PI3K-Akt-Mdm2-mediated pathway

The identification and development of novel nontoxic phytochemicals that target androgen and androgen receptor (AR) signaling remains a priority for prostate cancer (PCA) control. In the present study, we assessed the antiandrogenic efficacy of isosilybin B employing human PCA LNCaP (mutated AR), 22Rv1 (mutated AR) and LAPC4 (wild-type AR) cells. Isosilybin B (10-90 microM) treatment decreased the AR and prostate specific antigen (PSA) levels in LNCaP, 22Rv1 and LAPC4 cells, but not in non-neoplastic human prostate epithelial PWR-1E cells. Isosilybin B treatment also inhibited synthetic androgen R1881-induced nuclear localization of AR, PSA expression and cell growth, and caused G(1) arrest. In mechanistic studies identifying AR degradation, isosilybin B caused increased phosphorylation of Akt (Ser-473 and Thr-308) and Mdm2 (Ser-166), which was linked with AR degradation as pretreatment with PI3K inhibitor (LY294002)-restored AR level. Further, overexpression of kinase-dead Akt largely reversed isosilybin B mediated-AR degradation suggesting a critical role of Akt in AR degradation. Antibody pull-down results also indicated that isosilybin B treatment enhances the formation of complex between Akt, Mdm2 and AR, which promotes phosphorylation-dependent AR ubiquitination and its degradation by proteasome. Together, present findings identify a novel mechanism for isosilybin B-mediated anticancer effects in human PCA cells.

Discovery and development of sulforaphane as a cancer chemopreventive phytochemical

Sulforaphane (SF) is a phytochemical that displays both anticarcinogenic and anticancer activity. SF modulates many cancer-related events, including susceptibility to carcinogens, cell death, cell cycle, angiogenesis, invasion and metastasis. We review its discovery and development as a cancer chemopreventive agent with the intention of encouraging further research on this important compound and facilitating the identification and development of new phytochemicals for cancer prevention.

Ontogenic Profiling of Glucosinolates, Flavonoids, and Other Secondary Metabolites in Eruca sativa (Salad Rocket), Diplotaxis erucoides (Wall Rocket), Diplotaxis tenuifolia (Wild Rocket), and Bunias orientalis (Turkish Rocket)

As an influence of the Mediterranean diet, rocket species such as Eruca sativa L., Diplotaxis species, and Bunias orientalis L. are eaten all over the world at different ontogenic stages in salads and soups. They are all species within the plant order Capparales (glucosinolate-containing species), and all are from the family Brassicaceae. Predominantly, the leaves of these species are eaten raw or cooked, although Eruca flowers are also consumed. There is considerable potential with raw plant material for a higher exposure to bioactive phytochemicals such as glucosinolates, their hydrolysis products, and also phenolics, flavonoids, and vitamins such as vitamin C. These compounds are susceptible to ontogenic variation, and the few published studies that have addressed this topic have been inconsistent. Thus, an ontogenic study was performed and all samples were analyzed using a previously developed robust liquid chromatography/mass spectrometry method for the identification and quantification of the major phytochemicals in all tissues of the rocket species. Seeds and roots of both Eruca and Diplotaxis contained predominantly 4-methylthiobutylglucosinolate. Leaves of Eruca and Diplotaxis contained high amounts of 4-mercaptobutylglucosinolate with lower levels of 4-methylthiobutlyglucosinolate and 4-methylsulfinylbutylglucosinolate. Flowers of Eruca and Diplotaxiscontained predominantly 4-methylsulfinylbutyl-glucosinolate. In addition, roots of both Diplotaxisspecies contained 4-hydroxybenzylglucosinolate but 4-hydroxybenzylglucosinolate was absent from roots of Eruca. Seeds and seedlings of all Eruca contained N-heterocyclic compounds but no sinapine, whereas Diplotaxis contained sinapine but not the N-heterocycles. In all tissues of B. orientalis, 4-hydroxybenzylglucosinolate and 4-methylsulfinyl-3-butenylglucosinolate were predominant. All rocket tissues, except roots, contained significant levels of polyglycosylated flavonoids, with/without hydroxycinnamoyl acylation. The core aglycones were kaempferol, quercetin, and isorhamnetin. The exception was B. orientalis, which had a negligible seed flavonoid content as compared with the other species. Anthocyanins were only detected in Eruca flowers and consisted of a complex pattern of at least 16 different anthocyanins.

Anticancer Effect of Kalpaamruthaa on Mammary Carcinoma in Rats with Reference to Glycoprotein Components, Lysosomal and Marker Enzymes

A promising approach to reduce the occurrence of cancer is its treatment, specifically by chemical intervention through minor dietary constituents. Epidemiological studies suggest that specific pharmacologically active agents present in the diet might reduce cancer. A remarkable surge of interest in chemoprevention research has, thus, lead to the identification of many phytochemicals of dietary origin as effective potential chemotherapeutic agents. In the present investigation, attempt has been made to study the potency of Kalpaamruthaa (KA), a herbal preparation, against cancer. The changes in level of glycoprotein components, marker enzymes and lysosomal enzymes were carried out in 7,12-dimethylbenz(a)anthracene (DMBA) induced Sprague-Dawley rats. The changes in the body weights and volume were also determined. KA was administered at the dosage level of 100, 200, 300, 400 and 500 mg/kg body weight (BW) in olive oil orally for 14 d, after the induction period is completed (90 d). On administration of KA, the levels of the above enzymes and the changes in the body weights and volume were significantly normalized in a dose dependent manner. The present study shows that KA is effective at the dosage level of 300 mg/kg body weight in mammary carcinoma bearing rats.

Phytochemical screening and antiviral activity of some medicinal plants from the island Soqotra

Methanol and hot-aqueous extracts of 25 different plant species, used in Yemeni traditional medicine and growing, partly as endemic plants, on the island Soqotra have been investigated for their antiviral activity. In addition, the phytochemical identification of the main chemical constituents was performed. The extracts were assayed in two in vitro viral systems, which used influenza virus type A/MDCK cells and herpes simplex virus type 1/Vero cells, at non-cytotoxic concentrations. The herpes simplex virus type 1 showed more sensitivity than the influenza virus type A against the extracts investigated. The methanol extracts of Boswellia ameero, Boswellia elongata, Buxus hildebrandtii, Cissus hamaderohensis, Cleome socotrana, Dracaena cinnabari, Exacum affine, Jatropha unicostata and Kalanchoe farinacea showed anti-influenza virus type A activity with 50% inhibition (IC50) concentrations ranging from 0.7 to 12.5 microg/mL. In addition, 17 plants of the 25 investigated exhibited anti-HSV-1 activity. The antiviral activity of some active extracts was also observed on a molecular level.

An Improved HPLC Post-Column Methodology for the Identification of Free Radical Scavenging Phytochemicals in Complex Mixtures

The importance of natural antioxidants principally relates to their health-promoting properties. The discovery of new sources of established compounds or more potent compounds is a costly exercise and any technique capable of aiding this procedure would be highly significant. An approach combining chromatographic separation, component analysis and post-column identification of free radical scavenging has been reported. However, its effectiveness is dependent upon various factors and the number of samples analyzed without operator intervention is restricted. A more applicable technique using a 10% to 100% methanol with 2% acetic acid mobile phase and a citric acid-sodium citrate buffered methanolic 1,1-diphenyl2-picrylhydrazyl free radical reagent is presented, whereby free radical scavengers can be detected within crude extracts of variable polarity without special considerations. As an illustration, acetone, 70% (aq.) methanol and acetonitrile-soluble extracts were prepared from sage (Salvia officinalis L.) for extraction of polar and non-polar radical scavengers and analyzed. Radical scavenging components were identified as carnosic, caffeic and rosmarinic acids and luteolin-7-O-glycoside. Others radical scavengers were tentatively identified as benzoic and hydroxycinnamic acid derivatives, flavonoids and diterpenoids. Through the application of this technique, carnosic acid and rosmarinic acid were identified as the principal free radical scavengers.

브로콜리 용매추출물의 Bioactive Organosulfur 화합물의 분리 및 동정

브로콜리 중의 bioactive organosulfur phytochemicals를 분석하기 위해 브로콜리를 용매추출하여 GC/MSD에 의해 분리동정하였다. 브로콜리에 함유된 phytochemicals 중에서 isothiocyanate류가 40.42%로 대부분을 차지하였으며, glucosinolate 분해산물인 nitrile류는 5.12%로 isothiocyanate류에 비해 적었고, sulfide류는 0.84%로 매우 적었다. 분리 동정된 isothiocyanate류의 종류로는 3-butenyl, 4-methylthiobutyl, 4-methylthio-3-butenyl, 5-methylthiopentyl, 2-phenylethyl, 3-methylsulfinyl propyl 및 4-methylsulfinylbutyl isothiocyanate의 7종이었다. Isothiocyanate류 중에서 3-butenyl isothiocynate는 22.05%로 가장 많았으며, 그 다음으로 sulforaphane 16.50%로 2종의 isothiocyanate가 대부분을 차지하였다. Nitrile의 종류는 4-methylthiobutyl, 5-methylthiopentyl, 2-phenylethyl 및 4-methylsulfinylbutyl nitrile의 6종류가 확인되었다. 한편, 동정된 sulfide 종류로는 dimethyl disulfide, dimethyl trisulfide 및 dimethyl tetrasulfide이었다.

The phytochemical profile and identification of main phenolic compounds from the leaf exudate of Aloe secundiflora by high-performance liquid chromatography-mass spectroscopy.

The phytochemical profile of Aloe secundiflora (Aloeaceae) and the identity of eight major compounds, including the two main constituents, have been determined from the leaf exudate of this ethnoveterinary used species from Kenya and Tanzania. Analytical HPLC-MS studies of the exudate have revealed that it comprises a mixture of phenolic compounds, mainly anthrones (aloenin, aloenin B, isobarbaloin, barbaloin and other aloin derivatives), chromones and phenylpyrones with a low content of polysaccharides and aliphatic compounds. The high percentage of anthrones in the exudate could provide a first line of evidence for the use of the plant in ethnoveterinary practices.

Cytotoxicity, genotoxicity and oxidative reactions in cell-culture models: modulatory effects of phytochemicals.

Much research effort has focused on the identification of phytochemicals in fruit and vegetables which exert beneficial effects. Our research examines modulatory effects of phytochemicals on cytotoxicity, genotoxicity and oxidative reactions in cell systems. Two examples of our studies are discussed. First, the potential beneficial effects of flavonoids are demonstrated. Flavonoids are reported to exhibit a wide variety of biological effects, including antioxidant and free-radical-scavenging activities. The aim of the study was to determine if flavonoids could protect against H2O2-induced DNA damage, as measured by the comet assay, in Caco-2 and HepG2 cells. Both cell lines were supplemented with increasing concentrations of myricetin, quercetin and rutin for 24 h followed by exposure to H2O2 (50 microM) for 30 min. Exposure to H2O2 for 30 min at 37 degrees C resulted in significant DNA damage and pre-incubation with the flavonoids before H2O2 exposure significantly (P <0.05) protected Caco-2 and HepG2 cells against H2O2-induced DNA damage. Secondly, we illustrate the use of cellular models to study oxysterol-induced toxicity. Oxysterols are generated during the cooking and processing of foods and may be produced endogenously by the oxidation of membrane lipids. Recent findings suggest that oxysterols may modulate cytotoxicity by exerting effects on the induction of apoptosis. 7beta-Hydroxycholesterol (7beta-OHC) and 25-hydroxycholesterol, both of which are commonly found in foods, were investigated for their abilities to induce apoptosis in a human monocytic blood cell line, U937, and in the human hepatoma cell line, HepG2 cells. U937 and HepG2 cells were incubated for up to 48 h with 30 microM oxysterol. 7beta-OHC induced apoptosis in U937 cells as measured by non-random DNA fragmentation, condensed and fragmented nuclei, and the generation of hypodiploid cells. In contrast, oxysterols may induce cell death by a different mechanism in the hepatoma cells, possibly by necrosis.