antioxidant

Biotransformation of Green Tea Polyphenols and the Biological Activities of Those Metabolites.: Mol Pharm. 2007 Oct 27; Authors: Lambert JD, Sang S, Yang CS

Green tea ( Camellia sinensis, Theaceae) and its major polyphenol constituents, the catechins, have been reported to have many health benefits including the prevention of cancer and heart disease. Many mechanisms of action have been proposed based on in vitro models; however, the importance of most of these mechanisms remains to be determined in vivo. The bioavailability and biotransformation of tea catechins play a key role in determining the importance of various mechanisms in vivo. Likewise, the biological activity and bioavailability of tea catechin metabolites, an understudied area, are important in understanding the potential beneficial effects of tea. In this article, we review the data available on the biotransformation of the tea catechins and the limited data set available on the biological activities of the catechin metabolites. Careful interpretation of available data, carefully designed animal experiments, and integration of bioavailability and biological activity data are needed if the disease preventive activity of tea is to be understood. We hope this article will spark research efforts on some of the important questions regarding tea polyphenol bioavailability, biotransformation, and the biological activities of tea catechin metabolites.

PMID: 17963356 [PubMed - as supplied by publisher]

Phytodolor--effects and efficacy of a herbal medicine.: Wien Med Wochenschr. 2007;157(13-14):343-7 Authors: Gundermann KJ, Müller J

Herbal antirheumatics are successfully used in painful inflammatory or degenerative rheumatic diseases. One of these herbal medicines is Phytodolor (STW 1), a fixed combination of extracts from aspen leaves and bark (Populus tremula), common ash bark (Fraxinus excelsior), and golden rod herb (Solidago virgaurea). Its effects as well as those of its components have been verified in experimental and human pharmacological investigations. The mode of action of STW 1 includes antiinflammatory, antioedematous, antioxidative and analgesic properties, and it is considered to be broader than that of synthetic antirheumatics. Open clinical studies and randomised, placebo- or verum-controlled double-blind trials, performed in different subtypes of rheumatic diseases, confirm the pharmacological evidence of efficacy, such as by reducing the intake of non-steroidal antiinflammatory drugs (NSAIDs). STW 1 has a high drug safety. CONCLUSION: Phytodolor (STW 1) is a reasonable alternative to NSAIDs and to cyclooxygenase(COX)-2-inhibitors such as rofecoxib.

PMID: 17704984 [PubMed - indexed for MEDLINE]

Use of herbal preparations in the treatment of oxidant-mediated inflammatory disorders.: Complement Ther Med. 2007 Sep;15(3):207-16 Authors: Kaplan M, Mutlu EA, Benson M, Fields JZ, Banan A, Keshavarzian A

Complementary and alternative medicine (CAM) use has increased in popularity in recent years and herbal therapy alone is now a billion dollar market. For centuries herbs have been used as food and for medicinal purposes. Various herbs have been identified as possessing anti-inflammatory and antioxidative properties, and they are currently being used to treat inflammatory disorders as well as those caused by reactive oxygen species (ROS). Asthma, Alzheimer's disease, inflammatory bowel disease (IBD), rheumatoid arthritis (RA), and atherogenesis are all disorders where inflammation and ROS are involved in their pathogenesis. This review examines the pathogenesis of the above mentioned ROS-mediated inflammatory disorders, as well as discusses the antioxidant and anti-inflammatory mechanisms of various herbs and the clinical trials where herbs have been used to treat these disorders.

PMID: 17709066 [PubMed - indexed for MEDLINE]

A randomized, placebo-controlled, double-blind clinical trial of curcuminoids in oral lichen planus.: Phytomedicine. 2007 Aug;14(7-8):437-46 Authors: Chainani-Wu N, Silverman S, Reingold A, Bostrom A, Mc Culloch C, Lozada-Nur F, Weintraub J

We studied the efficacy of curcuminoids in the treatment of oral lichen planus (OLP), a chronic, mucocutaneous, immunological disease. Curcuminoids are components of turmeric (Curcuma longa) that have anti-inflammatory activity. Turmeric has been used in Ayurveda (Indian traditional medicine) for centuries. A randomized, double-blind, placebo-controlled trial was conducted. In all, 100 consecutive, eligible patients with OLP presenting to the oral medicine clinic at the University of California, San Francisco, were to be selected. Two interim analyses were to be conducted during the trial. The trial was conducted between February 2003 and September 2004. The first interim analysis was conducted in October 2004 using data from the first 33 subjects. Study subjects were randomized to receive either placebo or curcuminoids at 2000 mg/day for 7 weeks. In addition, all subjects received prednisone at 60 mg/day for the first 1 week. The primary outcome was a change in symptoms from baseline. Secondary outcomes were changes in clinical signs and occurrence of side effects. The first interim analysis did not show a significant difference between the placebo and curcuminoids groups. Conditional power calculations suggested a less than 2% chance that the curcuminoids group would have a significantly better outcome as compared with the placebo group if the trial were continued to completion. Therefore, the study was ended early for futility. Reaching a conclusion regarding the efficacy of curcuminoids based on the results of this study is not possible as it was ended early for futility. Curcuminoids at this dose were well tolerated and the results suggest that for future studies a larger sample size, a higher dose and/or longer duration of curcuminoids administration should be considered; however, for the next step, an RCT of a shorter duration, using a higher dose of curcuminoids, and without an initial course of prednisone, should be considered.

PMID: 17604143 [PubMed - indexed for MEDLINE]

The olive constituent oleuropein exhibits proteasome stimulatory properties in vitro and confers life span extension of human embryonic fibroblasts.: Rejuvenation Res. 2007 Jun;10(2):157-72 Authors: Katsiki M, Chondrogianni N, Chinou I, Rivett AJ, Gonos ES

Normal human fibroblasts undergo replicative senescence due to both genetic and environmental factors. Senescence and aging can be further accelerated by exposure of cells to a variety of oxidative agents that contribute among other effects to the accumulation of damaged proteins. The proteasome, a multicatalytic nonlysosomal protease, has impaired function during aging, while its increased expression delays senescence in human fibroblasts. The aim of this study was to identify natural compounds that enhance proteasome activity and exhibit antiaging properties. We demonstrate that oleuropein, the major constituent of Olea europea leaf extract, olive oil and olives, enhances the proteasome activities in vitro stronger than other known chemical activators, possibly through conformational changes of the proteasome. Moreover, continuous treatment of early passage human embryonic fibroblasts with oleuropein decreases the intracellular levels of reactive oxygen species (ROS), reduces the amount of oxidized proteins through increased proteasome-mediated degradation rates and retains proteasome function during replicative senescence. Importantly, oleuropein-treated cultures exhibit a delay in the appearance of senescence morphology and their life span is extended by approximately 15%. In summary, these data demonstrate the beneficial effect of oleuropein on human fibroblasts undergoing replicative senescence and provide new insights towards enhancement of cellular antioxidant mechanisms by natural compounds that can be easily up-taken through normal diet.

PMID: 17518699 [PubMed - indexed for MEDLINE]

Human hair growth enhancement in vitro by green tea epigallocatechin-3-gallate (EGCG).: Phytomedicine. 2007 Aug;14(7-8):551-5 Authors: Kwon OS, Han JH, Yoo HG, Chung JH, Cho KH, Eun HC, Kim KH

Green tea is a popular worldwide beverage, and its potential beneficial effects such as anti-cancer and anti-oxidant properties are believed to be mediated by epigallocatechin-3-gallate (EGCG), a major constituent of polyphenols. Recently, it was reported that EGCG might be useful in the prevention or treatment of androgenetic alopecia by selectively inhibiting 5alpha-reductase activity. However, no report has been issued to date on the effect of EGCG on human hair growth. This study was undertaken to measure the effect of EGCG on hair growth in vitro and to investigate its effect on human dermal papilla cells (DPCs) in vivo and in vitro. EGCG promoted hair growth in hair follicles ex vivo culture and the proliferation of cultured DPCs. The growth stimulation of DPCs by EGCG in vitro may be mediated through the upregulations of phosphorylated Erk and Akt and by an increase in the ratio of Bcl-2/Bax ratio. Similar results were also obtained in in vivo dermal papillae of human scalps. Thus, we suggest that EGCG stimulates human hair growth through these dual proliferative and anti-apoptotic effects on DPCs.

PMID: 17092697 [PubMed - indexed for MEDLINE]

Anti-stress, anti-HIV and vitamin C-synergized radical scavenging activity of mulberry juice fractions.: In Vivo. 2007 May-Jun;21(3):499-505 Authors: Sakagami H, Asano K, Satoh K, Takahashi K, Kobayashi M, Koga N, Takahashi H, Tachikawa R, Tashiro T, Hasegawa A, Kurihara K, Ikarashi T, Kanamoto T, Terakubo S, Nakashima H, Watanabe S, Nakamura W

Anti-stress and anti-HIV activity of mulberry juice were separated by centrifugation. The anti-stress activity was enriched in the supernatant fraction whereas the anti-HIV activity in the precipitate fraction. Oral administration of the supernatant fraction significantly reduced the elevated plasma level of lipid peroxide in mice loaded with water immersion restraint stress. The kinetic study revealed that the anti-stress activity was maintained for 4 hours after cessation of the administration of mulberry juice. The lignin fraction in the precipitate fraction scavenged superoxide and hydroxyl radicals more efficiently than other fractions, in a synergistic fashion with sodium ascorbate. Anti-HIV activity of mulberry juice was concentrated in the lignin fraction, whereas blueberry juice, which has no precipitating fibrous materials, did not show anti-HIV activity. The present study suggests the functionality of mulberry juice as an alternative medicine.

PMID: 17591360 [PubMed - indexed for MEDLINE]

Antioxidant activity relates to plant part, life form and growing condition in some diabetes remedies.: J Ethnopharmacol. 2007 Apr 24; Authors: McCune LM, Johns T

Selection, collection and preparation of 35 plant species used by traditional healers in the boreal regions of Canada for treatment of the symptoms of diabetes were supported empirically by antioxidant activity of the plants. Because antioxidants fluctuate with growth parameters and environmental factors, these remedies were evaluated in relation to the affect of plant part, life form and growing condition on the level of activity. The parts used here more frequently as medicines were roots and bark. Activity (IC(50)) of the bark extracts used medicinally averaged to 21.38+/-3.84ppm while root extracts used medicinally had an IC(50) of 185.11+/-32.18ppm in a free radical DPPH assay. In contrast the analysis of extracts of overall parts (medicinal or not) in these species found leaves and bark to have the least activity (112.22+/-30.63ppm and 123.02+/-21.13ppm, respectively). The highest activity was found in tree extracts (24.88+/-3.32ppm) as compared to herbs and shrubs, and increased activity was found in plant extracts from growing conditions of decreased water/fertility. The antioxidant activity of these traditional plant remedies have the potential to be partially deduced through environment signals interpreted by the traditional herbalist.

Mitochondrial oxidant signalling in Alzheimer's disease.: J Alzheimers Dis. 2007 May;11(2):175-81 Authors: Viña J, Lloret A, Vallés SL, Borrás C, Badía MC, Pallardó FV, Sastre J, Alonso MD

The role of free radicals in Alzheimer disease pathophysiology has been appreciated for a long time. Originally, radicals were considered as causative of oxidative damage. More recently their role as signalling molecules in this, as well as in other fields of free radical biology, has been underscored. Mitochondria are both generators and targets of radical damage in aging. In this paper we review evidence that radicals generated in mitochondria in the presence of Abeta are signals that trigger both the mitochondrial and the extra-mitochondrial pathways of apoptosis. There are gender specific differences in mitochondrial Abeta toxicity: mitochondria from young (but not from old) females appear to be protected. 17-beta Estradiol or phytoestrogens like genistein prevent the formation of oxidants by mitochondria and protect against mitochondrial Abeta toxicity. Experiments reported here indicate that phytoestrogens might have a role in the prevention of Alzheimer's disease.

Inhibition of cancer cell proliferation and suppression of TNF-induced activation of NFkappaB by edible berry juice.: Anticancer Res. 2007 Mar-Apr;27(2):937-48 Authors: Boivin D, Blanchette M, Barrette S, Moghrabi A, Béliveau R

BACKGROUND: Berries contain several phytochemicals, such as phenolic acids, proanthocyanidins, anthocyanins and other flavonoids. There has been growing interest in a variety of potential chemopreventive activities of edible berries. The potential chemopreventive activity of a variety of small berries cultivated or collected in the province of Québec, Canada were evaluated here. MATERIALS AND METHODS: Strawberry, raspberry, black currant, red currant, white currant, gooseberry, high-bush blueberry, low-bush blueberry, velvet leaf blueberry, serviceberry, blackberry, black chokeberry, sea buckthorn and cranberry were evaluated for antioxidant capacity, anti-proliferative activity, anti-inflammatory activity, induction of apoptosis and cell cycle arrest. RESULTS: The growth of various cancer cell lines, including those of stomach, prostate, intestine and breast, was strongly inhibited by raspberry, black currant, white currant, gooseberry, velvet leaf blueberry, low-bush blueberry, sea buckthorn and cranberry juice, but not (or only slightly) by strawberry, high-bush blueberry, serviceberry, red currant, or blackberry juice. No correlation was found between the anti-proliferative activity of berry juices and their antioxidant capacity (p > 0.05). The inhibition of cancer cell proliferation by berry juices did not involve caspase-dependent apoptosis, but appeared to involve cell-cycle arrest, as evidenced by down-regulation of the expression of cdk4, cdk6, cyclin D1 and cyclin D3. Of the 13 berries tested, juice of 6 significantly inhibited the TNF-induced activation of COX-2 expression and activation of the nuclear transcription factor NFkappaB. CONCLUSION: These results illustrate that berry juices have striking differences in their potential chemopreventive activity and that the inclusion of a variety of berries in the diet might be useful for preventing the development of tumors.