**Note: these highlights accompany complete sets of abstracts.
Herb Research Foundation
(A research service for HRF’s Business Leaders’ Circle)
Volume 1, May 2001
Selected Abstract Highlights
In an animal study designed to compare the protective antioxidant effects of onion oil and vitamin E against nicotine-induced oxidative damage, researchers concluded that onion oil was as effective in preventing peroxidation as vitamin E, a proven antioxidant.
Researchers describe a new, rapid in vitro method of measuring antioxidant activity and provide an illustration of its application in evaluating the activity of individual flavonoids and of apple juice. The researchers believe their method will prove useful in optimizing product development and evaluating health claims.
In a laboratory study, bamboo leaf extract (BLE, containing chlorogenic acid, caffeic acid, and luteolin 7-glucoside) exhibited both significant antioxidant activity and minor prooxidant activity. The researchers attributed the antioxidant activity to radical scavenging ability, and the prooxidant activity to “the reducing power of plant phenolics in the presence of transitional metal ions.”
A review with 50 references discusses mechanisms of tumor metastasis, epidemiological evidence of the anti-cancer properties of tea, and the inhibitory effects of tea catechins on cancer invasion, matrix metalloproteinase activities, angiogenesis, and gene expression.
In another study, researchers demonstrated that catechins were retained in green and black teas that were decaffeinated using methylene chloride as a solvent.
This literature review focuses on the polyphenol content of chocolate; ways in which processing affects chocolate polyphenol composition and quantity; and available methodologies for analysis, quantification, isolation, purification, and structure elucidation of polyphenols in cocoa components.
Researchers report results of a study designed to compare the antibacterial effect of xanthorrhizol (isolated from a methanol extract of Curcuma xanthorrhiza roots) against oral pathogens with that of chlorhexidine.
Estrogens in plants
In a review with 98 references, the authors explore the therapeutic potential of phytoestrogens in hormone-dependent cancers, cardiovascular disease, and osteoporosis, as well as ways in which the antioxidant activity of phytoestrogens may contribute to their health effects.
Kombucha (Tea fungus)
Kombucha tea, made by fermenting sugared tea with a culture of acetic bacteria and fungi, is purported to improve resistance against cancer and cardiovascular disease, promote digestion, reduce inflammation, and stimulate immune function. As a starting point for future research, the authors of this paper review existing research on the health benefits of tea and report on possible properties of kombucha constituents.
In an animal study, total peony glycoside (TPG) was effective in improving a variety of learning and memory functions in mice with experimentally induced dysmnesia (impaired memory).
Researchers investigated the effects of a ginseng protopanaxadiol saponin (IH-901, formed from ginsenosides Rb1, Rb2, and Rc) in inhibiting proliferation and inducing apoptosis of human myeloid leukemia cells (cell line HL-60). The investigators concluded that IH-901 dramatically suppressed HL-60 cell growth by inducing apoptosis (programmed cell death) via activation of caspase-3 protease.
In another in vitro study, ginsenoside Rg3 demonstrated growth inhibitory activity against human prostate cancer cells (cell line LNCaP). The researchers suggested that ginsenoside Rg3 activated the expression of cyclin-kinase inhibitors, arrested LCNaP cells at the G1 phase, and inhibited cell growth through caspase-3-mediated apoptosis.
A laboratory study demonstrated that the soy isoflavone genistein inhibited prostate cancer cell proliferation in a cell line (VeCaP) that expresses prostate specific antigen (PSA) in an androgen-independent manner. Earlier research has shown that genistein can inhibit PSA expression in the androgen-dependent prostate cancer cell line LNCaP. According to the authors, their research shows that genistein inhibits cell growth similarly in the two cell lines, but has different effects on PSA expression. They concluded that genistein inhibits prostate cancer cell proliferation independent of PSA-signaling pathways.
To test the liver-protective and restorative properties of Schisandra chinensis seed extract against drug induced hepatotoxicity, researchers divided rats into two groups: one of rats who received or did not receive carbon tetrachloride (CCl4), and one of rats who received CC4 and also were treated or not treated with Schisandra. CCl4-intoxicated rats that also received Schisandra demonstrated significantly better drug metabolism than CCl4-treated rats that did not receive Schisandra. According to the authors, their study suggests that Schisandra holds promise as a treatment for improving Phase I oxidative metabolism in the CCl4-damaged liver.
Scutellaria (Baikal skullcap)
This animal study showed that a total flavonoid extract from Scutellaria baicalensis leaf and stem was effective in inhibiting the elevation of total serum cholesterol, triglycerides, and low-density lipoprotein (LDL) cholesterol in rats fed a high-fat diet.
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a rapid new technology with potential applications in food analysis. In the first study to compare high-performance liquid chromatography (HPLC) and MALDI-TOF MS to quantify anthocyanins in food, the two technologies provided comparable anthocyanin profiles in highbush blueberries at different stages of anthocyanin development. HPLC distinguished anthocyanin isomers, while MALDI-TOF MS more rapidly identified and quantified anthocyanins with different masses.
A review paper with 57 references discusses factors that affect the resveratrol content of wine, including climate and vinification processes.
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