Journal of Medicinal Food

Epidemiological studies have shown an inverse relationship between serum lycopene levels and the risk of prostate cancer. The objective of this study was to measure the effect of lycopene on the proliferation of LNCaP human prostate cancer cells in culture. A new, water-dispersible lycopene in an appropriate vehicle was used. The stock solution was diluted in the medium to obtain lycopene concentrations of 10^-6, 10^-5, and 10^-4 M; their corresponding vehicles were similarly diluted to be used as controls. Cells were grown for 48 hours in RPMI-1640 medium supplemented with 10% fetal bovine serum and antibiotics. Lycopene was then added at different concentrations, and the cells were allowed to grow for 24, 48, 72, and 96 hours. Lycopene at concentrations of 10^-6 and 10^-5 M significantly reduced the growth of LNCaP cells after 48, 72, and 96 hours of incubation, by 24.4% to 42.8% (P < .05). The inhibitory effect of lycopene was significantly higher than that of the corresponding vehicle controls. In a follow-up experiment, a lower range of lycopene concentrations (10^-9 to 10^-7 M) was used to determine whether there was a dose-response effect. Lycopene significantly decreased the growth of cells in a dose-dependent manner when cells were incubated for 24, 48, 72, or 96 hours (F = 3.150, 11.27, 54.51, and 297.5, respectively; P < .05). The growth inhibitory effect of lycopene on human prostate cancer cells observed in this study suggests a possibly important role for lycopene as an antioxidant in human prostate cancer; however, investigations of other mechanisms are warranted.

Brain tissue is highly susceptible to oxidative damage due to its high utilization of oxygen and its poorly developed antioxidative defense mechanisms. Radiation or pro-oxidants interact with cells and tissues through secondary ionization mechanisms such as lipid peroxidation (LPO). LPO can be inhibited by antioxidants such as vitamins A, C, and E and the carotenoid β-carotene. β-Carotene, the provitamin A, plays an important radioprotective role due to its properties as a potent free radical scavenger, singlet oxygen quencher, and lipid antioxidant. Amaranthus gangeticus Linn., widely considered as a weed, has a high content of carotene, ascorbic acid, and folate and may prove an efficient antioxidant. To evaluate the antioxidative efficacy of Amaranthus, healthy Swiss albino mice from an inbred colony were treated with alcoholic extract of A. gangeticus leaves (AE) for 2 weeks, at 800 mg/kg body weight, before radiation exposure. Irradiated mice were examined and autopsied at intervals of 1, 3, 7, 15, and 30 days after exposure. Brain was removed by skull dissection, and various biochemical changes were sought. Radiation caused a maximum increase of 27% in LPO and a maximum decrease of 27.96% in protein content at day 7 in controls. However, in the experimental group the increase in LPO was 9.98% and the increase in protein content was 18.78% at day 7. By day 30 after irradiation, AE brought these values to near-normal levels. AE protected brain biochemical activity in this murine study and may prove beneficial for clinical use as a radioprotector.

Piper betle L. is a commonly used masticatory in Asia. This study was carried out to investigate the hepatoprotective and antioxidant properties of P. betle, using ethanol intoxication as a model of hepatotoxic and oxidative damage. Ethanol-treated rats exhibited elevation of hepatic marker enzymes and disturbances in antioxidant defense when compared with normal rats. Oral administration of P. betle extract (100, 200, or 300 mg/kg body weight) for 30 days significantly (P < .05) decreased aspartate aminotransferase (AST), alanine aminotransferase (ALT), thiobarbituric acid reactive substances (TBARS), and lipid hydroperoxides in ethanol treated rats. The extract also improved the tissue antioxidant status by increasing the levels of nonenzymatic antioxidants (reduced glutathione, vitamin C, and vitamin E) and the activities of free radical–detoxifying enzymes such as superoxide dismutase, catalase, and glutathione peroxidase in liver and kidney of ethanol-treated rats. The highest dose of P. betle extract (300 mg/kg body weight) was most effective. The results were comparable with the known hepatoprotective drug, silymarin. These results indicate that P. betle could afford a significant hepatoprotective and antioxidant effect.

There is a history of use of algae as foods and as food additives, or nutraceuticals. Although algae are a safe component of human foods and animal feeds, the effects of the algae other than as a source of protein are not clear. We examined the prevalence of an antiinflammatory activity in selected algae using, as an assay system, the inhibition of histamine release from mast cells. Methanolic extracts of eleven algae were examined for activity to inhibit the release of histamine from mast cells in vitro. This activity was found widely among the samples tested. The activities of these extracts were not uniformly stable in acid methanol. Selected extracts studied further did not separate with the use of size-exclusion filtration filters. LH-20 chromatography suggested at least two main elution areas of activity of the Chlorella extract. In summary, we saw wide phylogenetic dispersion of mast cell inhibition activity, suggesting that this antiinflammatory property is common in algae. This effect was apparently due to multiple activities within the algal extracts.

Chronic fatigue syndrome (CFS) is an illness characterized by persistent and relapsing fatigue, often accompanied by numerous symptoms involving various body systems. The etiology of CFS remains unclear; however, a number of studies have shown that oxidative stress may be involved in its pathogenesis. In the present study, a mouse model of CFS was used in which mice were forced to swim for one 6-minute session on each day for 15 days and the immobility period was recorded. There was a significant increase in immobility period in saline-treated mice on successive days. Intraperitoneal treatment with the potent antioxidants carvedilol (5 mg/kg) and melatonin (5 mg/kg) produced a significant reduction in immobility period. Similar results were observed with herbal preparations administered orally: Withania somnifera (100 mg/kg), quercetin (50 mg/kg), and St. John's wort (Hypericum perforatum L., 10 mg/kg). Biochemical analysis revealed that chronic swimming significantly induced lipid peroxidation and decreased glutathione (GSH) levels in the brains of mice. The rats also showed decreased levels of antioxidant defense enzymes, superoxide dismutase (SOD), and catalase. Co-administration of antioxidants carvedilol, melatonin, W. somnifera, quercetin or St. John's wort significantly reduced lipid peroxidation and restored the GSH levels decreased by chronic swimming in mice. Further, the treatment increased levels of SOD in the forebrain and of catalase. The findings strongly suggest that oxidative stress plays a significant role in the pathophysiology of CFS and that antioxidants could be useful in the treatment of CFS.

The purpose of this research was to test the ability of a whey protein concentrate (WPC) to inhibit gastric mucosal ulcerative lesions caused by oral administration to rats of absolute ethanol. Acute administration(single doses) of WPC resulted in 41% inhibition of the ulcerative lesion index (ULI), and 73% inhibition was obtained with repetitive doses. In a 10-days subchronic treatment study, the inhibition was 64%, all relative to a saline treatment (negative control). Alkylation of sulfhydryl compounds by subcutaneous injection of N-ethylmaleimide essentially eliminated the WPC protection. Treating the rats with an intraperitoneal injection of butathionine sulfoximine, which inhibits glutathione synthesis, reduced WPC protection to 35% and 52% for single and double doses, respectively. Taken as a whole, the results indicate that WPC does protect gastric mucosa from ethanol damage and that the protection depends on sulfhydryl compounds present in the WPC, including its capacity to stimulate glutathione synthesis.

A fraction from crude extract of Galega officinalis L. was purified by gel filtration on Sephadex G-25, Sepharose 4B, and ion-exchange chromatography on diethylaminoethyl (DEAE)-cellulose. The fraction with molecular weight 100-140 kDa appears to have a polysaccharide nature, including protein. The fraction inhibits platelet aggregation initiated by 25 μM adenosine 5′-diphosphate (ADP), 100 μg/ml collagen, and 0.8 U/ml thrombin with the 50% inhibiting concentration (IC₅₀) being 11.2 μg/ml for ADP, and the IC₁₀₀ being 15.1 μg/ml for collagen and IC₁₀₀ 19.6 μg/ml for thrombin.

Saponins from various plant sources have been suggested as possible anticarcinogens. Major dietary sources of saponins include legumes such as soybeans. This study was performed to determine the effect of soybean saponins on aflatoxin B₁(AFB₁)-induced mutagenicity and AFB₁-DNA adduct formation using Salmonella typhimurium and human liver hepatoma (HepG2) cells, respectively. Major antioxidants including L-ascorbic acid, α-tocopherol, all-trans-retinol, and butylated hydroxytoluene (BHT), previously reported to possess antimutagenic activity, were used as test materials to evaluate the relative effectiveness of saponins. Results indicated antimutagenicity was in the order of BHT > saponins > α-tocopherol > L-ascorbic acid. Soybean saponins exerted a significant effect, inhibiting the mutagenicity of AFB₁ by 52%, 64%, and 81% at concentrations of 600, 900, and 1,200 μg per plate, respectively. The amount of tritiated AFB₁ metabolites—DNA adducts formed in HepG2 cells was significantly reduced when cells were preincubated with 10 or 30 μg/ml of test materials. Soybean saponins inhibited AFB₁-DNA adduct formation by 50.1% at a concentration of 30 μg/ml, whereas L-ascorbic acid and BHT reduced adduct formation by 38.4% and 32.6%, respectively, at the same concentrations. These results indicate that soybean saponins possess not only a significant antimutagenic activity but a strong inhibitory action against carcinogen-induced DNA damages. Soybean saponins possibly block the initiation stage of carcinogenesis, and further studies are required to elucidate the mechanisms of action.