The inhibitory effect of bamboo extract on the development of 7,12-dimethylbenz[a]anthracene (DMBA)-induced breast cancer

Antimicrobial potential of extracts from leaves and culms of an Amazonian native bamboo

Antibiotics have shown less efficiency against resistance of pathogenic microorganisms. As a result, research centers have sought therapeutic alternatives against multidrug resistance of bacteria to antibiotics, one of which is using plant extracts. Bamboo extracts are used for several medicinal purposes. This study aimed to evaluate the antibacterial potential of hydroalcoholic extracts of culms and leaves of the species Guadua aff. lynnclarkiae on strains of Staphylococcus aureus, Streptococcus pneumoniae, and Klebsiella pneumoniae. We evaluated the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). Only the leaves of G. aff. lynnclarkiae showed a bactericidal effect for all tested strains with MBC ranging from 1.55 mg ml-1 to 25 mg ml-1. The culms had bacteriostatic action with MIC ranging from 1.55 mg ml-1 to 6.25 mg ml-1, and bactericidal action at the concentration of 6.25 mg ml-1 only for S. aureus. This study provides bases for the use of this Amazonian native bamboo in bioprospecting.

Experimental mammary carcinogenesis - Rat models

Mammary cancer is one of the most common cancers, victimizing more than half a million of women worldwide every year. Despite all the studies in this field, the current therapeutic approaches are not effective and have several devastating effects for patients. In this way, the need to better understand the mammary cancer biopathology and find effective therapies led to the development of several rodent models over years. With this review, the authors intended to provide the readers with an overview of the rat models used to study mammary carcinogenesis, with a special emphasis on chemically-induced models.

Biological activities and phytochemical profiles of extracts from different parts of bamboo (Phyllostachys pubescens)

Besides being a useful building material, bamboo also is a potential source of bioactive substances. Although some studies have been performed to examine its use in terms of the biological activity, only certain parts of bamboo, especially the leaves or shoots, have been studied. Comprehensive and comparative studies among different parts of bamboo would contribute to a better understanding and application of this knowledge. In this study, the biological activities of ethanol and water extracts from the leaves, branches, outer culm, inner culm, knots, rhizomes and roots of Phyllostachys pubescens, the major species of bamboo in Japan, were comparatively evaluated. The phytochemical profiles of these extracts were tentatively determined by liquid chromatography-mass spectrometry (LC-MS) analysis. The results showed that extracts from different parts of bamboo had different chemical compositions and different antioxidative, antibacterial and antiallergic activities, as well as on on melanin biosynthesis. Outer culm and inner culm were found to be the most important sources of active compounds. 8-C-Glucosylapigenin, luteolin derivatives and chlorogenic acid were the most probable compounds responsible for the anti-allergy activity of these bamboo extracts. Our study suggests the potential use of bamboo as a functional ingredient in cosmetics or other health-related products.

Identification of a novel Calotropis procera protein that can suppress tumor growth in breast cancer through the suppression of NF-κB pathway

Breast cancer is the most common cancer among women. To date, improvements in hormonal and cytotoxic therapies have not yet led to a sustained remission or cure. In the present study, we investigated the in vitro and in vivo antitumor activities of a novel Calotropis procera protein (CP-P) isolated from root bark. CP-P protein inhibited the proliferation and induced apoptosis of breast cancer cells through the suppression of nuclear factor kappaB (NF-kB) activation. CP-P, when administered individually or in combination with cyclophosphamide (CYC, 0.2 mg/kg) to rats with 7, 12-dimethyl benz(a)anthracene (DMBA)-induced breast cancer decreased tumor volume significantly without affecting the body weight. To elucidate the anticancer mechanism of CP-P, antioxidant activities such as superoxide dismutase (SOD), catalase (CAT), glutathione-s-transferase (GST) and non-enzymatic antioxidant - reduced glutathione (GSH), vitamin E and C generation in the breast were analyzed by various assays. SOD, CAT, GST, GSH, vitamin E and C levels were high in combination-treated groups (CP-P+CYC) versus the CYC alone-treated groups. Also, the combination was more effective in down-regulating the expression of NF-kB-regulated gene products (cyclin D1 and Bcl-2) in breast tumor tissues. Our findings indicate that CP-P possesses significant antitumor activity comparable to a commonly used anticancer drug, cyclophosphamide, and may form the basis of a novel therapy for breast cancer.

Effects of a high-fat diet and bamboo extract supplement on anxiety- and depression-like neurobehaviours in mice

High-fat diet is a major causative factor of overweight and obesity, which are associated with an increased risk of neuropsychiatric diseases, such as anxiety and depression. In the present study, we investigated the protective effects of bamboo extract (BEX) on anxiety- and depression-like neurobehaviours in mice treated with a high-fat diet. Male mice with CD-1 genetic background were treated for 2 months with either a standard or a high-fat diet (10 or 45 % energy from fat, respectively), with or without the BEX supplement (11 g dry mass per 17 MJ). The anxiety levels of mice were evaluated using open-field and hole-board tests, and depression was measured using the force-swimming test. The anxiety responses of the animals were found significantly increased after the high-fat diet treatment, and this elevation was effectively abolished by the BEX supplement. The high-fat diet seemed to have an anti-depressive effect in mice at the tested time point, but the effect of the BEX supplement on the depression level of the animals was not conclusive. The high-fat diet significantly decreased total glutathione content in the blood while the BEX supplement increased glutathione oxidation. In summary, the present study shows that decreased total glutathione concentration in the blood co-occurred with a high-fat treatment, high anxiety level and low depression level in mice, and when supplemented in a high-fat diet, BEX had an anxiolytic effect in mice.

Inhibitory effects of combination of lycopene and genistein on 7,12- dimethyl benz(a)anthracene-induced breast cancer in rats

Breast cancer is one of the most common cancers in women. Carotenoids and soy isoflavones have been postulated to have breast cancer preventive effects. We investigated the potential preventive effects of lycopene and genistein, alone and in combination, on breast cancer development in female Wistar rats treated with 7,12-dimethylbenz[a]anthracene (DMBA), a carcinogen known to induce breast tumors. Mammary carcinogenesis was initiated by a single, oral gavage of DMBA (80 mg/kg body weight) at 55 days of animal age. Fifty female Wistar rats were divided into 5 experimental groups having 10 animals per group: Group 1 (normal control), Group 2 (DMBA control), Group 3 (DMBA + lycopene), Group 4 (DMBA + genistein), and Group 5 (DMBA + lycopene and genistein). Rats were fed either lycopene (20 mg /kg bw) or genistein (2 mg /kg bw) by oral gavage (3 times per week) starting 2 wk prior to DMBA injection. Treatment was continued for 20 wk. Rats treated with DMBA developed mammary tumors with 100% tumor incidence during the 20-wk study. Inhibition of mammary cancer incidence by lycopene (70%), genistein (60%) and their combination (40%) was observed. Tumor weight decreased by 48%, 61%, and 67%, and mean tumor volume decreased by 18%, 35%, and 65% with lycopene, genistein, and lycopene + genistein, respectively (P < 0.01 for the combination). The proportions of adenocarcinoma masses decreased with lycopene and genistein combination (P < 0.05). Administration of lycopene and genistein combination suppressed breast cancer development and was associated with a decrease in MDA, 8-isoprostane, and 8-OhdG levels and with an increase in serum lycopene and genistein levels. Animals administered DMBA developed breast cancer, which was associated with increased expression of Bcl-2 and decreased expression of Bax, caspase 3, and caspase 9 in mammary tissues. Administration of genistein and lycopene in combination was more effective in inhibiting DMBA-induced breast tumors and modulating the expression of apoptosis associated proteins than the administration of each agent alone. Our results suggest that lycopene and genistein are potent antioxidants and, when given in combination, offer maximum protection against DMBA-induced mammary carcinogenesis.

The effect of bamboo extract on hepatic biotransforming enzymes--findings from an obese-diabetic mouse model

AIM OF THE STUDY

Bamboo leaves are used as a component in traditional Chinese medicine for the anti-inflammatory function. Our previous studies have demonstrated that an ethanol/water extract from Phyllostachys edulis ameliorated obesity-associated chronic systemic inflammation in mice, and therefore relieving the symptoms of type 2 diabetes. The aim of this project was to further investigate the effects of this bamboo extract on hepatic biotransformation enzymes in both lean and obese mice, as an initial step in the toxicological evaluation of using this traditional medicine in obese/diabetic population.

MATERIALS AND METHODS

Male C57BL/6J mice were randomized to 4 groups and fed standard (10% kcal from fat) diet with or without bamboo extract supplementation at a dose of 10 gram per kilogram diet (n=10 and n=9, respectively), or high fat (45% kcal from fat) diet with or without bamboo extract (n=8 and N=7, respectively). The dietary treatment lasted for 6 months. Subsequently, the activities and expression of the major Phase I and II hepatic biotransformation enzymes were assessed in subcellular fractions from murine livers.

RESULTS

Three groups of mice, lean bamboo extract-supplemented, obese/diabetic, and bamboo extract-supplemented obese/diabetic, showed greater activities of cytochromes P450 1a2 and 3a11 compared to control but no changes in the expression level of these proteins. For Phase II enzymes, bamboo extract supplementation in lean mice caused decreased glutathione-S-transferase activity (-12%) and greater uridine diphosphate glucuronosyltransferase activity (+46%), but had no effect on sulfotransferase activity. Conversely, the obese/diabetic condition itself increased glutathione-S-transferase and uridine diphosphate glucuronosyltransferase activities, but decreased total sulfotransferase activity and sulfotransferase 2a1 expression.

CONCLUSIONS

Bamboo extract and obesity/diabetes show significant independent effects on hepatic biotransformation as well as interaction effects in mice. These changes may alter the clearance of endo- and xenobiotics, including bamboo extract itself, hence this effect should be carefully considered in the medicinal application of bamboo extract as it has potential to alter its own metabolism and that of other medications concurrently administered to obese diabetic patients.