Different effects of heating and freezing treatments on the antioxidant properties of broccoli, cauliflower, garlic and onion. An experimental in vitro study

ABSTRACT BACKGROUND: Vegetables have some beneficial effects on human health due to their antioxidant compounds, like polyphenols. Cooking leads to many physical and chemical changes to plant structure that can alter the phytochemical compounds of vegetables. OBJECTIVES: To investigate the effects of heat treatment and freezing on the antioxidant properties of garlic, onion, broccoli and cauliflower. DESIGN AND SETTING: Experimental in vitro study in a university laboratory. METHODS: Fresh broccoli (Brassica oleracea var. italica), cauliflower (Brassica oleracea var. botrytis), garlic (Allium sativum) and onion (Allium cepa) were obtained from a local store. These vegetables were divided into three treatment groups: raw, heated and frozen. The heat treatment consisted of heating them in a drying oven at 150 °C for 20 minutes. The freezing treatment consisted of keeping them frozen at -20 °C until analysis. The total phenolic content, antioxidant activity and malondialdehyde levels of the vegetables were measured using the Folin-Ciocalteu phenol reagent, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and thiobarbituric acid reactive substances, respectively. RESULTS: Heat treatment had deleterious effects on the antioxidant properties of onion and garlic; and it decreased the antioxidant activity of broccoli. Freezing improved the antioxidant activity of broccoli and garlic, but had detrimental effects for cauliflower and onion. CONCLUSIONS: Heat treatment and freezing exhibit different effects on the antioxidant properties of broccoli, cauliflower, garlic and onion. Convenient cooking and storage patterns should be identified for each vegetable, to obtain the best nutritional benefit from the antioxidant compounds of vegetables.

Protective effect of Allium cepa (onion) seeds (AC) extract on histopathology of testis in STZ-induced male rats / Efecto protector del extracto de semillas de Allium cepa (cebolla) (AC) en la histopatología del testículo en ratas macho inducidas por STZ

SUMMARY: The aim of the present study was to evaluate the effect of the extract of Allium cepa (Onion) seeds (AC) on morphometric and histology of testis and biochemical parameters in STZ-induced male rats. Forty adult male Wistar rats (2 month old) were allocated into four groups of control, diabetic control, diabetic treated with 200 or 400 mg/kg/day of onion seed extract. Diabetes mellitus was induced using 60 mg/kg body weight of Streptozotocin as a single intraperitoneal injection. The extract was administered by stomach gavage for 28 days. The morphometric and histological structure of the testis, biochemical factors like glucose and testosterone levels were assessed. All analyses were done at the end of the four week study period. Data were compared by using Kruskal Wallis Test, Dunnett T3 and the degree of significance was set at P < 0.05 and P < 0.01. In diabetic+200 rats, the numbers of primary spermatocytes were significantly increased. In diabetic+400 rats, seminiferous tubular diameter was significantly increased and the level of testosterone hormone and testis weight was decreased significantly. In diabetic+200 and 400 rats, the numbers of spermatid, FBS and lumen diameter were significantly increased and the numbers of spermatozoa cells, body weight and volume density (VD) % lumen were decreased. Also, the numbers of spermatid in control diabetic rats was decreased. Our finding indicated that onion seed extract might be useful as a supplementary protective agent against adverse effects of diabetes on reproductive system in diabetic men.

RESUMEN: El objetivo del presente estudio fue evaluar el efecto del extracto de semillas de Allium cepa (cebolla) sobre la morfometría e histología de testículos y parámetros bioquímicos en ratas macho inducidas por estreptozotocina (STZ). Se asignaron cuarenta ratas macho Wistar adultas (2 meses de edad) en cuatro grupos: control diabético y diabético tratados con 200 o 400 mg / kg / día de extracto de semilla de cebolla. Se indujo diabetes mellitus utilizando 60 mg/kg de peso corporal de estreptozotocina por inyección única intraperitoneal. El extracto se administró por sonda gástrica durante 28 días. Se evaluaron la estructura morfométrica e histológica de los testículos, factores bioquímicos como la glucosa y los niveles de testosterona. Todos los análisis se realizaron al final del período de estudio de cuatro semanas. Los datos se compararon mediante el uso de Kruskal Wallis Test, Dunnett T3 y el grado de significación se estableció en P <0,05 y P <0,01. En el grupo diabético + 200, el número de espermatocitos primarios aumentó significativamente. En el grupo diabético + 400, el diámetro tubular seminífero aumentó significativamente en cambio el nivel de testosterona y el peso del testículo disminuyeron significativamente. En el grupo diabéticos + 200 y 400, los números de espermátidas, FBS y diámetro de luz se incrementaron significativamente y el número de espermatozoides, peso corporal y densidad de volumen (VD)% de lumen disminuyeron. Además, disminuyó el número de espermátidas en ratas diabéticas control. Nuestro estudio indicó que el extracto de semilla de cebolla podría ser útil como un agente protector adicional contra los efectos adversos de la diabetes en el sistema reproductivo en hombres diabéticos.

Therapeutic Effects of Allium sativum and Allium cepa in Schistosoma mansoni experimental infection / Efeitos terapêuticos do Allium sativum e Allium cepa na infecção experimental pelo Schistosoma mansoni

The effects of both garlic (Allium sativum) and onion (Allium cepa) on some biochemical parameters in Schistosoma mansoni infected mice individually and mixed either with or without the currently used drug, praziquantel (PZQ) were investigated. These involved some immunological parameters, namely IgM, IgG, interleukins 2 and 6 (IL-2 and 6) and tumor necrosis factor (TNF-α), some antioxidant enzymes [catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPX)]. In addition, parasitological and histopathological investigations were performed. No changes were observed in the normal control mice treated with dry extract of onion or garlic, individually or mixed, with or without PZQ, compared to the normal healthy control group. Infection with S. mansoni showed an increase in IgG, IgM, IL-2, IL-6, TNF-α and catalase enzyme, accompanied with a decrease in GPX and SOD antioxidant enzyme activities. Remarkable amelioration was noticed in the levels of all the measured parameters in S. mansoni infected mice after administration of the studied extracts. Moreover a significant reduction in worm burden, hepatic and intestinal eggs and oogram count was noticed which was reflected in normalization of liver architecture.

Os efeitos do alho (Allium sativum) e cebola (Allium cepa) em parâmetros bioquímicos de camundongos infectados pelo Schistosoma mansoni individualmente e misturados seja com ou sem as drogas correntemente usadas como o Praziquantel (PZQ), foram investigados. Isto envolveu parâmetros imunológicos tais como IgM, IgG, Interleucina 2 e 6 (IL-2 e 6), fator de necrose tumoral (TNF-α) e algumas enzimas anti-oxidantes [catalase, super-óxido dismutase (SOD) e glutationa peroxidase (GPX)]. Em adição foram realizadas investigações parasitológicas e histopatológicas. Nenhuma alteração foi observada nos camundongos controles normais tratados com extrato seco de cebola ou alho, individualmente ou misturado, com ou sem PZQ, comparados com os controles normais sadios. Infecção com o Schistosoma mansoni revelou um aumento em IgG, IgM, IL-2, IL-6, TNF-α e catalase, acompanhados de diminuição do GPX e atividade enzimática do anti-oxidante SOD. Melhora acentuada foi notada nos níveis de todos os parâmetros medidos em camundongos infectados com Schistosoma mansoni após administração dos extratos estudados. Mais ainda, significante redução na quantidade de vermes, e ovos no fígado e intestino e na contagem do oograma foi notada refletindo a normalização da arquitetura do fígado.

Anti-tuberculosis activity of selected medicinal plants against multi-drug resistant Mycobacterium tuberculosis isolates.

Background & objectives: Emergence of multi-drug resistant (MDR) and extensively-drug resistant (XDR) strains of Mycobacterium tuberculosis has further complicated the problem of tuberculosis (TB) control. Medicinal plants offer a hope for developing alternate medicines for the treatment of TB. The present study was done to evaluate in vitro anti-tubercular activity of five medicinal plants viz., Acalypha indica, Adhatoda vasica, Allium cepa, Allium sativum and Aloe vera. Methods: Aqueous extracts of leaves of A. indica, A. vasica, bulbs of A. cepa, cloves of A. sativum and pure gel of A. vera leaves, were tested in vitro for their activity against two MDR isolates (DKU-156 and JAL-1236), reference susceptible strain M. tuberculosis H37Rv as well as rapid grower mycobacterial pathogen M. fortuitum (TMC-1529) using Lowenstein Jensen (L-J) medium and colorimetric BacT/ALERT 3D system. Activity in L-J medium was evaluated by percentage inhibition which was calculated by mean reduction in number of colonies on extract containing as compared to extract free controls. Results: Extracts of all the five plants A. indica, A. vasica, A. cepa, A. sativum and A. vera exhibited anti-tuberculosis activity in L-J medium, the proportion of inhibition of these plants extract in respect mentioned above is 95, 32, 37, 72, 32 per cent, respectively for MDR isolate DKU-156 and 68, 86, 79, 72, 85 per cent, respectively for another MDR isolate JAL-1236, while for sensitive M. tuberculosis H37Rv, inhibition was found to be 68, 70, 35, 63 and 41 per cent, at 4 per cent v/v concentration in L-J medium. There was no inhibition against rapid grower M. fortuitum (TMC-1529). In BacT/ALERT also, extracts of these plants showed significant inhibition against M. tuberculosis. Interpretation & conclusions: Our findings showed that all these plants exhibited activity against MDR isolates of M. tuberculosis. While the anti-TB activity of A. vera, A. vasica and A. sativum against MDR isolates confirm earlier results, activity of the extracts of A. indica and A. cepa is reported for the first time. Further studies aimed at isolation and identification of active substances from the extracts which exhibited promising activities, need to be carried out.

Toxicity mechanisms of onion (Allium cepa) extracts and compounds in multidrug resistant erythroleukemic cell line

Onion (Allium cepa) is being studied as a potential anticancer agent, but little is known regarding its effect in multidrug resistance (MDR) cells. In this work, the cytotoxicity of crude onion extract (OE) and fractioned extract (aqueous, methanolic and ethyl acetate), as well as some onion compounds (quercetin and propyl disulfide) were evaluated in Lucena MDR human erythroleukemic and its K562 parental cell line. The capacity of OE to induce apoptosis and/or necrosis in these cells, the possible participation of oxidative stress and DNA damage were also assessed. Similar sensitivities were obtained for both tumoral cells, however only OE caused significant effects in the cells. In K562 cells, a significant increase of apoptosis was verified while the Lucena cells experienced a significant increase of necrosis. An antioxidant capacity was verified for OE discarding oxidative damage. However, OE provoked similar significant DNA damage in both cell lines. Thus, the OE capacity to overcome the MDR phenotype suggests anti-MDR action of OE.

Ação farmacológica do alho (Allium sativum L. ) e da cebola (Allium cepa L. ) sobre o sistema cardiovascular: revisão / Pharmacological effect of garlic (Allium sativum L. ) and onion (Allium cepa L. )on the cardiovascular system: review

Cardiovascular diseases affect millions of people and have high mortality and morbidity rates worldwide. Studies about the consumption of garlic and onion showed that these species have considerable beneficial effects against diseases such as hypertension, atherosclerosis and thrombosis, and are classifed, therefore, as functional foods. Their properties have been attributed to organosulfur compounds, particularly allicin, which are abundantly found in their tissues. This study reviewed the literature about the effects of garlic and onion on the cardiovascular system.

Enfermedades del sistema cardiovascular afectan millones de personas y son causadoras de elevados índices de mortalidad y morbilidad en el mundo. Estudios sobre el consumo de ajo y cebolla mostraron considerables beneficios en relación a enfermedades como hipertensión, trombosis y arterioesclerosis siendo considerados alimentos funcionales. Esas ventajas han sido atribuidas a la presencia en abundancia de compuestos orgánicos sulfurados en el tejido de esas plantas, destacándose entre ellos la aliicina. En este trabajo relatamos un estudio bibliográfico sobre la acción del ajo y la cebolla en el sistema cardiovascular.

As doenças do sistema cardiovascular atingem milhões de pessoas e são causadoras de elevado índice de mortalidade e morbidade mundial. Estudos realizados sobre o consumo do alho e cebola relataram que estas espécies apresentaram considerável efeito benéfico sobre enfermidades como hipertensão, aterosclerose e trombose, sendo desta forma, considerados como alimentos funcionais. Essas atividades têm sido atribuídas aos compostos orgânicos sulfurados, abundantes nos tecidos dessas plantas, destacando-se a aliicina. Desta forma, o presente estudo visa realizar um levantamento bibliográfico sobre o alho e a cebola quanto à sua ação sobre o sistema cardiovascular.

Heavy metals in selected edible vegetables and estimation of their daily intake in Sanandaj, Iran.

The levels of four different heavy metals [cadmium (Cd), lead (Pb), chromium (Cr) and copper (Cu)] were determined in various vegetables [leek (Allium ampeloprasum), sweet basil (Ocimum basilicum), parsley (Petroselinum crispum), garden cress (Lepidium sativum) and tarragon (Artemisia dracunculus)] cultivated around Sanandaj City. The contributions of the vegetables to the daily intake of heavy metals from vegetables were investigated. One hundred samples (20 samples per month) were collected for five months. Atomic absorption spectrometry was used to determine the concentrations of these metals in the vegetables. The average concentrations of each heavy metal regardless of the kind of vegetable for Pb, Cu, Cr and Cd were 13.60 +/- 2.27, 11.50 +/- 2.16, 7.90 +/- 1.05 and 0.31 +/- 0.17 mg/kg, respectively. Based on the above concentrations and the information of National Nutrition and Food Research Institute of Iran, the dietary intake of Pb, Cu, Cr and Cd through vegetable consumption was estimated at 2.96, 2.50, 1.72 and 0.07 mg/day, respectively. It is concluded that the vegetables grown in this region are a health hazard for human consumption.

Heat stable antimicrobial activity of Allium ascalonicum against bacteria and fungi.

To study antimicrobial activity of shallot in comparison with that of garlic and onion against 23 strains of fungi and bacteria, water extracts of garlic, shallot and onion bulbs were prepared. Each extract was studied in different forms for their antimicrobial activity viz., fresh extract, dry extract and autoclaved extract. Minimal inhibitory concentration and minimal lethal concentrations of these extracts were determined against all organisms by broth dilution susceptibility test. Fresh extract of garlic showed greater antimicrobial activity as compared to similar extracts of onion and shallot. However, dried and autoclaved extracts of shallot showed more activity than similar extracts of onion and garlic. Fungi were more sensitive to shallot extract than bacteria. Amongst bacteria, B. cereus was most sensitive (MIC=5 mg ml(-1)). The lowest minimum bactericidal concentration of shallot extract amongst bacteria tested was 5 mg ml(-1) for B. cereus. Amongst fungi, Aureobasidium pullulans and Microsporum gypseum were most sensitive (MIC= 0.15 mg ml(-1)). The lowest minimum lethal concentration was 2.5 mg ml(-1) for Microsporum gypseum and Trichophyton mentagrophytes. It was therefore, expected that the antimicrobial principle of shallot was different than the antimicrobial compounds of onion and garlic. In addition, the antimicrobial component of the shallot extract was stable at 121 degrees C.

Antidiabetic and antioxidant effects of S-methyl cysteine sulfoxide isolated from onions (Allium cepa Linn) as compared to standard drugs in alloxan diabetic rats.

Antidiabetic and antoxidant effects of S-methyl cysteine sulfoxide (SMCS) isolated from A. cepa and two standard drugs, glibenclamide and insulin were studied and compared in alloxan diabetic rats after using each of them for treatment for two months. These drugs ameliorated the diabetic condition significantly, viz. maintenance of body weight and control of blood sugar in rats. Further they lowered the levels of malondialdehyde, hydroperoxide and conjugated dienes in tissues exhibiting antioxidant effect on lipid peroxidation in experimental diabetes. This is achieved by their stimulating effects on glucose utilization and the antioxidant enzymes, viz. superoxide dismutase and catalase. The probable mechanism of action of SMCS and glibenclamide may be partly dependent on the stimulation of insulin secretions and partly due to their individual actions. In the amelioration of diabetes the standard drugs showed a better action, but as an antioxidant SMCS proved to be a better one.

Determination of antidiabetic activity in Allium cepa (onion) tissue cultures.

Seedling, seedling parts and callus cultures of onion were tested for their antidiabetic activity by feeding the tissue-extracts to diabetic rats. The results indicated much higher antidiabetic activity in callus cultures as compared to natural bulbs of onion. These results may be of pharmaceutical significance since the callus can be used as an alternative source for the isolation of antidiabetic compounds.