Phytochemical constituents and antibacterial activity of some green leafy vegetables

Objective:To investigate the antibacterial activity and photochemicals of five green leafy vegetables against a panel of five bacteria strains.Methods:Disc diffusion method was used to determine the antibacterial activity,while kanamycin was used as a reference antibiotic.The phytochemical screening of the extracts was performed using standard methods.Results:All methanol extracts were found active against all the test bacterial strains.Overall maximum extracts shows antibacterial activity which range from 6 to 15 mm.Proteins and carbohydrates was found in all the green leaves,whereas alkaloid.steroids.saponins,flavonoids.tannins were found in most of the test samples.Conclusions:The obtain result suggests that green leafy vegetables have moderate antibacterial activity and contain various pharmacologically active compounds and thus provide the scientific basis for the traditional uses of the studied vegetables in the treatment of bacterial infections.

Application of HPLC and ESI-MS techniques in the analysis of phenolic acids and flavonoids from green leafy vegetables (GLVs)

Diets containing high proportions of fruits and vegetables reduce the risk of onset of chronic diseases. The role of herbal medicines in improving human health is gaining popularity over the years, which also increases the need for safety and efficiency of these products. Green leafy vegetables （GLVs） are the richest source of phenolic compounds with excellent antioxidant properties. Increased consumption of diets containing phenolic compounds may give positive and better results to human health and significantly improves the immune system. Highly selective, susceptible and versatile analytical techniques are necessary for extraction, identifica- tion, and quantification of phenolic compounds from plant extracts, which helps to utilize their important biological properties. Recent advances in the pre-treatment procedures, separation techniques and spectro- metry methods are used for qualitative and quantitative analysis of phenolic compounds. The online coupling of liquid chromatography with mass spectrometry （LC-MS） has become a useful tool in the metabolic profiling of plant samples. In this review, the separation and identification of phenolic acids and flavonoids from GLVs by LC-MS have been discussed along with the general extraction procedures and other sources of mass spectrometer used. The review is devoted to the understanding of the structural configuration, nature and accumulation pattern of phenolic acids and flavonoids in plants and to highlighting the recent developments in the chemical investigation of these compounds by chromatographic and spectroscopic techniques. It concludes with the advantages of the combination of these two methods and prospects.

Nutrient and Phytochemical Composition of Five Wild Green Leafy Vegetables Consumed in Erie-Biase Local Government Area of Cross River State

This work on nutrient and phytochemical composition of five wild green leafy vegetables consumed in Erei-Biase Local Government Area of Cross River State, Nigeria was aimed at identifying and determining the nutrient, and phytochemical compositions of Amaranthus viridis (Ikorodotaseach), Aeschylus glabra (Ididieriri), Alphanostylis lepthanta (Emornegbandip), Calcasia saxatilis, (Igbongonokpa) and Lonchocarpus sericeus (Ajuokoh). Analysis of moisture, protein, fiber, ash, fat and carbohydrate, micronutrients and phytochemicals was done using standard methods, while vitamins were done using AOAC, (1995). The data generated were subjected to T-test, standard deviation, standard error of the mean. The result of the proximate analysis showed that Amaranthus viridis had the highest protein value (9.73%) and the lowest carbohydrate value (4.60%) respectively. Aeschylea glabra recorded the highest fat value [9.73%]. The micro nutrient result revealed that copper (CU) and phosphorous (Ph) values were low and that the value for the other micro-nutrient differed significantly with the exception of calcium (Ca) values which did not differed significantly (P Amaranthus viridis had the highest value of Vitamin C. The phytochemicals and anti-nutrient contents of the vegetables were moderately high but not higher than the safe levels. Hence they are recommended for consumption.

Estimation of Vitamins B-Complex (B₂, B₃, B₅and B₆) of Some Leafy Vegetables Indigenous to Bangladesh by HPLC Method

The current experiment was conducted for the simultaneous determination of several water-soluble vitamins like ribo- flavin (vitamin B2), niacin (vitamin B3), pantothenic acid (vitamin B5) and pyridoxine (vitamin B6) in five highly con- sumed local leafy vegetables named as bottle gourd leaves (Lagenaria vulgaris) (local name Lau shak), green amaranth leaves (Amaranthus viridis) (local name Data shak), red amaranth leaves (Amaranthus gangeticuss) (local name Lal shak), Indian spinach (Basella alba) (local name Pui shak) and bitter gourd leaves (Momordica charantia) (local name Korola shak). The analyses were performed by HPLC using an analytical reversed phase C-18 (ODS column, 250 × 4.6 mm, 5 μm, Phenomenex, Inc.) column with the mobile phase consisting of a mixture of buffer (hexane sulphonic acid sodium, potassium dihydrogen phosphate and triethylamine, pH 3.0) and methanol in the ratio of 96:4 (v/v) at a flow rate of 1 mL/min with UV detection at 210 nm. The retention times for the vitamins were obtained as 3.61 min, 6.37 min, 9.51 min and 11.51 min for Vitamins B2, B3, B5 and B6, respectively. These obtained values of the vitamins were compared with the values available in published literatures of Deshio Khaddar Pustiman (DKPM), Indian food value (IFV) and United States Department of Agriculture (USDA).

Effects of Simulated Acid Rain on Main Nutritional Indicators of Three Leafy Vegetables

The purpose of this paper was to identify content changes in the main nutritional indicators of three common leafy vegetables, and to provide a theoretical basis for the protection of leafy vegetables from acid rain. The experiment investigated the effects of simulated acid rain on four main nutritional indicators, including soluble sugar, total free amino acid, soluble protein and vitamin C during the application of simulated acid rain(SAR) in pakchoi(Brassica rapa chinensis), rape(Brassica campestris L.) and lettuce(Lactuca sativa Linn. var. ramosa Hort). The vegetables were respectively exposed to SAR of pH=7.0, 5.6, 5.0, 4.0, 3.0 and a control level of pH=6.5. The concentrations of the four main nutritional indicators were determined at harvest. The results show that nutritional quality of the three leafy vegetable species decreased with the declining of pH values of SAR. The higher the acidity of SAR was, the more significant the inhibitions were. Nutritional quality of lettuce was the most affected by simulated acid rain, followed by pakchoi and rape. The change range of soluble protein content was higher than those of the other three indicators’ contents, which indicates that soluble protein is most sensitive to simulated acid rain.

Bioavailability of Iron and Related Components in Cooked Green Leafy Vegetables Consumed in Cameroon

Green leafy vegetables (GLVs) are a potential source of iron to combat iron deficiency in iron deficient population. The aim of this study was to determine the bioavailability of iron in seven species of leafy vegetables (Solanumscrabrun, Venonia amygdalina, Cucurbita maxima, Amarathus hybridus, Colococia esculenta, Solanum macrocarpon and Telfairia occidentalis) consumed in Bamenda, Cameroon. A survey was carried out in 70 households in Bamenda, Cameroon to determine methods of preparation of these green leafy vegetables. Iron, antinutrients and vitamin C levels were determined using standard methods and the bioavailability of iron was determined using an in vitro dialys ability method. The vegetables used for the study were cooked with the addition of tomatoes, peanuts, melon seeds and soybean seeds. The loss of iron in GLVs was as a result of dilution caused by addition of the principal ingredients. The V. amygdalina cooked with soybean contained the highest level of iron (128.28 mg/100g). The S. scrabrum cooked with tomatoes had the highest Total phenolic coumponds of 0.91 g/100g;the C. esculenta recorded the highest with values ranging between 0.14 - 0.35 g/100g;the C. maxima cooked with soybean recorded the highest oxalate level (6.46 g/100g);and the vegetables cooked with melon seeds recording the highest in phytatelevels (70 - 1.63 g/100g). Vitamin C levels were highest in the S. macrocarpon cooked with tomatoes (199.96 mg/100g). Iron bioavailability was highest in A. hybridus cooked with tomatoes (28.09%). The iron bioavailability negatively correlated with phytates and positively with vitamin C. GLV consumed in Bamenda are good sources of iron whose bioavailability can be improved by using tomatoes in cooking.

Effects of Cooking and Processing Methods on Nitrate Content in Leafy Vegetables

[Objectives]The aim is to provide a theoretical basis for people to store and process vegetables more scientifically.[Methods]Changes in the nitrate content of three kinds of leafy vegetables (cabbage,lettuce and celery) cooked and processed by different methods were studied.[Results]After the three kinds of leafy vegetables were processed by different methods,the nitrate and vitamin C content of the leafy vegetables reduced,and their reduction was above 50% after they were boiled.After they were salted for 5 min,nitrate content decreased by 20%-40%,and changed slightly with time.Salting had a small effect on Vc content.After lettuce and celery were soaked in 0.05% NaCl solution for 30 min,the effect was the best.CaCl2 had an obvious effect on the reduction of nitrate content in lettuce.[Conclusions]The study is of great significance to safety production and evaluation of edible value of agricultural products.

Comparative Study of Proximate,Chemical and Physicochemical Properties of Less Explored Tropical Leafy Vegetables

The list of underutilized green leafy vegetables is enormous: ranging from commonly consumed and underutilized vegetables. There are data on commonly consumed vegetables, but information is sparse on nutritional, chemical and anti-nutritional properties of less explored vegetables. This work aimed to evaluate some attributes of less explored or underutilized leafy vegetables. Some nutritional and anti-nutritional contents of 10 under-utilized leafy vegetables(Amaranthus spinosus Linnaeus, Basella alba Linnaeus, Corchorous tridens L., Cyrtosperma senegalense(Schott), Erigeron floribundus Sch, Hoslundia opposita Vahl, Lagenaria siceraria(Molina) Standl, Ocimum basilicum L., Solanum aethiopicum L. and Talinum portulacifolium(Forssk.) Asch. ex Schweinf) were investigated. Cyrtosperma senegalense had the highest protein value(5.93%). Hoslundia opposita had the highest fat content(0.54%). Amaranthus spinosus was high in β-carotene content(346.3 mg · 100 g-1); Cyrtosperma senegalense had the highest moisture content. A. spinosus had the highest ascorbic acid content(108.1 mg · 100 g-1). The highest tannin level(0.0057%) was found in C. senegalense and the lowest(0.0003%) was found in Solanum aethiopicum. Saponin was the highest in C. tridens(0.0052%) and the lowest in T. portulacifolium(0.00014%). C. senegalense and S. aethiopicum had their highest and the lowest phytate values, respectively. Although anti-nutrients could interfere with nutrient utilization, their values in these vegetables were not at toxic levels.

Nutritional Potential of Two Leafy Vegetables <i>Leptadenia hastata</i>Decne and <i>Senna obtusifolia</i>Link Consumed in Senegal

This study focused on two woody leafy vegetables Leptadenia hastata Decne and Senna obtusifolia Link, commonly consumed in Senegal. Leaves were col-lected from three regions. Then, proximate analyses and micronutrients were carried out to evaluate their nutritional values. Results revealed that protein level of S. obtusifolia (SO) is richer (21.75%) than Leptadenia hastata (LH) (18.16%). The cellulose and carbohydrate contents of the two vegetable’s leaves are in the same order except those of LH from Widou which are less rich in cellulose (8.31%) and richest in carbohydrate (6.35%). These leaves are also good sources of various mineral elements and especially iron. Leaves of LH appear to be richer in iron and magnesium, while SO appears to be richer in calcium. Vitamin C intakes of SO leaves are better than those of LH and respectively range from 142 to 196.5 and 22.5 to 159.5 mg/100 g. According to the use of this leafy vegetable by the populations, a domestication opportunity is thus justified to ensure availability and accessibility of these significant sources of micronutrients.

Carotenoid Analysis of Several Dark-Green Leafy Vegetables Associated With a Lower Risk of Cancers

We have examined the carotenoid contents of several dark green vegetables found to be associated with a lower risk of various epithelial cancers in our epidemiological study and animal study. Samples of these vegetables were quantitatively examined by highperformance liquid chromatography (HPLC) on a C-18 reversed-phase column for individual carotenoid content. Pure reference compounds (alpha-carotene, beta-carotent, lycopene, canthaxanthin, and lutein) and internal standard (beta-Apo-8'-carotenal) were employed to quantify xanthophylls and carotenes in these vegetables. The results indicated that fresh, dark-green, leafy vegetables were high in beta-carotene (0.94-9.36 mg/100 g) and oxygenated carotenoids or xanthophylls, primarily lutein (0.94-7.39 mg/100 g),whereas lycopene and alpha-carotene were not prominent and canthaxanthin was non existent in these vegetables. These analyses suggest that consumption of carotenoids such as lutein in addition to beta-carotene may be associated with a lower risk of cancers

Determination of Leafy Vegetables Need in Water andNitrogen Use Efficiency by Using the Diviner 2000 andthe Isotopes Techniques: Case of Amaranth(Amaranthus cruentus)

A study was conducted to determine how the nitrogen(N)in the fertilisers can be quantified and what amounts of fertilizers should be given to leafy vegetables to achieve their requirements.This study also aimed to determine the efficient use of water by the plant.The experiment was laid out in a randomized complete block with three replicates and three levels of urea(T0=0 kg/ha,T1=43.5 kg/ha,T2=65 kg/ha).Estimation of growth parameters and biomass yield revealed that the treatments produced statistically identical values.But numerically,T1(43.5 kg of urea/ha)gave the highest yields and T2(65 kg of urea/ha)produced the lowest.It was the same for the determination of the water use efficiency(WUE)by the plant where T1 produced the highest values compared to T2.The yield curve as a function of the applied urea dose allowed the identification of the urea dose that corresponds to optimal yield in amaranth.From the dose of 65 kg of urea/ha,any increase becomes harmful to the plant.This results in a decrease in yield in the amaranth plant.

Prophylactic role of Premna herbacea,a dietary leafy vegetable in managing hepatic steatosis via regulating AMPK/SREBP1/ACC/HMGCR signaling pathway

Non-alcoholic fatty liver disease(NAFLD)includes a broad spectrum of liver dysfunction ranging from hepatic steatosis(intracellular triglyceride accumulation)to steatohepatitis.This study investigated the beneficial effect of Premna herbacea(a dietary leafy vegetable of North East India)and its active constituent in managing hepatic steatosis using high fat diet(HFD)-fed male Wistar rat and hepatocyte(CC1)cell culture models.Administration with methanolic leaf extract of Premna herbacea(PHME)(250 mg/kg body weight,oral gavage,20 weeks)reduced the gain in body weight and rise in serum lipid(triglyceride and total cholesterol)levels and enzymes(alkaline phosphatase and aspartate aminotransferase)responsible for liver dysfunction in high fat diet(HFD)-fed rats.PHME administration further upregulated the phosphorylation of AMPK,ACC,and HMGCR,downregulated SREBP1 signaling pathways of lipid metabolism,and prevented hepatic steatosis in liver tissues of HFD-fed rats.Moreover,studies on cultured hepatocytes revealed that treatment with both crude extract and its ethyl acetate fraction(PHEA)significantly reduced intracellular lipid accumulation in palmitate(PA,0.75 mM)-treated cells.Chemical profiling(HPLC,HRMS,^(1)H and^(13)C NMR)of PHEA demonstrated the presence of Verbascoside,a caffeoyl phenylethanoid glycoside as a major phyto-constituent,which prevented cellular lipid accumulation and regulated the alteration in AMPK/SREBP/ACC/HMGCR signaling pathways of lipid metabolism in PA-treated cells.In conclusion,this study showed the prophylactic role of Premna herbacea and its active molecule,Verbascoside as a potential functional food in ameliorating hepatic steatosis by regulating AMPK/SREBP/ACC/HMGCR signaling cascade.

Contamination of copper in leafy vegetables grown near Kalyan Railway Track, Maharashtra, India

Background:Majority of human population is suffering from vitamins and mineral deficiencies.Leafy vegetables are used to overcome this problem.Heavy metal contaminations of vegetables cannot be underestimated as these are important components for diet.In Mumbai almost all the farms are closer to railway tracks along the harbour,central and western railways;local farmers in the absence of proper irrigation facilities use water from the drains to grow their crops.This Untreated sewage water increases heavy metals in soil and crops along with pathogens.Utilization of sewage water containing heavy metals due to small scale industries in urban areas deserves special attention as it makes environment quite unsuitable for human and animal health and growth of plants.Copper is essential element while in excess it can cause many diseases.Methods:The present study is undertaken with an aim to study presence of heavy metal i.e.copper in the vegetables,water and soil alongwith physico-chemical parameters.Atomic absorption spectrophotometer was used to determine copper content in vegetable samples like Spinacia oleracea and Amaranthus caudatus.Results:The level of copper present in the vegetable was found to be higher than the permissible limits with water being the major cause of excessive copper contamination.The physicochemical parameters were found to be exceeding the drinking water and irrigation standards.Conclusion:The irrigation water is the major source of copper which increases the copper content higher than the permissible limits.But more sampling and research is essential to understand the ingress of heavy metals in the leafy vegetables.

Protective Roles of Some Leafy and Non-leafy Vegetables against the Severity of Arsenic-induced Skin Lesions among Women Living in Rural Bangladesh:A Case Control Study

Arsenicosis is common among villagers as they drink more contaminated-water since the arsenic-crisis in Bangladesh.Supplementation of vitamins and micronutrients in counteracting arsenic toxicity has been proved for arsenic treatment.This study was intended to assess protective and beneficial roles of some commonly eaten vegetables on the development and severity of arsenic-induced skin lesions.A case-control study among(N=122)adult rural-women(62 cases had various forms of arsenical skin-lesions e.g.melanosis/keratosis/mixed-lesions and 60 sex-age-matched healthy-controls)was conducted in Shaharstee Upazilla of Chandpur district,Bangladesh.Socio-demographic data recorded in a pre-tested-questionnaire,‘per-day vegetables ingestion’of cases and controls were measured qualitative and quantitatively(24-hour recall-methods,food-frequency/week and food history-record/week).Multiple logistic regression/MLR analyses were performed to find out protective roles of some dietary leafy-vegetables/LVs and non-leafy vegetables/NLVs on arsenicosis and their influences on the degree of severity of arsenicosis also determined.Abstinence from taking some LVs/NLVs among cases than controls is associated with increased risk for arsenicosis(P<0.05).Amongst all most-frequently eaten vegetables(n=17)per day Momordica diocia has the highest skin protective role on arsenicosis[Adjusted odds ratio/AOR 8.2,95%CI(2.11-31.9),P=<0.01],followed by Ipomoea acquatica(AOR:7.3),Basella alba(AOR:6.2),Solanum tuberosum(AOR:4.0),Vigna unguiculata sesquipedalis(AOR:3.2),Trichosanthes anguina(AOR:1.2)and Abelmoschus esculentus(AOR:1.2).Moreover,severe skin lesion was observed as compared to non-severe cases(mild/moderate)for less intake frequencies of vegetables.This study outlined that commonly eaten vegetables have protective and beneficial roles on arsenic-induced skin lesions.Large samples longitudinal study of this important field of therapeutic-intervention is warranted.

Selected fermented indigenous vegetables and fruits from Malaysia as potential sources of natural probiotics for improving gut health

In the Peninsular Malaysia and Northern Borneo island of Malaysia, various rich indigenous leafy vegetables and fruits grow and contribute to the nutritional and dietary values of the population. They have high water contents, thus, naturally vulnerable to rapid food spoilage. Food preservation and processing play a vital role in the inhibition of food pathogens in fruits and vegetables that are prevalent in Malaysia. Lactic acid fermentation is generally a local-based bioprocess, among the oldest form and well-known for food-processing techniques among indigenous people there. The long shelf life of fermented vegetables and fruits improves their nutritional values and antioxidant potentials. Fermented leaves and vegetables can be utilized as a potential source of probiotics as they are host for several lactic acid bacteria such as Lactobacillus confusus, Weissella paramesenteroides, Enterococcus faecalis, Lactobacillus plantarum, Lactobacillus buchneri, Lactobacillus paracasei, Lactobacillus pentosus, Pediococcus acidilactici, Pediococcus pentosaceus and Leuconostoc mesenteroides. These strains may be more viable in metabolic systems whereby they can contribute to a substantial increase in essential biologically active element than industrial starter cultures. This review is aimed to address some essential fermented fruits and vegetables in Malaysia and their remarkable reputations as a potential sources of natural probiotics.

Prospective study of total and various types of vegetables and the risk of metabolic syndrome among children and adolescents

BACKGROUND Data available on the association between consumption of various types of vegetables and metabolic syndrome (MetS) remain inconsistent. AIM To investigate the association between the intake of various types of vegetables and MetS among children and adolescents and MetS. METHODS The Tehran Lipid and Glucose Study cohort included 424 children and adolescents initially free of MetS. At the 3.6 year follow-up, 47 new cases of MetS were identified. A 168-item semi-quantitative food-frequency questionnaire was used to collect information about total and various types of vegetables consumed, including allium-, green leafy-, fruity-, root-, stalk-, starchy-, potatoes, and cabbage. MetS was defined according to the Cook et al[32] criteria. RESULTS The median (interquartile range) of total vegetable consumption was 217 (146- 344) g/d. After adjustment for demographic characteristics and dietary intake, higher total-(≥ 350 g/d) and higher allium vegetable consumption (≥ 30 g/d) in the fourth quartile were significantly and inversely associated with risk of MetS compared to the first quartile. Consumption of green leafy vegetables in the third (21.4-38.3 g/d) versus the first quartile (≤ 13.5 g/d) demonstrated a significant inverse association with lower risk of MetS in children and adolescents;associations for other types of vegetables consumed were not significant. CONCLUSION Consumption of vegetables, especially allium and green leafy vegetables, in sufficient amounts may be beneficial in reducing the risk of MetS among children and adolescents.

African Traditional Vegetables as Agents of Integrated Soil Fertility ManangementmCrotalaria and Amaranth Farming

The knowledge and understanding of African leafy vegetables has diminished over time, but in the recent past year there is more interest in their research for their nutritive and medicinal values. Of value are those that have the potential to ameliorate soil nutrient levels. This is with the background that despite inorganic fertilizers （IF） have a dramatic impact on agriculture in the world, the economic situation in Sub-Saharan African calls for alternative methods to reduce soil fertility degradation. The use of leguminous vegetables may be a solution. The study looks at the potential contribution of a leguminous traditional vegetable-- Crotalaria brevidens to soil nitrogen under various treatments. During the study which was conducted over two seasons, C. brevidens was grown under two treatments of IF and organic fertilizer （OF） with a control in which there was no fertilizer （NF） applied. A non-leguminous vegetable--Amaranthus dubious （Amaranth） was grown under the same treatments for comparison purposes. Soil analysis was done before and after planting in the treatment subplots. Growth parameters were measured every fortnight and these included leaf number, shoot length, dry weight and nodule number for Crotalaria. Results indicated that the leguminous vegetable was not affected by external inputs and there were no significant differences between treatments and control. The non-leguminous vegetables responded well to both IF and OF treatments in all the measured parameters. This underlines the potential for improving soil nitrogen levels using leguminous vegetables, especially as intercrops with the non-leguminous types.

电动叶菜收获机速度协同控制系统设计与试验

针对电动叶菜收获机切割、输送和行走三者速度不协调导致的叶菜损伤率高、功耗大和收获效率低等问题,开发了一种电动叶菜收获机速度协同控制系统。系统以可编程逻辑控制器为核心,利用信息传感模块对割刀电机的电流、电压和转速进行数据采集;主控模块根据速度协同控制算法对采集信号进行处理,得到负载信息并协同切割、输送和行走三者速度。田间试验结果表明:系统稳定可靠,能够根据收获情况动态协同各部件速度参数,叶菜损伤率为8.88%;与传统定速控制方法相比,收获机功耗降低了13.1%,收获效率提升了33.4%。

基于文献的叶菜类蔬菜施肥现状分析

利用文献资料分析了我国主要叶菜类蔬菜的施肥现状和施肥效应,阐述了叶菜类蔬菜上氮、磷、钾推荐施肥量,施肥效应包括相对产量、增产量、增产率、产量反应和养分的农学效率。影响叶菜类蔬菜产量的限制因子主要是氮,其次为钾,而后为磷。叶菜类蔬菜推荐施肥比农民习惯施肥减少氮、磷肥用量,适当增加钾肥用量,但却增加了产量。因此,在叶菜类蔬菜上合适的推荐施肥方法是实现节肥增效的有效途径。

烟剂对大棚藜麦菜光合作用和叶绿素含量的影响

在藜麦菜的温室大棚种植中,用12%百菌清烟剂与12%速克灵烟剂防治病害较为常用。为了研究这两种烟剂对藜麦菜的叶绿素含量和光合作用的影响,施用烟剂后第3天和第5天分别进行藜麦菜叶片叶绿素含量和光合速率的检测。结果显示,施用烟剂可以提高藜麦叶绿素的含量,提高光合速率,进而提高生产率。