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The antioxidant and free-radical scavenging activities of extract and fractions from corn silk (Zea mays L.) and related flavone glycosides
Abstract
This study was designed to evaluate both the antioxidant and free-radical scavenging activities of extract and fractions from corn silk. N-butanol fraction (BF) demonstrated the highest total phenolic content (164.1 ± 9.7 μg GAE/g DCS) and total flavonoids content (69.4 ± 5.1 μg RE/g DCS), accompanied with the highest antioxidant activity compared to other fractions through all antioxidant assays. Two flavone glycosides showing potent antioxidant activity were isolated from BF and identified, by comparing spectral data (UV, FAB-MS and NMR) with literature values, to be isoorientin-2″-O-α-l-rhamnoside and 3′-methoxymaysin. The two isolated flavone glycosides, particularly isoorientin-2″-O-α-l-rhamnoside, demonstrated significant total antioxidant activity, DPPH radical scavenging activity, reducing power and iron-chelating capacity, with EC50 values of 14.24 ± 1.49, 22.69 ± 2.33, 6.58 ± 1.07 and 30.25 ± 3.05 μg/ml, respectively. Results obtained indicated that corn silk extracts can be used potentially as a ready accessible and valuable bioactive source of natural antioxidants.Research highlights► In this study, the antioxidant and free-radical scavenging activities of crude ethanol extract and fractions of corn silk were systematically evaluated for the first time. ► Two flavone glycosides were isolated and identified from n-butanol fraction from corn silk, which demonstrated highest antioxidant and free-radical scavenging activities. ► The antioxidant activities of the two isolated flavone glycosides were investigated for the first time and the result demonstrated that they were potent antioxidants. ► The results in this study may the possibility of using corn silk as source of low-cost natural antioxidant.
... There are some literature reviews on yellow corn silk revealing that it contains high concentrations of phenolic compounds and flavonoids. Several reports have been published on biological effects of corn silk such as antiproliferative effects on human cancer cell lines, lipopolysaccharide-induced cell adhesion, antibiotic and antifungal, antioxidant effects, and anti-diabetic activity [8][9][10][11]. ...
... Hydro-alcoholic extract exhibited a good reducing power and was also a good bioactive source of natural antioxidants. Our results are similar to those found by other researchers, the hydro-ethanolic extract exhibited higher level of scavenging activity compared to the aqueous extract [8,38]. ...
... Significant correlation has been found between the reducing power activity and the TPC (R = 0.9792) and TFC (R = 0.9838) of corn silk fractions, indicating that the reducing power is highly related to the amount of phenolic compounds especially flavonoids that present in the extracts, which can serve as electron donor to terminate the radical chain reaction [8]. ...
This study aims to investigate phytochemical screening, total polyphenol and flavonoids content, antioxidant activities and to examine toxicity, anti-inflammatory and antinociceptive effects of different extracts of stigmata of Zea mays from Morocco. The flavonoids and total phenols content were performed for both extracts. The aqueous and hydro-ethanolic extracts were screened for their possible antioxidant activities by three test systems, namely DPPH free radical-scavenging, reducing power and molybdenum system. Oral and Sub-acute toxicity of the hydro-ethanolic extract was evaluated in vivo. Anti-inflammatory activity of the hydro-ethanolic extract was evaluated by Carrageenaninduced rat paw edema method. The antinociceptive effect was tested by using the formalin test. Phytochemical screening of the extracts revealed a presence of flavonoids, leucoanthocyans, heterosid sterodic, coumarins, alkaloids, cardiac glycosides, anthocyanins and tannins. The flavonoids and total phenols content show higher content of flavonoids and total phenols in the hydro-ethanolic extract. It showed better antioxidant activity than the aqueous extract in the three methods used. Furthermore, the hydro-ethanolic extract with a concentration of 250 and 500 mg/kg body weight inhibited the inflammation induced by carrageenan in rats at 66.67% and 86.67% compared to 60.8% for indomethacin at 10 mg/kg after 5 h of inflammation induction. However, at dose of 500 mg/kg extract showed a pro-inflammatory effect. In the formalin test, the tolerance time of the rats was significantly higher compared to the control group. These initial results tend to support the traditional use in the treatment of cystitis, oliguria, nephritis, renal lithiasis edema, albuminuria, heart disease, slimming cures of stigmata of Zea mays in Morocco.
... The adverse toxic and health risks of synthetic antioxidants have increased and this has attracted the attention of many researchers into the field of natural antioxidants (Mohammed et al., 2013) [17] . There is higher demand for natural antioxidants because they have the potential to provide protection against diseases that are free radical induced such as cancer and other cardiovascular diseases (Liu et al., 2011) [13] . Fruits and vegetables have been recognized to reduce the risk of chronic diseases on regular consumption due to their richness in antioxidants. ...
... The adverse toxic and health risks of synthetic antioxidants have increased and this has attracted the attention of many researchers into the field of natural antioxidants (Mohammed et al., 2013) [17] . There is higher demand for natural antioxidants because they have the potential to provide protection against diseases that are free radical induced such as cancer and other cardiovascular diseases (Liu et al., 2011) [13] . Fruits and vegetables have been recognized to reduce the risk of chronic diseases on regular consumption due to their richness in antioxidants. ...
... Other studies show corn has antioxidant activity and increases NO production by considering the inhibition of peroxynitrite formation induced by inhibition of tyrosine nitration [47]. The antioxidant activity of maize extracts is maybe due to the presence of phenolic compounds such as flavonoids and ferulic acid [48]. Ohsaki et al. documented ferulic acid decrease blood pressure through the reduction of ACE activity [28]. ...
... Flavonoids of corn silk (FCS) have been investigated and confirmed to own various pharmaceutical activities such as, antihypertensive, anti-inflammatory, antioxidative and antidiabetic (Liu et al., 2011). Nephroprotective effect of corn silk extract was also reported along with gentamicin renal toxicity (Sepehri et al., 2011). ...
... Flavonoids of corn silk (FCS) have been investigated and confirmed to own various pharmaceutical activities such as, antihypertensive, anti-inflammatory, antioxidative and antidiabetic (Liu et al., 2011). Nephroprotective effect of corn silk extract was also reported along with gentamicin renal toxicity (Sepehri et al., 2011). ...
The effects of different concentration of Arabic Gum (AG) and corn silk (CS) extracts against hepato-nephro toxicity which induced by gentamicin (GM) in experimental rats were investigated. 25 bioactive constituents in the extract of CS were investigated by GC-MS analysis; Phytol (3.325 μg/g) was the major constituent with antioxidant properties and can reduce free-radical generation in an in-vitro experimental system. GM at a dose 80 mg/kg, intraperitoneal (ip) for 8 sequential days was used to induce nephrotoxicity, manifested biochemically by a significant increase in serum creatinine, blood urea and uric acid. In addition, liver enzymes, Total Bilirubin increased and total protein decreased. All extracts showed a significant effect in improving kidney function, liver enzymes, total protein and Bilirubin. The histopathological investigation of liver and kidney in rats injected with GM showed that, the best improvement in liver enzymes were obtained by using 20% Arabic Gum Extract (AGE) +5% Corn Silk Extract (CSE) and 10% AGE ,while using 10% CSE, 10% AGE and 20% AGE improved kidney function compared with control (+) group.
... Also, Z.mays hairs, as an essential part of maize, have high pharmaceutical values, for example, it is a urinary emulsifier, which passes stones and gravel from the kidneys and bladder; these hairs work against benign prostatic hyperplasia, cystitis, gout, chronic nephritis, and other similar diseases [3]. In previous studies, a series of phenolic compounds such as rutin, quercetin, epicatechin, vanillic acid, gallic acid, and flavone have been identified and isolated from Z. mays hairs [4][5][6]. Polyphenols (containing at least two phenolic groups (hydroxybenzenes)) are present in most plant foods and have been considered as "antinutrients" [7,8]. Pharmacological studies have shown that phenolic compounds have an important function in human health [9], including anticancer actions [3,10] and antioxidant activity [11]. ...
The aim of this study was to achieve the best extraction efficiency of the hydroethanolic extract of Zea mays hairs. The impacts of ethanol concentration, extraction time, and solvent /material ratio were studied in relation to the performance of Zea mays extracts by ultrasonic extraction at 50 kHz and room temperature. All extracts were quantitatively characterized in terms of polyphenol content. Response surface methodology (RSM) was carried out to optimize the extraction process and increase extraction efficiency. In the experiments, different concentrations of ethanol:water were used. The efficiency of the extraction process was determined from an analysis of variance (ANOVA). The maximum extraction efficiency of the hydroethanolic extraction (31.37%) and the quantitative value of the polyphenol content (257.87 mg EAG/g extract) were obtained using a treatment time of 40 min, an ethanol:water (70 : 30), and a solvent/material ratio (11 mL/g). The results obtained indicate that ultrasonic-assisted extraction is an effective method for extracting natural compounds from Zea mays, thus allowing the full use of this abundant and inexpensive industrial waste.
... Chemical compounds that belong to the antioxidant group are the polyphenols, flavonoids, vitamin C, vitamin E, and carotenoids [4] . Flavonoid compounds can act as natural antioxidants because they have activity in binding oxygen radicals and inhibiting peroxidation [5] . The primary use of antioxidants is to stop or break the chain reaction of free radicals to save the body from damage due to free radicals. ...
... This result is not much different when compared with previous studies, which stated that AME has a total flavonoid level of 2.10% ± 0.24%. Compared to other extracts such as Zea mays L. peel extract with a total flavonoid content of 6.94% ± 0.51% (31), that of Alpinia galangal L. amounted to 1.378% (32) and that of Citrus hystrix peel amounted to 11.47% (33). The total flavonoids contained in AME were likely to be quite a lot. Figure 1. ...
Annona muricata L. extract (AME) exhibits cytotoxic activities on various types of cancer cells. This study aims to unveil the anticancer activity of AME as a cotreatment agent with doxorubicin (dox) on 4T1 cells and AME's relation to senescence. AME was obtained by maceration using 96% ethanol. AME was then subjected to qualitative analysis using TLC compared to quercetin (hRf = 75). Spectrophotometry analysis of AME resulted in a total flavonoid content of 2.3% ± 0.05%. Cytotoxic evaluation using the MTT assay revealed that AME showed an IC50 value of 63 µg/mL, while its combination (25 µg/mL) with dox (10 nM) decreased the viability of 4T1 cells to 58 % (CI = 0.15). Flowcytometry using propidium iodide staining confirmed that AME (13 and 25 µg/mL) caused cell cycle arrest in the G1 phase as a single treatment and G2/M arrest in combination with dox. However, by using the dichloro dihydrofluorescein diacetate staining assay, it turned out that AME at concentrations of 13 and 25 µg/mL decreased intracellular reactive oxygen species (ROS) levels both as a single treatment and in combination with dox. Senescence-associated β - galactosidase assay showed that AME decreased dox-induced senescence. AME alone and in combination with dox (cotreatment) showed cytotoxic effect synergistically on 4T1 cells, but this was not caused by an increase in intracellular ROS levels as well as senescence induction. Therefore, AME showed its potential to be a cotreatment agent with antioxidant property on triple-negative breast cancer cells.
... also reported that maysin (a C-glycoside flavone from centipedegrass) and its precursor chemical components could exhibit anti-oxidative activity via DPPH radical scavenging in vitro antioxidant model (5), and protect SK-N-MC cell lines against inhibition of H 2 O 2 -induced apoptotic cell death (6). Despite these health benefits of maysin and flavonoid derivatives, its cytoprotective effects against ionizing radiation (IR)-induced cell death in fibroblasts and the underlying mechanisms have not been elucidated yet. ...
Centipedegrass originates from China and South America, and has been reported to contain several C-glycosyl flavones and phenolic compounds, including maysin and luteolin. The present study aimed to investigate the radioprotective activity of centipedegrass extract (CGE) in radiation exposed-fibroblasts and to assess the affected molecular pathway. The radioprotective effects of CGE were determined in NIH-3T3 cells using Cell Counting Kit-8 and morphological changes were observed. Reactive oxygen species (ROS) levels and the apoptotic profile of NIH-3T3 cells were also measured. The expression levels of B-cell lymphoma-2 (Bcl-2) family proteins [Bcl-2, Bcl-2 like protein 4 (Bax), Bcl-2-associated death promoter (Bad), caspase-3, poly(ADP-ribose) polymerase (PARP)], AKT and MAPK family proteins (ERK, p38 and JNK) were measured in vitro. The results demonstrated that when 3T3 fibroblasts pretreated with CGE were subjected to H2O2-induced cell damage, their viability was significantly decreased. Additionally, CGE pretreatment decreased ROS levels and the protein expression levels of cleaved PARP upon H2O2 treatment, indicating that CGE induced cytoprotective effects against H2O2-induced oxidative stress. Moreover, significant protective effects of CGE against intracellular ROS, induced upon exposure to ionizing radiation (IR), were observed. The protective effects of CGE pretreatment were also determined by morphological observation of NIH-3T3 cells following exposure to IR. CGE pretreatment increased the expression levels of anti-apoptotic signals (Bcl-2, p-BAD) and decreased the levels of pro-apoptotic signals (Bax, Bad), and led to cleavage of PARP and caspase-3 proteins. Additionally, in cells pretreated with CGE, the phosphorylation of AKT and ERK was increased and that of p38 and JNK was decreased compared with in cells subjected only to IR. These results indicated that CGE may act as a radioprotector due to its anti-oxidative activity, restoring cell homeostasis and redox balance in radiation-exposed fibroblast cells. Therefore, it could be suggested that CGE may be an effective candidate in the treatment of oxidative stress-related diseases and in radioprotection.
... Contrary to the results of our study, the amount of carbohydrate and protein present was 27.8 g and 5.7 g, respectively, in a research carried out by Solihah et al. [13] The study by Jun et al. [14] showed the nutritional composition of the matured corn silk. Carbohydrate and protein percentage of matured corn silk is 29.74% and 8.95%, respectively. ...
... Traditionally, tannins are also used for the treatment of diarrhoea, haemorrhage, detoxification etc. 46,47 . Studies have shown that flavonoids and phenolic compounds present in plants have a wide variety of biological effects including antioxidant, anti-inflammatory, antimicrobial, anti-angiogenic, anticancer, anti-allergic properties etc. 48 . ...
Plants are excellent sources of functionally bioactive compounds and essential nutrients. The phytochemical constituents have enormous potential in treating both plant and human diseases. Parkia timoriana (Yongchak/Zawngtah), one of the most important underutilized plants popularly consumed in Manipur and Mizoram states of Northeastern region of India, is known for its ethnobotanical and ethnomedicinal values. A significant DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)), and Phosphomolybdate scavenging activity corresponding to high antioxidant potentials was shown by the extracts from different edible parts of P. timoriana. P. timoriana extract showed significant antibacterial potential against Bacillus pumilus, Bacillus subtillis, Escherichia coli and Pseudomonas aeruginosa. Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry (GC–MS) analyses of the extracts revealed the functional groups and bioactive compounds present in different edible parts of the plant. Characteristic peaks of phenols, carboxylic acids, alkenes, glycogen, alkyl halides, halogen, aliphatic amines, primary and secondary amines, esters, ether, aromatics, lipids, triglycerides, nitro compounds that had antimicrobial, anti-cancer and anti-inflammatory properties etc. were observed. The GC–MS analysis also revealed the occurrence of 49 bioactive compounds that are known to possess a variety of pharmacological activities. Subsequently, in silico molecular docking studies of the identified bioactive compounds predicted potential anticancer and anti-inflammatory properties. To the best of our knowledge, this is the first-hand report on the bioactive compounds of edible parts of P. timoriana extracts showing antioxidant, antimicrobial and pharmacological significance. This study can lead to the production of new herbal medicines for various diseases employing P. timoriana and perhaps leading to the creation of new medications.
... Grub senyawa bioaktif yang sebelumnya dilaporkan dapat diekstrak oleh etil asetat adalah alkaloid, aglicon, dan senyawa glikosida, sterol, terpenoid, dan flavonoid (Dehkharghanian et al., 2010;Liu et al., 2011;Widyawati et al. 2014). Penelitian ini juga memberikan informasi tambahan bahwa pelarut etil asetat juga mampu menarik senyawa fenol dan saponin dari dalam media kultur kapang. ...
The Trichoderma asperellum MT02 has been reported to has antibacterial activity against the Extended Spectrum β-Lactamase (ESBL) E. coli based on the screening results through an agar plug method. This study aimed to evaluate the antibacterial activity of T. asperellum MT02 and characterize the composition of the bioactive compounds group possessed in its crude extract. The isolate was cultured in the Malt Extract Broth (MEB) media (static, 27 oC, 15 days). The intracellular metabolites from mycelium were extracted using methanol while extracellular metabolites from broth media were extracted using ethyl acetate. The antibacterial activity of crude extracts was tested using the paper disc diffusion method while bioactive compounds were characterized using the phytochemical method. The results showed that the antibacterial activity of the broth media extract performed a greater activity than the crude extract from the mycelium. The crude extract from mycelia only contained flavonoid and phenol hydroquinone compounds while the crude extract from broth media contains alkaloids, flavonoids, phenols hydroquinone and saponins. Kapang Trichoderma asperellum MT02 telah dilaporkan memiliki potensi sebagai penghasil senyawa antibakteri melawan Extended Spectrum β-Lactamase (ESBL) E. coli berdasarkan hasil penapisan melalui metode agar plug. Penelitian ini bertujuan untuk mengetahui aktivitas antibakteri ekstrak kasar kapang T. asperellum MT02 serta komposisi golongan senyawa bioaktif yang dimiliki. Kapang dikultur pada media Malt Extract Broth (MEB) (statis, 27 oC, 15 hari) di mana metabolit intraseluler dari miselium diekstrak menggunakan metanol sedangkan metabolit ekstraseluler dari media kaldu diekstrak menggunakan etil asetat. Aktivitas antibakteri ekstrak kasar diuji menggunakan metode difusi kertas cakram sedangkan senyawa bioaktif dikarakterisasi menggunakan metode fitokimia. Hasil penelitian menunjukkan bahwa aktivitas antibakteri asal ekstrak media kaldu lebih baik dibandingkan ekstrak kasar asal miselium kapang. Ekstrak kasar kapang asal miselia hanya mengandung senyawa golongan flavonoid dan fenol hidrokuinon sedangkan ekstrak kasar asal media kaldu mengandung alkaloid, flavonoid, fenol hidroquinon dan saponin.
... Antioxidants effectively inhibit and neutralize free radical reactions by providing hydrogen or electron to the reaction chain [13]. Antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and others from synthetic sources are applied in food protection against oxidative damages [14]; however, concerns regarding the side effects of them have been increased among scientists and nutritionists. Therefore, the exploration of economical and physiological justified natural antioxidants rather than synthetic resources is of interest [5,15,16]. ...
Attempts regarding the improvement and development of novel rice with better quality and higher productivity have been increasing. Among approaches, mutation is a direct alteration on the genome and considered as one of the most beneficial routes to acquire new beneficial traits in rice. An experiment was carried out to explore the effects of N-methyl-N-nitrosourea (MNU) mutation on the antioxidant activities, phytochemical compounds, and momilactones A (MA) and B (MB) in rice. Two rice cultivars, K1 (an original cultivar DT84) and K2 (mutated DT84), were examined. Antioxidant activities, phenolic compounds, and momilactones of the rice grain, husk, and straw portions were measured and quantified. Antioxidant activities were higher in grain and straw of K2, whereas K1 showed greater antioxidant activity in rice husk. Additionally, K2 displayed higher total phenolic contents (TPC) in grain and straw as well as lower of it in the husk, but these variations significantly differed only in the straw portion. An increase in total flavonoid contents (TFC) was observed in the husk of K1, while K2 significantly enhanced TFC in straw. Both MA and MB, two compounds obtaining antidiabetes, anticancer, antimicrobial, antigout, and antiobesity properties, were detected and quantified in grain, husk, and straw of K1 and K2 samples. Generally, the contents of MA were higher than MB in all tested portions of rice crop. MA and MB were higher in straw followed by those in husk and grain, respectively. K2 contained higher amounts of MA and MB in straw and husk, but lower contents in grain compared with those in K1. This study illustrates that MNU mutation can improve grain quality and enhance bioactive compounds in straw, husk, and grain of rice. This approach has the potential to develop functional foods from rice, and therefore help farmers in developing countries to improve value in rice production.
... FRAP is a parameter that quantifies antioxidant activity related to the electron-donating capability of a molecule. e Fe 3+ in K 3 Fe(CN) 6 is reduced to Fe 2+ in the presence of an antioxidant, which results in the initial yellow test solution turning green or blue [36]. High FRAP values were obtained for all solvents in this study, with the exception of DW, and decreased in the order: aqueous methanol > aqueous acetone > aqueous ethanol >> pure water. ...
The quest for natural preservatives and functional foods with health benefits has seen an increasing demand for natural products having therapeutic value. Herein, we investigated the influence of ethanol, methanol, acetone (50%, 70%, and 90% v/v), and distilled water on selected properties of olive leaf extract and determined the yield, total phenolic content (TPC), antioxidant activity, and antimicrobial activity. Extracts were analyzed for their oleuropein, hydroxytyrosol, and tyrosol contents by high-performance liquid chromatography (HPLC). The highest extraction yield of 20.41% was obtained when using 90 vol% methanol, while the highest total polyphenol contents of 232 and 231 mggallic-acid-equivalent/100 g were obtained for 90 vol% methanol and 90 vol% ethanol, respectively. Antioxidant activity was determined using the α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging assay, by determining the ferric reducing antioxidant power (FRAP), and using the Fe2+-chelating activity assay, which provided the highest values when 90 vol% methanol was used (33.84%, 0.75, and 12.91%, respectively). HPLC analysis showed that the highest oleuropein contents corresponded to the extracts obtained using 90 and 70 vol% methanol (26.10 ± 0.20 and 24.92 ± 1.22 g/L, respectively), and the highest antimicrobial activity was observed for 90 vol% methanol and distilled water. Olive leaf extracts using 90 vol% methanol had high levels of polyphenols and were highly antioxidant and antimicrobial. The results of this study facilitate the commercial applications of natural extracts with antioxidant and antibacterial activities and are expected to establish a foundation for further optimization studies.
Five undescribed macrocarpene-type sesquiterpenes (1-5), along with a known analogue (6) were isolated from the crude extract of stigma maydis. The structures of these compounds were elucidated based on comprehensive spectroscopic analyses together with quantum chemical calculations of 13C NMR data and electronic circular dichroism (ECD) curves. All isolated compounds were tested for their neuroprotective effects against the injury of human neuroblastoma SH-SY5Y cells induced by H2O2. Among them, compounds 3 (65.89%) and 5 (64.38%) showed moderate neuroprotective activity at 50 μM.
The present study aims to prepare a phenolic extract of Ammi visnaga from its areal part and qualitative measurement of flavonoids and tannins present in the extract using Folin Ciacalteu and Quettier-Deleu methods. Antioxidant activities of different fractions of the extract was measured using DPPH•, FRAP, ß-carotene and total antioxidant capacity techniques. The nbutanol and ethyl acetate fractions designated as F3 and F6, respectively. Corrosion inhibition effect of quercetin and catechin and F3 and F6 was studied for mild steel in 1 M HCl using electrochemical procedures. Electrochemical studies showed that quercetin and catechin standards showed antagonistic effect towards mild steel acidic corrosion. Among the tested species, the F6 and F3 fractions showed highest efficiencies of 93% and 88%, at 0.15 g L-1 concentration, respectively. Potentiodynamic and electrochemical impedance spectroscopy (EIS) studies showed that tested species act as mixed-type corrosion inhibitors, respectively. Adsorption of catechin on metallic surface in acidic medium obeyed the Temkin and El-Awady models.
Zizyphus spina-christi (L.) Willd belongs to family (Rhamnaceae) is an armed shrub or evergreen tree called Christ’s thorn having a common Arabic names such as Sidr and Nabeq. The plant is a well-known native tree to a vast area of Africa with a wide distribution in the tropical and subtropical regions of the world. Generally, Ziziphus plants have been widely used in the traditional medicine for the treatment of various diseases. Among the different Ziziphus plants Ziziphus spina-christi has been reported to possess multi-biologically active ingredients including alkaloids, sterols like β sitosterol, flavonoids, triterpenoids, sapogenins and saponins. These biologically active ingredients can potentially serve as antibacterial, antioxidant, antimicrobial, anti-inflammatory agents. Therefore, regarding its active components as well as easiness of its cultivation, Ziziphus spina-christi plant is considered as a valuable tree for the development of many drugs in the future.
Whether flavonoids play significant antioxidant roles in plants challenged by photooxidative stress of different origin has been largely debated over the last few decades. A critical review of the pertinent literature and our experimentation as well, based on a free-of-scale approach, support an important antioxidant function served by flavonoids in plants exposed to a wide range of environmental stressors, the significance of which increases with the severity of stress. On the other side, some questions need conclusive answers when the putative antioxidant functions of plant flavonoids are examined at the level of both the whole-cell and cellular organelles. This partly depends upon a conclusive, robust, and unbiased definition of "a plant antioxidant", which is still missing, and the need of considering the subcellular reorganization that occurs in plant cells in response to severe stress conditions. This likely makes our deterministic-based approach unsuitable to unveil the relevance of flavonoids as antioxidants in extremely complex biological systems, such as a plant cell exposed to an ever-changing stressful environment. This still poses open questions about how to measure the occurred antioxidant action of flavonoids. Our reasoning also evidences the need of contemporarily evaluating the changes in key primary and secondary components of the antioxidant defense network imposed by stress events of increasing severity to properly estimate the relevance of the antioxidant functions of flavonoids in an in planta situation. In turn, this calls for an in-depth analysis of the sub-cellular distribution of primary and secondary antioxidants to solve this still intricate matter.
BACKGROUND
Zizyphus jujube Miller cv. Dongzao is extremely susceptible to reddening, browning, nutritional loss and perishability after harvest. In this study, we evaluated the mechanisms of calcium chloride and chitosan/nano‐silica composite film treatments on the quality, especially in reddening by physiological and metabolomic assays.
RESULTS
The treatment delayed the decline of phenylalanine ammonia‐lyase (PAL), chalcone synthase (CHS), and chalcone isomerase (CHI) activities. Meanwhile, the treated groups retarded the increases in anthocyanin and quercetin contents by inhibiting the gene expressions of flavonol synthase (FaFLS ), dihydroflavonol 4‐reductase (FaDFR ) and anthocyanidin synthase (FaANS ), while promoting leucoanthocyanidin reductase (FaLAR ) expression, which leads to retardation of fruit reddening. Anthocyanins were found to be responsible for post‐harvest winter jujube reddening through principal component analysis (PCA). Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) results indicated that the treated group delayed the decline of the quality of Dongzao and extended its shelf life.
CONCLUSION
The treatment induced the heightening of flavonoids metabolism. They enhanced the nutritional value and the ability to resist stress by delaying the decline of PAL, CHS, and CHI activities. Meanwhile, the treated groups retarded the increase in anthocyanin and quercetin contents by inhibiting the gene expressions of FaFLS , FaDFR and FaANS and promoting FaLAR expression, which leads to retardation of fruit reddening. Anthocyanins is to be responsible for post‐harvest winter jujube reddening. Coating treatment effectively delayed the decline of winter jujube quality.
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Aim: To evaluate the protective and therapeutic potentials of corn silk extract on gentamicin (CN)-induced nephrotoxicity in albino rats. Study Design: The rats were randomly selected and grouped as follows: Group 1 (NC): Were given only food and water. They served as negative control. Group 2 (PC): Were treated with 80 mg/kg/day of CN over a period of 7 days. They served as the positive control. Protective Treatment: Group 3a (CN+CSP 200 mg/kg): Concurrently treated with 200 mg/kg corn silk extract and 80 mg/kg/day of CN for 7 days. 200 mg/kg corn silk extract continued for 30 days. Group 3b (CN+CSP 400 mg/kg): Concurrently treated with 400 mg/kg corn silk extract and 80 mg/kg of CN for seven days. 400 mg/kg corn silk extract continued for 30 days. Therapeutic treatment: Group 4a (CN+CST 200 mg/kg): Induction of nephrotoxicity with 80 mg/kg/day of CN for seven days before the administration of 200 mg/kg of corn silk extract for 30 days. Group 4b (CN+CST 400 Original Research Article Nwachuku et al.; JOCAMR, 11(4): 13-23, 2020; Article no.JOCAMR.61894 14 mg/kg): Induction of nephrotoxicity with 80 mg/kg/day of CN for 7 days before the administration of 400 mg/kg of corn silk extract for 30 days. Methodology: At the end of the treatment, the animals were allowed to fast for 18 hours and later anaesthetized using chloroform. Whole blood samples were collected via cardiac puncture and put into lithium heparin bottles. The samples were then spun at 3500 rpm for 5 minutes to obtain plasma. Kidney specimens harvested were fixed in 10% formol saline. Sections were prepared using histological techniques and stained using Haematoxylin and Eosin stain. Urea was analysed using Berthelot's enzymatic colorimetric method, creatinine using Jaffe's enzyme-kinetic method while the estimation of Na + , K + , and Cl-were performed using Ion Selective Electrode (ISE) analyzer. Results: Significantly lower (p<0.05) values of creatinine and urea were seen in protective and therapeutic treatment groups when compared against positive control. Potassium indicated significantly lower values especially in the therapeutic groups when compared against negative control while chloride indicated significantly higher values in 400 mg/kg rats compared with positive control at p<0.05. Histology of the protective treatment groups showed slightly distorted glomerular space, vacuolations, and dilated proximal and distal tubules. The positive control and the therapeutic treatment groups indicated severely damaged glomerulus, glomerular space, proximal and distal tubules as well as loss of parenchymal materials and presence of kupffer cell infiltration were seen but less severe in the therapeutic group compared to the positive control. Conclusion: The results obtained suggest protective and therapeutic potentials of corn silk extract on gentamicin-induced nephrotoxicity in albino rats. However, the therapeutic efficacy was progressively gradual and not be fast-effective as documented in most traditional or herbal literatures.
In Martinique Helicoverpa Zea is a common pest of tomato responsible for significant economic losses. To fight against H. zea proliferation and damages corn could be used as a trap crop since H. zea larvae growth in the corn silk was inhibited by the presence of some flavonoids. However, only some corn varieties show an efficient inhibitory activity against H. zea depending on their flavonoid composition. In order to be able to select corn varieties with a promising inhibition potential to be tested as trap plant, a metabolomic approach was developed to compare the flavonoid composition of corn silks from resistant and no resistant varieties. The quantitative analysis using UHPLC/TQ MRM MS associated to statistical treatments allowed to determine the most concentrated and the discriminant flavonoids of the resistant Java variety that clearly stood out presenting a higher content in several C-glycosyl-O-glycosyl luteolin and apigenin derivatives such as maysin molecule.
Five terpenoids (1-5), including three new ent-kaurane diterpenoids (1-3), one new ent-rosane type diterpenoid (4) and one known triterpenoid (5), were isolated from stigma maydis (Zea mays L.). The structures of the compounds were elucidated by comprehensive spectroscopic analyses. The relative configurations of stigmanes A-D (1-4) were determined by NOESY experiments. In addition, the relative configuration of stigmane D (4) was further established by NMR calculations. The absolute configurations of these compounds were identified by a comparison of experimental and calculated specific rotations. The neuroprotective effects of these compounds against H2O2-induced injury in human neuroblastoma SH-SY5Y cells were evaluated, and the results showed that among the compounds, 2 exhibited the most significant neuroprotection. Further study demonstrated that 2 could activate nuclear factor E2-related factor (Nrf2), downregulate apoptosis and reactive oxygen species (ROS) generation, and increase antioxidant enzyme activities in SH-SY5Y cells. However, the neuroprotective effect was reversed when Nrf2 was silenced. In conclusion, this study suggested that terpenoids from stigma maydis exerted neuroprotective effects through Nrf2 activation.
The present study investigated the effect of different drying methods
on the drying kinetics and antioxidant activity of pink lotus flowers to
identify the suitable drying models describe the dehydration as well
as drying conditions giving minimum loss of antioxidant compounds
and antioxidant properties of product. Samples were dried by Freeze
Drying (FD), Oven Drying (OD) at 40, 50 and 60oC, Microwave Drying
(MWD) with the powers of 140, 420 and 700 W. Drying kinetics from
ODandMWDwere analyzedmathematically and the dehydration data
wasstatistically analyzed to obtain best fit among all available models
basing on coefficient of determinations (R2), reduced chi-square (χ2
) and Root Mean Square Error (RMSE). The dried lotus flowers were
analyzed Total Polyphenol Contents (TPC), Total Flavonoid Contents
(TFC) and Antioxidant Activity (AA). It was found that the Midilli etal.
model is the most appropriate model for drying behavior of samples
by both OD and MWD. The activation energies of drying were 56.29
kJ/mol and 6.48 W/g for OD and MWD, respectively. FD was found to
be the best method to give the highest antioxidant activity for lotus
flowers and the next one was the OD at 50oC.
The present investigation was performed to evaluate the effect of extraction methods (reflux and stirring) and solvent concentrations on total phenolics, flavonoids, and antioxidant activity as % inhibition, metal chelating activity, and phosphomolybdenum assay of normal maize (NM) and QPM. These compounds can be water‐soluble, insoluble or bound to the cell wall and making extraction difficult. Thus, extraction plays an important role in the quantification of antioxidant activity. Results revealed that the quality protein maize (QPM) extracts possess higher flavonoids and metal chelating activity than NM, prepared using the stirring method. A significant correlation was found between phenolics and antioxidative activity for both varieties and methods. Maize, as being an excellent source of bioactive compounds having beneficial effects on human health have great potential to reduce free radicals and protect the body from chronic diseases. Therefore, maize products can also be regarded as functional foods.
Corn husks are an important byproduct of the corn processing industry. Although they are a rich source of bioactive compounds, especially flavonoids, corn husks are usually disposed of or used as animal feed. In this paper, we investigate their recovery by an enzyme-assisted extraction process consisting of a pretreatment of the plant material with cellulase followed by solvent extraction with aqueous ethanol. A four-factor, three-level Box-Behnken design combined with the response surface methodology was used to optimize the enzyme dosage (0.3-0.5 g/100 g), incubation time (1.5-2.5 h), liquid-to-solid ratio (30-40 mL g −1) and ethanol concentration in the solvent (60-80% v/v). Under the optimal conditions, about 1.3 g of total flavonoids per 100 g of dry waste were recovered. A statistical analysis of the results was performed to provide a quantitative estimation of the influence of the four factors, alone or in combination, on the extraction yields. Overall, the results from this study indicate that corn husks are a valuable source of flavonoids and that they can be easily recovered by a sustainable and environmentally friendly extraction process.
Buckwheat hulls, by‐products of buckwheat processing, contain various flavonoids, but the antioxidant capacity and synergy of different flavonoids are unclear. The purpose of this study was to evaluate the antioxidant activity of flavonoid monomers and high‐flavonoid component (HBHF) in buckwheat hulls using chemical‐based assays and cellular‐based assays. Four kinds of flavonoids were identified as rutin, isoorientin, vitexin, and hyperoside from buckwheat hulls. In chemical‐based assays, rutin and HBHF showed relatively high free radical scavenging activities and total antioxidant capacities. In cellular‐based assays, however, HBHF showed much higher proliferation activity against cell damage than flavonoid monomers when HepG2 cell was oxidatively damaged by H2O2 or high glucose. The cytoprotective activities of flavonoid monomers and HBHF were closely associated with reducing levels of reactive oxygen species (ROS) and malondialdehyde (MDA) or increasing catalase (CAT) activity. In conclusion, buckwheat hull flavonoids are the favorable application candidates for natural antioxidants. This work was aimed at the evaluation of antioxidant and cell protective activities of buckwheat hull flavonoids and providing a favorable evidence for the therapeutic utilization of natural extract.
Phytotoxicity including autotoxicity and allelopathy is the immediate or indirect biochemical impact of one organism on the germination, growth, survival, and reproduction of other organisms or improvement of neighbouring plant species through the arrival of substances into the environment. is biological phenomenon e ect might be either growth-enhancing (synergistic) or inhibiting (hostile), contingent upon the chemical substances delivered from donor plants and target species. Allelopathy has been viewed not just as a nature-accommodating way to control unwanted plant spices and biocidal products, but, additionally, a potential explanation for causing autotoxicity in yield. e application of chemical agents to reduce weed infestation may have negative consequences on human health as well as the environment. Plants with allelopathy activities derived from secondary metabolites could be an alternative strategy and have an expected function in sustainable weed biocontrol and boost global agricultural production and food security. us, protecting biodiversity, ensuring food safety, improving food, and nutrient quality, as well as crop production, are urgently needed as population and consumption are increasing. So, the objective of this study is to present recent advancements on phytotoxicity and allelopathic e ect of plant extracts (sorghum, sun ower, rice, and corn), for sustainable food and crop production in agroecosystems.
Rheumatoid arthritis (RA) is an autoimmune disease responsible for significant human morbidity in modern life. However, oxidative stress is one of the key markers for determining pathophysiology of patients with RA. The interaction between cellular immune system and body’s endogenous and/or exogenous antigens produce reactive oxygen species (ROS) and reactive nitrogen species (RNS) in autoimmune disease like RA. ROS and RNS include highly toxic superoxide (O2⁻) and peroxynitrite (ONOO⁻) radicals, which activate the signaling cascades of inflammatory cells to synthesize pro-inflammatory cytokines and chemokines. Previous studies reported that Th1 cytokines could promote the development of autoimmune disorders like RA, whereas the Th2 cytokines may attenuate the same diseases. An increased awareness of the relationship between food and health led to a tremendous increase of antioxidant research in the last decade. Evaluation of the efficacy of dietary antioxidants is also becoming highly acceptable in RA research. A number of dietary phytomolecules are already established as having antioxidant activity in isolated synovial cellular infiltrate or peripheral blood neutrophils and lymphocytes. This review aims to highlight the oxidative stress in inflammatory cells of patients with RA and to summarize the clinical relevance of dietary antioxidants as a first step in assessing beneficial effect, safety and dose safety ratio in patients with RA.
The objective of this study was to investigate the antioxidant properties of cottonseed peptides. Results indicated that cottonseed peptides prepared by enzymatic hydrolysis and microbial fermentation both showed antioxidant properties. The cottonseed protein enzymatic hydrolysate with molecular weight less than 3 kDa exhibited excellent DPPH, ABTS and hydroxyl radical scavenging activity and ferrous ion chelating activity with EC50 values of 0.49±0.02, 2.05±0.02, 2.21±0.12, and 0.99±0.03 mg/mL, respectively. Amino acid composition analysis revealed that cottonseed protein hydrolysates are rich in acidic/basic and aromatic amino acids. In addition, among the 19 identified cottonseed protein-derived peptides, YSNQNGRF had the lowest CDOCKER energy and formed hydrogen bonds with Tyr334, Arg380, Arg415, Ser508, and Ser602, and van der Waals interactions with Asn382, Tyr525, Gln530, and Ser555, which all located in the binding site of Keap1-Nrf2 interaction. These findings suggested that the antioxidant peptides from cottonseed protein had the potential as functional ingredients in foods.
Zhourat is an herbal infusion popular in the Middle East consisting of a mixture of different plants. The aim of this study was to (1) to determine the best conditions to extract phenolic compounds from twelve plants and their combination (Rosa damascena (Wared Joury, Zer Wared), Viola odorata L., Matricaria chamomilla L., Althaaea officinalis Linn., Melissa officinalis, Elaeagnus angustifolia L., Foeniculum vulgare L., Pimpinella anisum L., Saccharum officinarum L., Prunus dulcis, Zea mays L.), and (2) to elucidate their bioactive potential (antioxidant and antimicrobial capacity). Different conditions were used for the extraction and the subsequent analysis was performed. Results showed that optimal extraction conditions vary greatly between different kind of plants. A mixture of 50% water/50% ethanol at 40°C appeared to be optimal to extract the antioxidant and antimicrobial compounds for the samples tested. The total phenolic content (TPC) ranged from 0.2 mg GAE/g and 11.4 mg GAE/g. Zer Wared and Wared extracts at 40 ˚C showed the highest free radical scavenging activity. For TPC and anti-radical properties, Zhourat blend extracts did not show any additional effect over individual plants, and results fell in mid-range. As for the antimicrobial effect, antibacterial properties varied among the different plants as well. No synergistic effects appeared for the Zhourat mixture as a whole; neither antimicrobial nor antioxidant tests showed added value in mixing twelve plants. Wared and Zer Wared seem to have the best antioxidant and antimicrobial properties, followed by the Zhourat mixture. The results suggested that the most available herbal infusions in Lebanon should better be consumed on their own, rather than in a Zhourat Mixture. The combination of herbal ingredients in Zhourat mixture mertits further inbestigation.
The effect of four different extraction methods on physicochemical characteristics and functionalities of chloro-phycocyanin (CP) was investigated. Swelling (S-CP), freezing and thawing (4FT-CP), ultrasonication with freezing and thawing (4FT+U-CP), and the high-pressure cell disruption (HPCD-CP) process affected CP differently, thus resulting in different levels of solubility, DPPH scavenging activity, ABTS scavenging activity, and reducing power. Among the four CPs, HPCD-CP had the highest CP content (15.3%), purity (1.66 ± 0.16), and ∆E value but the lowest ∆b value. The ζ potential of HPCD-CP (−38.8 mV) was the highest, but the average particle size of 4FT+U-CP (719.1 nm) was the highest. UV-Vis absorption spectra and fluorescence spectra illustrated that high-pressure cell disruption-assisted extraction had more profound impacts on the microenvironment of tetrapyrrole chromophores, the environment of aromatic amino acids, and the phycocyanobilin of CP. Furthermore, HPCD-CP and 4FT-CP showed higher solubility and antioxidant activities than S-CP, especially 4FT+U-CP. The results obtained in this study demonstrate that HPCD technology could obtain a food-grade C-phycocyanin product with higher CP concentration, purity, solubility, and antioxidant activity.
The discovery of new natural additives from agro-industrial waste is considered an important research topic. This study investigated the feasibility of ultrasound-assisted extraction (UAE) of antioxidant compounds from corn stigma (CS) and the effect of independent variables (time and solid-solvent ratio) and their interaction in the extraction of CS. Results indicated that the UAE method increases the antioxidant activity and reduces the extraction time by 67%. Optimized conditions for the simultaneous extraction of antioxidants and polyphenols from CS were obtained using 5 min and a solid-solvent ratio of 0.05 g mL-1. The CS extract obtained by UAE was characterized by ESI-ToF-MS and 27 phytochemicals were reported. The extract showed promising antifungal and antibacterial activities against 23 of the studied microorganisms. Therefore, the CS extract obtained by the UAE can be used as a source of bioactive and antimicrobial compounds for use as a functional ingredient in the food and pharmaceutical industry.
summary
The current study aimed to evaluate the preventive and curative role of aqueous extracts of Apium graveolens and Eruca sativa against the anemia induced by Phenyl hydrazine in albino rats.
The study was conducted in the animal house of the Iraqi Center for Cancer and Medical Genetics Research / Al-Mustansiriya University (ICCMGR) for the period from 1/12/2020 to 15/2/2021. The study included (45) white rats, Rattus norvegicus (Albino Rat), with an age ranging between (8-12) weeks and a weight ranging between (200-300 g). And in laboratory conditions of lighting, darkness, cleaning and temperatures.
The study was designed by distributing the animals into groups that included each group of 5 animals that were as follows: the first group (A) positive control, the second group (B) negative control with phenyl hydrazine-induced anemia, and the third group (C) suffering from induced anemia treated with aqueous extract The celery plant had a concentration of 150 mg/ kg, and the fourth group (D) had induced anemia treated with aqueous extract of the watercress plant at a concentration (250 mg/ kg), The fifth group (E) had induced anemia treated with aqueous extract of celery 150 mg / kg and watercress 250 mg / kg, the sixth group (F) had induced anemia treated with aqueous extract of celery at a concentration of 150 mg / kg and watercress 250 mg / kg and iron 4 mg/ kg), the seventh group (G) was injected with PHZ 60 mg / kg, after an hour, the aqueous extract of celery was dosed 150 mg / kg, and the eighth group (H) was injected with PHZ 60 mg /kg, and an hour later, the aqueous extract of watercress was dosed 250 mg / kg, and the ninth group (I) had induced anemia and treated with iron 4 mg / kg .
The study included a qualitative and quantitative examination of celery and watercress plants, identifying the effects of the aqueous extracts of plants in the current study and blood parameters CBC, determining the effective dose, calculating the correlation coefficient, calculating some coagulation factors,
b prothrombin time PT, International Normalized Ratio INR, calcium Ca, and measuring the oxidation variables Malondialdehyde MDA and lactate Dehydrogenase LDH, Superoxide dismutase SOD, Glutathione peroxidase GPX, and Glutathione GSH, measurement of liver function variables, alkaline phosphatase ALP, Alanine Transaminase ALT, Aspartate Transaminase AST, and renal function parameters Urea, Creatinine, and Erythropoietin (EPO).
The results of the current study of blood tests showed a significant increase (p < 0.01) in the values of WBC and MCV and a decrease in RBC and Hb values in the negative control group compared to the positive control. The groups (C, D, E, F, G, I) also showed a decrease Highly significant (p < 0.01) in MCV and WBC values compared to the negative control, and RBC and Hb values increased compared to the negative control, except for MCV values, Group (G) did not show any significant differences compared to the negative control, while group (H) indicated high levels of (RBC , Hb, MCV), while it did not indicate any significant differences in WBC values, and there were no significant differences in PLT values for all experimental groups compared to the negative control.
As well as for clotting factors and calcium, it showed no significant differences for the negative control compared to the positive, as well as the experiment groups showed no significant differences compared to the negative control, except for group (I) a significant decrease (p < 0.01) for calcium values, as well as in the group (E) indicated a high decrease Significant (p < 0.01) in the level of clotting factors compared to the negative control. As for the oxidants, the results indicated that there were significant differences (p < 0.01) in the oxidation level of (LDH, MDA) values in the negative group compared to the positive control. The rest of the experimental groups for the values of (LDH and MDA) showed a highly significant difference (p < 0.01) compared with the negative control. The results also showed a highly significant difference (p < 0.01) in the level of antioxidant variables (GSH GPX) for the
c
negative control compared with the positive control. Positive control, while it did not indicate any differences with the (SOD) variable.
The study also did not indicate any significant differences for the experimental groups of (SOD) values compared with the negative group, except for group (I), which showed a highly significant (p < 0.01), As for (GPX) values, significant differences (p < 0.01) were noted, as the level of the variable increased for all groups compared with the negative control, except for group (C) which did not show any significant differences, Also (GSH) values indicated a highly significant increase (p < 0.01) in the variable level for all groups compared with the negative control, except for the (H) group, which did not show any significant differences.
Liver function indicated that there were highly significant differences (p <0.01) in the level of (AST, ALP) compared to the positive control, while it did not indicate a statistically significant difference in the values of (ALT). The study also showed that there were highly significant differences (p < 0.01) in the ALP level for all study groups compared with the negative control. As for the level of (AST) a significant decrease (p < 0.01) was recorded for groups (E, H, I) compared to the negative control, while no significant differences were observed for the rest of the groups, while (ALT) values indicated that there were no significant differences for all groups compared to the negative control. The values of urea and creatinine indicated that there were no significant differences for the affected control compared to the positive control, and the values of urea recorded a highly significant (p < 0.01) in groups (C, D) and a highly significant decrease in group (I) compared to the negative control.
While no significant differences were observed for the rest of the groups, while there were no significant differences in creatinine values for all groups compared to the negative control, and the results of the study did not show any significant differences between the negative control and the positive control in the (EPO) variable, as well as no significant differences were observed. For the
d
rest of the groups (D, E, F, H,I) compared to the negative control with the exception of group (C, G) significant differences (p<0.01) were noted, as (EPO) recorded a highly significant increase for both groups.
We conclude from the current study that PHZ induces anemia in rats and affects the levels of blood variables, oxidation and antioxidants. Medicinal herbs can be considered a good tool for treating anemia because herbal plants contain substances such as flavonoids, phenols and coumarins that contain strong antioxidant properties to remove radicals. The study proved that the use of celery and watercress plants in the treatment of anemia gave valuable results, because the composition of the plant and its medicinal properties stimulate the production of red blood cells in anemia disease.
Management of glycaemic response is perhaps the most critical part of antidiabetic therapy. Hypoglycaemia is an avoidable complication caused by conventional drugs used in the treatment of diabetes. It triggers commonly during the intensification of anti-hyperglycemic therapy used to render glycemic control in diabetic patients. The commercial oral hypoglycaemic drugs, insulin, herbal medicines and plant extracts are therefore used as a part of the treatment of diabetes. The demand for treating diabetes, through herbal and plant resources is due to their lesser adverse reactions and better phytochemical benefits. Corn silk has been shown to have anti-allergic, anti-inflammatory, and anti-hypertensive effects when extracted in various solvents. Corn silk has medicinal characteristics and has long been used as a traditional medicine in many nations, although the mechanism of action is unknown. The hypoglycaemic effects of corn silk are investigated in this review. The phytochemical components present in corn silk-like flavonoids, phenolics, terpenoids, tannins, sterols, and alkaloids are phytochemical components that have hypoglycemic activity and a mechanism for lowering blood glucose levels. There is a lack of a homogenized database on the hypoglycemic properties of corn silk thus the present review attempts to critically analyse it and provide specific recommendations of its doses.
Corn Silk is a beneficial herb that possesses health-promoting nutrients, including flavonoids. It has been found safe for human consumption and used to treat many diseases like urinary tract infections, asthma, hypertension, dropsy, and pathological swelling. It has also been found advantageous against oxidative stress, hyperglycemia, urinary tract infections, edema, prostate disorders, cystitis, obesity, nephrotoxicity and renal dysfunction. The phytochemical in Corn Silk possesses antioxidant and anti-inflammatory properties. The bioactive compounds in Corn Silk that are beneficial for health include vitamins, carbohydrates, magnesium, proteins, calcium, sodium and magnesium salts, alkaloids, steroids, volatile salts, potassium, flavonoids, and many other phenolic compounds. Maysin is one of the flavonoids in Corn Silk. This review highlights the therapeutic effects of Corn Silk in healthcare.
The recovery of agricultural and food wastes are one of the main areas of current research for optimal biowaste management to reduce greenhouse gas (GHG) emissions that are generated when it is not properly treated. Corn silk (CS) as biowaste from the agricultural sector is a rich source of natural compounds especially polysaccharides. We present here a chemical activation method to convert CS to values added heterogeneous catalyst for the synthesis of triazoles compounds via copper catalyzed azide–alkyne cycloaddition (CuAAC) reaction. For this purpose, cuprous oxide coated CS ([email protected]2O) and multifunctional Fe3O4@SiO2–para-aminomethyl benzoic acid–CS–Cu2O composite (denoted as Fe3O4@SiO2‐pAMBA-CS‐Cu2O) were fabricated. Different analytical techniques have been used to describe the size, crystal structure, elemental composition and other physical properties of the fabricated catalysts. These heterogeneous catalysts showed excellent catalytic activities for the synthesis of 1,4-disubstituted-1,2,3-triazoles via click reaction in H2O at 70°C under base and external-reductant-free conditions. The magnetic properties of the catalyst allowed easy separation after reaction by simply applying an external magnet. Other advantages of this work are the recyclability of the catalyst, the absence of reducing agent and base, besides utilisation of bio wastes for the production of heterogeneous catalyst.
Zea maydis styli cum stigmatis ( Engl. corn silk) are well known in medical practice. In the scientific literature, a lot of information has been accumulated about the chemical composition and pharmacotherapeutic actions of this medicinal plant material. A chronological analysis of this information shows that earlier, the scope of scientific publications was mainly devoted to the study of the choleretic, diuretic, hemostatic kinds of Zea maydis styli cum stigmatis activity, and the identification of the active substances responsible for these types of action. Currently, there is a growing scientific interest not only in the individual natural compounds of the Zea maydis styli cum stigmatis composition, but also in the search for new aspects of their medical application.
The aim of the article is a review and systematization of modern scientific data in the field of the Zea maydis styli cum stigmatis chemical composition and their pharmacological action.
Materials and methods. For the information and analytical search, the scientific data posted on the following electronic resources were used: PubMed, Web of Science, ScienceDirect, Scopus, Google Scholar, eLibrary. The search was carried out in the period from 2005 to 2021 using the following keywords: Zea mays L.; Zea maydis styli cum stigmatis ; corn silk; chemical composition; pharmacological action.
Results. The review is devoted to the generalization and analysis of modern scientific data on the Zea maydis styli cum stigmatis chemical composition and their pharmacological action. It has been shown that, as before, the greatest attention of scientists is attracted by flavonoids in the Zea maydis styli cum stigmatis chemical composition. Alongside with them, phenolcarboxylic acids, vitamin K, phytosterols, volatile compounds and polysaccharides are of no small importance for the Zea maydis styli cum stigmatis pharmacological activity. Modern ideas about the Zea maydis styli cum stigmatis pharmacological activity have been expanded by summarizing the study results of their antioxidant, anti-inflammatory, antidiabetic, hypotensive, neuro- and photoprotective activities. The data on the effectiveness of their use as parts of the complex tumor diseases therapy have been published.
Conclusion. As a result of the data analysis of modern scientific literature, it has been found out that Zea maydis styli cum stigmatis are still in the sphere of scientists’ interest. Alongside with the flavonoids of this raw material, other groups of pharmacologically active substances are also being actively studied. It has been revealed that the information about potentially significant and confirmed types of the Zea maydis styli cum stigmatis therapeutic action is significantly updated. The results of this review may be useful for identifying promising directions for the development of the drugs based on Zea maydis styli cum stigmatis .
The harmful effects of sunlight on the skin have triggered several studies. They concentrated on the synthesis or extraction of natural compounds that can absorb ultraviolet (UV) radiation. In this study, we investigated the in vitro photo-protective potential of Viola odorata flowers extracts, in three states (fresh, dried, frozen), using three solvents (chloroform, ethyl acetate, ethanol) by sequential extraction. In vitro SPF values were determined by spectrophotometric method. Antioxidant activity was tested by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Total phenolic content (TPC) was measured using Folin-Ciocalteu method. The ethanolic extract fraction, at the concentration of 2 mg/ml, from the three flowers states had the best SPF values (27.249, 26.978, 27.907) respectively, followed by ethyl acetate extract fraction of dried flowers (SPF=21.11). The highest DPPH inhibition (about 85%) was also obtained in ethanolic extract fraction from the three states of flowers. The ethanolic extract fraction of fresh flowers showed the highest total phenolic content (18.575 mg GAE/g crud extract), followed by ethanolic extract fraction of dried flowers (15.06 mg GAE/g crud extract). There was a significant positive correlation between SPF values and each of antioxidant activity (R=0.92) and TPC (R=0.748) in the different extract fractions. Our results showed that ethnolic Viola odorata flowers extract, in different states, has a great potential to be used as a sunscreen agent due to its polyphenol content, which is also associated with strong antioxidant activity.
Response surface technique was employed for improving the extraction of corn silk polysaccharides (CSP). Temperature, liquid-to-solid ratio, and per extraction time were all examined as separate factors. The optimal extraction parameters were determined by fitting experimental data to a second-order polynomial; a liquid-to-solid ratio of 21.5 ml/g, temperature equivalent to 88°C, and extraction time of 1.87 h. The experimental yield of the extracted polysaccharides following the application of these conditions was 4.33 ± 0.08% (dry weight), which fit quite well with the predicted value. CSP’s strong scavenging capabilities against hydroxyls, 1,1-diphenyl-2-picrylhydrazyl radicals, and superoxide anions along with its excellent reducing potential, were demonstrated in an in vitro antioxidant experiment. Meanwhile, in vivo testing revealed that CSP substantially enhanced glutathione peroxidase and superoxide dismutase activities. The Malondialdehyde levels in the liver and serum of aged mice also underwent a decrease. This study found that CSP has a substantial antioxidant potential in vitro and in vivo , suggesting that it might be used as an antioxidant in food and medicine.
When harvesting corn, corn silk was discarded as waste, including the compounds isolated and identified from corn silk such as flavonoids, sterols, alkaloids, polysaccharides, organic acids, volatile oils, trace elements, and multivitamins. It not only pollutes the environment but also wastes resources. In this paper, extraction methods commonly used for extracting flavonoids from corn silk were reviewed, such as reagent method, enzymatic method, microwave, supercritical CO2 extraction, ultrasonic, and microwave-assisted ultrasonic. Flavonoids are natural antioxidants and have application value in scavenging free radicals, inhibiting bacteria, and regulating blood lipids. The in vitro biological activities of flavonoids from corn silk extracted by different extraction methods were also compared.
Zhuke-Hulu tea is an herbal tea widely enjoyed by people in Southern China. For the first time the phytochemical compositions of Zhuke-Hulu tea ethanol extract (ZHTE) were analyzed by GC-MS and UPLC-ESI-MS/MS, and the anti-oxidant and anti-inflammatory activities were evaluated. Several categories of substances in ZHTE were identified, among which organic acids, phenolics/phenolic acids and flavonoids were the major components. ZHTE showed significant anti-oxidant activity as measured by free radical scavenging assays and reducing power test. Moreover, ZHTE exhibited cytoprotective effect against H2O2-induced oxidative stress damage by enhancing endogenous anti-oxidant defense system and Nrf2 nuclear translocation. In addition, ZHTE also exerted anti-inflammatory efficiency by down-regulating the protein levels of iNOS and COX-2 as well as the production of pro-inflammatory cytokines. In parallel, ZHTE alleviated intestinal inflammation induced by dextran sulfate sodium (DSS) through reducing pro-inflammatory cytokines level, inhibiting inflammatory cell infiltration, and modulating gut microbiota. These findings provide a solid foundation for the nutraceutical benefits of Zhuke-Hulu tea and promote its consumption as a functional beverage.
The hypouricemic effect of corn silk flavonoids (CSFs) in vivo that were extracted by ethanol and fractionated by continuous elution with 40% (CSF-A) and 60% (CSF-B) ethanol solutions on polyamide column were investigated in this study. CSFs reduced serum uric acid (UA) level in a mouse model of potassium oxonate-induced hyperuricemia. CSF-B had the best hypouricemic effect, as it decreased the serum UA level by 26.69% and xanthine oxidase (XO) activity in the serum by 11.29%. The mechanism of action of CSF-B was related to the inhibition of XO activity and the promotion of UA excretion. CSF-B was found to contain 12 kinds of major flavonoids, five of which were speculated to influence its activity in the hyperuricemia mice. The five flavonoids were apigenin-6-C-glucoside-7-O-glucoside, kaempferol-3-O-rutinoside, luteolin-7-glucoside, luteolin-3′,7-di-O-glucoside, and naringenin, respectively. Structure analysis revealed that C-4′, C5 hydroxyl groups, and C2=C3 double bonds in CSF-B gave the latter its hypouricemic effect.
Practical applications
The prevalence of hyperuricemia has increased in recent times. Current hypouricemic drugs have side effects and can easily lead to various complications. Therefore, it is of great practical significance to find safer and more effective hypouricemic drugs. This study demonstrated that corn silk flavonoids may be used as a dietary supplement to manage hyperuricemia.
Corn silk has been widely used as a nutritional and medicinal supplement due to its pharmacological properties, but there is a lack of studies that correlate the extracts' chemical composition with their biological activities. Herein, we performed the large-scale chemical characterization of corn silk extracts and used chemometrics to correlate the chemical composition with the biological activities of the extracts. Twenty-two metabolites were identified by High-Performance Liquid Chromatography coupled to Mass Spectrometry (HPLC-MS), whereas twelve were identified by Gas Chromatography coupled to Mass Spectrometry (GC-MS). Chemometrics allowed us to discriminate extracts obtained in different organic solvents from in natura and commercial product samples and to pinpoint potential candidate metabolites for the antioxidant and anti-glioma activities. Two flavone glycosides (7 and 8), along with a O-methylated anthocyanidin (26) seems to be the main contributors for the biological activities of the corn silk extracts.
Cornsilk is maize waste containing phenolic compounds. In this study, freeze-drying, spray-drying, and microwave-drying techniques were evaluated for the encapsulation of cornsilk's phenolic compounds using maltodextrin as wall material. The results of antioxidant properties showed that freeze-drying was more efficient than microwave-drying and spray-drying techniques. The highest recovery of phenolic compounds was obtained with freeze-drying. The microstructure, DSC, and FTIR data showed that the encapsulation process was effective, and freeze-drying was the best drying technique. The physical properties of the microparticles greatly changed with the drying techniques. This study revealed that the phenolic compounds of the cornsilk extract can be successfully encapsulated and valorized.
The aim of this study was to use dried corn silk powder variety of VL Baby corn-1 for formulation of flavoured herbal tea with different combination of Thyme (Trachyspermum ammi), Clove (Syzygium aromaticum), Cinnamon powder (Cinnamomum verum), Timur (Zanthoxylum alatum), Tulsi (Holy basil) (Ocimum tenuiflorum), Gandraini (Achillea millefolium), Lemon grass (Cymbopogon citratus), Blend (Clove + Timur + Gandraini), and one only corn silk without any other herbs and to know antioxidant properties of developed tea. Result of sensory evaluation experiment showed that all combinations were liked moderately. Lemon grass flavour followed by cinnamon and clove blend obtained highest score. Total phenolic content, total flavonoid content, DPPH free radical scavenging activity and total antioxidant activity for all flavour are analyzed and reported. Results on DPPH free radical scavenging activity indicated that corn silk tea had 81.215 ± 0.75 µg/mL whereas blend with Timur had significant highest value and Thyme blend had lowest value 64.20 ± 0.40 among all eight different blends with corn silk. The values for total antioxidant capacity blends with Timur (Zanthoxylum alatu) in corn silk showed significantly (P < 0.05) highest value and Clove, Timur, Gandraini blends got lowest value.
Ziziphus spina-christi has been traditionally used as a folk medicine for a variety of therapeutic benefits. However, there is no well-documented information regarding the protective role of this plant against toxicity induced by the overdose of trace metals, including iron. This work aimed to investigate the major components, as well as the antioxidant profile of aqueous extracts from different Z. spina-christi plant parts (seed, pulp, and almond), and to assess the protective effect of seed extract against iron-induced oxidative DNA damage using Tetrahymena pyriformis as a cellular model. Cells were incubated with iron (II) chloride (FeCl2) FeCl2 (1000 μM) in the absence or presence of seed extract. Lipid peroxidation and reactive oxygen species production were measured using biochemical assays. Intracellular iron accumulation was evaluated through Perl’s Prussian blue staining and ferrozine assay. The DNA damage was evaluated by pulsed-field gel electrophoresis, PCR, and restriction enzyme digestion of metallothionein (MT) gene. HPLC–DAD analysis revealed 21 different phenolic compounds; most of them were identified in the seed extract, while the almond extract exhibited a weak phenolic composition. Accordingly, seed extract showed important in vitro antioxidant activities. Pre-treatment with seed extract significantly reduced the impact of FeCl2, by attenuating MTT reduction, preventing iron accumulation, modulated antioxidant enzyme activity, reduced lipid peroxidation and significantly inhibited DNA damage. Collectively, data showed that Ziziphus spina-christi seed might act as an iron chelator agent with antioxidant properties offering effective protection against cytotoxicity and oxidative DNA damage induced by iron (II) chloride overload.
Cholinesterases, involved in acetylcholine catabolism in the central and peripheral nervous system, have been strongly linked with neurodegenerative diseases. Current therapeutic approaches using synthetic drugs present several side effects. Hence, there is an increasing research interest in naturally-occurring dietary polyphenols, which are also considered efficacious. Food processing by-products such as brewer’s spent grain (BSG) would be a potential bio-source of polyphenols. In this study, polyphenol-rich BSG extracts using 60% acetone and 0.75% NaOH solutions were generated, which were further subjected to liquid–liquid partitioning using various organic solvents. The water-partitioned fractions of the saponified extracts had the highest total polyphenol content (6.2 ± 2.8 mgGAE/g dw) as determined by Folin–Ciocalteu reagent, while the LC-MS/MS showed ethyl acetate fraction with the highest phenolics (2.9 ± 0.3 mg/g BSG dw). The best inhibitions of acetyl- (37.9 ± 2.9%) and butyryl- (53.6 ± 7.7%) cholinesterases were shown by the diethyl ether fraction of the saponified extract. This fraction contained the highest sum of quantified phenolics (99 ± 21.2 µg/mg of extract), and with significant (p < 0.01) inhibitory contribution of decarboxylated-diferulic acid. Amongst the standards, caffeic acid presented the highest inhibition for both cholinesterases, 25.5 ± 0.2% for acetyl- and 52.3 ± 0.8% for butyryl-cholinesterase, respectively, whilst the blends insignificantly inhibited both cholinesterases. The results showed that polyphenol-rich BSG fractions have potentials as natural anti-cholinesterase agents.
The objective of this study was to examine the effects of diets supplemented with corn silk meal (CSM) and non-starch polysaccharide (NSP) enzyme on growth performance, blood biochemistry, immunological response, and growth-related gene expression in broiler chickens. A total of 270 broiler chickens were divided into six experimental groups: (1) basal diets (BD) as control; (2) BD supplemented with 0.5 g/kg feed NSP enzyme; the other four groups are CSM diets as following; (3) and (4) fed diet contain 40 and 80 kg/ton of CSM; (5) and (6) fed diet contain 40 and 80 kg/ton CSM and supplemented with 0.5 g/kg NSP enzyme. Body weight gain (BWG), feed conversion ratio (FCR), protein retention and fiber digestibility were synergistically improved (p < 0.05) when fed CSM supplemented with NSP enzyme. Moreover, a synergistic decrease (p < 0.05) in the serum glucose and total cholesterol were found. Immune organ weights and Newcastle disease virus titers were increased with CSM diets. Interestingly, the relative mRNAs of the growth hormone receptor (GHR) and insulin growth factor (IGF) were increased (p < 0.05) with the CSM and NSP enzyme: the relative mRNA expressions of cholecystokinin (CCK) and leptin were decreased by feeding CSM diets with the NSP enzyme. It could be concluded that the dietary inclusion of CSM with the NSP enzyme might improve growth performance, modify plasma lipids, and enhance immune response in broilers.
Natural bioactive compounds are not only an ideal substitute for synthetic finishing agents, but have also attracted numerous interests in the textile industry. Here, we used vine tea (Ampelopsis grossedentata) as dyestuff, and selected the pad-steaming process in the presence of natural mordant to realize the dyeing and fixation of flavonoids colorant on silk fabrics. Results indicated that it endowed silk fabrics with unique flavonoid functions that allowed bioactive finishing of silk fabrics. The optimal extraction process of flavonoids dye from A. grossedentata was achieved at a temperature of 100°C, time 0.5 h and a bath ratio of 1:20. We adjusted the pH value of the dye liquor to 3, by adding mordant, and found that the K/S value of the silk fabric reached the maximum using dip-padding and steaming process. In addition, the fabric showed excellent color fastness to rubbing. FTIR, SEM and EDS results further confirmed that the silk fabric was successfully dyed with flavonoids colorant. Results from antioxidant and antibacterial tests revealed that the dyed fabric had excellent anti UV properties (UPF: 173.58), excellent antioxidant activity and antibacterial properties against both Escherichia coli and Staphylococcus aureus. Collectively, our results affirmed the simplicity, high efficiency and energy saving attributes of natural products in dyeing and functional finishing of textiles, thus provide a new direction for clean modification of textile materials.
The aim of this study was to optimize the different solvents and extraction conditions on fiber contents of local corn silk powders. Each sample of corn silk powder extract was analyzed by enzymatic method for fiber content including soluble fiber, insoluble fiber and total fiber. Design using Factorial Randomized Block Design (RBD) with 4 factors are local varieties of cornsilk (Bisma, Arjuna and Srikandi Putih), different solvents (water, methanol, ethanol and ethyl acetate), different concentration of solvents ( methanol (60%, 70% and 80%), ethanol (60%, 70% and 80%), ethyl acetate (60%, 70% and 80%) and water), and ratio of material and solvent (1:5 (w/v), 1:10 (w/v), 1:15 (w/v) and 1:20 (w/v)). Response Surface Methodology (RSM) technique for optimum condition determination was used. Results showed that the difference in experimental conditions affects the content of soluble fiber, insoluble fiber, and total fiber produced by optimization analysis using the DX11.0® Program with RSM-Central Composite Design (CCD). In conclusion, Bisma variety, solvent of methanol, concentration of 80% solvent and ratio of (1:20) was selected as the optimum condition of which resulted in soluble fiber content of 0.85%, insoluble fiber of 0.60% and total fiber of 1.45%.
The antioxidant activity and contents of various polyphenol classes in the silks of fifteen maize hybrids with economic importance in Serbia were evaluated. Total polyphenols, tannins and proanthocyanidins were determined spectrophotometrically, after extraction of plant material with 70% aqueous acetone under sonication at room temperature. In addition, flavonoid content was determined. Antioxidant activity of aqueous acetone extracts was evaluated by FRAP assay. A positive linear correlation between antioxidant activity and contents of all investigated polyphenol classes was established. The highest antioxidant activity was observed in the extract of NS 640 hybrid, which had high levels of all polyphenol classes examined. Results suggested strongly that polyphenol content should be considered as an important feature of the herbal drug Maydis stigma. For that reason, the biological source of this herbal drug needs to be more precisely defined, as observed activities and polyphenol contents were greatly dependent on plant material source.
Bay leaves (BL) (Laurus nobilis L., Family: Lauraceae) are traditionally used orally to treat the symptoms of gastrointestinal problems, such as epigastric bloating, impaired digestion, eructation, and flatulence. In this study, lyophilized extracts (both water and ethanol) of BL were studied for their antioxidant properties. The antioxidant activity, reducing power, free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging and metal chelating activities were evaluated to determine the total antioxidant capacity of both BL extracts. Both extracts exhibited strong total antioxidant activity in linoleic acid emulsion. Concentrations of 20, 40, and 60 μg ml−1 showed 84.9, 95.7, 96.8, and 94.2, 97.7, and 98.6% inhibition of lipid peroxidation of linoleic acid emulsion, for water and ethanol extracts, respectively. On the other hand, 60 μg ml−1 of the standard antioxidants butylated hydroxyianisole (BHA), butylated hydroxytoluene (BHT), and α-tocopherol exhibited 96.6, 99.1, and 76.9% inhibition of lipid peroxidation in linoleic acid emulsion, respectively. In addition, the both BL extracts had effective reducing power, DPPH⋅ free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging and metal chelating activities at 20, 40, and 60 μg ml−1. The total amount of phenolic compounds in each BL extract was determined as gallic acid equivalents.
Ground corn tassels, a by-product of corn, were used as a source of phenolic compounds. Water, ethanol, methanol, acetone, hexane, chloroform, butanol, petroleum ether and methylene chloride were evaluated as different polarity solvents to extract these phenolic compounds. Ethanol exhibited the highest extraction ability for such phenolic compounds, followed by methanol and water, where the total phenols were 0.1575%, 0.1125% and 0.0737%, respectively. Antioxidant activity of corn tassels ranged from 83.0% to 85.2%, 69.9% to 83.7%, 69.8% to 80.4%, 22.2% to 49.1% and 14.8% to 19.3% radical scavenging activity (% RSA) for ethanol, methanol, acetone, butanol and water extracts, respectively. The ethanolic extract of the corn tassels was successfully utilised to retard the oxidation of sunflower oil and the obtained induction period values were comparable to those of tert-butylhydroquinone (TBHQ).
The longan (Dimocarpus Longan Lour.) peel was extracted with 95% ethanol employing microwave-assisted extraction and Soxhlet extraction method, the total phenolic content of microwave-assisted extract of Langan peel (MEL) and Soxhlet extract of Langan peel (SEL) reached 96.78mg/g and 90.35mg/g dry weight, respectively, expressed as pyrocatechol equivalents, which were quantified using Folin–Ciocalteu reagent. Subsequently, antioxidant properties of two extracts were investigated employing various established systems in vitro including 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, hydroxyl radical scavenging assay using a new resonance scattering (RS) method, reducing power and total antioxidant capacity. MEL and SEL showed excellent antioxidant in all test systems compared to synthetic antioxidant 2,6-di-ter-butyl-4-methylphenol (BHT) and the antioxidant activities of MEL were all superior to those of SEL. Furthermore, the suitability of MEL and SEL as substitute of BHT were determined in peanut oil, and the decrease of lipid oxidation were monitored using thiobarbituric acid-reactive substances (TBARS) assay. MEL and SEL treatment significantly (P
Ether, methanolic and aqueous extracts of lyophilized rambutan (Nephelium lappaceum L.) peels and seeds were evaluated for phenolic contents, antioxidant and antibacterial activities. High amounts of phenolic compounds were found in the peel extracts and the highest content was in the methanolic fraction (542.2 mg/g dry extract). Several potential antioxidant activities, including reducing power, β-carotene bleaching, linoleic peroxidation and free radical scavenging activity, were evaluated. The peel extracts exhibited higher antioxidant activity than the seed extracts in all methods determined (P < 0.05). The methanolic fraction was found to be the most active antioxidant as shown by their 50% DPPH inhibition concentration, 4.94 μg/mL. The results indicated this fraction exhibited greater DPPH radical scavenging activity than BHT and ascorbic acid (0.32 g dry extract/g BHT or ascorbic acid). Antibacterial activity against eight bacterial strains was assessed by disc diffusion and broth macrodilution methods. All peel extracts exhibited antibacterial activity against five pathogenic bacteria. The most sensitive strain, Staphylococcus epidermidis, was inhibited by the methanolic extract (MIC 2.0 mg/mL).
Antioxidant activities of wampee peel extracts using five different solvents (ethanol, hexane, ethyl acetate, butanol and water) were determined by using in-vitro antioxidant models including total antioxidant capability, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity, reducing power, and superoxide scavenging activity. Ethyl acetate fraction (EAF) exhibited the highest antioxidant activity compared to other fractions, even higher than synthetic antioxidant butylated hydroxyl toluene (BHT). In addition, the EAF exhibited strong anticancer activities against human gastric carcinoma (SGC-7901), human hepatocellular liver carcinoma (HepG-2) and human lung adenocarcinoma (A-549) cancer cell lines, higher than cisplatin, a conventional anticancer drug. The total phenolic content of wampee fraction was positively correlated with the antioxidant activity. This is the first report on the antioxidant and anticancer activities of the wampee peel extract. Thus, wampee peel can be used potentially as a readily accessible source of natural antioxidants and a possible pharmaceutical supplement.
Corn silk has been purified as an anticoagulant previously and the active component is a polysaccharide with a molecular mass of 135 kDa. It activates murine macrophages to induce nitric oxide synthase (NOS) and generate substantial amounts of NO in time and dose-dependent manners. It was detectable first at 15 h after stimulation by corn silk, peaked at 24 h, and undetectable by 48 h. Induction of NOS is inhibited by pyrolidine dithiocarbamate (PDTC) and genistein, an inhibitor of nuclear factor kappa B (NF-kappaB) and tyrosine kinase, respectively, indicating that iNOS stimulated by corn silk is associated with tyrosine kinase and NF-kappaB signaling pathways. IkappaB-alpha degradation was detectible at 10 min, and the level was restored at 120 min after treatment of corn silk. Corn silk induced nuclear translocation of NF-kappaB by phosphorylation and degradation of IkappaB-alpha.
The peroxisome proliferator-activated receptors play a pivotal role in metazoan lipid and glucose homeostasis. Synthetic activators of PPARalpha (fibrates) and PPARgamma (glitazones) are therefore widely used for treatment of dislipidemia and diabetes, respectively. There is growing evidence for herbal compounds to influence nuclear receptor signalling e.g. the PPARs. We recently reported carnosic acid and carnosol, both being diterpenes found in the labiate herbs sage and rosemary, to be activators of PPARgamma. The subsequent screening of a variety of ethanolic extracts, obtained from traditionally used herbs, for PPAR activation, led to an exceptionally high hit rate. Among 52 extracts nearly the half significantly activated PPARgamma and 14 activated PPARalpha in addition, whereas three of them were pan-PPAR activators, which also activated PPARdelta. The most active extracts, for which a concentration dependent effect could be shown, were the extracts of Alisma plantago aquatica (ze xie/european waterplantain), Catharanthus roseus (madagascar periwinkle), Acorus calamus (sweet calamus), Euphorbia balsamifera (balsam spurge), Jatropha curcas (barbados nut), Origanum majorana (marjoram), Zea mays (corn silk), Capsicum frutescens (chilli) and Urtica dioica (stinging nettle). The results of the present study provide a possible rationale for the traditional use of many herbs as antidiabetics.
Sasa borealis (Poaceae) is a perennial medicinal plant which is a major source of bamboo leaves in Korea. The n-BuOH extract of S. borealis leaves exhibited significant antioxidant activity against the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and a cytoprotective effect against oxidative damage in HepG2 cells. Bioactivity-guided fractionation by column chromatography led to the isolation of two antioxidative flavonoid C-glycoside derivatives, isoorientin (2) and isoorientin 2"-O-alpha-L-rhamnoside (4) along with tricin 7-O-beta-D-glucopyranoside (1) and apigenin 6-C-beta-D-xylopyranosyl-8-C-beta-D-glucopyranoside (3). Their structures were identified on the basis of chemical and spectroscopic methods. The radical scavenging activity and cytoprotective effect against oxidative damage of all the isolated compounds were also evaluated. Isoorientin (2) and isoorientin 2-O-alpha-L-rhamnoside (4) showed potent free radical scavenging activity with IC50 values of 9.5 and 34.5 microM, respectively, and strong cytoprotective effects against t-BOOH-induced oxidative damage in HepG2 cells, at very low concentrations of 1.1 microM isoorientin and 0.8 microM isoorientin 2-O-alpha-L-rhamnoside. This is the first report of the isolation and antioxidant activity of compounds 2 and 4 from S. borealis.
A total of 36 compounds, which comprised 99.4% of the extract, were identified by gas chromatography and mass spectrometry (GC-MS) in the volatile dichloromethane extract obtained from Egyptian corn silk. The main constituents of the volatile extract were cis-alpha-terpineol (24.22%), 6,11-oxidoacor-4-ene (18.06%), citronellol (16.18%), trans-pinocamphone (5.86%), eugenol (4.37%), neo-iso-3-thujanol (2.59%), and cis-sabinene hydrate (2.28%). Dried Egyptian corn silk was also directly extracted with petroleum ether, ethanol, and water. All extracts from solvent extraction and the volatile extract described above exhibited clear antioxidant activities at levels of 50-400 microg/mL in the 2,2-diphenyl-1-picrylhydrazyl (DPPH)/linoleic acid assay. The ethanol extract inhibited DPPH activity by 84% at a level of 400 microg/mL. All samples tested via the beta-carotene bleaching assay also exhibited satisfactory antioxidant activity with clear dose responses. This study indicates that corn silk could be used to produce novel natural antioxidants as well as a flavoring agent in various food products.
Antioxidant fractions from two different citrus species such as Rio Red (Citrus paradise Macf.) and Sour orange (Citrus aurantium L.) were extracted with five different polar solvents using Soxhlet type extractor. The total phenolic content of the extracts was determined by Folin-Ciocalteu method. Ethyl acetate extract of Rio Red and Sour orange was found to contain maximum phenolics. The dried fractions were screened for their antioxidant activity potential using in vitro model systems such as 1,1-diphenyl-2-picryl hydrazyl (DPPH), phosphomolybdenum method and nitroblue tetrazolium (NBT) reduction at different concentrations. The methanol:water (80:20) fraction of Rio Red showed the highest radical scavenging activity 42.5%, 77.8% and 92.1% at 250, 500 and 1000 ppm, respectively, while methanol:water (80:20) fraction of Sour orange showed the lowest radical scavenging activity at all the tested concentrations. All citrus fractions showed good antioxidant capacity by the formation of phosphomolybdenum complex at 200 ppm. In addition, superoxide radical scavenging activity was assayed using non-enzymatic (NADH/phenaxine methosulfate) superoxide generating system. All the extracts showed variable superoxide radical scavenging activity. Moreover, methanol:water (80:20) extract of Rio Red and methanol extract of Sour orange exhibited marked reducing power in potassium ferricyanide reduction method. The data obtained using above in vitro models clearly establish the antioxidant potential of citrus fruit extracts. However, comprehensive studies need to be conducted to ascertain the in vivo bioavailability, safety and efficacy of such extracts in experimental animals. To the best of our knowledge, this is the first report on antioxidant activity of different polar extracts from Rio Red and Sour oranges.
Flavone contents differed in silks of three maize lines with different resistance to larvae of fall amyworm (FAW), Spodoptera frugiperda Smith, and Southwestern corn borer (SWCB), Diatraea grandiosella Dyar. The main compound in the resistant (CML 67) and in the intermediate (CML 135) lines was apimaysin. In the susceptible line (CML 131) the main compound was 3methoxymaysin, which was absent from the other two lines. The same distribution pattern was found in the infested plants. The variation in flavone concentration among the 3 lines and among plants infested with Spodoptera frugiperda and Diatraea grandiosella, suggests a different defense mechanism of the plant against each of the two insects.
Flavonoids, with various biological activities, are considered as key compounds in propolis. In this study, quantitative determinations of flavonoids in propolis were conducted by two complementary colorimetric methods, aluminum chloride method and 2,4-dinitrophenylhydrazine method. Results suggested that the sum of flavonoid contents determined by the above two individual methods may represent the real content of total flavonoids. In this work, six raw propolis samples were investigated and the total contents of flavonoids ranged from 10.38 ± 0.14% to 24.91 ± 0.53%. As for the 12 commercial propolis products examined, the levels of total flavonoids in tinctures were all below 7% and those in powdery products varied from 2.97 ± 0.05% to 22.73 ± 0.72%.
Traditionally corn silk (CS) has been used as diuretic, antilithiasic, uricosuric, and antiseptic. It is used for the treatment of edema as well as for cystitis, gout, kidney stones, nephritis, and prostatitis. In the present study, the antioxidant properties of ethanol-water extract from CS were estimated by different methods. Also phenol and flavonoid content of the extract were measured by Folin Ciocalteu and AlCl3 assays. CS extract contained a significant amount of phenol and flavonoids. The percentage of DPPH radical scavenged by CS extract was 92.6 at a concentration of 1.6 mg ml -1. IC50 of the extract and the standard compounds butylated hydroxytoluene (BHA) and quercetin was 0.59, 0.053, and 0.025 mg ml-1, respectively. Iron chelating activity of the extract was less than the standard compounds. CS extract showed nitric oxide-scavenging effect less than the reference agent (quercetin). The extract showed a high reducing ability. According to ferric thiocyanate (FTC) method, the extract showed more than 88% inhibition of linoleic acid peroxidation. It might be concluded that some of the properties of CS in traditional medicine is due to its antioxidant ability.
Four potato (Solanum tuberosum) varieties – Bengueta, Ganza, Igorota and 125411.22 – were analyzed for total phenolic content and antioxidant activities to provide baseline data for Philippine potato varieties. Bengueta had the highest phenolic content with 50.0±1.5mg gallic acid equivalent (GAE)/100g (dry basis, DB). It also had the highest DPPH radical scavenging activity with an EC50 value of 30.6±3.6mg/mL (DB). The potato variety125411.22 had the highest reducing power with EC50 equal to 66.2±1.6mg/mL (DB), while Igorota had the highest iron-chelating capacity with an EC50 of 11.0±3.2mg/mL (DB) and the best inhibitory action against linoleic acid oxidation at 95.4±2.2% at 50mg/mL sample concentration. Methanolic potato extracts had better antioxidant activity than α-tocopherol and better iron chelating capacity than ethylenediamine tetraacetic acid (EDTA). Significant (*P
The antioxidative activities of hydroalcoholic extract of Achillea santolina were investigated employing various established in vitro systems including total antioxidant activity in linoleic acid emulsion system, 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide and hydroxyl radicals scavenging, reducing power, and inhibitory effect on protein oxidation as well as the inhibition of Fe2+/ascorbate induced lipid peroxidation in rat liver homogenate. Total phenolic and flavonoid content of A. santolina extract (ASE) was also determined by a colorimetric method. The results revealed that ASE has notable inhibitory activity on peroxides formation in linoleic acid emulsion system along with concentration-dependent quenching of DPPH and superoxide radicals. Furthermore, the extract showed both nonsite-specific (Fe2++H2O2+EDTA) and site-specific (Fe2++H2O2) hydroxyl radical scavenging suggesting potent hydroxyl radical scavenging and chelating ability for iron ions in deoxyribose degradation model. A linear correlation between ASE and the reducing power was also observed (r2=0.9981). ASE prevents thiobarbituric acid reactive substances formation in Fe2+/ascorbate induced lipid peroxidation in rat liver tissue in a dose-dependent manner. Moreover, free radical induced protein oxidation was suppressed significantly by the addition of ASE over a range of concentration. These results clearly demonstrated that A. santolina extract possess a marked antioxidant activity.
This work evaluated the modulation of reactive oxygen species (ROS) produced by the cisplatin–human DNA interaction in a cell-free experimental model by the carotenoids bixin and lycopene, extracted from natural dietary sources and purified through luminol- and Cypridina luciferin methoxy-analogue (MCLA)-enhanced chemiluminescence assays. The results showed that the ROS generation by DNA–cisplatin interaction was inhibited by both lycopene and bixin in a concentration-dependent manner. At a concentration of 100μM, lycopene and bixin inhibited superoxide anion (O2-) generation at 90% and 82%, respectively, and the total ROS generation at 44% and 42%, respectively. The formation of significant amounts of isomers or degradation products of both carotenoids was not observed after ROS scavenging, as evaluated by high-performance liquid chromatography. Taken together, these results suggest that carotenoids can be helpful to modulate the oxidative stress found in cancer therapy with cisplatin.
A new cyclohexenone (1) and a new caffeoyl ester derivative (2), together with the known compounds (-)-isolariciresinol 3-alpha -O-beta -D-glucopyranoside (3), (+)-1-hydroxypinoresinol 1-O-beta -D-glucopyranoside (4), isoacteoside (5), luteolin 4'-O-beta -D-glucopyranoside (6), and indole-3-carboxylic acid (7), were isolated from the leaves of Bauhinia tarapotensis. The structures of these new compounds were determined by spectroscopic data analysis. The antioxidant activities of 1-7 were determined by measuring their free radical scavenging effects, using the 1,1-diphenyl-2-dipicrylhydrazyl free radical (DPPH) and Trolox equivalent antioxidant activity (TEAC) methods, and the coupled oxidation of beta -carotene and linoleic acid. Compounds 3-5 showed good activities in the DPPH and TEAC tests, while compounds 1 and 2 were active in the coupled oxidation of beta -carotene and linoleic acid bioassay.
This article has been retracted at the request of the editors and authors. Please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).Reason: This paper appears to be very similar to another paper by the same authors which was published about the same time: “Tissue Culture of Some Lichens and Screening of Their Antioxidant, Antityrosinase and Antibacterial Properties”, B.C. Behera, Neeraj Verma, Anjali Sonone and Urmila Makhija, Phytother. Res., 21 (2007) 1159–1170.The similarity is too great to justify two primary publications.
The antioxidant activity of extracts from bark and heartwood of Acacia confusa was evaluated by various antioxidant assays, including free radical and superoxide radical scavenging assays and lipid peroxidation assay as well as hydroxyl radical-induced DNA strand scission assay. In addition, an ex vivo antioxidant assay using a flow cytometric technique was also employed in this study. The results indicate that both bark and heartwood extracts clearly have strong antioxidant effects. Similar inhibitory activities for each test sample were found for both 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical generation and lipid peroxidation. As for the superoxide radical scavenging activity, the heartwood extract was more effective than the bark extract. Furthermore, the heartwood extract protected ΦX174 supercoiled DNA against strand scission induced by ultraviolet photolysis of H2O2, and it reduced the amounts of intracellular hydrogen peroxide, a reactive oxygen species, when it was co-incubated with human promyelocytic leukemia (HL-60) cells under oxidative stress. Keywords: Acacia confusa; antioxidant activity; lipid peroxidation; reactive oxygen species; flow cytometry
Reduced derivatives of maysin [2 ''-O-alpha-L-rhamnosyl-6-C-(6-deoxy-xylo-hexos-4-ulosyl)luteolin] and 3'-methoxymaysin have been isolated and identified from several corn (Zea mays L.) inbreds. These include 2 ''-O-alpha-L-rhamnasyl-6-C-quinovosylluteolin (equatorial 4 ''-OH-maysin, eq-4 ''-OH-maysin), 2 ''-O-alpha-L-rhamnosyl-6-C-fucosylluteolin (axial 4 ''-OH-maysin, ax-4 ''-OH-maysin), and 2 ''-O-alpha-L-rhamnosyl-6-C-fucosyl-3'-methoxyluteolin (ax-4 ''-OH-3'-methoxymaysin). In addition to maysin and 3'-methoxymaysin, inbred Tx501 contains minor amounts of ax-4 ''-OH-maysin and ax-4 ''-OH-3'methoxymaysin. Corn Lines A103, GE275, ESDJ1, and CML131 contained relatively large levels of both ax-4 ''-OH-maysin and eq-4 ''-OH-maysin. Synthetic 4 ''-OH-maysin (obtained by NaBH4 reduction of maysin) was tested for growth inhibition of corn earworm (Helicoverpa tea Boddie) larvae in a laboratory bioassay and found to be almost as active as maysin, suggesting that incorporation by breeders of these compounds into silks could enhance the resistance of corn to corn earworm larvae.
This study evaluated the antioxidative activities of 50% ethanolic extract from red bean (Phaseolus radiatus L. var. Aurea). The antioxidative activities, including α,α-diphenyl-β-picryl-hydrazyl (DPPH) radicals scavenging effects, Fe2+-chelating ability, and reducing power, were studied in vitro. The antioxidative activity was found to increase with the concentration of the extract to a certain extent and then level off as the concentration further increased. Compared with commercial antioxidants, the red bean extract showed less scavenging effect on the DPPH radical and less reducing power than α-Tocopherol and BHT, but better Fe2+-chelating ability. No mutagenic effect toward any tester strains was found in the 50% ethanolic extract of red bean.
The growing interest in the substitution of synthetic food antioxidants by natural ones has fostered research on vegetable sources and the screening of raw materials for identifying new antioxidants. Oxidation reactions are not an exclusive concern for the food industry, and antioxidants are widely needed to prevent deterioration of other oxidisable goods, such as cosmetics, pharmaceuticals and plastics. Polyphenols are the major plant compounds with antioxidant activity, although they are not the only ones. In addition, other biological properties such as anticarcinogenicity, antimutagenicity, antiallergenicity and antiaging activity have been reported for natural and synthetic antioxidants. Special attention is focussed on their extraction from inexpensive or residual sources from agricultural industries. The aim of this review, after presenting general aspects about natural antioxidants, is to focus on the extraction of antioxidant compounds (mainly polyphenols) from agricultural and industrial wastes, as well as to summarize available data on the factors affecting their antioxidant activity and stability, and, in some cases, the reported major active compounds identified.
The antioxidant activities of different polarity solvents extracts from barley were evaluated by various antioxidant assays, including reducing power, free radical scavenging and lipid oxidation inhibition. Those various antioxidant activities were compared to standard antioxidants, butylated hydroxyluene (BHT) and ascorbic acid (Vit. C). The properties of the extracting solvents significantly affected the total phenolics, proanthocyanidins and antioxidant activities of barley extract. The highest contents of total phenolics and proanthocyanidins were obtained from extraction with 70% acetone. For three different solvent extracts, the antioxidant activities were in this order: 70% acetone extract > 70% ethanol extract ⩾ 70% methanol extract. Reducing powers of three extracts and their scavenging effects on 2, 2-diphenyl-1-picrylhydrazyl radicals were effective at amount of 200 μg. The 70% acetone extract of barley exhibited high antioxidant activity in linoleic acid system, which was not significantly (P < 0.05) different from BHT during the incubation time.
Activity-directed fractionation and purification processes were employed to identify the anti-Alzheimer active compounds from the root of Angelica sinensis. In this study, the ability of Angelica root to inhibit the aggregated amyloid β-peptide (agg Aβ1-40) induced damage of differentiated PC-12 cells (dPC-12), a well-known cell model for Alzheimer disease, was investigated. Air-dried roots of A. sinensis were extracted with methanol and then separated into ethyl acetate, n-butanol and water layers. Among them, only the ethyl acetate layer showed strong activity and therefore, subjected to separation and purification using various chromatographic techniques. Four compounds showing potent activity were identified by comparing spectral data (UV, NMR, and ESI-MS) with literature values to be Z-ligustilide, 11-angeloylsenkyunolide F, coniferyl ferulate and ferulic acid. They were found to significantly inhibit Aβ1-40 toxicity on dPC-12 cells at lower concentrations (1–10 μg/ml), but at high concentrations (>50 μg/ml) they were toxic to the dPC-12 cells, except 11-angeloylsenkyunolide F. DPPH scavenging activity of the extracts and isolated compounds have also been carried out to find the possible mechanism of the activity.
Yams (the tubers of the Dioscorea spp.), consumed and regarded as medicinal food in traditional Chinese herbal medicine, are seasonal foods and easily deteriorate during storage. It is of great importance to prolong the storage of yams for supplying in the off-season and without losing nutritional functionality. Three varieties of yams, Dioscorea alata (cultivars of Tai-Nung no. 2 and Ta-Shan) and D. purpurea (cultivar of Ming-Chien), were made into flours by freeze-drying, hot air-drying, and drum-drying in this report. The proximate compositions and physical properties, as well as antioxidant activities, of yam flours were determined. While drying methods showed significant effects on the moisture contents of yam flours, they had no marked effects on other components of yam flours. Colour attributes and physical properties were all affected by drying methods to different extents. While freeze-drying usually preserved more antioxidant activity of the yam flours, yam flours made of different yam varieties showed different antioxidant mechanisms.
There has been growing interest in the beneficial health effects of consuming fruits and vegetables. Mainly, the presence of phenolic antioxidants is believed to have the protective mechanisms. In the present study the fruit of Dillenia indica was extracted with ethyl acetate, methanol and water. The total phenolic content of the extracts was determined by Folin–Ciocalteu method and antioxidant activity of the extracts was assayed through some in vitro models such as antioxidant capacity by phosphomolybdenum method, β-carotene-linoleate model system, and radical scavenging activity using α,α-diphenyl-β-picrylhydrazyl (DPPH) method. The total phenolic contents of the fruit extracts as tannic acid equivalents were found to be highest in methanol extract (34.1%) followed by ethyl acetate extract (9.3%) and water extract (1.4%). Antioxidant capacity of the extracts as equivalent to ascorbic acid (μmole/g of the extract) was in the order of methanol extract > ethyl acetate extract > water extract. In comparison with butylated hydroxyanisole (BHA), at 100 ppm of concentration, the antioxidant and free radical scavenging activities of the extracts assayed through β-carotene-linoleate model system, and DPPH method were also found to be highest with methanol extract followed by ethyl acetate and water extracts. The results indicated that the extent of antioxidant activity of the extract is in accordance with the amount of phenolics present in that extract and the fruit of D. indica is rich in phenolics may provide a good source of antioxidant.
The relative antioxidant activities, against radicals generated in the aqueous phase, of a range of plant-derived polyphenolic flavonoids, constituents of fruit, vegetables, tea and wine, have been assessed. The results show that compounds such as quercetin and cyanidin, with 3',4' dihydroxy substituents in the B ring and conjugation between the A and B rings, have antioxidant potentials four times that of Trolox, the vitamin E analogue. Removing the ortho-dihydroxy substitution, as in kaempferol, or the potential for electron delocalisation by reducing the 2,3 double bond in the C ring, as in catechin and epicatechin, decreases the antioxidant activity by more than 50%, but these structures are still more effective than alpha-tocopherol or ascorbate. The relative significance of the positions and extents of hydroxylation of the A and B rings to the total antioxidant activity of these plant polyphenolics is demonstrated.
The recent explosion of interest in the bioactivity of the flavonoids of higher plants is due, at least in part, to the potential health benefits of these polyphenolic components of major dietary constituents. This review article discusses the biological properties of the flavonoids and focuses on the relationship between their antioxidant activity, as hydrogen donating free radical scavengers, and their chemical structures. This culminates in a proposed hierarchy of antioxidant activity in the aqueous phase. The cumulative findings concerning structure-antioxidant activity relationships in the lipophilic phase derive from studies on fatty acids, liposomes, and low-density lipoproteins; the factors underlying the influence of the different classes of polyphenols in enhancing their resistance to oxidation are discussed and support the contention that the partition coefficients of the flavonoids as well as their rates of reaction with the relevant radicals define the antioxidant activities in the lipophilic phase.
Treatment of human endothelial cells with cytokines such as tumour necrosis factor-alpha (TNF) or E. coli lipopolysaccharide (LPS) induces the expression of several adhesion molecules and enhances leukocyte adhesion to endothelial cell surface. Interfering with this leukocyte adhesion or adhesion molecules upregulation is an important therapeutic target for the treatment of bacterial sepsis and various inflammatory diseases. In the course of screening marketed European anti-inflammatory herbal drugs for TNF antagonistic activity, a crude ethanolic extract of corn silk (stigma of Zea mays) exhibited significant activity. The extract at concentrations of 9-250 micrograms/ml effectively inhibited the TNF- and LPS-induced adhesiveness of EAhy 926 endothelial cells to monocytic U937 cells. Similar concentration ranges of corn silk extract did also block the TNF and LPS but not the phorbol 12-myristate 13-acetate-induced ICAM-1 expression on EAhy 926 endothelial cell surface. The extract did not alter the production of TNF by LPS-activated macrophages and failed to inhibit the cytotoxic activity of TNF. It is concluded that corn silk possesses important therapeutic potential for TNF- and LPS-mediated leukocyte adhesion and trafficking.
The antioxidative activity of a total of 92 phenolic extracts from edible and nonedible plant materials (berries, fruits, vegetables, herbs, cereals, tree materials, plant sprouts, and seeds) was examined by autoxidation of methyl linoleate. The content of total phenolics in the extracts was determined spectrometrically according to the Folin-Ciocalteu procedure and calculated as gallic acid equivalents (GAE). Among edible plant materials, remarkable high antioxidant activity and high total phenolic content (GAE > 20 mg/g) were found in berries, especially aronia and crowberry. Apple extracts (two varieties) showed also strong antioxidant activity even though the total phenolic contents were low (GAE < 12.1 mg/g). Among nonedible plant materials, high activities were found in tree materials, especially in willow bark, spruce needles, pine bark and cork, and birch phloem, and in some medicinal plants including heather, bog-rosemary, willow herb, and meadowsweet. In addition, potato peel and beetroot peel extracts showed strong antioxidant effects. To utilize these significant sources of natural antioxidants, further characterization of the phenolic composition is needed.
Flavonoids are phenolic substances isolated from a wide range of vascular plants, with over 8000 individual compounds known. They act in plants as antioxidants, antimicrobials, photoreceptors, visual attractors, feeding repellants, and for light screening. Many studies have suggested that flavonoids exhibit biological activities, including antiallergenic, antiviral, antiinflammatory, and vasodilating actions. However, most interest has been devoted to the antioxidant activity of flavonoids, which is due to their ability to reduce free radical formation and to scavenge free radicals. The capacity of flavonoids to act as antioxidants in vitro has been the subject of several studies in the past years, and important structure-activity relationships of the antioxidant activity have been established. The antioxidant efficacy of flavonoids in vivo is less documented, presumably because of the limited knowledge on their uptake in humans. Most ingested flavonoids are extensively degraded to various phenolic acids, some of which still possess a radical-scavenging ability. Both the absorbed flavonoids and their metabolites may display an in vivo antioxidant activity, which is evidenced experimentally by the increase of the plasma antioxidant status, the sparing effect on vitamin E of erythrocyte membranes and low-density lipoproteins, and the preservation of erythrocyte membrane polyunsaturated fatty acids. This review presents the current knowledge on structural aspects and in vitro antioxidant capacity of most common flavonoids as well as in vivo antioxidant activity and effects on endogenous antioxidants.
Antioxidative effects of Maydis stigma methanolic extracts were studied on the level of lipid peroxidation in liposomes, induced by Fe(2+)/ascorbate system and measured spectrophotometrically by the TBA-test. The most significant inhibition of lipid peroxidation was observed when methanolic extracts of fully developed, mature corn silk were applied. The same test, performed after fractionation of the most active extract, showed that most of the activity was concentrated in fractions with moderate lipophilicity, containing phenolic acids, flavonoid aglyca and resembling monosides.
Diuretic and uricosuric properties have traditionally been attributed to corn silk, stigma/style of Zea mays L. Although the diuretic effect was confirmed, studies of the plant's effects on renal function or solute excretion were lacking. Thus, we studied the effects of corn silk aqueous extract on the urinary excretion of water, Na+, K+, and uric acid. Glomerular and proximal tubular function and Na+ tubular handling were also studied. Conscious, unrestrained adult male rats were housed in individual metabolic cages (IMC) with continuous urine collection for 5 and 3 h, following two protocols. The effects of 25, 50, 200, 350, and 500 mg/kg body wt. corn silk extract on urine volume plus Na+ and K+ excretions were studied in water-loaded conscious rats (2.5 ml/100 g body wt.) in the IMC for 5 h (Protocol 1). Kaliuresis was observed with doses of 350 (100.42 +/- 22.32-120.28 +/- 19.70 microEq/5 h/100 g body wt.; n = 13) and 500 mg/kg body wt. (94.97+/- 29.30-134.32 +/- 39.98 microEq/5h/100 g body wt.; n = 12; p<0.01), and the latter dose resulted in diuresis as well (1.98 +/- 0.44-2.41 +/- 0.41 ml/5 h/100 g body wt.; n = 12; p<0.05). The effects of a 500 mg/kg body wt. dose of corn silk extract on urine volume, Na+, K+ and uric acid excretions, and glomerular and proximal tubular function, were measured respectively by creatinine (Cler) and Li+ (ClLi) clearances and Na+ tubular handling, in water-loaded rats (5 ml/100 g body wt.) in the IMC for 3 h (Protocol 2). Clcr (294.6 +/- 73.2, n = 12, to 241.7 +/- 48.0 microl/ min/100 g body wt.; n = 13; p<0.05) and the Na+ filtered load (41.9 +/- 10.3, n = 12, to 34.3 +/- .8, n = 13, p<0.05) decreased and ClLi and Na+ excretion were unchanged, while K+ excretion (0.1044 +/- 0.0458, n=12, to 0.2289 +/- 0.0583 microEq/min/100 body wt.; n = 13; p<0.001) increased. For Na+ tubular handling, the fractional proximal tubular reabsorption (91.5 +/- 3.5, n = 12, to 87.5 +/- 3.4%; n = 13; p<0.01) decreased, and both fractional distal reabsorptions--I and II--increased (96.5 +/- 1.5, n = 12, to 97.8 +/- 0.9%; n = 13; p<0.01; and 8.2 +/- 3.5, n = 12, to 12.2 +/- 3.4%, n = 13, p<0.01, respectively). To summarize, in water-loaded conscious rats (2.5 ml/100 body wt.), corn silk aqueous extract is diuretic at a dose of 500 mg/kg body wt. and kaliuretic at doses of 350 and 500 mg/kg body wt. In water-loaded conscious rats (5.0 ml/100 g body wt.), corn silk aqueous extract is kaliuretic at a dose of 500 mg/kg body wt., but glomerular filtration and filtered load decrease without affecting proximal tubular function, Na+, or uric acid excretion.
Flavonoids and other polyphenolic compounds have powerful antioxidant effects in vitro in many test systems, but can act as pro-oxidants in some others. Whether pro-oxidant, antioxidant, or any of the many other biological effects potentially exerted by flavonoids account for or contribute to the health benefits of diets rich in plant-derived foods and beverages is uncertain. Phenolic compounds may help to protect the gastrointestinal tract against damage by reactive species present in foods or generated within the stomach and intestines. The overall health benefit of flavonoids is uncertain, and consumption of large quantities of them in fortified foods or supplements should not yet be encouraged.
Cinnamomum osmophloeum Kaneh. is an indigenous tree species in Taiwan. In this study, phytochemical characteristics and antioxidant activities of ethanolic extracts from the twigs of C. osmophloeum were investigated for the first time. The extracts were obtained successively using liquid-liquid partition to yield n-hexane (Hex), ethyl acetate (EtOAc), n-butanol (BuOH) and water fractions. The antioxidant activities of C. osmophloeum twig extracts were examined using various antioxidant assays, such as DPPH, NBT, reducing power, lipid peroxidation using mouse brain homogenates, metal chelating ability, and photochemiluminescence (PCL). In addition, total phenolic contents were also determined. Results revealed that the BuOH fraction exhibited the best performance in DPPH assay, NBT assay, reducing power assay and lipid peroxidation using mouse brain homogenates assay. Furthermore, the BuOH fraction has the highest total phenolic contents (496.7 mg of GAE/g). Consequently, kaempferol-7-O-rhamnoside was also isolated from the antioxidative BuOH fraction and its activity was also confirmed. These results demonstrated that ethanolic extracts of C. osmophloeum twigs have excellent antioxidant activities and thus it has great potential as a source for natural health products.
The three flavones were isolated from water extracts of corn silk by chromatography on macroporous resin, polyamide, ODS and Sephadex LH-20. Three compounds were identified as formononetin (7-hydroxy-4'-methoxyi