Free radical scavenging activity and immunomodulatory effect of Stachytarpheta angustifolia leaf extract

Phytochemical-Based Evidence of the Health Benefits of Bidens Pilosa Extracts and Cytotoxicity

Purpose

Bidens pilosa L. is traditionally used as a flavouring agent in foods, in the treatment of diseases, in agriculture as a biopesticide and herbicide, and in the phytoremediation of soils contaminated with heavy metals. The vast range of uses of B. pilosa for a variety of purposes is questionable, hence motivating the objectives of this study, which are to assess the cytotoxicity, health benefits, and/or risks of B. pilosa using chemical-based evidence.

Methods

A real-time cell analysis (xCELLigence system), ultra-high-performance liquid chromatography coupled to a quadrupole-time-of-flight mass spectrometer, high-performance liquid chromatography with a diode array detector, and chemical-based spectrophotometric methods were adopted in the study.

Results

High concentrations of the ethanol extracts exhibited cytotoxic activity on HepG2 (cancerous), and Vero (non-cancerous) cell lines, whereas the water extracts promoted cell proliferation at selected concentrations. The chemical profiling enabled the separation as well as characterisation of 137 phytochemicals. These were mainly phenolic acids, flavonoids, fatty acids, coumarins, and furanocoumarins. There was no toxic compound identified.

Conclusion

The ethanol extracts are generally more potent and exhibit stronger antioxidant activity and cytotoxicity, probably due to the presence of more flavonoids and phenolic acids, validating the uses of B. pilosa and its relevance as a source of functional phytochemicals.

Mutual Pan-African support paradigm to produce scientific evidence of traditional medical practices for use against COVID-19 and emerging pandemics

Africa is endowed with a profoundly rich and diverse system of plants and other bio-resources out of which, by traditional medicine practice, the people have satisfied their healthcare needs right from antiquity. In contemporary times, it has become necessary to modernize this traditional medical care system via scientific studies. Validation of the efficacy of health-enhancement products and drugs from plants and other bio-resources is predicated on diligent and intensive research accompanied by rigorous and conclusive clinical trials. Africa has eminently qualified human resources but due to the finance-intensive nature of medical research, individual African states on their own cannot fund the level of research desired for dealing with such serious issues as the COVID-19 pandemic. A collaboration among African states guided by a Mutual Pan-African support paradigm (MPASP) is a unique strategy for achieving success in any such a high-impact global project as the use of traditional medicine against COVID-19 and emerging pandemics; and this is hereby advocated.

Antioxidant-rich fraction of Amomum subulatum fruits mitigates experimental methotrexate-induced oxidative stress by regulating TNF-α, IL-1β, and IL-6 proinflammatory cytokines

The culinary spice Amomum subulatum was assessed for its phytochemical composition, in vitro antioxidant potential, and in vivo ameliorating effect against methotrexate (MTX)-induced toxicities. Phytochemical analysis of methanolic extract of A. subulatum dry fruits (MEAS) confirmed the presence of different bioactive secondary metabolites. MEAS scavenged reactive free radicals and inhibited lipid peroxidation in vitro. To confirm the antioxidant efficiency of MEAS, in vivo experiment was carried out in which MTX was administered to induce oxidative stress. Co-administration of MEAS reduced MTX-induced hepatic, renal, and pulmonary toxicities via significantly (p < .01) enhancing antioxidant status and reducing oxidative stress. MTX treatment significantly (p < .01) increased liver and kidney toxicity markers and increased proinflammatory cytokine (TNF-α, IL-1β, and IL-6) levels. However, co-administration of MEAS significantly (p < .01) reduced their levels, and tissue histopathology confirmed the protective effect of MEAS in maintaining normal tissue architecture following MTX treatment. Protective effect of MEAS is accredited to the antioxidant and anti-inflammatory properties exhibited by bioactive compounds in MEAS. PRACTICAL APPLICATIONS: Amomum subulatum (Black cardamom) is a folkloric and culinary spice used for its organoleptic, nutritional, and medicinal properties. This study demonstrated the phytochemical composition and antioxidant potential of methanolic extract of A. subulatum dry fruits (MEAS). Toxicities associated with MTX therapy limit its clinical application. MEAS attenuated methotrexate-induced oxidative stress, inflammation, and associated organ damages, suggesting the possible therapeutic application of A. subulatum in reducing oxidative stress and associated diseases. Our results showed that A. subulatum is a potential functional food, which may be used for the betterment of health due to its richness in antioxidant and anti-inflammatory phytochemicals.

Antimalarial, Antioxidant, and Toxicological Evaluation of Extracts of Celtis africana, Grosseria vignei, Physalis micrantha, and Stachytarpheta angustifolia

In many parts of the world, malaria undoubtedly poses a serious threat to health care systems. Malaria treatment has increasingly become complicated, primarily due to the emergence of widespread resistance of the malaria parasites to cheap and affordable malaria therapeutics. The use of herbal remedies to treat various ailments, including malaria and malaria-like ailments in Ghana is common. We herein report on the antiplasmodial and antioxidant activities as well as toxicological evaluation of four medicinal plants (Celtis africana, Grosseria vignei, Physalis micrantha, and Stachytarpheta angustifolia) commonly used to treat malaria in Ghana. Following Soxhlet extraction of plant samples in ethanol, extracts were screened against Plasmodium falciparum (3D7 strain) in an in vitro antiplasmodial assay. The phosphomolybdenum and DPPH (1, 1-diphenyl-2 picrylhydrazyl) assays were used to evaluate antioxidant activities while toxicity assessment was carried out in mice using the acute toxicity test and kidney and liver function tests. Extracts from Celtis africana and Physalis micrantha were very active towards the parasites with half-maximal inhibitory concentrations (IC50's) of 29.1 and 3.5 µg/mL, respectively. Extracts of Grosseria vignei and Stachytarpheta angustifolia were inactive, having IC50 values greater than 50 µg/mL. All extracts exhibited excellent total antioxidant capacities (>800 mg/g AAE) and good DPPH radical scavenging potential (IC50 range of 300-900 µg/mL). The median lethal dose (LD50) of all extracts in the toxicological evaluation was greater than 2000 mg/kg and there was no effect of extracts on the levels and activities of key biomarkers of liver and kidney function. The activities of these plants obtained in this study partly give credence to their folkloric use in herbal medicines and suggest that they could provide promising lead compounds for malaria drug discovery programs.

Chemical profile of Stachytarpheta schottiana by LC-HRMS/MS dereplication and molecular networking

Abstract Restingas are extreme environments present in the Atlantic Rainforest biome. These ecosystems show peculiar characteristics, like sandy soil, high salinity, and high solar exposure, which brings scientific interest to their native species. Stachytarpheta schottiana is an endemic Brazilian species found in Jurubatiba Restinga, and just like other species of the genus Stachytarpheta, is used in folk medicine. In this paper, we describe, for the first time, 28 secondary metabolites from S. schottiana polar extract, among them iridoids, flavonoids, lignans and phenylethanoids, with the use of LC-HRMS/MS dereplication and molecular networking methodologies. Many of these compounds have not been described yet for the genus Stachytarpheta, like astragalin, taxifolin, lamiide and the lignans secondary metabolites class. Also, in this paper, High Speed Counter-Current Chromatography (HSCCC) isolation and Nuclear Magnetic Resonance (NMR) of two compounds were used to correct a misidentification in the dereplication procedure and to create seeds for molecular networking. Some of the suggested known compounds found in this work have had their biological activities described in the literature, such as the hepatoprotective activity of verbascoside, that matches those already related for the genus Stachytarpheta and for the folk use of Stachytarpheta schottiana itself.

Evaluation of the antigenotoxic and antioxidant activity induced by Croton antisyphiliticus

This study aimed to investigate antigenotoxicity and antioxidant potential of extract, fractions and vitexin from C. antisyphiliticus. Methanolic extract was fractionated through solvents of increasing polarity. The composition of extracts and fractions were evaluated through phytochemical screening. Micronucleus test was performed in mice to evaluate the antigenotoxicity. Antioxidant activity was measured using the assay 1,1-diphenyl-2-picrylhydrazyl (DPPH), iron ion chelating, thiobarbituric acid assay and nitric oxide scavenging. Treatment with extract, fractions and vitexin did not produce an increase in Micronucleus mean values. However, Micronucleus (MN) mean values decreased in relation to control. methanolic extract presented antioxidant potential for DPPH (81%), iron ion chelating (77.8%), Thiobarbituric Acid (TBARS) (32.49%) and Nitric Oxide (NO) (80.97%). Ethyl acetate fraction showed the highest antioxidant activity (65.46%). The vitexin showed a Inhibitory Concentration (IC50) of DPPH value smaller in relation to control. Vitexin flavonoid was detected by High Performance Liquid Chromatography (HPLC), infrared spectrometry and nuclear magnetic resonance. It can be inferred that methanolic extract, fraction ethyl acetate and vitexin isolated from C. antisyphiliticus is endowed with antigenotoxic and antioxidant potential.

In vitro antioxidants and hepatoprotective effects of Pleurotus tuber-regium on carbon tetrachloride-treated rats

Objectives This study has characterized the phytoconstituents and evaluated the in vitro antioxidant and hepatoprotective effects of Pleurotus tuber-regium induced by carbon tetrachloride (CCl4). In vitro antioxidant assay of ethanol extract of P. tuber-regium and gas chromatography-mass spectrometry analyses to identify the phytoconstituents were carried out. Methods Sixty rats were divided into six groups of 10 animals in each group and treated as follows for 13 weeks. Group I (control) received 3 mL/kg olive oil intraperitoneal twice weekly in addition to feed and water ad libitum. Group II received CCl4 3 mL/kg twice weekly. Groups III, IV and V received 100, 200 and 500 mg/kg wild edible P. tuber-regium mixed with feed by ingestion daily in addition to 3 mL/kg CCl4 twice weekly, respectively. Group VI received 500 mg P. tuber-regium daily. Liver and body weights were recorded. Liver function tests, oxidative stress biomarkers, bilirubin, ascorbic acid and α-tocopherol were assayed. Histopathology of the liver was carried out. The gas chromatography-mass spectroscopy analysis yielded 10 antioxidants. Results CCl4 increased the levels of alanine transaminase, aspartate transaminase, alkaline phosphatase, bilirubin and malondialdehyde from 24±1.778 iu/L, 53±3.7 iu/L, 257±19 iu/L, 0.45±0.03 mg/dL and 1.90±0.42 μmol/L in the control group to 48±2.5 iu/L, 81±2.10 iu/L, 495±38 iu/L, 1.20±0.09 mg/dL and 14.0±2.6 μmol/L in the treated group, respectively. Conclusions P. tuber-regium prevented the necrosis, edema and vein congestion observed in the CCl4-only group. P. tuber-regium is effective in protecting the liver against CCl4-induced damage.

Antioxidant activities of Clerodendrum cyrtophyllum Turcz leaf extracts and their major components

This study was designed to investigate the antioxidant properties of the extracts and subfractions of various polarities from Clerodendrum cyrtophyllum Turcz leaves and the related phenolic compound profiles. The ethyl acetate fraction (EAF) showed the most potent radical-scavenging activity for DPPH radicals, ABTS radicals, and superoxide anion (O2·-) radicals as well as the highest reducing power of the fractions tested; the n-butyl alcohol fraction (BAF) was the most effective in scavenging hydroxyl radical (OH·), and the dichloromethane fraction (DMF) exhibited the highest ferrous ion chelating activity. Twelve phenolic components were identified from the EAF of C. cyrtophyllum. Additionally, acteoside (1) was found to be a major component (0.803 g, 0.54%) and show DPPH and ABTS radical scavenging activities with IC50 values of 79.65±3.4 and 23.00±1.5 μg/ml, indicating it is principally responsible for the significant total antioxidant effect of C. cyrtophyllum. Our work offers a theoretical basis for further utilization of C. cyrtophyllum as a potential source of natural, green antioxidants derived from plants.

Fruit Extract of Pithecellobium dulce (FPD) ameliorates carrageenan-induced acute inflammatory responses via regulating pro-inflammatory mediators

Unravelling the precise mechanisms underlying the anti-inflammatory action of fruit extract of Pithecellobium dulce (FPD) is quite complex. Hence the prime approach of this particular study is to unveil intriguing insights to its possible anti-inflammatory mechanisms. Anti-inflammatory effects of FPD were determined against experimentally induced acute and chronic inflammation in mice paw edema models. Administration of FPD significantly reduced the acute and chronic inflammation via regulating pro-inflammatory mediators such as pro-inflammatory cytokines (TNF-α, IL-6, and IL-1ß), Cycloxygenase 2 (COX-2), and inducible nitric oxide synthase (iNOS) compared to control group. The overall results suggest that FPD mitigates inflammation by regulating the inflammatory mediators. PRACTICAL APPLICATIONS: Fruit of Pithecellobium dulce is comestible and has been widely distributed in Asian pacific region. Non-steroidal anti-inflammatory drugs (NSAIDS) are among the most conventional treatment strategy against pain and inflammation. Although, chronic use of NSAIDS are associated with severe side effects such as gastrointestinal irritation, hepatic injury, excessive bleeding, and cardiovascular disorders. Hence identification of more effective complementary and alternative therapeutic approach from natural resources with fewer side effects could improve the quality of life of those receiving NSAIDS. Administration of fruit extract of Pithecellobium dulce ameliorates carrageenan-induced acute inflammatory responses, as evidenced by paw edema measurement, expression of antioxidant enzymes such as glutathionine, super oxide dismutase, pro-inflammatory cytokine analysis (IL-1β, IL-6, and TNF-α), vascular permeability measurement, expression of COX-2 and iNOS. Further, confirmed the involvement of HO-1 pathway in anti-inflammatory action of FPD. The outcome of this present investigation could have a broad range of applications in alleviating inflammatory disorders.

Vicilin-A major storage protein of mungbean exhibits antioxidative potential, antiproliferative effects and ACE inhibitory activity

Enzymatic hydrolysates of different food proteins demonstrate health benefits. Search for diet related food protein hydrolysates is therefore of interest within the scope of functional foods. Mungbean is one of the popular foods in India because of rich protein source. In this study, mungbean vicilin protein (MBVP) was enzymatically hydrolysed by alcalase and trypsin under optimal conditions. We have studied the antioxidant, antiproliferative and angiotensin-converting enzyme (ACE) inhibitory activities of mungbean vicilin protein hydrolysate (MBVPH) vis-a-vis alcalase-generated mungbean vicilin protein hydrolysate (AMBVPH) and trypsin-generated mungbean vicilin protein hydrolysate (TMBVPH). The results showed that MBVPH exhibited higher antioxidant potential, ACE inhibitory and antiproliferative activities than MBVP. The alcalase treated hydrolysate displayed highest ACE inhibitory activity with IC50 value of 0.32 mg protein/ml. The MBVP showed significant antiproliferative activity against both MCF-7 and MDA-MB-231 breast cancer cells at the doses between 0.2-1.0 mg/ml. The data suggested that MBVPH can be utilized as physiologically active functional foods with sufficient antihypertensive activity. The results indicate that mungbean can be utilized as a rich resource of functional foods.

The gastro protective effects of Cibotium barometz hair on ethanol-induced gastric ulcer in Sprague-Dawley rats

BACKGROUND

Cibotium barometz is a medical herb used traditionally in the Malaysian peninsula for several ailments, including gastric ulcer. The aim of this study was assessment the anti-ulcer effects of C. barometz hair on ethanol-induced stomach hemorrhagic abrasions in animals. Seven groups of Sprague Dawley (SD) rats were administered 10% Tween 20 in the normal control and ulcer control groups, and omeprazole 20 mg/kg and 62.5, 125, 250, and 500 mg/kg of C. barometz hair extract in the experimental groups. After 60 min, the normal control group of rats was orally administered 10% Tween 20, while absolute ethanol was orally administered to the groups of ulcer control, omeprazole and experimental groups. Stomachs of the rats were examined macroscopically and histologically. Homogenates of stomachs were used to evaluate endogenous antioxidant enzyme activities.

RESULTS

Rats pre-fed with plant extract presented a significant decrease in the sore area, increased pH of gastric contents and preserved stomach wall mucus compared to the ulcer group. Histologically, rats pre-fed with C. barometz hair extract showed mild to moderate disruptions of the surface epithelium while animals pre-fed with absolute ethanol showed severe disruptions of the stomach epithelium with edema and leucocyte penetration of the submucosal layer. A Periodic acid Schiff (PAS) staining revealed that each rat pre-treated with the plant extract displayed an intense uptake of stomach epithelial glycoprotein magenta color compared to the ulcer control group. Immunohistochemical analysis revealed that rats pre-fed with the plant extract showed an up-regulation of the heat shock protein 70 (HSP70) and down-regulation of Bax proteins compared to ulcer control rats. Homogenates of the stomach tissue demonstrated significant increases in the endogenous antioxidant enzymatic activity and decreased lipid peroxidation (MDA) in rats pre-treated with C. barometz hair extract compared with the ulcer control rats. In acute toxicity, the liver and kidney revealed no hepatotoxic or nephrotoxic effects histologically.

CONCLUSIONS

The gastric cytoprotective action of C. barometz hair extract might be attributed to antioxidants, an increase in gastric pH, stomach mucus preservation, increased endogenous antioxidant enzymes, decreased lipid peroxidation, up-regulation of HSP70 and down-regulation of Bax proteins.

Phytochemical Evaluation of Moth Bean (Vigna aconitifolia L.) Seeds and Their Divergence

In the present study, phytochemical contents of 25 moth bean (Vigna aconitifolia) seed accessions were evaluated. This includes protease inhibitors, phytic acid, radical scavenging activity, and tannins. The studies revealed significant variation in the contents of theses phytochemicals. Presence of photochemical composition was correlated with seed storage proteins like albumin and globulin. Qualitative identification of total seed storage protein abundance across two related moth bean accessions using two-dimensional gel electrophoresis (2D-GE) was performed. Over 20 individual protein fractions were distributed over the gel as a series of spots in two moth bean accessions. Seed proteome accumulated spots of high intensity over a broad range of pI values of 3–10 in a molecular weight range of 11–170 kDa. In both seed accessions maximum protein spots are seen in the pI range of 6–8.

Mesoporous nanocrystalline TiO2 loaded with ferulic acid for sunscreen and photo-protection: safety and efficacy assessment

In the present study, the use of surfactant-free mesoporous TiO₂ combined with an antioxidant and photo-protecting agent, such as ferulic acid (FA), as a sunscreen was investigated for the first time.

Counteracting effects on free radicals and histological alterations induced by a fraction with casearins

ABSTRACTCasearia sylvestris Swartz is a medicinal plant widely distributed in Brazil. It has anti-inflammatory, antiulcer and antitumor activities and is popularly used to treat snakebites, wounds, diarrhea, flu and chest colds. Its leaves are rich in oxygenated tricyclic cis-clerodane diterpenes, particulary casearins. Herein, we evaluated the antioxidant activities of a fraction with casearins (FC) isolated from C. sylvestrisand histological changes on the central nervous system and livers of Mus musculus mice. Firstly, in vitro studies (0.9, 1.8, 3.6, 5.4 and 7.2 μg/mL) revealed EC50 values of 3.7, 6.4 and 0.16 µg/mL for nitrite, hydroxyl radical and TBARS levels, respectively. Secondly, FC (2.5, 5, 10 and 25 mg/kg/day) was intraperitoneally administered to Swiss mice for 7 consecutive days. Nitrite levels in the hippocampus (26.2, 27.3, 30.2 and 26.6 µM) and striatum (26.3, 25.4, 34.3 and 27.5 µM) increased in all treated animals (P < 0.05). Lower doses dropped reduced glutathione, catalase and TBARS levels in the hippocampus and striatum. With the exception of this reduction in TBARS formation, FC displayed only in vitro antioxidant activity. Animals exhibited histological alterations suggestive of neurotoxicity and hepatotoxicity, indicating the need for precaution regarding the consumption of medicinal formulations based on Casearia sylvestris.

Antioxidant activities of Indigofera cassioides Rottl. Ex. DC. using various in vitro assay models

OBJECTIVE

To evaluate the antioxidant potential of methanolic leaf extract of Indigofera cassioides (MEIC) using various in vitro antioxidant assay systems.

METHODS

Antioxidant and free radical scavenging activity of MEIC was assayed by using different in vitro models like ABTS, DPPH, nitric oxide, superoxide, hydrogen peroxide and hydroxyl radical. Reductive ability of the extract was tested by the complex formation with potassium ferricyanide. Further total phenol and flavonoid contents of the crude extract were also determined. Rutin and ascorbic acid were used as standards.

RESULTS

MEIC exhibited potent and concentration dependent free radical scavenging activity in all the tested models. Reductive ability was also found to increase with increase in MEIC concentration. Total phenol and flavonoid content determination showed that the extract is rich in phenols and flavonoids.

CONCLUSIONS

All the results of the in vitro antioxidant assays reveal potent antioxidant and free radical scavenging activity of the leaves of Indigofera cassioides, equivalent to that of standard ascorbic acid and rutin. This potent antioxidant activity may be attributed to its high phenolic and flavonoid contents.

Antioxidant compounds from ethanol extracts of bamboo (Neosinocalamus affinis) leaves

Activity-guided fractionation of Neosinocalamus affinis leaves led to obtain two new flavonoids, 4'-O-((7″R,8″S)-8″-guaiacylglyceryl)-pleioside B (9) and apigenin 6-C-β-d-fucopyranosyl-7-O-β-d-glucopyranoside (10) along with eight known compounds. Their structures were elucidated on the basis of spectroscopic data (UV, IR, NMR, and MS). Among these 10 compounds, farobin A (4) and isoorientin (7) showed significant antioxidant activity evaluated by 1,1-diphenyl-2-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), superoxide anion and nitric oxide (NO) radical-scavenging assays.

Phytochemical Analysis, Antioxidant and Anti-Inflammatory Activity of Calyces from Physalis peruviana

Physalis peruviana calyces are used extensively in folk medicine. The crude ethanolic extract and some fractions of calyces were evaluated in order to explore antioxidant and anti-inflammatory activities. The anti-inflammatory activity was evaluated by the TPA-induced ear edema model. The antioxidant in vitro activity was measured by means of the superoxide and nitric oxide scavenging activity of the extracts and fractions. The butanolic fraction was found to be promising due to its anti-inflammatory and antioxidant activities. Therefore, a bio-assay guided approach was employed to isolate and identify rutin (1) and nicotoflorin (2) from their NMR spectroscopic and MS data. The identification of rutin in calyces of P. peruviana supports the possible use of this waste material for phytotherapeutic, nutraceutical and cosmetic preparations.

The use of plants in the traditional management of diabetes in Nigeria: pharmacological and toxicological considerations

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence of diabetes is on a steady increase worldwide and it is now identified as one of the main threats to human health in the 21st century. In Nigeria, the use of herbal medicine alone or alongside prescription drugs for its management is quite common. We hereby carry out a review of medicinal plants traditionally used for diabetes management in Nigeria. Based on the available evidence on the species׳ pharmacology and safety, we highlight ways in which their therapeutic potential can be properly harnessed for possible integration into the country׳s healthcare system.

MATERIALS AND METHODS

Ethnobotanical information was obtained from a literature search of electronic databases such as Google Scholar, Pubmed and Scopus up to 2013 for publications on medicinal plants used in diabetes management, in which the place of use and/or sample collection was identified as Nigeria. 'Diabetes' and 'Nigeria' were used as keywords for the primary searches; and then 'Plant name - accepted or synonyms', 'Constituents', 'Drug interaction' and/or 'Toxicity' for the secondary searches.

RESULTS

The hypoglycemic effect of over a hundred out of the 115 plants reviewed in this paper is backed by preclinical experimental evidence, either in vivo or in vitro. One-third of the plants have been studied for their mechanism of action, while isolation of the bioactive constituent(s) has been accomplished for twenty three plants. Some plants showed specific organ toxicity, mostly nephrotoxic or hepatotoxic, with direct effects on the levels of some liver function enzymes. Twenty eight plants have been identified as in vitro modulators of P-glycoprotein and/or one or more of the cytochrome P450 enzymes, while eleven plants altered the levels of phase 2 metabolic enzymes, chiefly glutathione, with the potential to alter the pharmacokinetics of co-administered drugs.

CONCLUSION

This review, therefore, provides a useful resource to enable a thorough assessment of the profile of plants used in diabetes management so as to ensure a more rational use. By anticipating potential toxicities or possible herb-drug interactions, significant risks which would otherwise represent a burden on the country׳s healthcare system can be avoided.

Synthesis and biological evaluation of novel pyrazoline derivatives as anti-inflammatory and antioxidant agents

A series of novel 5-aryl-3-cyclopropyl-4,5-dihydropyrazole derivatives 2a-p were synthesized via cyclization of chalcones 1a-h with thiosemicarbazide or semicarbazide HCl and evaluated as anti-inflammatory/antioxidant agents. The structures were confirmed by elemental analyses and spectral data. The free radical scavenging activity toward superoxide was determined. Their effect on hepatocytes viability and nitric oxide (NO) production in LPS-stimulated macrophages was also determined. The results showed that compounds 2e and 2n demonstrated the highest free-radical scavenging and anti-inflammatory activities, thus can be useful in the prevention of oxidative stress and inflammation-related disorders.

Investigation of the extracts from Bidens pilosa Linn. var. radiata Sch. Bip. for antioxidant activities and cytotoxicity against human tumor cells

The aim of this study was to evaluate antioxidant activities and cytotoxicity against human tumor cell lines of extracts from Bidens pilosa Linn. var. radiata Sch. Bip. (BP). Total phenolic and flavonoid contents of the extracts were determined by ultraviolet spectrophotometry. Furthermore, the antioxidant properties of different polarity fractions extracted from BP were evaluated using DPPH and ABTS radical scavenging test and FRAP assay. The ethyl acetate fraction (EE-BP) showed the highest antioxidant activity compared to other fractions. In addition, the anti-proliferative activities of the extracts on four human tumor cells, namely MCF-7, HepG2, MGC 803 and RKO, were investigated by MTT method. The EE-BP displayed the most remarkable anti-proliferative effect against the tumor cells, particularly RKO cell in dose- and time-dependent manner. The antioxidant activities and cytotoxicity correlated highly with the total phenolic and flavonoid contents, respectively. Furthermore, The active ingredient BP-6, namely 5,7,4'-trihydroxy-3,3'-dimethyl-flavonol, was isolated and purified with the purity above 99.00% and content of 0.15% in EE-BP detected by HPLC, which could significantly inhibit the proliferation of RKO cells with the IC(50) value of 6.66 μmol/l. In order to characterize the apoptotic RKO cells, flow cytometry and DNA fragmentation assay were performed. Apoptotic cell numbers increased in a dose-dependent manner after the treatment with different concentrations of EE-BP and BP-6 for 12 and 6 h, respectively. DNA ladders in apoptotic RKO cells could be easily visualized when exposed to 200 μg/ml of the EE-BP for 36 h. Taken together, our work indicated that BP had potentially therapeutic value against colorectal cancer.

Total phenolic contents and free radical scavenging activities of different extracts of seabuckthorn (Hippophae rhamnoides) pomace without seeds

In this study, 100% methanolic extract (ME), 70% aqua-methanolic extract (AME) and 100% aqueous extract of seabuckthorn byproduct were used to evaluate antioxidant activity. The total phenolic contents were high in AME (84.28 ± 1.58 mg of Gallic Acid Equivalent (GAE)/gm of extract) compared to other extracts. All the extracts scavenged different in vitro radicals in a concentration-dependent manner. The IC(50) values were lowest in AME for 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, 2,2-diphenyl-1-picrylhydrazyl, superoxide and nitric oxide radicals, while ME had lowest values for hydroxyl radicals. The reducing power of the extracts increased in a dose-dependent manner and was highest in AME. The findings of this study revealed that seabuckthorn pomace without seed is one of the important resources as an antioxidant for food, pharmaceuticals, cosmetic or nutraceutical industries.

Poly(2-hydroxyethyl methacrylate)-quercetin Conjugate as Biomaterial in Ophthalmology: An "ab initio" Study

A novel polymeric material with antioxidant properties and suitable for ophthalmic application was synthesized by free radical grafting reaction between 2-hydroxyethyl methacrylate and quercetin. The presence of quercetin in the polymeric chain was confirmed by FT-IR and UV-Vis analyses, while an estimation of the amount of quercetin bound per gram of polymer was obtained by the Folin-Ciocalteu assay. The conjugate shows high biocompatibility (HET-CAM assay) and antioxidant and anti-inflammatory properties which were extensively investigated by specific in vitro tests.