Phenolic profile and antioxidant activity from peels and seeds of melon (Cucumis melo L. var. reticulatus) and their antiproliferative effect in cancer cells

Melon (Cucumis melo L.) has high economic value and in recent years, its production has increased; however, part of the fruit is wasted. Usually, inedible parts such as peel and seeds are discarded during processing and consumption. Extracts of melon residues were prepared and their phenolic compounds, antioxidants and antiproliferative activities were evaluated. Total phenolic compounds were found in hydroethanolic, hydromethanolic, and aqueous extracts, especially for melon peel (1.016 mg gallic acid equivalent/100 g). Flavonoids total content found for melon peel aqueous extract was 262 µg of catechin equivalent (CA)/100 g. In all extracts of melon peel significant amounts of gallic acid, catechin, and eugenol were found. For total antioxidant capacity, reported as ascorbic acid equivalent, the hydroethanolic and hydromethanolic extracts in peels and hydromethanolic in seeds were 89, 74, and 83 mg/g, respectively. Different extracts of melon showed iron and copper ions chelating activity at different concentrations, especially melon peel aqueous extract, reaching values of 61% for iron and 84% for copper. The hydroethanolic extract of melon peel presented a significant ability for hydroxyl radicals scavenging (68%). To assess the antiproliferative potential in human cancer cell lines, such as kidney carcinoma, colorectal carcinoma, cervical adenocarcinoma and cervical carcinoma, MTT assay was performed. The proliferation was inhibited by 20-85% at extracts concentrations of 0.1-1.0 mg/mL in all cancer cell lines. The results suggest that melon residues extracts display a high antioxidant activity in in vitro assays and have effective biological activity against the growth of human tumor cells.

Phlorotannins from Brown Algae: inhibition of advanced glycation end products formation in high glucose induced Caenorhabditis elegans.

Advanced Glycation End products (AGE) generated in a non enzymatic protein glycation process are frequently associated with diabetes, aging and other chronic diseases. Here, we explored the protective effect of phlorotannins from brown algae Padina pavonica, Sargassum polycystum and Turbinaria ornata against AGEs formation. Phlorotannins were extracted from brown algae with methanol and its purity was analyzed by TLC and RP-HPLC-DAD. Twenty five grams of P. pavonica, S. polycystum, T. ornata yielded 27.6±0.8 µg/ml, 37.7 µg/ml and 37.1±0.74 µg/ml of phloroglucinol equivalent of phlorotannins, respectively. Antioxidant potentials were examined through DPPH assay and their IC50 values were P. pavonica (30.12±0.99 µg), S. polycystum (40.9±1.2 µg) and T. ornata (22.9±1.3 µg), which was comparatively lesser than the control ascorbic acid (46±0.2 µg). Further, anti-AGE activity was examined in vitro by BSA-glucose assay with the extracted phlorotannins of brown algae (P. pavonica, 15.16±0.26 µg/ml; S. polycystum, 35.245±2.3 µg/ml; T. ornata, 22.7±0.3 µg/ml), which revealed the required concentration to inhibit 50% of albumin glycation (IC50) were lower for extracts than controls (phloroglucinol, 222.33±4.9 µg/ml; thiamine, 263 µg/ml). Furthermore, brown algal extracts containing phlorotannins (100 µl) exhibited protective effects against AGE formation in vivo in C. elegans with induced hyperglycemia.

Fermentation and enzyme treatments for sorghum

Sorghum (Sorghum bicolor Moench) is the fifth most produced cereal worldwide. However, some varieties of this cereal contain antinutritional factors, such as tannins and phytate that may form stable complexes with proteins and minerals which decreases digestibility and nutritional value. The present study sought to diminish antinutritional tannins and phytate present in sorghum grains. Three different treatments were studied for that purpose, using enzymes tannase (945 U/Kg sorghum), phytase (2640 U/Kg sorghum) and Paecilomyces variotii (1.6 X 10(7) spores/mL); A) Tannase, phytase and Paecilomyces variotii, during 5 and 10 days; B) An innovative blend made of tanase and phytase for 5 days followed by a Pv increase for 5 more days; C) a third treatment where the reversed order of B was used starting with Pv for 5 days and then the blend of tannase and phytase for 5 more days. The results have shown that on average the three treatments were able to reduce total phenols and both hydrolysable and condensed tannins by 40.6, 38.92 and 58.00 %, respectively. Phytase increased the amount of available inorganic phosphorous, on the average by 78.3 %. The most promising results concerning tannins and phytate decreases were obtained by the enzymes combination of tannase and phytase. The three treatments have shown effective on diminishing tannin and phytate contents in sorghum flour which leads us to affirm that the proposed treatments can be used to increase the nutritive value of sorghum grains destined for either animal feeds or human nutrition.

Alterações ultraestruturais em larvas de Aedes aegypti submetidas ao diterpeno labdano, isolado de Copaifera reticulata (Leguminosae), e à uma fração rica em taninos de Magonia pubescens (Sapindaceae) / Ultrastructural alterations in larvae of Aedes aegypti subject to labdane diterpene isolated from Copaifera reticulata (Leguminosae) and a fraction enriched with tannins of Magonia pubescens (Sapindaceae)

INTRODUÇÃO: Dengue é um importante problema de saúde pública, em vários países, e tem como principal vetor o Aedes aegypti, mosquito mais adaptado às áreas urbanizadas. Apresenta-se, pela primeira vez, as alterações ultraestruturais em larvas de 3º estádio, desse mosquito, causadas pelos larvicidas naturais, um diterpeno labdano, extraído de Copaifera reticulata, e uma fração rica em taninos catéquicos, extraída de Magonia pubescens, evidenciando o mecanismo de ação dessas substâncias. MÉTODOS: Os experimentos foram realizados com larvas de 3º estádio em solução de 0,9ppm, do diterpeno (3-β-acetoxylabdan-8(17)-13-dien-15-óico) e de 3,7ppm, da fração majoritária de tanino catéquico de massa molecular 864Da. Obtiveram-se as substâncias através de fracionamentos cromatográficos sucessivos, identificadas por ressonância magnética nuclear de hidrogênio e espectrometria de massas. As larvas que atingiram estado letárgico foram coletadas e dissecadas e seus tubos digestórios fixados, desidratados, emblocados e polimerizados. Cortes ultrafinos foram feitos e contrastados com acetato de uranila 3 por cento e citrato de chumbo, posteriormente, levados ao microscópio eletrônico. RESULTADOS: As principais alterações ultraestruturais provocadas pelos diterpeno e tanino sobre larvas de Aedes aegypti foram vacuolização citoplasmática, desorganização e degeneração celular, mudança estrutural dos microvilos e deslocamento das células da lâmina basal. CONCLUSÕES: O diterpeno e a fração rica em taninos catéquicos provocaram a morte das larvas de Aedes aegypti através da destruição celular no intestino médio.

INTRODUCTION: Dengue is an important public health problem in many countries and its main vector Aedes aegypti, is the mosquito most adapted to urban areas. For the first time, the mechanism of action of labdane diterpenoid extracted from Copaifera reticulata and the fraction enriched of catechin tannins extracted from Magonia pubescens is demonstrated through ultrastructural alterations of Aedes aegypti larvae. METHODS: Experiments were performed using a 0.9ppm solution of diterpenoid and 3.7ppm of the fraction as the main catechin tannin of molecular mass 846Da. The compounds were obtained by thin layer chromatography and identified by nuclear magnetic resonance of hydrogen and mass spectrometry. Larvae that achieved lethargic state were collected and dissected. Next, they were contrasted with 1 percent uranyl acetate, dehydrated, embedded and polymerized. Ultrathin sections were made, mixed with 3 percent uranyl acetate and lead citrate and placed in an electron microscope. RESULTS: The main ultrastructural alterations caused by the diterpenoid and by tanins in larvae of Aedes aegypti were: cytoplasmic vacuolation, alteration of microvilli, cellular aging, cell disruption and degeneration, formation of secretion vesicles and structural changes in microvilli, irregular nuclei and displacement of cells in the basal lamina. CONCLUSIONS: The fraction containing tannins and the diterpenoid caused the death of Aedes aegypti larvae by cell destruction in the midgut.

Compuestos fenólicos presentes en las hojas de la especie colombiana Polygonum segetum Kunth / Fenolic compounds in the leaves of Polygonum segetum Kunth

The flavonoids 5-hydroxy-7,8,4'-trimethoxy isoflavone and 5,3',4'-trihydroxy-7-methoxyflavanon ,the tannin derivate Ethyl gallate and lignang homoegonol 5-(3''-Hydroxypropyl)-7-methoxy-2-(3',4'-dimethoxyphenyl)benzofuran were isolated and purified from Polygonum segetum Kunth leaves using column chromatography and thin layer chromatography methods. These substances were identified on the basis of their physical properties (melting point and Rf value), qualitative chemical reactions and spectroscopic techniques UV and NMR (experiments 1H, 13C, 1H-1H COSY, HMQC) and spectrometric techniques GC-MS according to their complexity.

El presente estudio se encaminó a determinar los metabolitos secundarios presentes en las hojas de la especie vegetal: Polygonum segetum Kunth, colectada del humedal Juan Amarillo (Bogotá-Colombia). Como resultado se aislaron e identificaron a partir de propiedades físicas y técnicas espectroscópicas de UV, 1HRMN, COSY, DEPT 135, HMQC y APT, la 5-hidróxi-7,8,4´-trimétoxi isoflavona, el galato de etilo (derivado de taninos) y la 5,3´,4´-trihidróxi-7-metóxi flavanona. Además, por análisis GC-MS se identifico el lignano 5-(3,4-dimetóxifenil)-7-metóxibenzofuranpropanol homoegonol.

Atividade larvicida de taninos isolados de Magonia pubescens St. Hil. (Sapindaceae) sobre Aedes aegypti (Diptera, Culicidae) / Larvicidal activity of tannins isolated of Magonia pubescens St. Hil. (Sapindaceae) against Aedes aegypti (Diptera, Culicidae)

Apresenta-se, pela primeira vez, o estudo fitoquímico das frações larvicidas, isoladas da Magonia pubescens, monitorado pelo estudo de eficácia sobre larvas de 3° estádio de Aedes aegypti, na busca de alternativas para o controle desse mosquito e obtenção de estruturas químicas passíveis de aprimoramento da atividade pela via sintética de outros derivados. As frações bioativas foram monitoradas quimicamente através de cromatografia de camada delgada, utilizando como revelador uma solução ácida de vanilina, e analisadas por ressonância magnética nuclear de hidrogênio e espectrometria de massas. Os bioensaios com as frações foram realizados em quintuplicata, à temperatura de 28±1°C, 80±5 por cento de umidade relativa e fotofase de 12 horas. As concentrações letais encontradas da fração MP-9, que apresentou o maior potencial larvicida, CL50 e CL90, foram de 3,1 e 36,6ppm, respectivamente. Todos os experimentos foram acompanhados por uma série controle, contendo o mesmo número de larvas.

Antioxidant activity of active tannoid principles of Emblica officinalis (amla).

The antioxidant activity of tannoid active principles of E. officinalis consisting of emblicanin A (37%), emblicanin B (33%), punigluconin (12%) and pedunculagin (14%), was investigated on the basis of their effects on rat brain frontal cortical and striatal concentrations of the oxidative free radical scavenging enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), and lipid peroxidation, in terms of thiobarbituric acid-reactive products. The results were compared with effects induced by deprenyl, a selective monoamine oxidase (MAO) B inhibitor with well documented antioxidant activity. The active tannoids of E. officinalis (EOT), administered in the doses of 5 and 10 mg/kg, i.p., and deprenyl (2 mg/kg, i.p.), induced an increase in both frontal cortical and striatal SOD, CAT and GPX activity, with concomitant decrease in lipid peroxidation in these brain areas when administered once daily for 7 days. Acute single administration of EOT and deprenyl had insignificant effects. The results also indicate that the antioxidant activity of E. officinalis may reside in the tannoids of the fruits of the plant, which have vitamin C-like properties, rather than vitamin C itself.

Phytochemical and biological study of certain Terminalia species growing in Egypt

A comparative study of the lipid, fatty acids, protein and amino acid content of the fruits of four Terminalia species, viz., T.bellerica Roxb., T.arjuna W. and A., T.muelleri Benth. and T.myriocarpa Heurck and Muell. is carried out. Determination of the tannin content of the different organs; bark, stem, leaf and fruit, isolation and identification of ethyl gallate and gallic acid from the fruits of T. bellerica as well as apigenin-7 -O-glucoside and quercetin-3-O-glucoside from the leaves of the same plant is achieved. A toxicological study, pharmacological and antimicrobial screening of the alcohol and aqueous extracts of the fruits and bark of T. bellerica is also carried out

Essential oil composition and tannin contents of the leaves of Eugenia uniflora L grown in Egypt

The essential oil prepared by hydrodistillation [0.32%] of the leaves of Eugenia uniflora L. [family Myrtaceae] was analyzed by capillary gas chromatography coupled to mass spectrometry [CGC-MS]. The results showed that the oil is rich in oxygenated sesquiterpenes [constitute 63.3% of the oil composition]. They are composed mainly of selina-1, 3,7 [11]-trien-8-one [20.33%], furanodiene [16.52%], oxidoselina-1,3,7 [11]-trien-8-one [10.53%], selina-11-en-4 alpha-01 [6.23%] and spathulenol [4.39%]. The essential oil of the leaves exhibited significant antibacterial activity against Sarcina lutea and Mycobacterium phlei. It also exhibited good antifungal activity against C and ida albicans and Trichophyton mentagrophytes. The phytochemical and thermographical studies revealed the presence of condensed tannins [22.2%, 18.5% and 17.4%] as determined by hide powder, gelatine and Cu acetate methods, respectively

Papel de los polifenoles en el bajo valor nutritivo de la Vicia faba / Role of polyphenols in the low nutritive value of Vicia faba

La inclusión de harina de habas (Vicia faba) en la dieta de animales de experimentación produce un retardo en el crecimiento, semejante al inducido por la adición de 0.2% de ácido tánico en dietas control de caseína. Tanto los extractos hidroalcohólicos obtenidos a partir de semillas de havas. Asimismo, la presencia de ácido tánico al 0.05, 0.1 y 0.2% en las soluciones de glucosa, disminuye proporcionalmente la absorción de ésta por el intestino. Los resultados en cuestión parecen sugerir que los polifenoles afectan, al menos parcialmente, el valor nutritivo d ela leguminosa (Vivia faba), si bien otros componentes d elas mismas también podrían estar involucrados