Bioactivity-guided isolation of the antidiabetic principle in Pterocarpus Santalinoides leaf extract

Abstract Pterocarpus santalinoides is used in Nigerian ethnomedicine to treat diabetes mellitus. This study aimed to establish the antidiabetic property of the plant, and isolate and characterize its active principle. Dried and pulverized leaves (500 g) of P. santalinoides were extracted with 1.8 L of 80 % hydromethanol by cold maceration. The dried extract (10 g) was partitioned into n-hexane, ethyl acetate (EtOAc), n-butanol, and water. Antidiabetic activitiy-guided isolation by column chromatographic separation of the EtOAc soluble and purification of the sub-fractions by repeated preparative thin layer chromatography (pTLC) yielded a C-glycosyl flavonoid, identified as isovitexin. The chemical structure was elucidated based on high-resolution mass spectroscopy, 1D, and 2D nuclear magnetic resonance spectroscopic analyses. Alloxan-induced diabetic rat model was adopted for antidiabetic screening. The extract of P. santalinoides (100-200 mg/kg), fraction F4 (50 mg/kg), sub-fraction F4.3 (10 mg/kg), and the semi-purified compound F4.3.2 (5 mg/kg) significantly (p<0.05) reduced the fasting blood glucose of alloxan-induced diabetic rats, causing 48.4, 69.4, 57.7 and 64.5 % antidiabetic activity respectively, compared with > 68 % recorded in glibenclamide (2 mg/kg) control. These results reveal that isovitexin is the antidiabetic principle in P. santalinoides

Ocotea nutans (Nees) Mez: structural elucidation of C-hetorosides flavonoids and evaluation of their antioxidant and antibacterial properties from ethyl acetate extract.

The Ocotea genus exhibits a variety of pharmacological, antibacterial and antioxidant effects. The aim of the present study was to evaluate the antioxidant potential and antibacterial properties of the ethyl acetate fraction of Ocotea nutans leaves. Isolation and identification of the phenolic compounds from the fraction was also carried out. The isolated compounds were characterised by one- and two-dimensional nuclear magnetic resonance analysis and identified as vitexin (1) and isovitexin (2). The ethyl acetate fraction of Ocotea nutans leaves demonstrated considerable antioxidant potential. The observed minimum inhibitory concentration of 250 µg.mL-1 was classified as a moderate antibacterial activity against Enterococcus faecalis. Findings from this study demonstrate the utility of this plant as a potential source of antioxidant and antibacterial agents.

Pasteurization of passion fruit Passiflora setacea pulp to optimize bioactive compounds retention.

Passiflora setacea is a wild species of passion fruit with interesting functional properties. Fruit seasonality demands conservation methods to enable its consumption throughout the year. We evaluated High Temperature Short Time (HTST) and Low Temperature Long Time (LTLT) binomials on physical, chemical, antioxidant and sensory characteristics of Passiflora setacea pulps. In natura (IN) and pasteurized pulps were analysed for DPPH, FRAP, ORAC, total phenolic content (TPC), vitamin C, bioactive amines, flavonoids, color, remaining enzymatic activity (REA), microbiological analyzes, sensory evaluation and physical stability. All binomials reached microbiological standards. Binomials 82 °C/20 s and 82 °C/40 s were selected for providing higher total antioxidant activity (TAA), TPC and lower REA. The highest levels of antioxidant activity, flavonoids, vitamin C were kept by 82 °C/20 s, without difference from IN pulp. LTLT binomial showed higher retention of bioactive amines, but also higher REA. Sensory acceptance was not affected by the binomials but pasteurized-cooked flavor was more checked for 82 °C 40 s than IN pulp.

Chemical constituents and allelopathic activity of Machaerium eriocarpum Benth.

The analysis by HPLC-PDA of the hydroalcoholic extract of the leaves of M. eriocarpum together with the injection of the fractions containing the already identified metabolites allowed the detection of at least 5 flavonoids, of which two are derived from apigenin and three from luteolin. After isolating larger amounts of isovitexin (I), assays were performed to evaluate the allelopathic activity together with the crude extract. The results show that the initial inhibition indexes were very similar to those observed in the treatments with F17 (Fraction enriched in isovitexin) and F18 (isovitexin), mainly in the concentrations of 500 and 1000 mg L-1. The index of the number of lateral roots, an increase of the inhibitory effect is observed with the increase of the concentration of M. eriocarpum extract.

Towards the cosmetic application of Passiflora coccinea (Aubl.): antioxidant activity and photo protective capacity of the methanolic and glycolic leaf extracts

The present study aimed at the evaluation of Passiflora coccinea (Aubl.) antioxidant and photo protective in vitro activities, looking forward to their application as antiaging or sunscreen agents in cosmetic formulations. Methanolic and glycolic leaf extracts were prepared by three methods: ultrasound assisted extraction (UAE, 30 min.), maceration at room temperature (72 h) and maceration at 30 ºC (72 h). The antioxidant activities of the extracts were measured by DPPH and ORAC-FL assays and they were incorporated into a cosmetic emulsion to have their sun protection factor (SPF) measured spectrophotometricaly. The antioxidant activity of the emulsions were measured by DPPH and ORAC as well. C-glycosyl-flavones were identified in the extracts by ESI-MS/MS, in comparision with standards. The UAE methanolic extract and the maceration at 30 ºC glycolic extract were submmited to HPLC-DAD analysis and isovitexin was quantifyed in both by a validated method. The methanolic extract antioxidant activity was independent of the extraction method, higher than reported for other species of Passiflora and detectable when incorporated into the emulsion formulation. Maceration at 30oC was the most suitable method for glycolic extraction and its antioxidant activity was lower than the value presented by the methanolic extracts. None of the extracts exhibited a SPF value. Isovitexin in the UAE methanolic extract was 12.67 times higher than the most active glycolic extract, aside of their similar chromatographic profiles. Although a SPF value was not detected, the results indicate that P. coccinea can be a potential new source of antioxidants for topical antiaging formulations.

Effect of training system and climate conditions on phytochemicals of Passiflora setacea, a wild Passiflora from Brazilian savannah.

Passiflora setacea is a Brazilian savannah fruit known as a good source of phytochemicals. The phytochemical composition is influenced by environmental factors and management techniques such as training system. This study aimed to evaluate the influence of training system (espalier or trellis) and environmental factors (temperature, precipitation and sunlight exposure) on antioxidant capacity and bioactive composition of P. setacea pulp. Total phenolic compounds (TP), proantocyanidins (PA), total flavonoids (TF), vitamin C and total antioxidant activity were analyzed. Five flavonoids (orientin, isoorientin, vitexin, isovitexin and hesperetin) were determined by HPLC-DAD, using calibration curves. Training system presented no effects on TP, PA, TF and antioxidant activity, whereas rainy season year 2 increased FRAP values, TF, orientin, isovitexin and hesperetin content, which could be associate to climate stressful condition leading to higher levels of these compounds.

Comparison of two Jatropha species (Euphorbiaceae) used popularly to treat snakebites in Northeastern Brazil: Chemical profile, inhibitory activity against Bothrops erythromelas venom and antibacterial activity.

ETHNOPHARMACOLOGICAL RELEVANCE: Jatropha species (Euphorbiaceae) are largely used in traditional medicine to treat different pathologies in Africa, Asia and Latin America. In Northeastern Brazilian folk medicine, several Jatropha species, such as Jatropha gossypiifolia L. and Jatropha mollissima (Pohl) Baill., are indistinctly used to treat snakebites. AIM OF THE STUDY: To compare two of the Brazilian most used Jatropha species for snakebites (J. gossypiifolia and J. mollissima), in relation to their ability to inhibit local edematogenic activity of Bothrops erythromelas snake venom in mice, their in vitro antibacterial activity and phytochemical profile. MATERIAL AND METHODS: Aqueous leaf extracts of J. gossypiifolia (AEJg) and J. mollissima (AEJm) were prepared by decoction. AEJg and AEJm were compared chemically, by thin layer chromatography (TLC) and high-performance liquid chromatography with diode array detection (HPLC-DAD) analysis. They were also pharmacologically compared, using the mouse model of paw edema induced by Bothrops erythromelas snake venom (BeV), and in vitro by broth microdilution and agar dilution antimicrobial tests. RESULTS: Flavonoids were detected as the major compounds in both extracts. However, AEJg and AEJm showed quantitatively different chemical profiles by HPLC-DAD. AEJg presented fewer peaks of flavonoids than AEJm, however, when the intensity of peaks were analyzed, these compounds were at high concentration in AEJg, even using the same concentration of both extracts. Differences were also observed in the biological activity of the two extracts. While no difference was observed when the extracts were administered by oral route (P > 0.05), by the intraperitoneal route AEJg presented anti-edematogenic activity significantly (P < 0.001) higher than AEJm. In antimicrobial assays, only AEJg presented antibacterial activity against Staphylococcus epidermidis, Staphylococcus aureus and Bacillus cereus. CONCLUSIONS: Although used indistinctly by folk medicine, our results suggested that AEJg is more active than AEJm in relation to its antiedematogenic and antibacterial activities. Significant differences were observed in their phytochemical profiles, especially a higher content of C-glycosylated flavonoids in the most active species, which could justify the different biological effects observed. These findings strengthen the potentiality of J. gossypiifolia species for use as complementary treatment for local effects induced by Bothrops venoms and could be helpful for distinction of the species and control quality assessment of future herbal medicines based on Jatropha plants.

Isovitexin as marker and bioactive compound in the antinociceptive activity of the Brazilian crude drug extracts of Echinodorus scaber and E. grandiflorus

Abstract Echinodorus scaber Rataj and Echinodorus grandiflorus (Cham. & Schltdl.) Micheli, Alismataceae, are popularly used to relieve inflammatory complaints and as diuretic. A study on the antinociceptive effect and selected marker compounds in eleven extracts from different locations was undertaken and their antinociceptive effect was assessed. The fingerprints were compared by HPLC-DAD and the content of vitexin, isovitexin, isoorientin and vitexin-2-O-rhamnoside were determined. All samples presented antinociceptive activity reducing the writhes by 36.4-62.5% and 47.4-79.8% at 10 and 50 mg/kg, respectively; indomethacin (5 mg/kg) reduced writhes by 82.6-90.1%. The content of the flavonoids C-glycosides, however, presented a strong variation. Isovitexin and isoorientin were found in all the samples, with content ranging from traces to 14.70 µg/mg and 2.12-84.27 µg/mg extract, respectively, while vitexin-2-O-rhamnoside occurred in quantifiable amounts only in 3 out of 11 samples ranging from 5.43 to 33.13 µg/mg extract; vitexin was not detected at all or detected in trace amounts. According to the fingerprints, the samples could be arranged in four main groups. All eleven extracts showed antinociceptive activity. Isovitexin was the only flavonoid present in all samples and can be regarded, acting in synergy with the other compounds or not, as the responsible for the antinociceptive activity. Therefore, isovitexin is a good choice as chemical marker when the antinociceptive activity of E. scaber and E. grandiflorus is investigated.

Rapid identification and quantitative analysis of chemical constituents of Gentiana veitchiorum by UHPLC-PDA-QTOF-MS

ABSTRACT Gentiana veitchiorum Hemsl., Gentianaceae, a traditional Tibetan medicine, was used for the treatment of liver jaundice with damp-heat pathogen, as well as for headache and chronic pharyngitis. A rapid ultra-performance liquid chromatography, photodiode array detector, quadrupole time-of-flight mass spectrometry method was developed for the fast and accurate identification and quantification of the chemical constituents of G. veitchiorum. In fact, eighteen compounds were detected and identified on the basis of their mass spectra, fragment characteristics and comparison with published data. Especially, the MS fragmentation pathways of iridoid glycosides and flavone C-glycosides were illustrated. Five compounds among them were quantified by UHPLC-PDA, including swertiamarin, gentiopicroside, sweroside, isoorientin, and isovitexin. The proposed method was then validated based on the analyses of linearity, accuracy, precision, and recovery. The overall recoveries for the five analytes ranged from 96.54% to 100.81%, with RSD from 1.05% to 1.82%. In addition, ten batches of G. veitchiorum from different areas were also analyzed. The developed method was rapid and reliable for both identification and quantification of the chemical constituents of G. veitchiorum, especially for simultaneous qualitative and quantitative analysis of iridoid glycosides and flavone C-glycosides.

Seasonal variations in the amount of isoorientin and isovitexin in Cecropia glaziovii Sneth. leaves over a two-year period / Variación estacionaria en el contenido de isoorientina e isovitexina en hojas de Cecropia glaziovii Sneth. durante un período de dos años

Cecropia glaziovii Sneth. (Urticaceae) is a common tree from Southeast and South of Brazil, being widely used in traditional medicine to treat heart and respiratory conditions. C-glycosylflavonoids have being described as the major compounds for this genus, however, no seasonality studies of individual flavonoids was conducted for any Cecropia specie. In this work, the content of isoorientin and isovitexin in aqueous extract from the leaves of C glaziovii during a two-year period was determined by high-performance liquid chromatography with diode array detector (HPLC-DAD). Seasonal alterations in the content of these two majority C-glycosylflavonoids as well its possible correlation with the pluviosity in the period of January/2008 to January/2010 were determined. Isoorientin presented higher content in November/09 (6.04 mg/g of extract) and lower content in May/08 (1.01 mg/g of extract). The higher content of isovitexin was observed in March/09 and the lower in September/08 (11.42 and 4.47 mg/g of extract, respectively). Although they have distinct behaviors, it was not observed correlation between the values of pluviosity and the production of these C-glycosylflavonoids.

Cecropia glaziovii Sneth. (Urticaceae) es un árbol comúnmente encontrada en el Suroriente y Sur de Brasil, siendo ampliamente utilizada en la medicina tradicional para el tratamiento de problemas cardíacos y respiratorios. Flavonoides C-glucósidos vienen siendo descritos como los compuestos mayoritarios del género, sin embargo, ningún estudio de estacionalidad de flavonoides analizados de modo individual fue realizado con ninguna especie de Cecropia. En el presente trabajo, el contenido de isoorientina e isovitexina en el extracto acuoso de las hojas de C. glaziovii durante un período de dos años fue determinado por HPLC-DAD. Variaciones estacionarias en el contenido de esos dos flavonoides C-glucósidos así como la posible correlación con la pluviosidad en el periodo de Enero/2008 hasta Enero/2010 fueron determinados. Isoorientina presentó mayor contenido en Noviembre/09 (6,04 mg/g de extracto) y menos contenido en Mayo/08 (1,01 mg/g de extracto). El mayor contenido de isovitexina fue observado in Marzo/09 y el menor contenido in Septiembre/08 (11,42 y 4,47 mg/g de extracto, respectivamente). Aunque los flavonoides poseen distintos comportamientos, no fue observada correlación entre los valores de pluviosidad y la producción de esos compuestos.

Genotoxicity and acute and subchronic toxicity studies of a standardized methanolic extract of Ficus deltoidea leaves

OBJECTIVE: Ficus deltoidea leaves have been used in traditional medicine in Southeast Asia to treat diabetes, inflammation, diarrhea, and infections. The present study was conducted to assess the genotoxicity and acute and subchronic toxicity of a standardized methanol extract of F. deltoidea leaves. METHODS: Sprague Dawley rats were orally treated with five different single doses of the extract and screened for signs of toxicity for two weeks after administration. In the subchronic study, three different doses of the extract were administered for 28 days. Mortality, clinical signs, body weight changes, hematological and biochemical parameters, gross findings, organ weights, and histological parameters were monitored during the study. Genotoxicity was assessed using the Ames test with the TA98 and TA100 Salmonella typhimurium strains. Phytochemical standardization was performed using a colorimeter and high-performance liquid chromatography. Heavy metal detection was performed using an atomic absorption spectrometer. RESULTS: The acute toxicity study showed that the LD50 of the extract was greater than 5000 mg/kg. In the subchronic toxicity study, there were no significant adverse effects on food consumption, body weight, organ weights, mortality, clinical chemistry, hematology, gross pathology, or histopathology. However, a dose-dependent increase in the serum urea level was observed. The Ames test revealed that the extract did not have any potential to induce gene mutations in S. typhimurium, either in the presence or absence of S9 activation. Phytochemical analysis of the extract revealed high contents of phenolics, flavonoids, and tannins. High-performance liquid chromatography analysis revealed high levels of vitexin and isovitexin in the extract, and the levels of heavy metals were below the toxic levels. CONCLUSION: The no-observed adverse effect level ...