Targeted metabolite analysis of Catharanthus roseus and its biological potential

Catharanthus roseus is nowadays one of the most studied medicinal plants. In this work, further knowledge on different parts of this species (leaves, stems, seeds and petals) was achieved, namely phenolics by HPLC-DAD and organic acids and amino acids by HPLC-UV. Also, the biological potential, expressed as acetylcholinesterase inhibitory activity was accessed and, in some parts, an acetylcholinesterase inhibitory capacity higher than 85% was found (IC₅₀ at 422, 442 and 2683 μg/mL in leaves, stems and petals, respectively). C. roseus aqueous extract revealed to be a rich source of phenolics, namely caffeoylquinic acids and flavonoids derivatives (up to 4127 mg/kg in stems, 4484 mg/kg in seeds, 8688 mg/kg in leaves and 41125 mg/kg in petals), organic acids (962, 6678, 25972 and 12463 mg/kg in seeds, petals, stems and leaves, respectively), such as citric acid (over 85% in some plant parts), and amino acids (31557, 39327, 50540 and 159697 mg/kg in stems, petals, seeds and leaves, respectively), of which arginine was a major compound.     

Antioxidant properties of selected tropical wild edible mushrooms

Selected species of wild edible mushrooms were obtained from the interior areas of East Malaysia to determine the total phenolics and antioxidant properties, including free radical scavenging, reducing power and metal chelating activities. The in vitro antioxidant activities of petroleum ether (PE) and methanolic extracts of the edible wild mushrooms were comparable to the cultivated oyster mushroom. The radical scavenging activity was the highest in PE extract of Pleurotus porrigens (angel's wings) (85%), while methanolic extract of Hygrocybe conica (witch's hat mushroom) exhibited the highest (94%) chelating effect at 20 mg/ml. PE extracts were more effective than methanolic extract in scavenging ability on DPPH radicals, whereas methanolic extracts were more effective in reducing power and chelating ability on ferrous ions as evidenced by their lower EC₅₀ values. Principal component analysis (PCA) indicated phenolic group was the primary factor contributing to the metal chelating ability for PE extract although phenolic was better correlated with reducing power in methanolic extracts.     

Analysis of phenolic compositions in cranberry dietary supplements using UHPLC-HRMS

The potential human health benefits of American cranberry (Vaccinium macrocarpon Ait.) leads to the popularity of its dietary supplements in the U.S. market. However, the qualities of the cranberry dietary supplements (CDSs) have never been carefully evaluated. In this study, the phenolic components in ten different CDSs were analyzed using ultra-high-performance liquid chromatography high-resolution mass spectrometry (UHPLC-HRMS). The study found quercetin and myricetin aglycones in most CDSs, but not in cranberry fruits, despite otherwise similar phenolic profiles between CDS and cranberry fruits in general. One supplement with high levels of B-type proanthocyanidins and non-cranberry flavonol rutin was determined to be adulterated by other botanical extracts. The CDSs only possessed 4%–11% of the phenolic contents comparing to their claimed fresh cranberry equivalents, emphasizing the urgency of standardized product quality control and labelling for CDS manufacture and marketing.     

Walnut (Juglans regia L.) leaves: phenolic compounds, antibacterial activity and antioxidant potential of different cultivars.

Different cultivars of walnut (Juglans regia L.) leaves (Cv. Lara, Franquette, Mayette, Marbot, Mellanaise and Parisienne) grown in Portugal, were investigated in what concerns phenolic compounds and antimicrobial and antioxidant properties. Phenolics analysis was performed by reversed-phase HPLC/DAD and 10 compounds were identified and quantified: 3- and 5-caffeoylquinic acids, 3- and 4-p-coumaroylquinic acids, p-coumaric acid, quercetin 3-galactoside, quercetin 3-pentoside derivative, quercetin 3-arabinoside, quercetin 3-xyloside and quercetin 3-rhamnoside. The antimicrobial capacity was screened against Gram positive (Bacillus cereus, B. subtilis, Staphylococcus aureus) and Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae) and fungi (Candida albicans, Cryptococcus neoformans). Walnut leaves selectively inhibited the growth of Gram positive bacteria, being B. cereus the most susceptible one (MIC 0.1mg/mL). Gram negative bacteria and fungi were resistant to the extracts at 100mg/mL. Lara walnut leaves were also submitted to antibacterial assays using 18 clinical isolates of Staphylococcus sp. Antioxidant activity was accessed by the reducing power assay, the scavenging effect on DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals and beta-carotene linoleate model system. In a general way, all of the studied walnut leaves cultivars presented high antioxidant activity (EC(50) values lower than 1mg/mL), being Cv. Lara the most effective one.     

Evaluation of NO-suppressing activity of several Mediterranean culinary spices.

Excess nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) is implicated in the development of a number of diseases. Due to the absence of any natural specific enzymatic defense system in vivo, the consumption of certain foods which exhibit selective suppressive ability as regards NO overproduction might boost the host's protective effects against NO-mediated toxicity. Spices, rich in phenolics, are speculated conceivably to act as potential NO-scavengers or iNOS suppressors. The relative NO-suppressing activity of methanol extracts deriving from nine Mediterranean culinary spices was determined by measuring their inhibitory effect upon NO production for lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. In addition, the specifics of the suppressing mechanism were further explored. All of the spices tested, with the exception of clove, displayed a rather linear dose-dependent NO-suppressing effect without there appearing to exist any effect upon cell viability. Furthermore, the NO-suppressing capacity of certain spices was able to be ranked based upon their IC(50) (the concentration of spice extracts is required to cause 50% inhibition of NO production by LPS-activated RAW 264.7 cells), the ranking appearing as: rosemary (0.031%)>tarragon (0.052%)>cinnamon (0.059%)>oregano (0.106%)>basil (0.162%)>marjoram (0.236%)>allspice (0.269%)>and thyme (0.270%). Only cinnamon displayed excellent NO-scavenging ability, whereas all of the other spices demonstrated moderate to poor activities in this regard. Moreover, the inhibitory effect of tested spices upon the iNOS protein level was almost equivalent to their suppressive effect upon NO production. It would appear that inhibition of iNOS expression was the primary mechanism of action of spices as regards their exerting NO-suppressing activity.     

Chemical composition and biological activities of Helicteres vegae and Heliopsis sinaloensis

Context: Helicteres vegae Cristóbal (Sterculiaceae) (Hv) and Heliopsis sinaloensis B.L. Turner (Asteraceae) (Hs) are endangered and poorly studied plant species; related plants have been used against chronic-degenerative and infectious diseases. Therefore, Hv and Hs could be sources of bioactive compounds against these illnesses.

Objective: To determine the chemical composition and biological activities (antioxidant, antimutagenic and antimicrobial) of Hv and Hs leaves (L) and stems (S).

Materials and methods: Methanol extracts (ME) of each plant/tissue were evaluated for their phytochemicals; phenolics (HPLC-DAD-ESI-MS); antioxidant activity (AA) (0.125–4?mg/mL) (DPPH, ABTS, ORAC and β-carotene discoloration); antimutagenicity (0.5 and 1?mg/plate) (Ames assay, tester strain Salmonella enterica serovar Typhimurium YG1024, 1-nitropyrene as mutagen); activity against human pathogens (1?mg/mL); and toxicity (0.01–2?mg/mL) (Artemia salina assay).

Results: All ME showed flavonoids and triterpenes/steroids. The ME-SHv had the highest content of total phenolics (TP) (2245.82?±?21.45?mg GAE/100?g d.w.) and condensed tannins (603.71?±?1.115?mg CE/100?g d.w.). The compounds identified were flavonoids (kaempferol 7-O-coumaroylhexoside, and two kaempferol 7-O-rhamnosylhexosides) and phenolics [rosmarinic acid, and 3′-O-(8″-Z-caffeoyl) rosmarinic acid]. The ME-LHs showed the highest content of flavonoids (357.88?mg RE/g d.w.) and phenolic acids (238.58?mg CAE/g d.w.) by HPLC. The ME-SHv showed the highest AA. All ME were strong antimutagens (63.3-85.7%). Only the Hs extracts were toxic (ME-LHs, LC₅₀?=?94.9?±?1.7?μg/mL; ME-SHs, LC₅₀?=?89.03?±?4.42?μg/mL).

Discussion and conclusions: Both Hv and Hs are potential sources of preventive and therapeutic agents against chronic-degenerative diseases.     

Analysis of protein amino acids,non-protein amino acids and metabolites,dietary protein,glucose, fructose,sucrose, phenolic,and flavonoid content and antioxidative properties of potato tubers,peels, and cortexes (pulps)

The composition and antioxidative activity of whole potato tubers from five Korean cultivars, three peels from one cultivar, and eight pulps (cortexes) after peeling from six different cultivars were evaluated. Whole tubers were sectioned into three parts followed by analysis of the peels and pulps of each part. The following characteristics were determined: the dimensions and water content of whole tubers; nutritional protein content consisting of protein and free amino acids by an automated Kjeldahl nitrogen assay; free non-protein amino acids, metabolites, and fructose, glucose, and sucrose content by HPLC; phenolic compounds by HPLC and LC/MS; total phenolics and flavonoids by colorimetry; and antioxidative properties by ABTS, DPPH, and FRAP assays. The results demonstrate differences and similarities in the content of nutritional and bioactive compounds and in their bioactivities from whole potatoes, peels, and pulps. The present study reports for the first time the analysis of multiple potato nutrients and bioactive components as well the antioxidative properties of whole potatoes, peels, and pulps derived from the same tubers. The described methods are expected to facilitate the analysis of commercial and newly-developed potato cultivars, peels, and pulps and relate their composition and antioxidative activities to their reported nutritional, health-promoting, and industrial properties.     

Analysis of Peganum harmala,Melia azedarach and Morus alba extracts against six lethal human cancer cells and oxidative stress along with chemical characterization through advance Fourier Transform and Nuclear Magnetic Resonance spectroscopic methods towards green chemotherapeutic agents

Traditional medicines implicate consumption of plant crude extracts, which may consist of extensive phytochemical diversity. Overall, the most biologically active extract of Peganum harmala (seeds) exhibited significant cytotoxic activity on Artemia salina with LC₅₀ value of 61.547 µg/mL, while P. harmala (roots) [LC₅₀ = 124.229 µg/mL] and M. azedarach (fruits) [LC₅₀ = 147.813 µg/mL] showed moderate cytotoxic potential. P. harmala (seeds) extract also showed the maximum antitumor potential with 52.278 µg/mL LC₅₀. Branches of P. harmala and Morus alba were not active in both bioassays. These outcomes were further reinforced by the levels of phenolics and flavonoids checked against gallic acid and quercetin equivalents, respectively, by standard curves. Current study aims to isolate, structurally characterize and analyze the bioactive compound from plant extracts by using chromatographic and spectrophotometric techniques. Bioactivity guided isolation of extracts led to the isolation of PH-HM-16 from ethyl acetate fraction P. harmala seeds. Chemical structure of PH-HM-16 was elucidated by ESI-MS, ¹H NMR, ¹³C NMR, HSQC and IR spectrum. The results demonstrated significant positive anticancer activities against six human cancer cell lines assessed through MTT cancer cell growth inhibition assay. PH-HM-16 was most effective against prostate cancer cell lines [IC₅₀ = 17.63 µg/mL] followed by breast cancer cell line MCF7 [IC₅₀ value of 41.81 µg/mL]. IC₅₀ value of PH-HM-16 against human myeloid leukemia cell line HL-60 and human colorectal tumor cells HCT-116 was observed as 68.77 µg/mL and 71.54 µg/mL respectively. The IC 50 value of PH-HM-16 compound was not significant against human gastric cancer SGC-7901 (111.89 µg/mL) and human lung adenocarcinoma epithelial cell line A549 (176.04 µg/mL). Isolated bioactive metabolite PH-HM-16 possesses significant antitumor potential so this could be the first step to develop an effective anticancer agent. Hence, this compound represents a promising potential to be chemically standardized or developed into pharmaceuticals for the chemoprevention and/or the treatment of certain types of cancer, especially as adjuvant phytotherapeutics in conventional chemotherapy.     

水芹总酚酸退黄作用的实验研究

目的观察水芹总酚酸（OJTPA）对α-萘异硫氰酸酯（ANIT）所致大鼠黄疸模型的退黄作用。方法将Wistar大鼠随机分为6组：正常组、ANIT模型对照组、茵栀黄颗粒阳性药物组、OJTPA高、中、低（300、150、75mg·kg^-1）3个剂量组。各给药组连续给药7d,最后一次给药1h后,ANIT按75mg·kg^-1体质量灌服大鼠诱发黄疸模型,正常组给等量的花生油。72h后取血取肝,检测血清总胆红素（T-Bil）含量以及肝组织中丙二醛（MDA）含量和超氧化物歧化酶（SOD）活力,同时观察肝脏组织病理学的改变。结果模型组大鼠血清T-Bil含量及肝脏MDA含量明显升高（P〈0．01）,肝脏SOD活性明显降低（P〈0．01）;OJTPA能明显对抗这种改变,其退黄率分别为58．12％、43．12％、22．19％。肝脏组织病理学检查证实,OJTPA能减轻中毒大鼠肝细胞损伤程度。结论OJTPA退黄效果肯定,其机制可能与抗脂质过氧化有关。