Journal: Journal of natural medicines
Medicinal properties of parasitic plants were investigated by means of ethnobotanical study in some areas of northeastern Thailand. Important traditional usages are: Scurrula atropurpurea nourishes blood, Dendrophthoe pentandra decreases high blood pressure, and Helixanthera parasitica treats liver disease. Their systematics were also determined. The research is based on findings obtained from 100 parasite-host pairs. Of these, eight parasitic species were recorded; they are members of two families, viz. family Loranthaceae, namely D. lanosa, D. pentandra, H. parasitica, Macrosolen brandisianus, M. cochinchinensis and S. atropurpurea, and family Viscaceae, namely Viscum articulatum and V. ovalifolium. In addition, each parasitic species is found on diverse hosts, indicating non-host-parasitic specificity. Species-specific tagging of all species studied was carried out using the rbcL and psbA-trnH chloroplast regions. These tag sequences are submitted to GenBank databases under accession numbers JN687563-JN687578. Genetic distances calculated from nucleotide variations in a couple of species of each genus, Dendrophthoe, Macrosolen, and Viscum, were 0.032, 0.067 and 0.036 in the rbcL region, and 0.269, 0.073 and 0.264 in the psbA-trnH spacer region, respectively. These variations will be used for further identification of incomplete plant parts or other forms such as capsule, powder, dried or chopped pieces.
Three new triterpenoid saponins, tomentoside A (1), B (2) and C (3), along with four known saponins (4-7) were isolated from the root of Anemone tomentosa. The structures of the new compounds were elucidated as 3-O-β-D-ribopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)]-α-L-arabinopyranosyl hederagenin 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (1), 3-O-β-D-ribopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)]-β-D-xylopyranosyl hederagenin 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (2) and 3-O-β-D-galactopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosyl oleanolic acid 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (3) on the basis of chemical and spectral evidence. In the oligosaccharide chains of compound 3, the characteristic D-galactose residue is a rare structural feature and secondly encountered among triterpenoid saponins from Anemone.
Yohimbine is the major alkaloid found in the stem bark of yohimbe, Pausinystalia johimbe (Rubiaceae), an evergreen tree native to Africa. The objectives of the current study were to provide a detailed anatomy of yohimbe bark, as well as to determine the quantity of yohimbine in the raw yohimbe products sold online. Twelve commercial raw materials of yohimbe were analyzed by microscopic and ultra performance liquid chromatography-UV-MS methods. The study revealed that three samples were probably adulterated and four other samples contained various levels of impurities. Yohimbine was not detected in one sample, whereas its presence in other samples was found to be in the range 0.1-0.91%. The present work also provides a detailed anatomy of the stem bark of yohimbe, with light and scanning electron microscopy images, for proper identification and authentication.
A potential DNA barcode, ITS2, was studied to discriminate herbal materials to confirm their identities and ensure their safe application in pharmaceuticals. Here, a total of 4385 samples of 2431 species were collected, and these samples are from 61 commonly used herbs and their closely related species or adulterants. Based on assessments of the extent of genetic divergence, the DNA barcoding gap and the ability for species discrimination, our results suggest that ITS2 is a powerful tool for distinguishing herbs. For the first dataset including 61 herbs, ITS2 correctly identified 100 % of them. For the second dataset containing 51 herbs and their 2382 closely related species, ITS2 could discriminate correctly 48 herbs from their closely related species. For the third dataset comprising 34 herbs and their 111 adulterants, ITS2 could distinguish successfully all the herbs from their adulterants. In conclusion, the ITS2 region is an efficient marker for the authentication of herbal materials, and our study will accelerate the process of the application of the DNA barcoding technique in differentiating herbs.
Phytochemical investigation of the stigmas of Crocus sativus resulted in the isolation of eight glycosides (1-8) including a new safranal glycoside (2) and a new carotenoid pigment (6). The structures of the new compounds were identified as (4R)-4-hydroxy-2,6,6-trimethylcyclohex-1-enecarbaldehyde 4-O-[β-D-glucopyranosyl(1 → 3)-β-D-glucopyranoside] (2) and trans-crocetin-1-al 1-O-β-gentiobiosyl ester (6) on the basis of extensive chemical and spectroscopic evidence.
Determination of the absolute configuration (AC) is often a challenging aspect in the structure elucidation of natural products. When chiral compounds possess appropriate chromophore(s), electronic circular dichroism (ECD) may provide a powerful approach to the determination of their absolute configuration. Recently, ECD calculations by time-dependent density functional theory (TDDFT) have come to be used more commonly. In the present review, we give several examples of recent studies using TDDFT-calculated ECD spectra for the AC determination of natural products.
Two kinds of peony roots-white peony root (WPR) and red peony root (RPR)-are used for different remedies in traditional Chinese medicine; however, most of them are derived from the same botanical origin, Paeonia lactiflora. The difference between WPR and RPR has been debated for a long time. This study attempted to clarify the genetic and chemical characteristics of WPR and RPR in order to provide a scientific dataset for their identification and effective use. The nucleotide sequence of nrDNA internal transcribed spacer (ITS) and the contents of 8 main bioactive constituents were analyzed from specimens of P. lactiflora, P. veitchii and two related species as well as crude drug samples of WPR, RPR and peony root produced in Japan. Of the samples derived from P. lactiflora, the WPR produced in the southern parts of China and the RPR produced in the northern parts of China were clearly divided into two subgroups within the P. lactiflora group based on similarity of the ITS sequences. The nucleotides at positions 69, 458 and 523 upstream of the ITS sequence served as molecular markers to discriminate between WPR and RPR. Quantitative analysis indicated that the RPR samples obviously contained a higher content of paeoniflorin and paeonol, but a lower content of albiflorin than the WPR produced in the southern parts of China and peony root produced in Japan. The WPR available from Chinese markets was usually processed by sulfur fumigation, which resulted in an extremely low content of paeoniflorin. This study indicated that WPR and RPR were not only geographically isolated, but also genetically and chemically separated. The ITS sequence provided a genetic index for their identification.
Phyllanthus emblica is an euphorbiaceous plant that has long been used in traditional medicines for health promotion, anti-aging and also for treatment of wide ranges of symptoms and diseases. The aim of this study is to investigate the pharmacological activity of the plant branch. Alcohol based extracts of P. emblica branch were prepared in 50 % ethanolic extract by maceration (EPE) and methanolic extract by Soxhlet apparatus (MPE). EPE and MPE contained high total phenolic content and strong antioxidative activity. By HPLC analysis, gallic acid and vanillic acid are the major phenolic compounds of these extracts. Both EPE and MPE inhibited tyrosinase activity stronger than the ethanolic extract of P. emblica fruit (IC50 of 247.37 ± 18.57 and 193.75 ± 44.90 versus 4346.95 ± 166.23 μg/ml). EPE significantly inhibited the mRNA expressions of tyrosinase, and tyrosinase related proteins (TRP-1 and TRP-2) in B16 murine melanoma cells and suppressed the expression of LPS-induced pro-inflammatory genes (COX-2, iNOS, TNF-α, IL-16 and IL-6) in RAW 264.7 murine macrophage cells in a dose-dependent manner. These extracts significantly suppressed the carrageenan-induced paw edema in rats in a dose-dependent manner.
Listeria monocytogenes is a major foodborne pathogen that causes life-threatening illnesses in humans. With emergence of antibiotic resistance in L. monocytogenes, there is considerable interest in testing the efficacy of alternative therapies for controlling listeriosis in humans. This study investigated the efficacy of three phytochemicals, namely trans-cinnamaldehyde (TC), carvacrol (CR), and thymol (TY) in reducing L. monocytogenes virulence in the recently established invertebrate model, Galleria mellonella. In addition, the effect of phytochemicals on the transcription of antimicrobial peptide genes in G. mellonella (responsible for host defense) was investigated using real-time quantitative polymerase chain reaction. G. mellonella larvae were inoculated with L. monocytogenes (10(5) CFU/larvae) either with or without the subinhibitory concentration (chemical concentration not inhibiting bacterial growth) of phytochemicals. The larvae were incubated at 37 °C for 5 days, and their mortality was scored at 24-h intervals. The transcriptional response of the defense genes was studied in inoculated and uninoculated larvae at 6 h post challenge. The experiments were repeated at least six times with replicates. All phytochemicals enhanced the survival rates of G. mellonella infected with lethal doses of L. monocytogenes (P < 0.05). CR and TC at 0.01 % concentration were found to be the most effective treatments, and increased larval survival rates by 80 % and 50 %, respectively, on day 5 (P < 0.05). The phytochemicals also upregulated the expression of antimicrobial peptide genes in G. mellonella larvae challenged with L. monocytogenes (P < 0.05). Results suggest that TC, CR, and TY could potentially be used to control listeriosis. Further investigation in an appropriate mammalian model is warranted.
Dengue fever causes mortality and morbidity around the world, specifically in the Tropics and subtropic regions, which has been of major concern to governments and the World Health Organization (WHO). As a consequence, the search for new anti-dengue agents from medicinal plants has assumed more urgency than in the past. Medicinal plants have been used widely to treat a variety of vector ailments such as malaria. The demand for plant-based medicines is growing as they are generally considered to be safer, non-toxic and less harmful than synthetic drugs. This article reviews potential anti-dengue activities from plants distributed around the world. Sixty-nine studies from 1997 to 2012 describe 31 different species from 24 families that are known for their anti-dengue activities. About ten phytochemicals have been isolated from 11 species, among which are compounds with the potential for development of dengue treatment. Crude extracts and essential oils obtained from 31 species showed a broad activity against Flavivirus. Current studies show that natural products represent a rich potential source of new anti-dengue compounds. Further ethnobotanical surveys and laboratory investigations are needed established the potential of identified species in contributing to dengue control.