Browsing by Author "Jones, O. Moody"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item Cyclotide Discovery in Gentianales Revisited—Identification and Characterization of Cyclic Cystine-Knot Peptides and Their Phylogenetic Distribution in Rubiaceae Plants(2013-11-04) Johannes, Koehbach; Alfred, F. Attah; Andreas, Berger; Roland, Hellinger; Toni, M. Kutchan; Eric, J. Carpenter; Megan, Rolf; Mubo, A. Sonibare; Jones, O. Moody; Gane, Ka-Shu Wong; Steven, Dessein; Harald, Greger; Christian, W. GruberCyclotides are a unique class of ribosomally synthesized cysteine-rich miniproteins characterized by a head-to-tail cyclized backbone and three conserved disulfide-bonds in a knotted arrangement. Originally they were discovered in the coffee-family plant Oldenlandia affinis (Rubiaceae) and have since been identified in several species of the violet, cucurbit, pea, potato, and grass families. However, the identification of novel cyclotide-containing plant species still is a major challenge due to the lack of a rapid and accurate analytical workflow in particular for large sampling numbers. As a consequence, their phylogeny in the plant kingdom remains unclear. To gain further insight into the distribution and evolution of plant cyclotides, we analyzed ~300 species of >40 different families, with special emphasis on plants from the order Gentianales. For this purpose, we have developed a refined screening methodology combining chemical analysis of plant extracts and bioinformatic analysis of transcript databases. Using mass spectrometry and transcriptome-mining, we identified nine novel cyclotide-containing species and their related cyclotide precursor genes in the tribe Palicoureeae. The characterization of novel peptide sequences underlines the high variability and plasticity of the cyclotide framework, and a comparison of novel precursor proteins from Carapichea ipecacuanha illustrated their typical cyclotide gene architectures. Phylogenetic analysis of their distribution within the Psychotria alliance revealed cyclotides to be restricted to Palicourea, Margaritopsis, Notopleura, Carapichea, Chassalia, and Geophila. In line with previous reports, our findings confirm cyclotides to be one of the largest peptide families within the plant kingdom and suggest that their total number may exceed tens of thousands.Item Detection of cysteine-rich peptides in Tragia benthamii Baker (Euphorbiaceae) and in vivo antiinflammatory effect in a chick model(Published online by De Gruyter, 2021-06-16) Alfred, F. Attah; Abobarin, I. Omobola; Jones, O. Moody; Mubo, A. Sonibare; Olubori, M. Adebukola; Samuel, A. OnasanwoTragia benthamii (TBM) commonly called the climbing nettle is a tropical plant claimed to have numerous anti inflammatory effects in sub Saharan African ethnomedicine which lacks scientific evidence. Aqueous extracts of TBM were further prepurified on a RP-C18 parked solid phase system to obtain 20% aqueous fraction. This fraction was enzymatically and chemically analyzed (by MALDI TOF MS and MS/MS) to contain interesting low molecular weight cysteine-rich stable peptides within the range of 2.5–3.2 KDa. The 20% aqueous fraction was further tested in vivo using carrageenan-induced foot edema (acute inflammation) in seven-day old chicks with diclofenac as reference drug. The cytotoxicity of this active fraction was investigated using the brine shrimp lethality assay. The brine shrimp cytotoxicity assay produced LC50 above 1000 μg/mL. Pretreatment with the TBM extract (30–300 mg/kg, i.p) dose dependently (P<0.01) reduced foot edema with maximal inhibition of 0.253 ± 0.180 (84.3%) at 300 mg/kg body weight, which was comparable to that of diclofenac with inhibition (P<0.05) of 0.410 ± 0.271 (74.5%) at 10 mg/kg body weight. The study has therefore shown for the first time, the detection of cysteine-rich biologically active peptides in T. benthamii and the stable peptide extracts from this ethnomedicinal plant, which is not toxic to Artemia salina, exhibits anti inflammatory activity in a chick in vivo model. This may provide scientific evidence for its use in the treatment of inflammation and pain in traditional medicine. Further in-depth vivo and in vitro studies will be required to investigate its anti inflammatory activity including effect on HUVEC-TERT, the possible inhibition of ICAM-1 surface expression and the mechanism of the anti inflammatory effect.Item Ethobotanical survey of Rinorea dentata (Violaceae) used in South-Western Nigerian ethnomedicine and detection of cyclotides(Elsevier Ireland Ltd, 2016) Alfred, F. Attah; Roland, Hellinger; Mubo, A. Sonibare; Jones, O. Moody; Sarah, Arrowsmith; Susan, Wray; Christian, W. GruberEthnopharmacological relevance: People living in the tropical rain forest of South-Western Nigeria use Rinorea dentata (P. Beauv.) Kuntze (Violaceae) in ethno-veterinary medicine to facilitate parturition. There are no evidence-based pharmacological investigations for the uterotonic activity of this plant. Aims of study: (i) Collection of data about the ethnopharmacological uses of R. dentata and evaluation of its uses and applications in health care; (ii) determining potential uterotonic effects in vitro, and (iii) chemical characterization of R. dentata, which is a member of the Violaceae family known to express circular cystine-knot peptides, called cyclotides. Materials and methods: The ethnopharmacological use of R. dentata in settlement camps within the area J4 of Omo forest has been investigated by semi-structured questionnaires and open interviews. Use index analysis has been performed by seven quantitative statistical models. Respondents’ claim on the beneficial ethno-veterinary application of the plant to aid parturition has been investigated in vitro by myometrial contractility organ bath assays. The bioactive plant extract was screened by chemical derivatization and mass spectrometry-based peptidomics using reversed-phase HPLC fractionation and MALDI-TOF/TOF analysis. Results: Based on the survey analysis, medicinal preparations of R. dentata have been used for antimicrobial and anti-malaria purpose in humans, and for aiding parturition in farm animals. The latter application was mentioned by one out of six respondents who claimed to use this plant for any medicinal purpose. The plant extract exhibited a weak uterotonic effect using organ bath studies. The plant contains cyclotides and the peptide riden A has been identified by de novo amino acid sequencing using mass spectrometry. Conclusion: Few dwellers around the settlement camps of the tropical forest of Omo (Nigeria) use R. dentata for various health problems in traditional veterinary and human medicine. The weak uterotonic effect of the cyclotide-rich extract is in agreement with the low use value index obtained for this plant. Cyclotides have been reported in the genus Rinorea confirming the ubiquitous expression of these stable bioactive plant peptides within the family of Violaceae.