Browsing by Author "Alfred, F. Attah"
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Item Cardioprotective Effects of Curcumin-Nisin Based Poly Lactic Acid Nanoparticle on Myocardial Infarction in Guinea Pigs(2018-11-09) Williams, E. E. Nabofa; Oluwadamilola, O. Alashe; Oyetunde, T. Oyeyemi; Alfred, F. Attah; Ademola, A. Oyagbemi; Temidayo, O. Omobowale; Adeolu, A. Adedapo; Akinola, R. A. AladaMyocardial infarction (MI) is the most prevalent cause of cardiovascular death. A possible way of preventing MI maybe by dietary supplements. The present study was thus designed to ascertain the cardio-protective effect of a formulated curcumin and nisin based poly lactic acid nanoparticle (CurNisNp) on isoproterenol (ISO) induced MI in guinea pigs. Animals were pretreated for 7 days as follows; Groups A and B animals were given 0.5 mL/kg of normal saline, group C metoprolol (2 mg/kg), groups D and E CurNisNp 10 and 21 mg/kg respectively (n = 5). MI was induced on the 7th day in groups B-E animals. On the 9th day electrocardiogram (ECG) was recorded, blood samples and tissue biopsies were collected for analyses. Toxicity studies on CurNisNp were carried out. MI induction caused atrial fibrillation which was prevented by pretreatment of metoprolol or CurNisNp. MI induction was also associated with increased expressions of cardiac troponin I (CTnI) and kidney injury molecule-1 (KIM-1) which were significantly reduced in guinea pig’s pretreated with metoprolol or CurNisNp (P < 0.05). The LC50 of CurNisNp was 3258.2 μg/mL. This study demonstrated that the formulated curcumin-nisin based nanoparticle confers a significant level of cardio-protection in the guinea pig and is nontoxic.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.Item Evaluation of multifunctional activity of bioactive peptide fractions from the leaves of Nauclea diderrichii (De Wild. and T. Durand) Merrill and Ixora brachypoda DC(Elsevier B.V., 2021-02) Omonike, O. Ogbole; Abraham, Nkumah; Toluwanimi, E. Akinleye; Fredrick, E. Olisaedu; Alfred, F. AttahBioactive peptides are known for health-promoting properties due to several pharmacological effects they modulate in physiological systems. Herein, the presence of peptides particularly cyclic peptides, was investigated in two Rubiaceae members; Nauclea diderichii (De Wild. and T. Durand) Merrill and Ixora brachypoda DC by thin layer chromatography (TLC) chemical detection, and their multifunctional bioactivity evaluated. Crude and pre-purified peptides were obtained from both plants using aqueous and solid-phase extractions, respectively. The peptide fraction of N. diderrichii showed good DPPH scavenging activity (IC50 = 3.43 μg/mL) compared to the standard Gallic acid (IC50 = 1.44 μg/mL). Peptide fractions of both plants displayed inhibitory effects (MIC = 6.25 μg/mL) against bacteria and fungi strains except Escherichia coli, relative to standard drugs (MIC = 0.31 μg/mL). Both displayed significant toxicity to brine shrimp nauplii (LC50≤ 220.8 μgmL-1) as well as MCF-7 and RD cancer cells (IC50 ≤ 34.0 μgmL-1). The enterovirus species B and C tested were remarkably susceptible to the peptide fractions (IC50 ≤ 3.20 μg/mL).Item Evaluation of peptide-rich root extracts of Calliandria portoriscensis (Jacq.) Benth (Mimosaceae) for in vitro antimicrobial activity and brine shrimp lethality(BMC Complementary Medicine and Therapies, 2020-02-03) Omonike, O. Ogbole; Nkiruka, C. Ndabai; Toluwanimi, E. Akinleye; Alfred, F. AttahBackground Several Host defence peptides (HDPs) are low molecular weight (< 50 amino acids residues) peptides detected in several ethnomedicinal plants and have particularly gained research interest in recent times. Due to their wide range of bioactivity, occurrence, abundance and ability to induce very little resistance, they hold promising potentials in drug development. This study investigated the presence of bioactive peptides in the roots of Calliandra portoricensis (CPr) (Mimosaceae) and evaluated its antimicrobial activity against gram-negative and gram-positive bacteria. Methods The crude peptide extract was obtained and pre-purified on pre-loaded tube of RP-C18 solid phase cartridges (strata giga tube C18-E; 5 g, 20 mL, Phenomenex, Germany). Peptide enriched fraction was chemically analysed for arginine-rich/aromatic amino acid-rich peptides using a modified G-250 analytical stain and ninhydrin on thin layer chromatography (TLC) for a preliminary screening. Furthermore, MALDI TOF/TOF peptidomics was used to detect the presence and masses of the peptides. Extracts from CPr were used to test the ability to inhibit microbial growth using p-INT (Para-iodonitrotetrazolium violet) dye, with 0.1% gentamycin as positive control. The concentration that inhibits the growth of microorganisms by 50% (IC50) were determined. Toxicity of the two extracts was accessed using freshly hatched nauplii of Artemia salina. Data analysis were evaluated using Microsoft excel and GraphPad Prism5. Results Low molecular weight (LMW) peptides were detected in CPr using TLC and MALDI-TOF MS. Generally, the extracts exhibited good inhibition (70–95%) against the gram-negative and gram-positive bacteria, except MRSA6 typed strain. Enhanced activity was observed in the pre-purified peptide fraction than in the methanol crude, except on MRSA6. The greatest antimicrobial inhibition by pre-purified peptide fraction was against MRSA22 (IC50 = 0.69 ± 0.33 μg/mL). The crude methanol extract (LC50 = 5.13 μg/mL) was slightly more toxic than the peptide extract (LC50 = 6.12 μg/mL). Conclusions This is the first report on detection of bioactive LMW peptides in Mimosaceae family. These peptides appear to be rich in arginine and aromatic amino acids. The peptide extract, in its pre-purified form showed a lower Brine shrimp cytotoxicity and an enhanced antimicrobial activity against the tested gram-negative and gram-positive bacteria.Item Heavy Metals, Proximate Analysis and Brine Shrimp Lethality of Vernonia amygdalina and Ocimum gratissimum Growing in Crude Oil-Rich Delta State, Nigeria(2021-11-24) Oluwatofunmilayo, Arike Diyaolu; Alfred, F. Attah; Emmanuel, T. Oluwabusola; Jones, Olanrewaju Moody; Marcel, Jaspars; Rainer, EbelVernonia amygdalina (VA) and Ocimum gratissimum (OG) are among the most frequently consumed vegetables in Kokori and Abraka communities of Delta State, Nigeria. However, the continuous crude oil exploration and spillages in Kokori may threaten their safety for use as food and medicine. Twelve samples of VA and OG obtained from crude oil-rich and crude oil-free communities were comparatively analysed for proximate composition, heavy metals, and cytotoxicity. Data obtained were subjected to various multivariate statistical techniques, including principal component analysis (PCA), biplot, and analysis of variance (ANOVA), to investigate the correlations between the vegetables from the different communities and the effect of crude oil exploration and spill on plant biomass. Results obtained indicate a significant difference (p < 0.05) in the proximate composition of VA and OG and higher heavy metal content for VA from the crude oil-spill Kokori. Two VA collections from Kokori were exceptionally toxic to cellular crustaceans.Item In vitro antiviral activity of peptide‑rich extracts from seven Nigerian plants against three non‑polio enterovirus species C serotypes(Virology Journal, 2021) Omonike, O. Ogbole; Toluwanimi, E. Akinleye; Abraham, O. Nkumah; Aminat, O. Awogun; Alfred, F. Attah; Moses, O. Adewumi; Adekunle, J. AdenijiBackground: As frequent viral outbreaks continue to pose threat to public health, the unavailability of antiviral drugs and challenges associated with vaccine development underscore the need for antiviral drugs discovery in emergent moments (endemic or pandemic). Plants in response to microbial and pest attacks are able to produce defence molecules such as antimicrobial peptides as components of their innate immunity, which can be explored for viral therapeutics. Methods: In this study, partially purified peptide-rich fraction (P-PPf ) were obtained from aqueous extracts of seven plants by reverse-phase solid-phase extraction and cysteine-rich peptides detected by a modified TLC method. The peptide-enriched fractions and the aqueous (crude polar) were screened for antiviral effect against three non-polio enterovirus species C members using cytopathic effect reduction assay. Results: In this study, peptide fraction obtained from Euphorbia hirta leaf showed most potent antiviral effect against Coxsackievirus A13, Coxsackievirus A20, and Enterovirus C99 (EV-C99) with IC50 < 2.0 μg/mL and selective index ≥ 81. EV-C99 was susceptible to all partially purified peptide fractions except Allamanda blanchetii leaf. Conclusion: These findings establish the antiviral potentials of plants antimicrobial peptides and provides evidence for the anti-infective use of E. hirta in ethnomedicine. This study provides basis for further scientific investigation geared towards the isolation, characterization and mechanistic pharmacological study of the detected cysteine-rich peptides.Item Peptidomics screening for the discovery of uterotonic plant peptides(BMC Pharmacology and Toxicology, 2012) Johannes, Koehbach; Alfred, F. Attah; Margaret, O’Brien; Michael, Freissmuth; Christian, W. GruberDrug discovery from natural products is still one of the biggest sources of novel lead compounds. In particular, plant cyclotides, disulfide-rich peptides comprising three conserved disulfide bonds in a knotted arrangement, known as cyclic cystine knot motif, and a head-to-tail cyclization, have been extensively investigated over the last four decades for their use as scaffolds in drug development. However, their distribution among flowering plants still remains limited to few species of the families of Rubiaceae (coffee), Violaceae (violet), Cucurbitaceae (cucurbit), Fabaceae (bean) and recently Solanaceae (potato family), but it is very likely that cyclotides are more widely distributed since their predicted number in Rubiaceae alone is ~50.000. Additionally, the pharmacological validation of plants used in traditional medicines may trigger the discovery of novel uterotonic compounds.Item Uterine contractilityofplantsusedtofacilitatechildbirthin Nigerian ethnomedicine(Journal of Ethnopharmacology, 2012-07-03) Alfred, F. Attah; Margaret, O’Brien; Johannes, Koehbach; Mubo, A. Sonibare; Terry, J. Smith; Christian, W. GruberEthnopharmacological relevance: Pregnant women in Nigeria use plant preparations to facilitate childbirth and to reduce associated pain. The rationale for this is not known and requires pharmacological validation. Aim of study: Obtain primary information regarding the traditional use of plants and analyze their uterine contractility at cellular level. Materials and methods: Semi-structured, open interviews using questionnaires of traditional healthcare professionals and other informants triggered the collection and identification of medicinal plant species. The relative traditional importance of each medicinal plant was determined by its use-mention index. Extracts of these plants were analyzed for their uterotonic properties on an in vitro human uterine cell collagen model. Result: The plants Calotropis procera, Commelina africana, Duranta repens, Hyptis suaveolens, Ocimum gratissimum, Saba comorensis, Sclerocarya birrea, Sida corymbosa and Vernonia amygdalina were documented and characterized. Aqueous extracts from these nine plants induced significant sustained increases in human myometrial smooth muscle cell contractility, with varying efficiencies, depending upon time and dose of exposure. Conclusion: The folkloric use of several plant species during childbirth in Nigeria has been validated. Seven plants were for the first time characterized to have contractile properties on uterine myometrial cells. The results serve as ideal starting points in the search for safe, longer lasting, effective and tolerable uterotonic drug leads.