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Papers by abraham nkumah

CRC Press eBooks, Jan 16, 2024

Journal of Pharmacy & Biore Sources, May 9, 2024

Global concerns over antibiotic-resistant microbial pathogens have spurred a quest for innovative... more Global concerns over antibiotic-resistant microbial pathogens have spurred a quest for innovative, stable, and targetspecific molecules like bioactive peptides. This study evaluates the antimicrobial properties and toxicity of peptideenriched extracts from Newbouldia laevis leaves. Aqueous extraction, thin layer chromatography (TLC), and Phenomenex's Stratum Giant Tube C18-E were used to obtain partly purified fraction (PPF) and crude peptide extracts (CPE). Antimicrobial inhibitory capacity was determined using pINT dye, with gentamicin and fluconazole as standards. Cytotoxicity was assessed with Artemia salina nauplii. Microsoft Excel and GraphPad Prism 5 was used in analysing the data. Peptides were detected in CPE and PPF via TLC and modified G-250. PPF demonstrated more efficacy (IC50: 5.89μg/mL to 33.94μg/mL) against bacteria and fungi, with low toxicity (LC50: 5964.87µg/mL for PPF and 1094.20µg/mL for CPE) in the Brine shrimp lethality assay. The study presents the discovery of bioactive peptides from the leaves of Newbouldia laevis. Consequently, bioactive peptides extracted from this plant hold potential as foundational compounds for the development of novel broad-spectrum antibiotics aimed at combating microbial infections.

Virology Journal, Aug 4, 2021

Background: As frequent viral outbreaks continue to pose threat to public health, the unavailabil... more Background: 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 IC 50 < 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.

The Korean Society of Health-System Pharmacists, Aug 1, 2014

Natural product research, 2021

Termitomyces species are known edible mushrooms in Nigeria, believed to have exceptional culinary... more Termitomyces species are known edible mushrooms in Nigeria, believed to have exceptional culinary and nutraceutical properties. Methanol extract from fruiting bodies of Termitomyces robustus was evaluated for antidiabetic activity using in vitro α-amylase and α-glucosidase assays. The isolation and structural elucidation of metabolites from the T. robustus extract afforded five compounds including a new natural product γ-glutamyl-β-phenylethylamine 3 and four known phenyl derivatives: tryptophan 1, 4-hydroxyphenylacetic acid 2, 4-hydroxyphenylpropionic acid 4, and phenyllactic acid 5. Structures were elucidated from analyses of spectroscopic data (1 D and 2 D NMR, HRESIMS) and all isolated compounds were tested for α-amylase and α-glycosidase inhibitory activity. The in vitro assay established crude extract to possess α- amylase and α-glucosidase inhibition with IC50 of 78.05 µg/mL and 86.10 µg/mL, respectively. The isolated compounds compared favourably with the standard drug, acar...

Turkish Journal of Pharmaceutical Sciences, 2021

Introduction: Mushrooms are fungi with nutritional and health benefits. Lentinus squarrosulus Mon... more Introduction: Mushrooms are fungi with nutritional and health benefits. Lentinus squarrosulus Mont. an edible fungus has traditional utilization and relevance in local therapy for the management of metabolic diseases. In that view, the present study evaluated the in vitro antiobesity, anti-diabetic and cytotoxic potential of the chloroform/methanol extract (CME) and aqueous extract (AE) of the mushroom. Methods: Lentinus squarrosulus was identified using molecular biology tools. The CME and AE obtained sequentially were subjected to alpha-amylase, alpha-glucosidase and lipase inhibitory enzyme assays, as well as total phenolic content (TPC) and total flavonoid content (TFC) estimations. The cytotoxic potential of L. squarrosulus extract fractions were assessed using the brine shrimp lethality assay. Results: The molecular identification of the mushroom showed that the internal transcribed spacer (ITS) sequence was an equivalent match to that of L. squarrosulus with a high percentage...

Mycology, 2019

Mushrooms are cherished as sources of food, nutrients and medicine. Inadequate data on the identi... more Mushrooms are cherished as sources of food, nutrients and medicine. Inadequate data on the identity and medicinal properties of many wild Nigerian mushrooms has limited their utilization. This work was carried out to identify and authenticate a puffball mushroom using molecular tools and investigate its antidiabetic properties. Taxonomic guides were employed in morphological identifying the mushroom as Lycoperdon umbrinum, methanol extract of fruiting bodies was evaluated for antidiabetic activity using in vitro α-amylase assay and in vivo activity in the alloxan-induced diabetic rat model. The macro fungus was identified using Internal Transcribed Spacers (ITS) sequence analysis after which sequences generated were compared using the basic local alignment search tool (BLAST) at NCBI GenBank. In the acute in vivo test, the 400 mg/kg dose showed the best activity with percentage reduction in blood glucose 29.3%, compared with 5 mg/kg glibenclamide at 15%. The in vitro assay established that the extract possessed potent activity with IC50 of 0.46 µg/mL compared to its DCM, butanol fractions and acarbose (IC50 5.3 µg/mL, 5.6 µg/mL, 45 µg/mL) respectively. BLAST analysis revealed the mushroom (accession number, KRO78278.1) to show 98% identity to Calvatia gigantea. The study established the identity of this mushroom and confirmed its antidiabetic activity.

Virology Journal

Background As frequent viral outbreaks continue to pose threat to public health, the unavailabili... more Background 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 ag...

CRC Press eBooks, Jan 16, 2024

Journal of Pharmacy & Biore Sources, May 9, 2024

Global concerns over antibiotic-resistant microbial pathogens have spurred a quest for innovative... more Global concerns over antibiotic-resistant microbial pathogens have spurred a quest for innovative, stable, and targetspecific molecules like bioactive peptides. This study evaluates the antimicrobial properties and toxicity of peptideenriched extracts from Newbouldia laevis leaves. Aqueous extraction, thin layer chromatography (TLC), and Phenomenex's Stratum Giant Tube C18-E were used to obtain partly purified fraction (PPF) and crude peptide extracts (CPE). Antimicrobial inhibitory capacity was determined using pINT dye, with gentamicin and fluconazole as standards. Cytotoxicity was assessed with Artemia salina nauplii. Microsoft Excel and GraphPad Prism 5 was used in analysing the data. Peptides were detected in CPE and PPF via TLC and modified G-250. PPF demonstrated more efficacy (IC50: 5.89μg/mL to 33.94μg/mL) against bacteria and fungi, with low toxicity (LC50: 5964.87µg/mL for PPF and 1094.20µg/mL for CPE) in the Brine shrimp lethality assay. The study presents the discovery of bioactive peptides from the leaves of Newbouldia laevis. Consequently, bioactive peptides extracted from this plant hold potential as foundational compounds for the development of novel broad-spectrum antibiotics aimed at combating microbial infections.

Virology Journal, Aug 4, 2021

Background: As frequent viral outbreaks continue to pose threat to public health, the unavailabil... more Background: 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 IC 50 < 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.

The Korean Society of Health-System Pharmacists, Aug 1, 2014

Natural product research, 2021

Termitomyces species are known edible mushrooms in Nigeria, believed to have exceptional culinary... more Termitomyces species are known edible mushrooms in Nigeria, believed to have exceptional culinary and nutraceutical properties. Methanol extract from fruiting bodies of Termitomyces robustus was evaluated for antidiabetic activity using in vitro α-amylase and α-glucosidase assays. The isolation and structural elucidation of metabolites from the T. robustus extract afforded five compounds including a new natural product γ-glutamyl-β-phenylethylamine 3 and four known phenyl derivatives: tryptophan 1, 4-hydroxyphenylacetic acid 2, 4-hydroxyphenylpropionic acid 4, and phenyllactic acid 5. Structures were elucidated from analyses of spectroscopic data (1 D and 2 D NMR, HRESIMS) and all isolated compounds were tested for α-amylase and α-glycosidase inhibitory activity. The in vitro assay established crude extract to possess α- amylase and α-glucosidase inhibition with IC50 of 78.05 µg/mL and 86.10 µg/mL, respectively. The isolated compounds compared favourably with the standard drug, acar...

Turkish Journal of Pharmaceutical Sciences, 2021

Introduction: Mushrooms are fungi with nutritional and health benefits. Lentinus squarrosulus Mon... more Introduction: Mushrooms are fungi with nutritional and health benefits. Lentinus squarrosulus Mont. an edible fungus has traditional utilization and relevance in local therapy for the management of metabolic diseases. In that view, the present study evaluated the in vitro antiobesity, anti-diabetic and cytotoxic potential of the chloroform/methanol extract (CME) and aqueous extract (AE) of the mushroom. Methods: Lentinus squarrosulus was identified using molecular biology tools. The CME and AE obtained sequentially were subjected to alpha-amylase, alpha-glucosidase and lipase inhibitory enzyme assays, as well as total phenolic content (TPC) and total flavonoid content (TFC) estimations. The cytotoxic potential of L. squarrosulus extract fractions were assessed using the brine shrimp lethality assay. Results: The molecular identification of the mushroom showed that the internal transcribed spacer (ITS) sequence was an equivalent match to that of L. squarrosulus with a high percentage...

Mycology, 2019

Mushrooms are cherished as sources of food, nutrients and medicine. Inadequate data on the identi... more Mushrooms are cherished as sources of food, nutrients and medicine. Inadequate data on the identity and medicinal properties of many wild Nigerian mushrooms has limited their utilization. This work was carried out to identify and authenticate a puffball mushroom using molecular tools and investigate its antidiabetic properties. Taxonomic guides were employed in morphological identifying the mushroom as Lycoperdon umbrinum, methanol extract of fruiting bodies was evaluated for antidiabetic activity using in vitro α-amylase assay and in vivo activity in the alloxan-induced diabetic rat model. The macro fungus was identified using Internal Transcribed Spacers (ITS) sequence analysis after which sequences generated were compared using the basic local alignment search tool (BLAST) at NCBI GenBank. In the acute in vivo test, the 400 mg/kg dose showed the best activity with percentage reduction in blood glucose 29.3%, compared with 5 mg/kg glibenclamide at 15%. The in vitro assay established that the extract possessed potent activity with IC50 of 0.46 µg/mL compared to its DCM, butanol fractions and acarbose (IC50 5.3 µg/mL, 5.6 µg/mL, 45 µg/mL) respectively. BLAST analysis revealed the mushroom (accession number, KRO78278.1) to show 98% identity to Calvatia gigantea. The study established the identity of this mushroom and confirmed its antidiabetic activity.

Virology Journal

Background As frequent viral outbreaks continue to pose threat to public health, the unavailabili... more Background 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 ag...