List of Titles

Correlation of Total Phenolic, Flavonoid and Tannin Content of Bryophyllum pinnatum (Lam.) (Crassulaceae) Extract with the Antioxidant and Anticholinesterase Activities

Authors: Elufioye, Taiwo O , Olusola, Damilare M , Oyedeji, Adebola Omowunmi
Date: 2019
Subjects: Cholinesterase inhibitors , Antioxidants , Bryophyllum pinnatum
Language: English
Type: text , article
Identifier: http://hdl.handle.net/11260/1536 , vital:37776 , https://doi.org/10.5530/pj.2019.11.158
Description: Bryophyllum pinnatum is a perennial herb used in traditional medicine against varieties of ailments such as memory disorder. This study quantitatively estimated the total phenolic (TPC), total flavonoid (TFC) and total proautocyanidin (TPA) contents of extract and fractions of B. pinnatum and correlated them with its antioxidant and anticholinesterase activities. Methanolic extract of the dried leaves was partitioned into n-hexane, ethyl acetate and aqueous fractions. Total phenolic, flavonoids and proanthocyanidins content were estimated as gallic acid or quercetin equivalents. DPPH and nitric oxide scavenging activity as well as ferric reducing power assays were used to evaluate antioxidant activity, using 2,6-di-tert-butyl4-methylphenol (DDM) and ascorbic acid as standards. In vitro anticholinesterase activity was evaluated by Ellmann’s colorimetry assay with phsiostigmine (serine) and donepezil as positive control. The crude methanol extract had the highest phenolic, flavonoid and tannin content. The ethyl acetate fraction had the highest DPPH radical scavenging effect (IC50 0.004 mg/ml) while the aqueous fraction had the highest NO scavenging and ferric reducing effects with values of IC50 0.012 mg/ml and 0.007 mg/ml respectively. The ethyl acetate fraction had the best cholinesterase inhibitory effect (IC50 0.951 µg/ml AChE; 3.546 µg/ml BuChE). DPPH radical scavenging effect correlated strongly with total phenolic, flavonoids and proautocyanidins (r2 0.896, 0.651 and 0.619 respectively) while ferric reducing power showed weak correlation and NO scavenging as well as AChE inhibition had no correlation. The study shows DPPH radical scavenging could be due to the phenolic content while other class of compounds are responsible for the cholinesterase inhibition.
Full Text:
Date Issued: 2019

Ursolic Acid and its derivatives as bioactive agents

Authors: Mlala, Sithenkosi , Oyedeji, Adebola Omowunmi , Gondwe, Mavuto , Oyedeji, Opeoluwa Oyehan
Date: 2019
Subjects: Noncommunicable diseases , Pentacyclic triterpenoids , Ursolic acid , Clinical trials
Language: English
Type: text , article
Identifier: http://hdl.handle.net/11260/1576 , vital:37793 , https://doi.org/10.3390/molecules24152751
Description: Non-communicable diseases (NCDs) such as cancer, diabetes, and chronic respiratory and cardiovascular diseases continue to be threatening and deadly to human kind. Resistance to and side effects of known drugs for treatment further increase the threat, while at the same time leaving scientists to search for alternative sources from nature, especially from plants. Pentacyclic triterpenoids (PT) from medicinal plants have been identified as one class of secondary metabolites that could play a critical role in the treatment and management of several NCDs. One of such PT is ursolic acid (UA, 3 β-hydroxy-urs-12-en-28-oic acid), which possesses important biological effects, including anti-inflammatory, anticancer, antidiabetic, antioxidant and antibacterial effects, but its bioavailability and solubility limits its clinical application. Mimusops caffra, Ilex paraguarieni, and Glechoma hederacea, have been reported as major sources of UA. The chemistry of UA has been studied extensively based on the literature, with modifications mostly having been made at positions C-3 (hydroxyl), C12-C13 (double bonds) and C-28 (carboxylic acid), leading to several UA derivatives (esters, amides, oxadiazole quinolone, etc.) with enhanced potency, bioavailability and water solubility. This article comprehensively reviews the information that has become available over the last decade with respect to the sources, chemistry, biological potency and clinical trials of UA and its derivatives as potential therapeutic agents, with a focus on addressing NCD.
Full Text:
Date Issued: 2019

Cultivation of medicinal plants in South Africa: A solution to quality assurance and consistent availability of medicinal plant materials for commercialization

Authors: Oyedeji, Adebola Omowunmi
Date: 2018
Identifier: http://hdl.handle.net/11260/1584 , vital:37794
Full Text:

Biosynthesis of silver nanoparticles from Acacia mearnsii De Wild stem bark and its antinociceptive properties

Authors: Avoseh, Opeyemi N , Oyedeji, Opeoluwa O , Aremu, Olukayode , Nkeh-Chungag, Benedicta N , Songca, Sandile P , Oyedeji, Adebola Omowunmi , Mohan, Sneha , Oluwafemi, Oluwatobi S
Date: 2017
Subjects: Metal nanoparticles , Acacia mearnsii , Nociceptive pain
Language: English
Type: text , article
Identifier: http://hdl.handle.net/11260/1528 , vital:37774 , https://doi.org/10.1080/17518253.2017.1287310
Description: The biosynthesis of silver nanoparticles (Ag-NPs) using the hydrosol extract of the dry stem bark of Acacia mearnsii as reducing and capping agents, and their antinociceptive properties are hereby reported. By varying the temperature and reaction time, the temporal evolution of the optical and morphological properties of the as-synthesized material was investigated. The NPs were characterized by UV–visible absorption spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS) and x-ray diffractometry (XRD) The optical analyses show that the position of the maximum surface plasmon resonance (SPR) peak is red-shifted as the reaction temperature decreased. The TEM micrographs show that the as-synthesized Ag-NPs are spherical while the X-ray diffraction shows that the material is highly crystalline with face-centered cubic structures. The anti-inflammatory efficacy, analyzed by the formalin model, indicates that the as-synthesized Ag-NPs are very effective, with an inhibition rate of about 76%.
Full Text:
Date Issued: 2017