Browsing by Author "Hughes, Gail Denise"

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    Comparative study of the antioxidant constituents, activities and the gc-ms quantification and identification of fatty acids of four selected helichrysum species
    (MDPI, 2022) Akinyede, Kolajo Adedamola; Hughes, Gail Denise; Ekpo, Okobi Eko
    Helichrysum Mill. (Asteraceae) is a plant genus comprising distinctively of aromatic plants of about 500–600 species. Since most of these plants have not been previously studied, extensive profiling helps to validate their folkloric uses and determine their potential value as sources of plantderived drug candidates. This study, therefore, aims to investigate the antioxidant activity (DPPH, NO, FRAP); total antioxidant capacity, total phenolic, total flavonoid, and fatty acid compositions of the aqueous acetone extracts from four Helichrysum plants namely, Helichrysum pandurifolium, Helichrysum foetidum, Helichrysum petiolare, and Helichrysum cymocum. The results obtained showed that the H. cymocum extract had the best DPPH radical scavenging activity (IC50 = 11.85 ± 3.20 µg/mL) and H. petiolare extract had the best nitric oxide scavenging activity (IC50 = 20.81 ± 3.73 µg/mL), while H. pandurifolium Schrank extract (0.636 ± 0.005 µg/mL) demonstrated the best ferrous reducing power, all of which are comparable with results from ascorbic acid used as the standard. The IC50 values of the radical scavenging activity ranged from 11.85–41.13 µg/mL (DPPH), 20.81–36.19 µg/mL (NO), and 0.505–0.636 µg/mL (FRAP), for all the plants studied. The H. petiolare has the highest total antioxidant capacity (48.50 ± 1.55 mg/g), highest total phenolic content (54.69 ± 0.23 mg/g), and highest total flavonoid content (56.19 ± 1.01 mg/g) compared with other species.
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    In vitro evaluation of the anti-diabetic potential of aqueous acetone Helichrysum petiolare extract (AAHPE) with molecular docking relevance in diabetes mellitus
    (MDPI, 2021-12) Akinyede, Kolajo Adedamola; Oyewusi, Habeebat Adekilekun; Hughes, Gail Denise; Ekpo, Okobi Eko
    Diabetes mellitus (DM) is a chronic metabolic condition that can lead to significant complications and a high fatality rate worldwide. Efforts are ramping up to find and develop novel α-glucosidase and α-amylase inhibitors that are both effective and potentially safe. Traditional methodologies are being replaced with new techniques that are less complicated and less time demanding; yet, both the experimental and computational strategies are viable and complementary in drug discovery and development. As a result, this study was conducted to investigate the in vitro anti-diabetic potential of aqueous acetone Helichrysum petiolare and B.L Burtt extract (AAHPE) using a 2-NBDG, 2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl) amino)-2-deoxy-D-glucose uptake assay. In addition, we performed molecular docking of the flavonoid constituents identified and quantified by liquid chromatography-mass spectrometry (LC-MS) from AAHPE with the potential to serve as effective and safe α-amylase and α-glucosidase inhibitors, which are important in drug discovery and development. The results showed that AAHPE is a potential inhibitor of both α-amylase and α-glucosidase, with IC50 values of 46.50 ± 6.17 (µg/mL) and 37.81 ± 5.15 (µg/mL), respectively. This is demonstrated by a significant increase in the glucose uptake activity percentage in a concentrationdependent manner compared to the control, with the highest AAHPE concentration of 75 µg/mL of glucose uptake activity being higher than metformin, a standard anti-diabetic drug, in the insulinresistant HepG2 cell line. The molecular docking results displayed that the constituents strongly bind α-amylase and α-glucosidase while achieving better binding affinities that ranged from ∆G = −7.2 to −9.6 kcal/mol (compared with acarbose ∆G = −6.1 kcal/mol) for α-amylase, and ∆G = −7.3 to −9.0 kcal/mol (compared with acarbose ∆G = −6.3 kcal/mol) for α-glucosidase. This study revealed the potential use of the H. petiolare plant extract and its phytochemicals, which could be explored to develop potent and safe α-amylase and α-glucosidase inhibitors to treat postprandial glycemic levels in diabetic patients.
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    Medicinal properties and in vitro biological activities of selected helichrysum species from South Africa: A review
    (MDPI, 2021) Akinyede, Kolajo Adedamola; Cupido, Christopher Nelson; Hughes, Gail Denise
    The genus Helichrysum Mill comprises hundreds of species that are mostly flowering perennial shrubs. Some of these plants that belong to the Helichrysum species are used in traditional medicine to treat cough, back pain, diabetes, asthma, digestive problems, menstrual pain, chest pain, kidney disorders, skin disorders, wounds, open sores, among other conditions, but, only a few scientific studies are reported in the literature with sufficient information that validates the acclaimed folkloric benefits of these plants. This review, therefore, provides a comprehensive update of the available information on the cytotoxicity, genotoxicity, anti-proliferative, anti-bacterial, anti fungal, anti-viral, anti-HIV, anti-malarial, anti-ulcerogenic, anti-tyrosinase, anti-inflammatory, and anti-oxidant activities of selected Helichrysum species of interest: H. petiolare, H. cymocum, H. foetidum, and H. pandurifolium Schrank, using scientific databases as well as electronic and print sources. The ethnobotanical and morphological characteristics as well as the phytochemical composition and biological activities of these plants are elucidated. The scientific rationale for their current use is discussed based on the evidence in the literature.