Pharmacognosy- Scholarly Publications

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    Open Access
    Antimalarial and Antioxidant Potentials of Extract and Fractions of Aerial Part of Borreria ocymoides DC (Rubiaceae)
    (PhCOGNET, 2017) Adesegun, S.A.; Orabueze, C.I.; Coker, H.A.
    Introduction: Borreria ocymoides(Burm F) DC is a weak, erect and decumbent herb that has several folkloric, ethno medicinal uses and is included in antimalarial preparations by some traditional healers. It is also used in treatment of ring worm, eczema and microbial infections. Objectives: To evaluate antimalarial activity of extract and fractions of Borreria ocymoidesin Plasmodium bergheiinfected mice and to investigate their antioxidant activity using 1, 1-diphenyl-2-picryl-hydrazile (DPPH). Methods:The methanol extract of aerial part of B. ocymoidesand the solvent fractions obtained from partition between organic solvents were assessed for antimalarial activity against chloroquine sensitive Plasmodium bergheiNK65 infected mice using the suppressive and curative test procedures. Chloroquine (10 mg/ml) was used as positive control. The antioxidant activity was evaluated using DPPH radical scavenging ability and determination of total phenolic content. Results:The crude extract (250 and 500 mg kg-1) produced a dose dependent anti-plasmodial activity in the suppressive and curative tests. The chemo suppression activity was best in the ethyl acetate fraction (87.31%) and in the order ethyl acetate >dichloromethane > hexane > aqueous fraction. The DPPH radical scavenging activity of the extract increased with concentration. The antioxidant activity was less than ascorbic acid used as positive control. Oral administration up to 5 g/kg produced no noticeable deleterious effect 24 hours after dosing and up to 7 days afterwards. Conclusion:The results indicated that the extract has a potent anti-plasmodial activity against Plasmodium berghei and the activity seems to reside in the mid-polar fractions. Thus, the plant is a potential source of new antimalarial agents.
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    Open Access
    Antinociceptive and Antioxidant Activities of Methanol Extract and Fractions of the Root Bark of Callichilia stenopetala Stapf. (Family Apocynaceae) In Mice
    (Natural Product Research Group, University of Benin., 2017) Orabueze, C.I.; Adesegun, S.A.; Coker, H.A
    The root of Callichilia stenopetala is used as chewing stick in the treatment of toothache and for oral hygiene in South-East Nigeria. The study assessed the antinociceptive and antioxidant activities of methanol root bark extract and fractions of C. stenopetala. Analgesic activity of methanol root bark extract of C. stenopetala and its fractions were evaluated using chemical (acetic acid and formalin) and thermal (hot plate and tail immersion) tests in mice. Morphine sulphate, acetyl salicylic acid and diclofenac sodium at 4, 100 and 10 mg kg-1, respectively were used as standards. Antioxidant potential was evaluated using DPPH (1, 1-diphenyl-2-picrylhyrazyl) free radical scavenging activity and total phenolic content (TPC) assays. Oral acute toxicity was also evaluated. The extract (250 and 500 mg kg-1), ethyl acetate and aqueous fractions (200 mg kg-1) reduced acetic acid-induced writhing with percentage reduction of 65.14, 84.06, 93.27 and 50.63 %, respectively. The ethyl acetate fraction and methanol extract at 500 mg kg-1 significantly increased reaction times in tail immersion and hot plate tests. The formalin test results for the ethyl acetate fraction suggested involvement of central mechanism of pain inhibition. In DPPH scavenging assay and TPC, the extract showed good antioxidant potential, with most of the activity prominent in the polar fractions. At 8000 mg kg-1 no death of animal occurred. These findings suggested that C. stenopetala has pain alleviating effect which may be due to its antioxidant activity and this further substantiated the claimed traditional use of the plant in the management of acute toothache.
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    Open Access
    Antioxidant and In-vitro Antidiabetic Activities of Fermented Peels of Citrus x Sinensis (l.) Osbeck (Rutaceae)
    (Sami Publishing Company/Iranian Chemical Science and Technologies Association, 2021-12-24) Oyawaluja, A. A.; Oiseoghaede, J. O.; Odukoya, O. A.; Kubiat, B. E.
    Introduction: The various parts of Citrus sinensis plant have been employed over the years for medicinal purposes. As part of the concept of waste to wealth, the medicinal importance of the peels was exploited. This study aimed at determining the antioxidant and in vitro antidiabetic activities of fermented peel extracts of C. sinensis. Method: Fermentation of the peels was carried out, and phytochemical tests were done. DPPH free radical scavenging activity, anti-lipid peroxidation and Antidiabetic assay method were performed in vitro using standard procedures. Results: C. sinensis were rich in polyphenols and reducing sugars. Radical scavenging assay showed an IC50 of 0.57μg/ml and 1.60μg/ml for fresh peels and dried peels respectively for DPPH assay, and 0.67μg/ml (fresh) and 0.72μg/ml (dried) for anti-lipid peroxidation assay. The α-amylase inhibition assay showed that the fermented fresh peels and fermented dried peels had IC50 values of 2.23μg/ml and 2.73μg/ml respectively. The α-glucosidase assay showed better inhibition by the extracts. Fermented fresh and dried peels had IC50 values of 0.03μg/ml and 0.03μg/ml respectively. Conclusion: Fermented fresh peels of C. sinensis expressed relatively stronger protection in the antioxidant and antidiabetic assays than the fermented dried peels. This study revealed that extracts can be considered as an important addition to the therapeutic management for diabetes.
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    Open Access
    Analgesic and Antioxidant Activities of Stem Bark Extract and Fractions of Petersianthus macrocarpus
    (Wolters Kluwer ‑Medknow, 2016) Orabueze, C.I.; Adesegun, S.A.; Coker, H.A
    Background: Petersianthus macrocarpus(Lecythidaceae) is widely used in the folk medicine in Nigeria to relieve pain and fever associated with malaria. This study evaluated the analgesic and antioxidant activities of the methanol extract and fractions of the stem bark of the plant. Materials and Methods:The analgesic activity was determined in mice using hotplate and acetic acid‑induced writhing models. Morphine sulphate (5 mg/kg, i.p.) and aspirin (100 mg/ml, p.o.) were used as reference analgesic agents. The antioxidant potential was evaluated using 1,1‑diphenyl‑2‑picrylhydrazyl (DPPH) radical; reducing power, iron chelating properties and determination of total phenolic content. Results:The extract at 200 and 500 mg/kg, produced an insignificant (P> 0.05) increase in pain threshold in hotplate but a significant (P< 0.05) increase at 1000 mg/kg. The extract significantly (P< 0.05) reduced the writhing induced by acetic acid in mice in a dose dependent manner. Fractionation increased the analgesic activities significantly (P< 0.05) in ethyl acetate and aqueous fractions (200 mg/kg). The extract demonstrated strong DPPH radical scavenging activity with IC 50 0.05 mg/ml, good reducing power and weak iron chelating activities. The total phenol content was 142.32 mg/gin term of gallic acid. The antioxidant effects were more pronounced in ethyl acetate and aqueous fractions. Conclusion: The findings of the study suggested that the extract has strong analgesic and antioxidant activities which reside mainly in the polar fractions thus confirming the traditional use of the plant to alleviate pains.
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    Open Access
    Ikirydinium A: a new indole alkaloid from the seeds ofHunteria umbellata (K. Schum)
    (Elsevier Ltd, 2011) Ajala, O.S.; Piggott, A.M.; Plisson, F.; Khalil, Z; Huang, X.; Adesegun, S.A.; Coker, H.A.; Capon, R.J.
    Chemical investigations into samples ofHunteria umbellata(K. Schum) collected in Osun State, Nigeria,led to the discovery of a new indole alkaloid, ikirydinium A, featuring an unprecedented 3-alkylpyridinium-indole-2-carboxylate scaffold. Ikirydinium A was found to exhibit antimicrobial activity (IC500.6lM) againstBacillus subtilisATCC 6051. The involvement of a common intermediate in the biosynthesis of ikirydinium A and vinblastine is hypothesized