Department of Pharmacognosy

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Browsing Department of Pharmacognosy by Author "Adesegun, S.A."

Now showing 1 - 7 of 7
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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
    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
    Antiplasmodial activity of leaf extract and fractions of Rutidea smithii Hiern (Rubiaceae)
    (West African Journal of Pharmacy, 2019) Adesegun, S.A.; Iwunze, N.; Orabueze, C.I.; Ota, D.; Coker, H.A.B.
    Background: Resistance to malaria infection has been of great public health concern all over the world especially in developing countries thus there is need for development of new antimalarial drugs. Natural products including medicinal plants are veritable sources for drug discovery hence their investigation for possible antimalarial effects. Rutidea smithii is a woody climbing plant used traditionally in treatment of headache, cold and fever . Objective: T o investigate the in vivo antimalarial activity of ethanol leaf extract and fractions of Rutidea smithii in chloroquine sensitive Plasmodium berghei infected mice. Methods: Swiss albino mice were intraperitoneally infected with chloroquine sensitive P . berghei (ANKA strain). The mice were treated orally using suppressive and curative models with graded doses of extract of R. smithii (100, 200 and 400 mg/kg), fractions (50, 100 and 200 mg/kg) and standard antimalarial drug; chloroquine (10 mg/kg). Preliminary phytochemical screening and acute toxicity study were also carried out. Results: In the suppressive and curative tests, the extract demonstrated significant dose reduction in parasite level (p < 0.05) in infected mice and the survival time was also prolonged. The antimalarial activity of the fractions increased in the order hexane < butanol < aqueous < ethylacetate. The extract was devoid of toxicity up to the highest dose tested (2000 mg/kg). Conclusion: Rutidea smithii has potent in vivo antiplasmodial activity against P . berghei which resides mainly in ethylacetate fraction thus is a veritable source of new antimalarial agents.
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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
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    Open Access
    In vivo antimalarial and in vitro antioxidant activities of hydro-methanol leaf extract of Fadogia cienkowskii Schweinf. (Rubiaceae)
    (A KeSoBAP Publication, 2019) Orabueze, C.I.; Adesegun, S.A.; Ejeatuluchukwu, O.; Ota, D.A; Coker, H.A
    Background: Rapid parasite resistance to antimalarial drugs necessitate continuous search for new drugs. Fadogia cienkowskii Schweinf. (Rubiaceae) is one of the several plants utilized in South-East Nigeria for treatment of malaria fever. Objective: The aim of the study was to evaluate antimalarial and antioxidant potentials of leaf extract of F. cienkowskii. The phytochemical profile and toxic heavy metal content were also evaluated. Methodology: Antimalarial activity of crude leaf extract of F. cienkowskii (100 – 400 mg kg-1) was assessed against chloroquine sensitive Plasmodium berghei (NK65) using suppressive and curative test models. Chloroquine 10 mg kg -1 was used as positive control. Antioxidant activity was evaluated using 1,1-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power methods. The presence of heavy metals in the raw material was evaluated using Atomic Absorption Spectrophotometric technique and modified Lorke’s method was employed to test for oral acute toxicity. Results: The results showed that the test plant exhibited antimalarial activities in both models in a dose-dependent manner. The comparison analysis showed that at 400 mg kg-1, the suppressive and curative effects were 93.44% and 72.47% respectively. All the animal groups that received test extract lived longer and weight loss was prevented compared to the negative control group. The test extract exhibited antioxidant potential in DPPH scavenging and FRAP assays compare with Vitamin C. All the tested heavy metals were present but within permissible range. Acute toxicity study of extract revealed no immediate adverse effect(s). Conclusion: These results support the traditional use of F. cienkowskii in management of malaria fever.
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    Open Access
    Potential antimalarial activity of Coccinia barteri leaf extract and solvent fractions against Plasmodium berghei infected mice
    (Elsevier, 2020) Orabueze, I.C.; Obi, E.; Adesegun, S.A.; Coker, H.A.
    ETHNOPHARMACOLOGICAL RELEVANCE: Coccinia barteri (Hook. F.) is traditional used in Southeast of Nigeria in management of fever. This study aimed to evaluate the antimalarial activities of hydro-methanol crude extract and solvent fractions of Coccinia barteri leaf. MATERIALS AND METHODS: Two animal models employed for the study were, 4-day suppressive and curative assays against chloroquine sensitive Plasmodium berghei NK65. Level of parasitaemia, mean survival time (MST), anal temperature and weight loss were measured to assess antimalarial efficacy of the extract/fractions. Chloroquine (10 mg kg-1) was used as positive control. Chemo-profile of extract was evaluated using GC-MS, HPLC techniques and standard phytochemical analysis. Preliminary toxicity test was done using modified Lorke's method. RESULTS: The crude extract (100-400 mg kg-1) and solvent fractions (20-80 mg kg-1) demonstrated antimalarial activity in both models compared to controls. Semi purified fractions of the extract produced stronger percentage chemosuppression and inhibition of parasite. The % inhibition of the fractions, hexane, chloroform, ethyl acetate and aqueous at 80 mg kg-1 were 96.0 0, 95.29, 89.86 and 96.00% respectively on day 8 (D8). While on D14, 100% parasite clearance, indicating cure was obtained for hexane, chloroform and aqueous fraction treatment groups, no death occurred in these groups. Ethyl acetate fraction treated groups lived longer but were not fully protected. Some marker compounds were identified. CONCLUSIONS: These results support the use of C. barteri as malaria remedy and potential source of antimalarial templates. Long acting parasitaemia reduction effect indicates its possible combination potential in poly-herbal combination therapy.