N-Butanol Fraction of Dioscorea dumetorum Tuber Aqueous Extract Exhibited Potent Antimalarial Activity in Plasmodium berghei-infected Mice.

Evaluations of biocidal potential of Euclea crispa stem bark extract and ability to compromise the integrity of microbial cell membrane

In vitro antiplasmodial activity, cytotoxicity, and gas chromatography – flame ionization detector metabolites fingerprint of extracts and fractions from Tetrorchidium didymostemon

Hepatoprotective potential of antioxidant potent fraction from Urtica dioica Linn. (whole plant) in CCl4 challenged rats

This study was carried out to investigate the antioxidant activity of bamboo (Sasa borealis) leaf extract by measuring electron donating ability, superoxide dismutase (SOD)-like activity, reducing power, and lipid peroxidation inhibitory activity. Two crude extracts by water or 70% EtOH and five fractions of n-hexane, chloroform, ethyl acetate, n-butanol, and aqueous from the crude extract of 70% EtOH were prepared for this study. The crude extracts of water and 70% EtOH yielded 8.5% and 11.4%, respectively and the yields of n-hexane, chloroform, ethyl acetate, n-butanol, and aqueous fractions were 5.1% to 0.6%. Total polyphenol contents of the water and the 70% EtOH crude extracts were not significantly different; however, their total flavonoid contents were significantly greater in the 70% EtOH than in the water crude extract. Total polyphenol contents were the highest in chloroform fraction followed by ethyl acetate and n-butanol fractions and total flavonoid contents were the highest in ethyl acetate fraction followed by chloroform and n-hexane fractions. The two crude extracts as well as the five fractions showed election donating ability, SOD-like ability, reducing power, and lipid peroxidation inhibitory activity. Most of the antioxidant activities of each crude extract or fractions increased proportionally with the concentration. These results indicate that bamboo (Sasa borealis) leaf extracts show antioxidant activities due to its substantial content of polyphenol including flavonoid. Thus, it could be concluded that crude extracts by water or 70% EtOH and the fractions from the 70% EtOH extract, especially chloroform, ethyl acetate and n-butanol, would be useful as natural antioxidant substances.

Sargassum sp. is one of the brown seaweed that contains bioactive compounds, which have antioxidant and alpha glucosidase inhibitor activity. This research aimed to determine the rendemen, secondary metabolic, total phenolic, antioxidant, and alpha glucosidase inhibitor from the extract and fractions of Sargassum sp. The research method used was an experiment by extracting Sargassum sp with methanol and the extract were fractionated with different polarity solvents (n-hexane, ethyl acetate, and ethanol). Data were analyzed descriptively. The analysis parameters consisted of rendemen, secondary metabolic (qualitative), total phenolics, antioxidants (DPPH and FRAP), and alpha glucosidase inhibitors. The results showed that the rendemen of the n-hexane, ethyl acetate, and ethanol fractions were 4,15, 5,81, and 4,94%, respectively. The secondary metabolic analysis of methanol extract were alkaloids, steroids/terpenoids, saponins, and phenolic. The n-hexane fraction were steroids/terpenoids, saponins, and phenolic. The ethyl acetate fraction were alkaloids, steroids/terpenoids, saponins, and phenolic. The ethanol and water fractions contained only saponins. The total phenolic content of the methanol extract, n-hexane, ethyl acetate, and etanol fractions were 21161,03, 7854,46, 1626,89, and 80,17 ppm. Antioxidants in methanol extract, n-hexane, ethyl acetate, ethanol fractions using DPPH were 329,42, 466,25, 535,08, and 80,17 ppm. Antioxidants in methanol extract, n-hexane, ethyl acetate, and ethanol fractions using FRAP were 196,15, 294,88, 364,26, and 492,68 ppm. Alpha glucosidase inhibitor in n-hexane fraction with an IC50 value of 538110,9 ppm. Extract and fractions of Sargassum sp. with different polarity solvents contained different secondary metabolic. Saponins were found in all solvents, phenolics and steroids/terpenoids were found in methanol extract, n-hexane, and ethyl acetate fractions, alkaloids were found in methanol exract and ethyl acetate fraction. The n-hexane fraction showed the highest activity in total phenol, antioxidant, and alpha glucosidase inhibitor.

Purpose: To evaluate the in vivo and in vitro antiplasmodial activity of Jussiaea linifolia extracts using validated models.Methods: Methanol extract was partitioned into n-hexane, ethyl acetate and n-butanol fractions and subjected to antiplasmodial and cytotoxic activity assays. The in vivo assay adopted Peter’s four-day suppressive and Ranes curative tests to estimate Plasmodium berghei NK47 growth suppression while the in vitro antiplasmodial activities were performed using chloroquine-sensitive Plasmodium falciparumNF54 and L6 mammalian myoblast to determine growth inhibition and cytotoxicity respectively.Results: Acute toxicity test showed that the methanol extract displayed LD50 > 5000 mg/kg. The in vitro assays revealed that the extract and ethyl acetate fraction elicited significantly higher IC50 of 1.15 μg/mL (L6 83.2 μg/mL) and 0.785 μg/mL (L6 > 100 μg/mL), respectively against P. falciparum compared with n-hexane (> 100 μg/mL; L6 5.89 μg/mL) and n-butanol (48.1 μg/mL; L6 12.84 μg/mL) fractions. In the in vivo suppressive model, 400 mg/kg of ethyl acetate soluble fraction elicited a 97.1 % (p < 0.05; mean survival time > 21 days) P. berghei suppression compared with untreated group. Also, the ethyl acetate soluble evoked the highest suppression of parasitemia (94.17 %) in the curative model when compared with untreated. The extract and fractions of J. linifolia were found to restore packed cell volume in infected mice to their respective baselines compared with continued decline in untreated group.Conclusion: The study validates the traditional use of J. linifolia as an antimalarial decoction in some rural communities and shows that the ethyl acetate soluble fraction of methanol extract could be a source of lead antiplasmodial compounds.

Due to the distinguished medicinal value of Chrysobalanus icaco, it was of great interest to conduct phytochemical and antioxidant investigations on it. In this study, the polyphenol profile and antioxidant activity of C. icaco methanol crude extract and fractions were investigated. The crude extract of C. icaco was subjected to fractionation using methanol, n-hexane, ethyl acetate, and n-butanol as solvents. 2, 2-diphenyl-1picryl-hydrazyl (DPPH), 2,2’-azino-bis-(3- ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric ion reducing power (FRAP), ascorbate oxidase, total phenolic content, total flavonoids and polyphenol profile was determined using standard methods. A significant increase was observed in the DPPH radical scavenging activity, total flavonoids, total phenol, FRAP, ABTS, TAC and ascorbate oxidase of the crude extract when compared to methanol, ethyl acetate, n-hexane, n-butanol, and aqueous fractions. Polyphenols such as kaempferol, chlorogenic acid, catechin, quercetin, galic acid, pomolic acid, rutin, epicatechin, stigmasterol, sitosterol and caffeic acid were found in the different fractions. The total polyphenols content of different fractions of C icaco extract were as follows; methanol fraction > n-hexane fraction > ethyl acetate fraction > n-butanol fraction > aqueous fraction. The findings revealed that C icaco kernel could be used as a potent source of molecules with positive health attributes.

Malaria is an infectious disease that is responsible for approximately one million deaths across the world each year. The emergence and rapid spread of resistance to the established antimalarial drugs demands the development of a new generation of medicines to treat the many millions of people who are likely to be infected by chloroquine- and even artemisinin-resistant Plasmodium parasites. The primary theme explored within this thesis has been application of the “inverted silver bullet” approach to antimalarial drug discovery. This strategy involves investigating targets that are well conserved between the parasite and human host, and for which good inhibitors of the human homologue are known. The cyclic nucleotide phosphodiesterase (PDE) enzymes fit this profile. The human PDEs (hPDE1-11) and Plasmodium falciparum PDEs (PfPDEα-δ) are predicted to be structurally homologous. They also meet the second criterion in that inhibitors of the human forms are established as drugs, such as sildenafil (Viagra®). There is also evidence that inhibiting the PfPDEs will dramatically alter the cell biology of the protozoa, perhaps most significantly its asexual reproduction. Two variations of this strategy have been examined in this thesis. In Chapters 2 and 3, a direct inhibitor repurposing strategy has been followed. Homology models of the PfPDEs were developed based upon hPDE9 from which an analogy was identified between the binding sites of the four PfPDEs and hPDE1. This led to a series of 1H-pyrazolo[4,3-d]pyrimidin-7(6H)-one derivatives, known hPDE1 and hPDE9 inhibitors, being selected for re-examination as inhibitors of Plasmodium falciparum parasite growth. The synthesis of target compounds was achieved in a divergent, nine-step synthesis. Gratifyingly, 6 of 22 compounds were identified as submicromolar IC50 inhibitors of parasite growth, with 5-benzyl-3-isopropyl-1H-pyrazolo[4,3-d]pyrimidin-7(6H)-one (IC50 = 0.08-0.72 μM), and 5-(2-chlorobenzyl)-3-isopropyl-1H-pyrazolo[4,3-d]pyrimidin-7(6H)-one (IC50 = 0.06-0.97 μM) emerging as superior compounds. The latter also demonstrated decreased activity against hPDE isoforms (hPDE9 IC50 = 1.8 μM) compared to the former. This demonstrates the potential to gain selectivity for P. falciparum growth inhibition over hPDE inhibition. However, it remains unknown if the observed antiplasmodial activity is occurring through PfPDE inhibition, and so future work should focus on the validation of this mechanism or the identification of an alternative. In Chapters 4 and 5, an approach geared to generating novel chemotypes was examined. The reported antiplasmodial and hPDE inhibitory activity of flavonoid structures provided a starting point to scarcely reported classes of bicyclic compounds. The synthesis of three series of 6,7-fused ring system-based scaffolds was explored, and while progress was made toward each, the synthetic challenges prevented full assessment of their potential. Instead, a fourth series, the 2-tetrahydropyranchromanones, was synthesised and found to contain effective inhibitors of both Plasmodium falciparum growth and hPDE activity. In particular, 8-(3,4-dimethoxyphenyl)-6-methyl-2-(tetrahydro-2H-pyran-4-yl)chroman-4-one demonstrated antiplasmodial activity (IC50 = 2.6-10 μM) as well as showing inhibitory activity against hPDE4 and hPDE1. As above, the mechanism(s) underpinning the antiplasmodial activity remain to be established. All in all, this thesis strongly supports the concept of the “inverted silver bullet” approach to drug discovery and presents at least two series of compounds that represent good starting points for the ongoing development of novel antimalarial therapies. If formal attribution of a PDE inhibition mechanism is elucidated, the work will provide a powerful endorsement of the use of protein structure-based design in identifying compounds likely to be effective and expediting the drug discovery process, particularly in comparison to the mass screening strategies undertaken elsewhere. The work also highlights that many chemicals in “druggable” chemical space have still not been synthesised, so the search for structural novelty could lead to the ready identification of many new bioactive molecules.

The continuous search for novel compounds against microbial infections and oxidative stress-induced debilitating diseases like diabetes has intensified in recent years. This study evaluated the phytochemical constituents, time-kill antimicrobial, antioxidant, and antidiabetic potentials of whole fruit extracts of Nauclea latifolia Smith. The antibacterial potential was evaluated using micro-broth dilution method and the degree of mortality was examined at different concentrations over a period of 2 h against Staphylococcus aureus and Shigella sonnei as representative organisms. The antioxidant activity of the extracts was determined using 1, 1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide (NO), hydrogen peroxide (H2O2) and iron chelating assays. The antidiabetic potential was determined by evaluating the inhibitory effects of the extracts on the activities of α-amylase and α-glucosidase, while the modes of the enzymes inhibition were assessed using Lineweaver-Burk kinetics.The crude extract displayed minimum inhibitory concentration (MIC) ranging between 0.19 and 1.56 mg/mL. The lowest MIC value displayed by the n-hexane, ethylacetate and n-butanol fraction was 0.19, and 0.39 mg/mL by the chloroform fraction. Total mortality was recorded by n-butanol fraction at 3xMIC (0.57 mg/mL) after 15 min of contact time and ethylacetate fraction after 60 min of contact time against Stapylococcus aureus at the same concentration. Also total mortality was recorded after 60 min of contact time at 3xMIC by n-butanol fraction against Shigella sonnei. The ethyl acetate fraction has the highest total phenol (413.4 mg/g) and total flavonol (8.3 mg/g) contents which is significantly different (p < .05) from all other extracts. For the flavonoid content, the n-butanol fraction had the highest content (35.6 mg/g) followed by n-hexane, ethylacetate and chloroform fraction, respectively. N-butanol fraction showed the highest radical scavenging activities while chloroform and n-butanol fraction showed strong inhibitory potentials against α-amylase and α-glucosidase, respectively. The results obtained showed that whole fruit of Nauclea latifolia elicited noteworthy antimicrobial, antioxidant and antidiabetic activities which are attributed to the presence of its phytoconstituents and thus support its folkloric uses in the treatment of microbial infections and oxidative stress-mediated diseases like hyperglycemia.

Background: Patients use anticonvulsant drugs to manage and handle disorders that are associated with seizures such as epilepsy. One of such drugs is Phenobabirone which is relatively expensive. These drugs however, have made patients to continue to experience inadequate seizure control even while using them. There is need to investigate cheaper sources of anticonvulsant agents. The leaves of Cleistopholis staudtii has been used traditionally to handle convulsant cases and could in future shows therapeutic relevance and use. . Objectives: This research investigated the Anticonvulsant effects of methanol leaf extracts and fractions of Cleistopholis staudtii on swiss white mice. It also compared the anticonvulsant effect of these fractions of the Cleistopholis staudtii leaves with those of Phenobabirone. Methodology: Fifty Swiss white mice (18-32g) were divided into ten (10) groups (n=3)as they were given orally; 10ml/kg 5% tween 80 (Control Group), , 200mg/kg crude extract (Group 3), 400mg/kg crude extract ( Group 4), 200mg/kg N-hexane fraction (group 5), 400mg/kg N-hexane fraction (Group 6), 200mg/kg Ethylacetate fraction ( Group 7), 400mg/kg Ethylacetate fraction ( Group 8), 200mg/kg Butanol fraction (group 9), 400mg/kg Butanol fraction ( Group 10) while Group 2 ( Positive control) was given 60mg/kg Phenobarbitone intraperitoneally . The groups had free access to water. These treatment were for seven(7) days after which they were injected with 200mg/kg Isoniazide and observations were made in regards to convulsion. Results: The control group had convulsions at 34.7±6.07 minutes, while phenobarbitone delayed seizures to 90±0.0 minutes. The crude extract delayed convulsions to 47.3±14.91 minutes at 200 mg/kg and 65±21.93 minutes at 400 mg/kg. The N-Hexane fraction had a similar delay effect to phenobarbitone at both dosages, while the Ethyl Acetate and Butanol fractions had variable results. Mortality rates were 100% in the control group, reduced to 33% with phenobarbitone. The crude extract caused 100% mortality at both doses, and the N-Hexane, Ethyl Acetate, and Butanol fractions had 67% mortality at 400 mg/kg and 100% at lower doses. Phenobarbitone was the most effective, with 0.67±0.09 convulsions, compared to the crude extract with 6.7±1.50 convulsions at 200 mg/kg and 8.7±1.50 at 400 mg/kg. The N-Hexane fraction had 8.7±3.42 convulsions at 200 mg/kg and 10.3±1.70 at 400 mg/kg, while the Ethyl Acetate and Butanol fractions resulted in higher convulsion counts, especially at lower doses. Conclusion: The Research showed that the Butanol Fraction of methanol leaf extracts of Cleistopholis staudtii exhibited better anticonvulsant effects in Swiss white mice.

Plutella xylostella L. is the major pest of crucifers globally, causing significant yield loss. Aphis craccivora Koch is the main sucking pest of legumes that transmit viral diseases, leading to economic yield reduction. To minimize loss due to pests, farmers/growers use synthetic insecticides frequently for their control, which led to insecticide resistance, detrimental to natural enemies of pest, environment, etc. Therefore, in this study, the insecticidal activity of plant extract, fractions, and pure steroidal saponins from Trillium govanianum was evaluated for their bio-efficacy against targeted pests. Parent extract was found more effective (LC50 = 1541.2 mg L-1 ) against larvae of P. xylostella after 96 h than n-butanol, n-hexane, and ethyl acetate fractions (LC50 = 3030, 3578 and 3878.1 mg L-1 , respectively). For A. craccivora, ethyl acetate fraction (LC50 = 2186.3 mg L-1 ) was most effective after 96 h than n-hexane fraction (LC50 = 2234.6 mg L-1 ), n-butanol fraction (LC50 = 2696.3 mg L-1 ) and parent extract (LC50 = 3709.1 mg L-1 ). Among pure molecules, govanoside B was found more effective (76% mortality, LC50 = 3279.5 mg L-1 ) followed by borassoside E (74%, LC50 = 3467.1 mg L-1 ) against A. craccivora after 96 h. Parent extract/fractions of T. govanianum showed promising efficacy against larvae of P. xylostella and A. craccivora. Further, field study is required for its bio-efficacy against targeted pests for validation and formulation development.

Background: Solanum aculeastrum is reportedly used in several diseases including gonorrhea, bronchitis, jigger infestations and wounds, and cancers. We conducted an exhaustive phytochemical and GC-MS profiling of its methanol extract and solvents’ fractions. Methods: About 4500g of dried berries of S. aculeastrum was extracted with methanol, part of which was partitioned into fractions of n-hexane, dichloromethane, ethyl acetate, n-butanol and aqueous fractions. These fractional preparations were subjected to phytochemical and GC-MS profiling except aqueous fraction. Results: The percentage yield of 430.69g of methanol extract of berries of S.aculeastrum was 9.57%w/w, while the yields of dried 19.4g of n-hexane, 38.4g of DCM, 6.4g of ethyl acetate, 81.03g of n-butanol and 21.2g of the freeze-dried aqueous fractions were 7.08%w/w, 14.03 %w/w, 2.33%w/w, 29.60%w/w and 7.74%w/w respectively. The relative presence of glycosides, alkaloids, tannins, flavonoids, terpenoids, phenols, saponins were confirmed except quinones. GC-MS profiling of methanol extract identified 32 compounds including alkane, alcohol, carbohydrate, fatty acids, terpenoids, glycerides, vitamins and some unclassified compounds. 25 compounds including terpenoids, alkene, fatty acids, vitamin and unclassified compounds were identified in n-hexane fractions. The DCM fraction yielded 20 compounds including isoprenoid, terpenoids, amino acids, carboxylic acid and unclassified compounds. 22 compounds were identified in ethyl acetate fraction including phenol, fatty acids, alcohol, terpenoids, glycerolipid and unclassified compounds. The n-butanol fraction yielded 11 compounds including fluorinated aromatic substance, hormonal antineoplastic and a non-steroidal anti-inflammatory agent. Conclusion: This study has further elaborated on the bioactive compounds in berries of S. aculeastrum, to aid robust understanding of its pharmacologic activities.

Isolation, biological evaluation and validated HPTLC-quantification of the marker constituent of the edible Saudi plant Sisymbrium irio L.

BackgroundDiabetes mellitus is a metabolic disorder of glucose metabolism and management of blood glucose level is the hallmark in the treatment of this disease. The present study investigated chemical composition, in vitro antioxidant and antidiabetic activity of different fractions of 80% methanol Piper guineense leaves extract.Materials and methodsThe crude methanolic extract of P. guineense was obtained following 80% methanol cold extraction and was successively partitioned with dichloromethane (DCM), ethyl acetate (EtOAc), n-butanol (nBuOH) and aqueous solvents to give four fractions. The chemical composition of the fractions from P. guineense was determined using gas chromatography coupled with mass spectrometry (GC-MS) and their potentials as antioxidant and anti-diabetes were evaluated.ResultsThe percentage yields were 3.16, 2.22, 0.68 and 0.66% (w/w) in n-butanol, DCM, aqueous and ethyl acetate fractions of P. guineense methanolic extract, respectively. The GC-MS analyses identified a total of 71 and 34 phytochemicals in n-butanol and ethyl acetate fractions respectively. Tributyl acetylcitrate (10.95%) and phytol (9.11%) were the major components in the n-butanol fraction while ethyl piperonyl cyanoacetate (27.35%) and phytol (15.17%) were the major constituents in the ethyl acetate fraction. Ethyl acetate fraction had the highest ferric reducing antioxidant power with a value of 53.96 ± 0.40 mgAAE/g while n-butanol fraction possessed highest total antioxidant power (9.98 ± 0.15) followed by aqueous fraction (9.72 ± 0.02). The ethyl acetate and n-butanol fractions with IC50 value of 0.24 ± 0.07 and 0.83 ± 0.15 μg/mL respectively elicited significant inhibitory activities against α-glucosidase while only n-butanol fraction (IC50 = 0.33 ± 0.09 μg/ml) exhibited appreciable inhibition against α-amylase activity. However, none of the four fractions showed significant inhibitory activity towards dipeptidyl-peptidase-IV.Conclusionn-butanol and ethyl acetate fractions of 80% methanol P. guineense leaves extract can be a potential source of bioactive compounds of pharmacological importance in the management of diabetes.

Breast cancer is a major problem in the health sector, one type of malignant cancer in Indonesia and the world. Medical therapy for cancer patients has had side effects such as nausea, vomiting, weakness, diarrhea and hair loss. The arumanis mango rind, in previous research, contains secondary metabolites of flavonoids, phenolics, saponins and tannins. Arumanis mango rind extract has been studied to have antioxidant activity with an IC50 of 18.29 µg/ml and a toxic, toxicity test with an LC50 of 169.04 µg /ml. The aim of the research was to determine the cytotoxic potential of arumanis mango rind extract and fractions against T47D cancer cells using the Microtetrazolium (MTT) method from the percentage of cancer cell viability, IC50, and cancer cell morphology. It was using ethanol extract, n-hexane fraction, ethyl acetate fraction, and n-butanol fraction, with concentrations of 1000, 100, 10, 1, 0.1 μg/ml against T47D cancer cells. Data were the life cell absorbance obtained from the ELISA reader, to calculate the percentage of T47D cell viability, obtain IC50, then observe the morphology of the cancer cells. The results of the percentages of cell viability ( μg/ml ) from the ethanol extract were 81.1: 103.5; 137.3; 163; 165.5, n-hexane fraction were 28.5; 82.7; 105.1; 130.5; 132.5, ethyl acetate fraction were 15.9; 27.2; 101.7; 134.1; 162.7, n-butanol fraction were 32.6; 75.6; 82.8; 122.3; 146.4, doxorubicin as a comparison were 22.6; 38.4; 45.4; 53.4; 56. The IC50 results of the ethanol extract, the n-hexane fraction, the ethyl acetate fraction, the n-butanol fraction, and doxoburicin were 32.21; 616.59; 90.57; 338.84, and 1.44. The best of cancer cell morphology was doxorubicin, ethanol extract, and ethyl acetate fraction. The conclusion that the extract and fraction of arumanis mango rind had cytotoxic potential against T47D cancer cells from the percentages of cell viability, IC50 and cancer cell morphology, and the best of result are ethanol extract, ethyl acetat fraction, also doxorubicin as comparison drug.