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The study evaluated the effect of extracts of the seeds and pod parts of Lessertia montana on diabetes and freeradicals. Free radical scavenging activities of the extracts was tested against 1,1-diphenyl-2-picrylhydrazyl (DPPH),nitric oxide, 2,2-azinobis (3-ethylbenzothiazoline-6) sulphonic acid (ABTS), hydroxyl radical and reducing power,metal chelating assays, while the antidiabetic activity was assessed via the inhibition and kinetics of α-amylase andα-glucosidase. The pod decoction extract revealed the best radical scavenging activities in DPPH, ABTS, and metalchelating (with IC50 values 1,371, 730, and 798 µg/ml, respectively) compared with other extracts and control havingan IC50 (3,094, 4,125, and 523 µg/ml, respectively) values. While the aqueous ethanolic extract for both parts exhibitedthe highest reducing capabilities of 2.969 (pod) and 3.457 (seeds) at 1 mg/ml, the aqueous extract of the seed showedthe best inhibitory activities in two of the six tested assays, namely, hydroxyl radical (717 µg/ml) and metal chelating(59 µg/ml). The kinetics of inhibition of α-amylase and α-glucosidase by aqueous ethanolic extract of the pod wascompetitive and non-competitive, respectively, while the two enzymes were uncompetitively inhibited by ethanolicextract of the seed. The investigation corroborated the antioxidative and antidiabetic potentials of the leaf as previouslyestablished from our group.
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Objective: To investigate the free radical scavenging, antidiabetic, kinetics and cytotoxic potentials of flavonoids extract of Dicoma anomala root by using standard methods. Methods: Antioxidant activity of the flavonoids was investigated at scavenging free radicals such as 1,1- diphenyl-2-picrylhydrazyl, nitric oxide, hydroxyl radical, reducing capabilities, 2,2-azinobis (3-ethylbenzothiazoline-6) sulfonic acid as well as metal chelating capability at different concentrations (0.125-1.000 mg/mL) while the antidiabetic activity was evaluated via the inhibition and kinetics of carbohydrate digestive enzymes including, alpha glucosidase, sucrase and maltase. Brine shrimp lethality assay was also employed to examine the cytotoxic effects of the extract by using different range of concentrations (0.125-2.000 mg/mL). Results: The study revealed the best antioxidant activity of the extract in 1,1-diphenyl-2-picrylhydrazyl, 2,2-azino-bis (3-ethylbenzothiazoline-6) sulfonic acid and nitric oxide having IC50 values of (386.90±4.91), (736.00±38.12), (629.30±9.62) g/mL respectively compared with quercetin (standard) with IC50 [(522.20±12.38), (1 021.00±15.61) and (1 075.00±29.35) g/mL] respective values while it was insignificantly (P>0.05) at par with quercetin for reducing power. Similarly, the extract exhibited a moderate inhibition of alpha glucosidase (43.1%), sucrase (33.4%) and maltase (29.9%) activities which were significantly (P<0.05) better than acarbose (18.4%, 12.7% and 24.9% respectively) although acarbose (46.1%) inhibited the higher activity of alpha amylase than the extract (13.7%). The kinetics of mode of inhibition of alpha amylase, alpha glucosidase, sucrase and maltase by flavonoids extract of Dicoma anomala revealed an uncompetitive, non-competitive, competitive and non-competitive inhibition respectively. The result of the lethality assay showed a potent cytotoxic effect of the flavonoids with LC50 value 0.510 mg/mL. Conclusions: The results obtained from this study are suggestive of the antioxidative, antidiabetic and cytotoxic potentials of flavonoids root extract of Dicoma anomala.
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Objective:To investigate the free radical scavenging,antidiabetic,kinetics of enzyme inhibition and cytotoxic potentials of flavonoid-rich extract of Gazania krebsiana leaves using standard methods.Methods:Antioxidant activity of the flavonoids was investigated at scavenging free radicals such as 1,1-diphenyl-2-picryl hydrazyl,nitric oxide,hydroxyl radical,reducing capabilities,2,2-azinobis (3-ethylbenzothiazoline-6) sulphonic acid as well as metal chelating capability at different concentrations (125-1 000 μg/mL) while the antidiabetic activity was evaluated via the inhibition and kinetics of carbohydrate digestive enzymes including α-αmylase,α-glucosidase,sucrase and maltase.Brine shrimp lethality assay was also employed to examine the cytotoxic effects at various concentrations (125-2 000 μg/mL).Results:The study showed the best antioxidant activity in 2,2-azinobis (3-ethylbenzothiazoline-6)sulphonic acid,hydroxyl radical,nitric oxide and metal chelating with IC5o values of (1 089.00±19.29),(719.40±5.35),(633.10±5.31),(1 116.00±22.92) μg/mL,respectively;as compared with butylated hydroxyl anisole (standard) with IC50 of 1 166,747,639 and 1 363 μg/mL,respectively.Similarly,strong inhibition of α-glucosidase as well as moderate inhibition of sucrase and maltase enzyme activities which were significantly (P＜0.05) better than acarbose were also observed in the study;though acarobse activity against α-amylase was better than the extract.The kinetics or mode of inhibition of α-amylase by the extract revealed an uncompetitive inhibition,competitive for α-glucosidase and non-competitive inhibitions for both sucrase and maltase,while the result of the lethality assay showed a potent cytotoxic effect with LC50 value of 359 μg/mL.Conclusion:The results obtained from this study are suggestive of the antioxidative,antidiabetic and cytotoxic potentials of flavonoid-rich extract of Gazania krebsiana.
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Objective To evaluate the antioxidant and antidiabetic activities of Sutherlandia montana E. Phillips & R.A. Dyer leaf extracts using the in vitro model. Methods The antioxidant activities of aqueous, decoction, ethanol and hydro-ethanol extracts of the plant were determined using seven different assays; the antidiabetic potential was evaluated through the inhibition of key carbohydrate hydrolysing enzymes (α-amylase and α-glucosidase), while the modes of the enzymes inhibition were assessed using enzyme kinetic analysis. Results The ethanol extract exhibited the best scavenging activity (IC
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OBJECTIVE@#To evaluate antimicrobial potential of the fractions partitioned from Euclea crispa leaf extract and determination of their impact on cell membrane disruption.@*METHODS@#Antimicrobial potentials were evaluated via susceptibility test, determination of minimum inhibitory concentrations (MICs) and time-kill kinetics of the potent fractions. Degree of membrane disruption was determined by the amount of proteins and nucleotides released from within the cells and SEM images of the membrane after 120 min of treatment.@*RESULTS@#The largest inhibition zone (25.5 ± 0.50 mm) was obtained by ethylacetate fraction against Aeromonas hydrophilla at 10 mg/mL. The lowest MIC (0.16 mg/mL) was exhibited by n-butanol and ethylacetate fractions against test bacteria while all fractions exhibited MIC values between 0.31 and 1.25 mg/mL against susceptible yeast. n-Butanol fraction achieved absolute mortality against Bacillus pumulis (B. pumulis) and Klebsiella pneumoniae (K. pneumoniae) after 90 and 120 min contact time respectively at 1 × MIC. Total mortality also achieved by n-hexane fraction against B. pumulis and K. pneumoniae after 90 and 120 min respectively at 2 × MIC. Ethylacetate fraction achieved absolute mortality against both bacteria after 120 min at 2 × MIC. n-Hexane fraction achieved total mortality against Candida albicans after 120 min at 1 × MIC. Maximum amount of proteins (0.566 μg/mL) was released from K. pneumoniae by n-butanol fraction at 2 × MIC after 120 min of treatment while the maximum amount of nucleotides released (4.575 μg) was from B. pumulis by n-hexane fraction under similar condition.@*CONCLUSION@#This study suggests the leaf of Euclea crispa a source of bioactive compound with membrane attack as one of the mechanisms of its biocidal action.
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Objective To evaluate antimicrobial potential of the fractions partitioned from Euclea crispa leaf extract and determination of their impact on cell membrane disruption. Methods Antimicrobial potentials were evaluated via susceptibility test, determination of minimum inhibitory concentrations (MICs) and time-kill kinetics of the potent fractions. Degree of membrane disruption was determined by the amount of proteins and nucleotides released from within the cells and SEM images of the membrane after 120 min of treatment. Results The largest inhibition zone (25.5 ± 0.50 mm) was obtained by ethylacetate fraction against Aeromonas hydrophilla at 10 mg/mL. The lowest MIC (0.16 mg/mL) was exhibited by n-butanol and ethylacetate fractions against test bacteria while all fractions exhibited MIC values between 0.31 and 1.25 mg/mL against susceptible yeast. n-Butanol fraction achieved absolute mortality against Bacillus pumulis (B. pumulis) and Klebsiella pneumoniae (K. pneumoniae) after 90 and 120 min contact time respectively at 1 × MIC. Total mortality also achieved by n-hexane fraction against B. pumulis and K. pneumoniae after 90 and 120 min respectively at 2 × MIC. Ethylacetate fraction achieved absolute mortality against both bacteria after 120 min at 2 × MIC. n-Hexane fraction achieved total mortality against Candida albicans after 120 min at 1 × MIC. Maximum amount of proteins (0.566 μg/mL) was released from K. pneumoniae by n-butanol fraction at 2 × MIC after 120 min of treatment while the maximum amount of nucleotides released (4.575 μg) was from B. pumulis by n-hexane fraction under similar condition. Conclusion This study suggests the leaf of Euclea crispa a source of bioactive compound with membrane attack as one of the mechanisms of its biocidal action.
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<p><b>OBJECTIVE</b>To investigate the toxic implications of ethanolic stem bark extract of Azadirachta indica (A. indica) at 50, 100, 200 and 300 mg/kg body weight in Wistar rats.</p><p><b>METHODS</b>Fifty male rats of Wistar strains were randomly grouped into five (A-E) of ten animals each. Animals in Group A (control) were orally administered 1 mL of distilled water on daily basis for 21 days while those in Groups B-E received same volume of the extract corresponding to 50, 100, 200 and 300 mg/kg body weight.</p><p><b>RESULTS</b>The extract did not significantly (P>0.05) alter the levels of albumin, total protein, red blood cells and factors relating to it whereas the white blood cell, platelets, serum triacylglycerol and high-density lipoprotein cholesterol decreased significantly (P<0.05). In contrast, the final body weights, absolute weights of the liver, kidney, lungs and heart as well as their organ-body weight ratios, serum globulins, total and conjugated bilirubin, serum cholesterol, low-density lipoprotein cholesterol and computed atherogenic index increased significantly. The spleen-body weight ratio, alkaline phosphatase, alanine and aspartate transaminases, sodium, potassium, calcium, feed and water intake were altered at specific doses.</p><p><b>CONCLUSIONS</b>Overall, the alterations in the biochemical parameters of toxicity have consequential effects on the normal functioning of the organs of the animals. Therefore, the ethanolic extract of A. indica stem bark at the doses of 50, 100, 200 and 300 mg/kg body weight may not be completely safe as an oral remedy and should be taken with caution if absolutely necessary.</p>