Antibacterial and antioxidant activities of hydroalcoholic stem bark extract of Schotia latifolia Jacq

Objective:To investigate the antibacterial and antioxidant activities of hydroalcoholic extract of Scholia latifolia（S.latifolia） bark commonly used in South Africa traditional medicine for the treatment of various ailments.Methods:The antibacterial test and MIC was determined by using agar well diffusion and dilution methods respectively against eight strains of bacteria. The total phenol,proanthocyanidin and flavonoid contents of 5.latifolia were assessed using Standard methods.The antioxidant activity of the extract was evaluated using ferric reducing power and the free radical scavenging activity against 1.1-diphenyl-2-picrylhydrazyl（DPPH）, 2.2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic-acid（ABTS）,nitric oxide（NO）,hydrogen peroxide（H2O2） and lipid oxidation（LO）.Results:The antibacterial activity demonstrated an appreciable effect against all the gram positive bacteria at MIC between 0.016 and 10 mg/ml. while that of gram negative bacteria was above 10 mg/mL.The plant extract exhibited high concentration of proanthocyanidin[（300.00±0.10） mg CE/g].followed by flavonoid[（12.46±0.04 mg） TE/g]and phenol[（1 l.06±0.03） mg QE/g]contents.Similarly,the extract at 0.5 mg/mL scavenges DPPH.ABTS.H2O2.LO and NO by 87.55%.89.47%.77.15%.86.48%and 77.75%of the radicals respectively.The reducing power was also found to be concentration dependent Conclusions: Our data suggest that S.latifolia extract has antibacterial and antioxidants activity and thus could be used as alternative therapv against antibiotic resistance bacteria and to prevent man) radical related diseases.

Antioxidant, antibacterial and phytochemical properties of two medicinal plants against the wound infecting bacteria

Objective: To investigate the antioxidant, antibacterial and phytochemical properties of ethanol extracts of Brachylaena elliptica and Brachylaena ilicifolia against wound infecting bacteria normally found in diabetic patients.Methods: The in vitro antioxidant activity of the two plants extracts were investigated spectrophotometrically using 1,1-diphenyl-2-picrylhydrazyl, nitric oxide, azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt, hydrogen peroxide(H_2O_2) and ferric reducing power. The antibacterial assay and minimum inhibitory concentration(MIC) was determined using the agar dilution method against five bacteria strains using amoxycillin and ciprofloxacin as positive control. The phytochemical analyses(tannins,total phenol, flavonoids, flavonols, proanthocyanidin, alkaloids and saponins) were assessed using standard methods.Results: The ethanol extract of both plants exhibited strong antioxidant activities in some cases when compared to the standards(vitamin C and BHT). The antibacterial activity of both plants showed an appreciable broad spectrum activity against these wound pathogens with MIC value ranges between 0.3 mg/m L and 5 mg/m L. Tannins,phenols, flavanols, proanthocyanidins and alkaloids content of B. ilicifolia were significantly higher than those in B. elliptica. However, there were no significant differences in the flavanoid content of both plants extracts.Conclusions: These results indicated that the ethanol leaf extracts of these plants have antioxidant and antibacterial activity against the tested bacteria possibly due to the presence of bioactive compounds and therefore could be used as alternative therapy against wound infection caused by these bacteria in diabetic patients.

Phytochemical and antioxidant activities of Rumex crispus L. in treatment of gastrointestinal helminths in Eastern Cape Province, South Africa

Objective: To evaluate the antioxidant activities and phytochemical content of the leaf and root extracts of Rumex crispus using the solvents extraction; methanol extract,ethanol extract, acetone extract(ACE), and water extract.Methods: Total flavonoids content, total phenolic content, and total proanthocyanidin were evaluated using spectrophotometric equivalents of the standards, quercetin, gallic acid and catechin respectively. The antioxidant activities of the plant extracts were determined using ABTS, DPPH, ferric reducing antioxidant power, total antioxidant capacity and nitric oxide scavenging assays.Results: The flavonoids and phenols contents of the extracts were in the range of(19.39 ± 4.08) to(526.23 ± 17.52) mg QE/g and(16.95 ± 12.03) to(240.68 ± 3.50) mg GAE/g, respectively. ACE of the leaf has the highest value of total flavonoids content(526.23 ± 17.52) mg QE/g while ACE of the root has the highest value of total phenolic content(240.68 ± 3.50) mg GAE/g. The highest content of total proanthocyanidin(645.38 ± 1.33) mg CE/g was in ACE of the root. Significant amounts of saponin and alkaloid were also present in the root and leaf extracts. All solvent fractions showed significant antioxidant activities(P < 0.05) with ACE of the root having the highest scavenging value as shown in DPPH, ABTS, total antioxidant capacity, nitric oxide and ferric reducing antioxidant power(IC50= 0.014 mg/m L, <0.005 mg/m L, 0.048 mg/m L,0.067 mg/m L, and 0.075 mg/m L, respectively).Conclusions: In this study, the mean phytochemical content of the root of Rumex crispus is higher than that of the leaf and this may have contributed to its high antioxidant activities. This may also justify the frequent use of the root more than the leaves in traditional medicine for the cure of helminthic infections.

Nutritional evaluation of Kedrostis africana (L.) Cogn:An edible wild plant of South Africa

Objective:To evaluate the nutritional composition and elemental constituents of Kedrostis africana and their safety aspect.Methods:Proximate parameters(moisture,ash,crude fibre,crude fat,proteins,and carbohydrate and energy) were evaluated using ALASA methods,and elemental analysis by ICP-OES technique.Results:The results from nutritional analysis showed that the tuber used for this study had a low content of crude fat and high content of ash,crude protein,crude fibre,carbohydrate and energy having the recommended dietary allowances.The tuber was rich in major minerals Na,K,Ca and Mg,there was sufficient amount of trace elements Fe,Cu,and Zn while the anti-nutrients oxalate,phytate,alkaloids,and saponins were detected in amounts that are not harmful according to Food and Agriculture Organization/World Health Organization.Conclusions:The outcome of this study suggests that this wild plant has very good nutritional potentials to meet the recommended dietary allowance and it could be a cheap source of essential nutrients that may ameliorate most nutritional challenges and can contribute remarkably to the amount of nutrient intake in human and animal diet.

Phytochemical screening and in vitro evaluation of antioxidant and antimicrobial activities of Kedrostis africana(L.)Cogn

Objective: To investigate phytochemical, antioxidant and antimicrobial activities of Kedrostis africana(K. africana).Methods: Dried tubers of K. africana were extracted in acetone, water and ethanol. The total phenol, flavonoid, proanthocyanidin and tannin contents were determined spectrometrically. The antioxidant activity was examined using 2,2-diphenyl-1-picrylhydrazyl,2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt, nitric oxide and hydrogen peroxide assays. The antimicrobial activity was determined by agar dilution method using minimum inhibitory concentration against 3 g positive and three gram negative strains while four fungal strains were also investigated.Results: Total phenol, flavonoids, proanthocyanidin and tannin contents ranged from(5.32 ± 0.01) to(10.51 ± 0.01) mg GAE/g;(42.58 ± 0.02) to(529.23 ± 0.01) mg QE/g;(15.05 ± 0.00) to(585.64 ± 0.00) mg CE/g and(0.301 ± 0.010) to(0.937 ± 0.000) mg TAE/g, respectively. The IC_(50) values of the ethanol extract for 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and hydrogen peroxide were 0.054 and 0.057 mg/mL,respectively, aqueous extract had an IC_(50) value of 0.135 7 mg/mL for nitric oxide while the acetone extract had an IC_(50) value of 0.300 mg/mL for 2,2-diphenyl-1-picrylhydrazyl.The ethanol extract demonstrated effective antimicrobial activity against the tested pathogenic species with minimum inhibitory concentrations values ranging from 2.5–5.0 mg/mL for bacteria and(0.312 5–5.000 0) mg/mL for fungi, respectively.Conclusions: The tuber of K. africana showed potent free radical scavenging property and antimicrobial activity.

辣木籽精油的细胞毒性及其提取方法对化学成分的影响（英文）

目的:研究水蒸汽蒸馏法(HDE)和无溶剂微波萃取法(SME)对辣木籽精油化学组成的影响,并评估精油的细胞毒性。创新点:比较了不同的提取精油方法对精油的化学成分及其细胞毒性的影响。方法:分别采用HDE和SME两种方法提取辣木籽精油,然后使用气相色谱-质谱法分析其化学成分。通过比较在不同浓度和孵化时间下盐水虾卵的孵化率和幼虾的死亡率来检测精油的细胞毒性。结论:HDE和SME两种方法提取的辣木籽精油分别含有16和26种化学成分,各自占总可识别成分的97.515%和97.816%。因此,SME提取法含有更多的成分。盐水虾卵分别在含有两种精油、海水和氯霉素的样品中孵化24 h后,孵化率分别为60.0%(HDE)、56.7%(SME)、63.3%(海水)和15.0%(氯霉素),精油中的孵化率远高于含有氯霉素的样品的孵化率(P<0.05)。同时,SME和HDE精油对幼虾的半致死量分别为2908.23和3473.63μg/ml(大于1000μg/ml被认为无毒)。因此,两种方法提取的精油可广泛适用于药物、食品防腐剂、抗氧化剂和香料等添加剂。

Evaluation of acute and subacute toxicity of whole-plant aqueous extract of Vernonia mespilifolia Less. in Wistar rats

Objective： This study investigated the acute and subacute toxicity of whole-plant aqueous extract of Vernonia mespilifolia Less. （AEVM） in rats for evaluating its safety profile. Methods： AEVM for the acute （2000 and 5000 mg/kg） and subacute （200, 400 and 600 mg/kg） toxicity studies was administered orally to rats according the guidelines 425 and 407 of Organization for Economic Cooperation and Development, respectively. Food and water intake as well as body and organ weight of animals were recorded. Signs of toxicity were assessed, and hematological, biochemical and histopathological analyses were performed. Results： In the acute toxicity study, a single dose of the aqueous extract at 2000 or 5000 mg/kg caused no mortality in the animals, suggesting that the median lethal dose is greater than 5000 mg/kg. In the subacute toxicity study, administration of the extract for 28 d, at all doses, caused no significant changes in the body weights or organ weights of rats in the treated groups when compared with the control group. In addition, hematological and biochemical parameters also revealed no toxic effects of the extract on rats. Histological sections of the heart, liver and kidney from test animals showed no signs of degen- eration. Conclusion： These results showed that AEVM at dosage levels up to 600 mg/kg is nontoxic and could also offer protection on some body tissues. AEVM could, therefore, be considered safe.