In vitro time kill assessment of crude methanol extract of Helichrysum pedunculatum leaves

The in vitro antibacterial activities and time kill regimes of crude methanol extract of Helichrysum pedunculatum was assessed using standard microbiological procedures. The experiment wasconducted against a panel of bacterial species made up of clinical, environmental and reference strains. The extract was active against eleven of the twenty-one bacteria tested at a concentration of 10 mg/ml. Minimum Inhibitory Concentration (MIC) values for all the susceptible bacteria ranged between 0.1 – 5.0mg/ml. The average log reduction in viable cell count in time kill assay ranged between 0.17 Log10 to 6.37 Log10 cfu/ml after 6 h of interaction, and between 0.14 Log10 and 6.99 Log10 cfu/ml after 12 h interaction in 1×MIC and 2×MIC of the extract. The extract was bactericidal against 8 of the test bacteria at 1×MIC and against 9 of the test bacteria at 2×MIC from 12 h interaction period. At both MIC levels, the extract was bactericidal to all the reference strains and four of the six environmental strains at both MIC levels after 12 h of interaction. Also the extract was bactericidal to four of the six environmental strains at both MIC levels after 12 h of interaction and bacteriostatic during the first 6 h of interaction. Inhibitory levels of crude methanol extract of H. pedunculatum could be bacteriostatic or bactericidal independentof Gram’s characteristic

Effects of direct-fed lactic acid bacteria on weight gain and ruminal pH of two south African sheep breeds

A ruminant’s digestion depends on microbial degradation of feed rather than endogenous enzyme degradation as in most monogastric animals. The study was conducted to assess the effects of Lactic Acid Bacteria (LAB) strains administered as direct-fed microbials on weight gain and ruminal pH of Damara and Meatmaster sheep breeds. Sixty-four Damara and Meatmaster sheep breeds [Damara males (36.6 } 8.3 kg); Damara females (28.9 } 6.9 kg); Meatmaster males (24.6 } 3.4 kg); Meat master females (21.5 } 3.1 kg)] were subjected to a 30-day trial and divided into five treatment groups as follows: pellets with no antibiotic and no probiotics administered (T1); pellets with no antibiotics, only Lactobacillus rhamnosus SCH administered (T2); pellets with no antibiotics, only Lactobacillus rhamnosus AF3G administered (T3); pellets with no antibiotics, with the combination of Lactobacillus rhamnosus SCH and Lactobacillus rhamnosus AF3G, administered (T4); pellets fortified with antibiotic and no probiotic administered (T5). The animals were fed on commercial pellets fortified with or without antibiotics. Animals were each weighed, and rumen fluids were collected using a stomach tube, and pH was read immediately, before and at the end of the trials. Data obtained were subjected to analysis of variance using SPSS version 4.0. The results showed that the effect of treatment, sex and some of their interactive effects were significant (p <0.001) on the body weight of sheep irrespective of breed. The effect of treatments revealed that the animals in the combination of probiotics gained more weight than those in other groups. Damara breed had a heavier body weight than Meatmaster while males were 6 kg heavier relative to females (p <0.001). Only breed was significant (p <0.05) on weight gained. Treatment (p <0.05), breed (p <0.001) and their interactive effect (p <0.05) were significant on ruminal pH. The highest pH value was 7.27 for the T5 group and 7.37 for the Damara breed. Results suggest that LAB may have beneficial effects on the growth performances of sheep and therefore may be suitable as future growth promoters in sheep production, as they don't have any harmful residues compared to antibiotics

Preliminary phytochemical screening and In vitro antioxidant activities of the aqueous extract of Helichrysum longifolium DC

<p>Abstract</p> <p>Background</p> <p>Many oxidative stress related diseases are as a result of accumulation of free radicals in the body. A lot of researches are going on worldwide directed towards finding natural antioxidants of plants origins. The aims of this study were to evaluate <it>in vitro </it>antioxidant activities and to screen for phytochemical constituents of <it>Helichrysum longifolium </it>DC. [Family Asteraceae] aqueous crude extract.</p> <p>Methods</p> <p>We assessed the antioxidant potential and phytochemical constituents of crude aqueous extract of <it>Helichrysum longifolium </it>using tests involving inhibition of superoxide anions, DPPH, H₂O₂, NO and ABTS. The flavonoid, proanthocyanidin and phenolic contents of the extract were also determined using standard phytochemical reaction methods.</p> <p>Results</p> <p>Phytochemical analyses revealed the presence of tannins, flavonoids, steroids and saponins. The total phenolic content of the aqueous leaf extract was 0.499 mg gallic acid equivalent/g of extract powder. The total flavonoid and proanthocyanidin contents of the plant were 0.705 and 0.005 mg gallic acid equivalent/g of extract powder respectively. The percentage inhibition of lipid peroxide at the initial stage of oxidation showed antioxidant activity of 87% compared to those of BHT (84.6%) and gallic acid (96%). Also, the percentage inhibition of malondialdehyde by the extract showed percentage inhibition of 78% comparable to those of BHT (72.24%) and Gallic (94.82%).</p> <p>Conclusions</p> <p>Our findings provide evidence that the crude aqueous extract of <it>H. longifolium </it>is a potential source of natural antioxidants, and this justified its uses in folkloric medicines.</p

Preliminary study of the antioxidant properties of flowers and roots of Pyrostegia venusta (Ker Gawl) Miers

<p>Abstract</p> <p>Background</p> <p>Free radical stress leads to tissue injury and can eventually to arthritis, atherosclerosis, diabetes mellitus, neurodegenerative diseases and carcinogenesis. Several studies are ongoing worldwide to find natural antioxidants of plant origin. We assessed the <it>in-vitro </it>antioxidant activities and screened the phytochemical constituents of methanolic extracts of <it>Pyrostegia venusta </it>(Ker Gawl) <it>Miers</it>.</p> <p>Methods</p> <p>We evaluated the antioxidant potential and phytochemical constituents of <it>P. venusta </it>using 1,1-Diphenyl-2-picrylhydrazyl (DPPH), 2, 2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and ferric reducing antioxidant power (FRAP) assays. Gas chromatography-mass spectroscopy (GC-MS) studies were also undertaken to assess the phytochemical composition of the flower extracts.</p> <p>Results</p> <p>Phytochemical analyses revealed the presence of terpenoids, alkaloids, tannins, steroids, and saponins. The reducing ability of both extracts was in the range (in μm Fe(II)/g) of 112.49-3046.98 compared with butylated hydroxytoluene (BHT; 63.56 ± 2.62), catechin (972.02 ± 0.72 μm) and quercetin 3208.27 ± 31.29. A significant inhibitory effect of extracts of flowers (IC₅₀= 0.018 ± 0.69 mg/ml) and roots (IC₅₀= 0.026 ± 0.94 mg/ml) on ABTS free radicals was detected. The antioxidant activity of the extracts of flowers (95%) and roots (94%) on DPPH radicals was comparable with that of ascorbic acid (98.9%) and BHT (97.6%). GC-MS study revealed the presence of myoinositol, hexadecanoic acid, linoleic acid, palmitic acid and oleic acid in the flower extracts.</p> <p>Conclusion</p> <p>These data suggest that <it>P. venusta </it>is a natural source of antioxidants. The extracts of flowers and roots of <it>P. venusta </it>contain significant amounts of phytochemicals with antioxidative properties and could serve as inhibitors or scavengers of free radicals. <it>P. venusta </it>could be exploited as a potential source for plant-based pharmaceutical products. These results could form a sound basis for further investigation in the potential discovery of new natural bioactive compounds.</p

Studies on the in vitro time kill assessment of crude acetone and aqueous extracts of Helichrysum pedunculatum leaves

Helichrysum pedunculatum is used in folklore remedies to dress wound acquired after circumcision rite. This led to the study of in vitro antibacterial activities of this medicinal plant. Using standardmicrobiological procedures, six bacteria species made up of four gram positive and two gram negative bacteria were screened for susceptibility to crude acetone and aqueous extracts of this plant. Theminimum inhibitory concentrations (MICs) of the acetone extract against the susceptible bacteria was 5.0 mg/ml while that of the aqueous extract ranged between 0.5 - 35 mg/ml. Average log reduction in viable cell count in time kill assay of the acetone extract ranged between 0.64 Log10 and 5.99 Log10 cfu/ml after 6 h of interaction, and between 5.99 Log10 and 6.06 Log10 cfu/ml after 12 h interaction in 1 × MIC and 2 × MIC, and between 0.10 Log10 to 0.33 Log10 cfu/ml after 6 h of interaction, and 0.23 Log10 and 0.56 Log10 cfu/ml after 12 h interaction in 1 × MIC and 2 × MIC for the aqueous extract. The effect of the aqueous extract was only bacteriostatic on both reference and environmental strains and the clinical isolates were outrightly resistant to this extract (not reported here). This is worrisome and thiscould be one reason why, there is an incidence of high death rate resulting from circumcision wounds infection even after treating such wounds with H. pedunculatum leaf. Perhaps the plant could be ofmore relevance in combination therapy and a source of resistance modifying principles which is the subject of on going studies in our group

The bioactive potentials of two medicinal plants commonly used as folklore remedies among some tribes in West Africa

Jatropha curcas and Newboulda laevis are medicinal plants used for the treatment of ailments such as diarrhoea, dysentery, sexually  ransmitted diseases, jaundice and several other diseases caused bymicro-organisms. The antibacterial activities of the leaves of the plants were assessed against a panel of selected bacterial pathogens. Methanolic leaf extracts of J. curcas and N. laevis exhibited antibacterial activity against eight of the thirteen tested bacterial isolates at a final concentration of 20 mg/ml. The zones of inhibition exhibited by J. curcas ranged between 12 and 17 mm while that of N. laevis varied between 10 and 23 mm. The minimum inhibitory concentration of J. curcas extract ranged between 0.625 and 10.00 mg/ml, while that of N. laevis extract varied between 0.313 and 10 mg/ml. The standard antibiotic – streptomycin had MIC values of between 0.0313 and 0.0625 mg/ml. Phytochemical compounds present in the extract of J. curcas include alkaloids, saponins, steroids and tannins, while those present in N. laevis extract includes alkaloids, flavonoids and tannins

In vitro antimicrobial and phytochemical properties of crude extract of stem bark of Afzelia africana (Smith)

Afzelia africana is used in folklore remedies for the treatment of diarrhoea, gastrointestinal disorders and gonorrhoea among other ailments; hence we assessed the in vitro antimicrobial activities of thisimportant medicinal plant. Thirty bacterial isolates as well as four fungal isolates were tested in this study. The crude extract of the stem bark of the plant exhibited antimicrobial activities at a concentration of 25 mg/ml against twenty-one of the bacterial isolates, (i.e. 72.41% of the tested isolates) comprising both Gram positive and Gram negative strains. The zones of inhibition exhibited by the extract against the test bacterial species ranged between 13 and 22 mm. The Minimum Inhibitory Concentrations (MIC) of the extract vary between 1.56 and 12.50 mg/ml while the Minimum Bactericidal Concentration (MBC) ranged between 3.13 and 25.00 mg/ml. However, the extract lacked activity against all four tested fungal species. Phytochemical assay revealed the presence of alkaloids, tannins, flavonoids and saponins in the extract. We conclude that the stem bark of A. africana is a promising candidate as source of new antibacterial compounds