https://vital.seals.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 https://vital.seals.ac.za/vital/access/manager/Repository/vital:11164 Wed 12 May 2021 22:19:24 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:11268 5 mg/ml for all the extracts. Average log reductions in viable cell counts for all the extracts ranged between 0.1 Log10 and 7.5 Log10 cfu/ml after 12 h interaction at 1 × MIC and 2 × MIC. Most of the extracts were rapidly bactericidal at 2 × MIC achieving a complete elimination of most of the test organisms within 12 h exposure time. The effect of combinations of the crude extracts of H. pedunculatum leaves and eight antibiotics was investigated by means of checkerboard and time-kill methods. In the checkerboard method, synergies of between 45.83-56.81 percent were observed and this is independent of Gram reaction, with combinations in the aqueous extract yielding largely antagonistic interactions (18.75 percent). The time kill assay also detected synergy that is independent of Gram reaction with a ≥ 3Log10 potentiation of the bactericidal activity of the test antibiotics. We conclude that the crude leaf extracts of H. pedunculatum could be potential source of broad spectrum antibiotics resistance modulating compounds. The interactions between crude extracts of H. longifolium in combination with six first-line antibiotics using both the time-kill and the checkerboard methods were carried out. The time-kill method revealed the highest bactericidal activity exemplified by a 6.7 Log10 reduction in cell density against Salmonella sp. when the extract and Penicillin G are combined at ½ × MIC. Synergistic response constituted about 65 percent, while indifference and antagonism constituted about 28.33 percent and 6.67 percent in the time kill assay, respectively. The checkerboard method also revealed that the extracts improved bactericidal effects of the antibiotics. About 61.67 percent of all the interactions were synergistic, while indifference interactions constituted about 26.67 percent and antagonistic interactions was observed in approximately 11.66 percent. The in vitro antioxidant property and phytochemical constituents of the aqueous crude leaf extracts of H. longifolium and H. pedunculatum was investigated. The scavenging activity on superoxide anions, DPPH, H2O2, NO and ABTS; and the reducing power were determined, as well as the flavonoid, proanthocyanidin and phenolic contents of the extracts. The extracts exhibited scavenging activity in all radicals tested due to the presence of relatively high total phenol and flavonoids contents in the extracts. Our findings suggest that H. longifolium and H. pedunculatum are endowed with antioxidant phytochemicals and could serve as a base for future drugs. Bioactivity-guided fractionation of the leaves of H. longifolium and H. pedunculatum yielded two known compounds. From the n-hexane fraction of H. longifolium a compound was isolated (Stigmasterol) and from the ethyl acetate fraction of H. pedunculatum another compound (β-sitosterol) was isolated. The compounds were isolated and identified using various techniques. The antimicrobial, anti-inflammatory, antioxidant, analgesic and anti-pyretic activities of these compounds have been reported in literatures. In general, the experiments and tests conducted in this study appear to have justified the folkloric medicinal uses of H. longifolium and H. pedunculatum for the treatment of stress related ailments and wound infections and make a substantial contribution to the knowledge base of the use of herbal medicine for the treatment of the microbial infections.]]> Wed 12 May 2021 19:21:16 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:11254 Wed 12 May 2021 16:44:12 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:26493 Wed 12 May 2021 16:29:46 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:2096 Wed 07 Jul 2021 13:13:52 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:11177 Thu 13 May 2021 15:44:32 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:10119 Thu 13 May 2021 06:09:09 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:11240 0.05); and efficient bactericidal activity (100% bacterial cells killed) at 1/2MIC and 4xMIC over different time intervals, 36-72hrs and 18-72hrs respectively. The appearance of bands on the thin layer chromatography (TLC) chromatogram spotted with the chloroform extracts of PH and CRT; and developed with hexane: ethyl acetate: acetic acid (HEA) and methanol: acetic acid: water (MAAW) solvent systems indicated the presence of compounds. Purification of the compounds contained in these extracts over silica gel column yielded numerous fractions which were evaluated for antibacterial activity and purity. PHF5 was the most active fraction with a mean MIC50 value of 1.25mg/mL. Volatile compounds belonging to different known chemical families in honey were identified in all the active fractions obtained from PH. Conversely, only four compounds were identified in the active fractions obtained from CRT hence the non volatile constituents could be of prime relevance with respect to antibacterial activity of this honey. Of novelty was the presence of thiophene and N-methyl-D3-azirdine compounds, essential precursors used for the synthesis of natural products and pharmaceuticals with vital biomedical properties. Linalool demonstrated potent inhibitory (MIC95, 0.002- 0.0313mg/mL) and bactericidal activity (0.0039-0.313mg/mL) against the test isolates. On the other hand, a significant difference was recorded (P < 0.05) in comparing the activity of linalool compound to the fractions. PH could serve as a good economic source of bioactive compounds which could be employed as template for the synthesis of novel anti-H. pylori drugs. However, further studies are needed to determine the non volatile active ingredients in PH and CRT as well as toxicological testing]]> Thu 13 May 2021 05:55:33 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:11160 Thu 13 May 2021 05:52:52 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:11882 0.05) as compared with other solvent extracts. The free radical scavenging activity of the extracts was high even at lower concentrations (0.025 mg/ml) except in DPPH and lipid peroxidation. The ferric reducing potential of the extracts was concentration dependent and significantly different from Vitamin C and butylated hydroxytoluene (BHT) that were used as standard drugs. The present study showed a high level of scavenging activity of the leaf extracts of Aloe ferox in all the solvent extracts. Both ethanol and methanolic extract showed potent antioxidant activities than acetone and aqueous extracts. The study indicated that the leaf extracts of Aloe ferox might be a valuable source of natural antioxidant for both medicine and food industries. A. ferox leaf consists of the gel, latex and mesophyll layer; however, the main active constituents of the latex and the leaf exudate of Aloe ferox are anthraquinones which are believed to be responsible for the laxative property. The laxative compound in Aloe ferox leaf extract was isolated and characterized by extracting the plant material in methanol and extract suspended in distilled water. Partitioning was done with n-hexane, ethyl acetate and butanol respectively and was co-spotted with the over-the-counter (OTC) laxative drugs. This led to the successive column chromatography and thin layer chromatography (TLC) of the most active ethyl acetate fraction on silica gel with benzene/ethanol/ammonia hydroxide (BEA: 90:10:1), ethyl acetate/methanol/water (EMW: 40:5.4:5) and chloroform/ethyl acetate/formic acid (CEF: 50:40:10) as the mobile phase. The successive chromatograph and TLC afforded two compounds of Rf 0.420 (blue) and 0.831 (yellow) with the over-the-counter (OTC) drugs. These compounds were not totally elucidated due to their small quantity and instability. However, hydroxyl (OH) and carboxyl groups (COOH) was established as common to the extracted compounds, which might be responsible for the biological activity recorded for the plant extract.]]> Thu 13 May 2021 04:36:56 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:29137 Thu 13 May 2021 03:41:07 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:11260 Thu 13 May 2021 03:38:41 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:31257 Thu 13 May 2021 01:34:35 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:4234 Thu 13 May 2021 01:09:35 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:11311 Thu 13 May 2021 00:03:33 SAST ]]>