14 results on '"McGaw,Lyndy J."'
Search Results
2. In vitro antioxidant activity of crude extracts of Harpagophytum zeyheri and their anti-inflammatory and cytotoxicity activity compared with diclofenac
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Ncube, Sibonokuhle F., McGaw, Lyndy J., Njoya, Emmanuel Mfotie, Ndagurwa, Hilton G. T., Mundy, Peter J., and Sibanda, Samson
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- 2021
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3. Invasive Alien Species as a Potential Source of Phytopharmaceuticals: Phenolic Composition and Antimicrobial and Cytotoxic Activity of Robinia pseudoacacia L. Leaf and Flower Extracts.
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Uzelac, Mirela, Sladonja, Barbara, Šola, Ivana, Dudaš, Slavica, Bilić, Josipa, Famuyide, Ibukun M., McGaw, Lyndy J., Eloff, Jacobus N., Mikulic-Petkovsek, Maja, and Poljuha, Danijela
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BLACK locust ,INTRODUCED species ,HYDROXYCINNAMIC acids ,ANTI-infective agents ,QUORUM sensing ,ACID derivatives - Abstract
Black locust (Robinia pseudoacacia L.), an invasive tree in Europe, commonly known for its negative impact on biodiversity, is a rich source of phenolic compounds recognized in traditional medicine. Since the metabolite profile depends on the environment and climate, this study aimed to provide the first LC-MS phytochemical screening of the black locust from the Istria region (Croatia). The compounds were extracted from leaves and flowers with 70% ethanol and 80% methanol. Total phenolics (TP) and flavonoids (TF), as well as antioxidant capacity (AC) measured by ABTS (17.49–146.41 mg TE/g DW), DPPH (24.67–118.49 mg TE/g DW), and FRAP (7.38–77.53 mg TE/g DW) assays, were higher in leaf than in flower extracts. Higher TP and total non-flavonoid (TNF) values were displayed in ethanolic than in methanolic extracts. In total, 64 compounds were identified, of which flavonols (20) and hydroxycinnamic acid derivatives (15) were the most represented. Flavanols such as catechin dominated in leaf extracts, followed by flavonols, with kaempferol glucuronyl rhamnosyl hexosides as the main compound, respectively. Flower extracts had the highest share of flavones, followed by ellagitannins, with luteolin dirhamnosyl hexosides and vescalagin, respectively, being predominant. The extracts had good quorum sensing, biofilm formation prevention, and eradicating capacity. The results provided new insights into the phytochemical properties of R. pseudoacacia as the first step toward its potential pharmaceutical use. [ABSTRACT FROM AUTHOR]
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- 2023
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4. Potential Use of Tannin Extracts as Additives in Semen Destined for Cryopreservation: A Review.
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Liman, Mohammed S., Hassen, Abubeker, McGaw, Lyndy J., Sutovsky, Peter, and Holm, Dietmar E.
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TANNINS ,SEMEN ,FROZEN semen ,SEMEN analysis ,GENITALIA ,PLANT polyphenols ,SPERM motility - Abstract
Simple Summary: Freezing of semen used for artificial reproductive technologies (ART) affects the survival and vigour of sperm cells due to excessive production of reactive oxygen species (ROS) during the freezing and thawing processes. ROS plays a physiological role in sperm function but excessive ROS production from damaged sperm cells can hinder sperm's motility and their ability to fertilise an oocyte. Tannins, a class of water-soluble plant polyphenols, are known to have antioxidant and other health-promoting effects and may serve as binders/acceptors to reduce the deleterious effects of excessive ROS produced during the freezing and thawing process. This review is the first to analyse the available data supporting the use of tannins as additives to semen extenders to improve the survival of cryopreserved spermatozoa during storage and after thawing. It is concluded that tannins and their derivatives have naturally protective properties with the potential to ameliorate sperm cell survival after freezing. Cryopreservation and storage of semen for artificial insemination (AI) result in excessive accumulation of reactive oxygen species (ROS). This leads to a shortened life span and reduced motility of spermatozoa post-thawing, with consequent impairment of their function. However, certain levels of ROS are essential to facilitate the capacitation of spermatozoa required for successful fertilisation. Tannins, as well-known antioxidant compounds, may act as ROS binders/acceptors/scavengers to inhibit the damaging effects of ROS. This review comprises an analysis of the semen cryopreservation protocol and health functions of tannins, as well as the effects of ROS on fresh and cryopreserved semen's longevity and fertilisation. Additionally, we surveyed available evidence of the effects of tannin extract feed supplementation on male fertility. We furthermore interrogated existing theories on tannin use as a potential additive to semen extenders, its relationship with semen quality, and to what degree existing theories have been investigated to develop testable new hypotheses. Emphasis was placed on the effects of tannins on ROS, their involvement in regulating sperm structure and function during cryopreservation, and on post-thaw sperm motility, capacitation, and fertilising ability. The diverse effects of tannins on the reproductive system as a result of their potential metal ion chelation, protein precipitation, and biological antioxidant abilities have been identified. The current data are the first to support the further investigation of the incorporation of tannin-rich plant extracts into semen extenders to enhance the post-thaw survival, motility, and fertilising ability of cryopreserved spermatozoa. [ABSTRACT FROM AUTHOR]
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- 2022
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5. The synergistic potential of various teas, herbs and therapeutic drugs in health improvement: a review.
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Malongane, Florence, McGaw, Lyndy J, and Mudau, Fhatuwani N
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HERBAL teas , *ANTIOXIDANTS , *ANTINEOPLASTIC agents , *ANTI-infective agents , *SENSORY evaluation , *CATECHIN , *FLAVANOLS , *PROANTHOCYANIDINS - Abstract
Tea is one of the most widely consumed non-alcoholic beverages in the world next to water. It is classified as Camellia sinensis and non- Camellia sinensis (herbal teas). The common bioactive compounds found mainly in green teas are flavan-3-ols (catechins) (also called flavanols), proanthocyanidins (tannins) and flavonols. Black tea contains theaflavins and thearubigins and white tea contains l-theanine and gamma-aminobutyric acid (GABA), while herbal teas contain diverse polyphenols. Phytochemicals in tea exhibit antimicrobial, anti-diabetic and anti-cancer activities that are perceived to be helpful in managing chronic diseases linked to lifestyle. Many of these phytochemicals are reported to be biologically active when combined. Knowledge of the synergistic interactions of tea with other teas or herbs in terms of biological activities will be of benefit for therapeutic enhancement. There is evidence that various types of teas act synergistically in exhibiting health benefits to humans, improving consumer acceptance and economic value. Similar observations have been made when teas and herbs or medicinal drugs were combined. The aim of this review is to highlight potential beneficial synergies between combinations of different types of teas, tea and herbs, and tea and medicinal drugs. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]
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- 2017
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6. Extracts of six Rubiaceae species combined with rifampicin have good in vitro synergistic antimycobacterial activity and good anti-inflammatory and antioxidant activities.
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Aro, Abimbola O., Dzoyem, Jean P., Eloff, Jacobus N., and McGaw, Lyndy J.
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THERAPEUTIC use of plant extracts ,ANTITUBERCULAR agents ,CELL culture ,CELL lines ,COMBINATION drug therapy ,FISHER exact test ,RESEARCH funding ,RIFAMPIN ,DRUG development ,IN vitro studies ,ONE-way analysis of variance - Abstract
Background: The Rubiaceae family has played a significant role in drug discovery by providing molecules with potential use as templates for the development of therapeutic drugs. This study was designed to study the in vitro synergistic effect of six Rubiaceae species in combination with a known anti-TB drug. The antioxidant and anti-inflammatory activity of these species were also evaluated to investigate additional benefits in antimycobacterial treatment. Methods: The checkerboard method was used to determine the antimycobacterial synergistic activity of plant extracts combined with rifampicin. The antioxidant activity of extracts was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Anti-inflammatory activity via inhibition of nitric oxide (NO) production was performed in LPS-activated RAW 264.7 macrophages using the Griess assay. Results: Combination of rifampicin with the crude extracts resulted in a 4 to 256-fold increase of activity of extracts. The crude extract of Cremaspora triflora produced the best synergistic effect with rifampicin, with a fractional inhibitory concentration (FIC) index of 0.08 against Mycobacterium aurum. Extracts of Psychotria zombamontana had the best antioxidant activity with an IC
50 value of 1.77 µg/mL, lower than the IC50 of trolox and ascorbic acid (5.67 µg/mL and 4.66 µg/mL respectively). All the extracts tested inhibited nitric oxide (NO) production in a concentration dependent manner with the percentage of inhibition varying from 6.73 to 86.27 %. Conclusion: Some of the Rubiaceae species investigated have substantial in vitro synergistic effects with rifampicin and also good free radical scavenging ability and anti-inflammatory activity. These preliminary results warrant further study on these plants to determine if compounds isolated from these species could lead to the development of bioactive compounds that can potentiate the activity of rifampicin even against resistant mycobacteria. [ABSTRACT FROM AUTHOR]- Published
- 2016
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7. Cytotoxic, antimicrobial, antioxidant, antilipoxygenase activities and phenolic composition of Ozoroa and Searsia species (Anacardiaceae) used in South African traditional medicine for treating diarrhoea.
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Ahmed, Aroke S., McGaw, Lyndy J., Moodley, Nivan, Naidoo, Vinasan, and Eloff, Jacobus N.
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ANTI-infective agents , *ANTIOXIDANTS , *THERAPEUTICS , *DIARRHEA , *LIPOXYGENASES , *PLANT phenols , *TRADITIONAL medicine , *ANACARDIACEAE - Abstract
The safety and effectiveness of many of the medicinal plants used in traditional medicine by rural people with little or no access to allopathic drugs is yet to be evaluated. With this in mind, Ozoroa and Searsia (previously known as Rhus ) species traditionally used in South Africa to treat microbial infections and gastrointestinal disorders were selected for in vitro evaluation of biological activities and cytotoxicity. Phenolic-enriched leaf extracts were prepared using mixture of 1% HCl acidified 70% acetone and n-hexane. The crude extract was further fractionated with solvent of different polarities. Crude extracts and fractions were tested against Staphylococcus aureus , Pseudomonas aeruginosa , Escherichia coli , Enterococcus faecalis , Aspergillus fumigatus , Candida albicans and Cryptococcus neoformans . In addition, the antioxidant potentials were determined by DPPH, ABTS, hydroxyl radical scavenging and linoleic acid peroxidation inhibition. The cytotoxic activity of the crude extracts was assayed against Vero cells. The crude extract and the various fractions had good biological activities. The most noteworthy activity is the growth inhibition of the hexane and dichloromethane fractions with MIC values as low as 19 μg/ml. The ethyl acetate and butanol fractions had moderate to low antimicrobial activities with MICs ranging from 39 to 2500 μg/ml. The polar fractions were more active against the fungal pathogens compared with the non-polar fraction. In the DPPH antioxidant assays, the active compounds were concentrated in the polar fractions (IC 50 of the crude extract ranged between 0.90 and 15.82 μg/ml). The ethyl acetate fraction was the most active (IC 50 ranging between 0.84 and 7.92 μg/ml). Although the water fraction was the most polar, the antioxidant activities were low due to the transfer of the active components into the ethyl acetate and butanol fractions. The crude extracts also had good linoleic acid peroxidation inhibition (LC 50 ranging between 13.99 and 40.45 μg/ml). Crude extracts and fractions of the Ozoroa mucronata , O. paniculosa , Searsia leptodictya , S. pendulina , and S. pentheri species tested in this study had good activities relating to diarrhoea mechanisms of pharmacological relevance. However, use of phenolic-enriched crude extracts from these plants for diarrhoeal treatment or any other diseases need to be applied with caution as most of the plant extracts were reasonably toxic against Vero cell line. A next step in the possible application of these extracts to treat diarrhoea would be to identify the bioactive and toxic compounds. [ABSTRACT FROM AUTHOR]
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- 2014
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8. In vitro antibacterial, antioxidant and cytotoxic activity of acetone leaf extracts of nine under-investigated Fabaceae tree species leads to potentially useful extracts in animal health and productivity.
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Dzoyem, Jean P., McGaw, Lyndy J., and Eloff, Jacobus N.
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FOLIAR diagnosis ,ANALYSIS of variance ,ANIMAL experimentation ,ANTIBIOTICS ,ANTIOXIDANTS ,BACTERIA ,BIOLOGICAL assay ,CELL culture ,FISHER exact test ,PRIMATES ,RESEARCH funding ,TOXICITY testing ,PHYTOCHEMICALS ,FREE radical scavengers ,DESCRIPTIVE statistics ,IN vitro studies - Abstract
Background The Fabaceae family is the second largest family of medicinal plants, containing more than 490 species which are being used as traditional medicine. The aim of this study was to determine the antioxidant and antibacterial activity as well as the cytotoxicity of acetone leaf extracts of nine tree species from the Fabaceae family that have not been investigated well previously for possible use in animal health and production. Methods The antibacterial activity was determined by a serial microdilution method against three Gram-positive and three Gram-negative bacteria. Antioxidant activity was determined using free-radical scavenging assays. The safety of the extracts was ascertained using the 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on Vero African green monkey kidney cells. Results Six of the nine acetone extracts had significant antibacterial activity against at least one of the six bacterial species with (MIC 20-80 μg/mL). The Crotalaria capensis extract had the highest activity against Salmonella typhimurium, followed by Indigofera cylindrica with MICs of 20 μg/mL and 40 μg/mL respectively. The Dalbergia nitidula extract had free radical scavenging capacity (IC
50 of 9.31 ± 2.14 μg/mL) close to that of the positive control Trolox in the DPPH assay. The Xylia torreana extract also had high activity (IC50 of 14.56 ± 3.96 μg/mL) in the ABTS assay. There was a good correlation between antioxidant activity and total phenolic content (R2 values > 0.8). The extracts had weak or no toxicity to Vero cells, compared to the positive control doxorubicin with the LC50 varying from 10.70 ± 3.47 to 131.98 ± 24.87 μg/mL at the concentrations tested. Conclusion Extracts of D. nitidula, X. torreana, C. capensis and I. cylindrica had a low cytotoxicity and high antimicrobial and/or antioxidant activity. These species are therefore promising candidates for the development of useful antimicrobial/antioxidant preparations with a low cytotoxicity that may be useful in promoting animal health and productivity. [ABSTRACT FROM AUTHOR]- Published
- 2014
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9. Antimicrobial Activity, Antioxidant Potential, Cytotoxicity and Phytochemical Profiling of Four Plants Locally Used against Skin Diseases.
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Asong, John A., Amoo, Stephen O., McGaw, Lyndy J., Nkadimeng, Sanah M., Aremu, Adeyemi O., and Otang-Mbeng, Wilfred
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SKIN diseases ,EICOSANOIC acid ,CERCOPITHECUS aethiops ,SHIGELLA flexneri ,BIOACTIVE compounds ,CAROTENES ,PHTHALIC acid - Abstract
Although orthodox medications are available for skin diseases, expensive dermatological services have necessitated the use of medicinal plants as a cheaper alternative. This study evaluated the pharmacological and phytochemical profiles of four medicinal plants (Drimia sanguinea, Elephantorrhiza elephantina, Helichrysum paronychioides, and Senecio longiflorus) used for treating skin diseases. Petroleum ether and 50% methanol extracts of the plants were screened for antimicrobial activity against six microbes: Bacillus cereus, Shigella flexneri, Candida glabrata, Candida krusei, Trichophyton rubrum and Trichophyton tonsurans using the micro-dilution technique. Antioxidant activity was conducted using 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging and β-carotene linoleic acid models. Cytotoxicity was determined against African green monkey Vero kidney cells based on the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. Spectrophotometric and Gas Chromatography-Mass Spectrometry (GC-MS) methods were used to evaluate the phytochemical constituents. All the extracts demonstrated varying degrees of antimicrobial potencies. Shigella flexneri, Candida glabrata, Trichophyton rubrum and Trichophyton tonsurans were most susceptible at 0.10 mg/mL. In the DPPH test, EC
50 values ranged from approximately 6–93 µg/mL and 65%–85% antioxidant activity in the β-carotene linoleic acid antioxidant activity model. The phenolic and flavonoid contents ranged from 3.5–64 mg GAE/g and 1.25–28 mg CE/g DW, respectively. The LC50 values of the cytotoxicity assay ranged from 0.015–5622 µg/mL. GC-MS analysis revealed a rich pool (94–198) of bioactive compounds including dotriacontane, benzothiazole, heptacosane, bumetrizole, phthalic acid, stigmasterol, hexanoic acid and eicosanoic acid, which were common to the four plants. The current findings provide some degree of scientific evidence supporting the use of these four plants in folk medicine. However, the plants with high cytotoxicity need to be used with caution. [ABSTRACT FROM AUTHOR]- Published
- 2019
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10. Pharmacological properties and radical scavenging potential of 5-demethyl sinensetin obtained from Loxostylis alata.
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Gado, Dorcas A., Abdalla, Muna Ali, Ehlers, Marthie M., and McGaw, Lyndy J.
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QUERCETIN , *AFRICAN traditional medicine , *EGGS , *STENOTROPHOMONAS maltophilia , *ENTEROBACTER cloacae , *CERCOPITHECUS aethiops , *SALMONELLA typhimurium - Abstract
• Pharmacological properties of 5-demethyl sinensetin from L. alata were explored. • 5-Demethyl sinensetin has promising antioxidant and anti-inflammatory properties. • Potential anticancer properties of 5-demethyl sinensetin are worth further research. Loxostylis alata Spreng. ex Rchb. (Anacardiaceae) is used in South African traditional medicine to alleviate labor pain and to boost the immune system. A polymethoxyflavone (PMF), identified as 5-hydroxy-4′,5′,6,7-tetramethoxyflavone (5-demethyl sinensetin) isolated from the ethyl acetate extract of L. alata, was evaluated for its in vitro pharmacological properties. Antibacterial activity of 5-demethyl sinensetin was determined using a microdilution assay against clinical bacterial isolates from hens' eggs including: Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Salmonella Typhimurium and Stenotrophomonas maltophilia. Antioxidant activity was determined using free-radical scavenging assays. The anti-inflammatory activities of the compound were determined by evaluating its inhibitory effect on the activity of the pro-inflammatory enzyme 15- lipoxygenase, as well as its ability to inhibit nitric oxide (NO) release from macrophages. Furthermore, it was investigated for potential in vitro cytotoxic effects using the 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) test against African green monkey (Vero) kidney and Madin–Darby bovine kidney (MDBK) cell lines. 5-Demethyl sinensetin had antibacterial activity against the tested bacteria with minimum inhibitory concentration (MIC) values ranging from 0.312 to 0.500 mg/mL. Strains of Salmonella Typhimurium were more susceptible than the other pathogens with MIC = 0.312 mg/mL. The 5-demethyl sinensetin had good antioxidant activity with IC 50 values of 1.23 ± 0.15 μg/mL using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method and 0.14 ± 0.09 μg/mL with the 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) method compared to the positive controls ascorbic acid and Trolox. The 5-demethyl sinensetin inhibited nitric oxide production in a dose-dependent manner in LPS-stimulated RAW 264.7 macrophages. Nitric oxide (NO) production was inhibited by 87.9% at a concentration of 50 μg/mL with no toxic effect on the macrophages (viability of > 80%), while inhibiting the metabolism of 15-lipoxygenase (15-LOX) with an IC 50 = 3.26 ± 0.35 μg/mL in comparison to the positive control quercetin. On the other hand however, cytoxicity to Vero (LC 50 = 0.010 mg/mL) and MDBK (LC 50 = 0.014 mg/mL) cells was observed with 5-demethyl sinensetin. The compound 5-demethyl sinensetin had potent antioxidant and anti-inflammatory properties, although it was toxic to the cell lines used in this study. There is therefore a need for further research to explore the potential anticancer properties of this important plant species. [ABSTRACT FROM AUTHOR]
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- 2023
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11. The 15-lipoxygenase inhibitory, antioxidant, antimycobacterial activity and cytotoxicity of fourteen ethnomedicinally used African spices and culinary herbs.
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Dzoyem, Jean Paul, Kuete, Victor, McGaw, Lyndy J., and Eloff, Jacobus N.
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PHENOL analysis , *MUTAGEN analysis , *ALTERNATIVE medicine , *ANIMAL experimentation , *ANTIBIOTICS , *ANTIOXIDANTS , *BIOLOGICAL assay , *BIOLOGICAL models , *DOSE-effect relationship in pharmacology , *ENZYME inhibitors , *FLAVONOIDS , *FRUIT , *MYCOBACTERIUM , *EDIBLE plants , *PRIMATES , *SPICES , *PHYTOCHEMICALS , *PLANT extracts , *STATISTICAL significance , *DESCRIPTIVE statistics , *IN vitro studies , *PHARMACODYNAMICS - Abstract
Ethnopharmacological relevance Culinary herbs and spices are widely used ethnomedically across Africa. They are traditionally employed in the treatment of several ailments including inflammation disorders, pain alleviation and infectious diseases. Pharmacological studies are necessary to provide a scientific basis to substantiate their traditional use and safety. In this study, the 15-lipoxygenase inhibitory, antioxidant, antimycobacterial and the cytotoxic activities, total phenolic and flavonoid contents of fourteen edible plants were investigated. Materials and methods The 15-lipoxygenase inhibitory activity was evaluated by the ferrous oxidation-xylenol orange (FOX) assay method. The antioxidant activity was determined using free-radical scavenging assays. The antimycobacterial activity was determined by a broth microdilution method against three species of mycobacteria: Mycobacterium smegmatis , Mycobacterium aurum and Mycobacterium fortuitum using tetrazolium violet as growth indicator. The cytotoxicity was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on Vero monkey kidney cells. Results All the extracts tested had some 15-lipoxygenase inhibitory activity ranging from 32.9 to 78.64%. Adansonia digitata (fruit) had the highest antioxidant capacity (IC 50 values of 8.15 μg/mL and 9.16 μg/mL in the DPPH and ABTS assays respectively; TEAC of 0.75 in the FRAP assay) along with the highest amount of total phenolics (237.68 mg GAE/g) and total flavonoids (16.14 mg E/g). There were good correlations between DPPH and ABTS values ( R 2 0.98) and between total phenolics and total flavonoids ( R 2 0.94). Tamarindus indica had significant antimycobacterial activity against Mycobacterium aurum (MIC 78 μg/mL). As could be expected with edible plants, all the extracts had a relatively low cytotoxicity with LC 50 values higher than 102 μg/mL with the exception of the two Aframomum species (33 and 74 μg/mL). Conclusions This study provides scientific support for some of the the traditional uses and the pharmacological activities of the culinary herbs and spices investigated. The results suggest that increasing intake of some of these herbs may be useful in preventing or reducing the progression of lifestyle-related diseases. The diversity of the pharmacological activities of the extract from the fruit of Adansonia digitata suggested that this plant might be valuable for application in human and animal health. [ABSTRACT FROM AUTHOR]
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- 2014
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12. Anti-inflammatory and antioxidant properties of leaf extracts of eleven South African medicinal plants used traditionally to treat inflammation.
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Ondua, Moise, Njoya, Emmanuel Mfotie, Abdalla, Muna Ali, and McGaw, Lyndy J.
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PHENOL analysis , *ALKANES , *ANIMAL experimentation , *BIOLOGICAL assay , *ETHANOL , *FLAVONOIDS , *INFLAMMATION , *INFLAMMATORY mediators , *LEAVES , *MACROPHAGES , *METHANOL , *NITRIC oxide , *OXIDOREDUCTASES , *POWDERS , *RODENTS , *SOLVENTS , *PLANT extracts , *OXIDATIVE stress , *AFRICAN traditional medicine , *LIPOPOLYSACCHARIDES , *CELL survival , *PHARMACODYNAMICS - Abstract
Abstract Ethnopharmacological relevance Inflammation is a complex mechanism employed by the body to promote healing and restoration to normal function in the event of injury. Eleven plant species were selected in this study based on their use in traditional medicine against inflammation in South Africa. Methods Hexane, acetone, ethanol, methanol and water extracts of the powdered plants were prepared and a total of fifty-five extracts were tested for their anti-inflammatory and antioxidant activities. The anti-inflammatory activity of extracts was evaluated via the 15-lipoxygenase (15-LOX) inhibitory and the nitric oxide (NO) inhibition assays using lipopolysaccharide (LPS)-activated RAW 264.7 murine macrophages. Total flavonoid and total phenolic contents were determined. The antioxidant activity of the extracts was performed using radical scavenging DPPH (2, 2-diphenyl-1-picrylhydrazyl) and electron reducing ABTS (2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) assays. Results The hexane extract of Typha capensis (TC) had good lipoxygenase inhibitory activity with IC 50 of 4.65 µg/mL, significantly (p < 0.05) higher than that of the positive control quercetin (IC 50 = 24.60). The same extract also had good nitric oxide inhibitory activity with 86% NO inhibition and cell viability of 97% at 50 µg/mL. The TC acetone extract had the best antioxidant activity with IC 50 of 7.11 and 1.91 µg/mL respectively in the DPPH and ABTS assays. Following fractionation of the TC plant material, the ethyl acetate fraction had interesting antioxidant activity and the methanol/water (35%) and hexane fractions had good 15-LOX inhibitory activity. The antioxidant and anti-inflammatory activities therefore resided in both polar and more non-polar fractions. Conclusion The acetone extract of Typha capensis and its fractions had good anti-inflammatory and antioxidant activities, supporting the medicinal use of this species against inflammation. Other species including Ficus elastica, Carpobrotus edulis, Cotyledon orbiculata and Senna italica also had good activity worthy of further investigation. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]
- Published
- 2019
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13. In vitro bioactivity of the fractions and isolated compound from Combretum elaeagnoides leaf extract against selected foodborne pathogens.
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Erhabor, Rosemary C., Aderogba, Mutalib A., Erhabor, Joseph O., Nkadimeng, Sanah M., and McGaw, Lyndy J.
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MEDICINAL plants , *STAINS & staining (Microscopy) , *ANTI-infective agents , *BIOFILMS , *ANTIOXIDANTS , *ORGANIC compounds , *APOPTOSIS , *RUTIN , *TREATMENT effectiveness , *LEAVES , *FOOD poisoning , *DESCRIPTIVE statistics , *PLANT extracts , *BIOLOGICAL assay , *FREE radical scavengers , *MICROBIAL sensitivity tests , *CYTOTOXINS , *CALORIMETRY , *PHARMACODYNAMICS - Abstract
Combretum species are used traditionally for the treatment of diarrhoea, hookworm, fever, inflammation, pain and infectious diseases. Infections are commonly caused by the intake of food contaminated with foodborne pathogens. These are a significant concern in the food industry owing to their ability to form biofilms and cause food spoilage, despite the availability of modern food preservation techniques. Combretum elaeagnoides Klotzsch (Combretaceae) is used in southern African traditional medicine against infections and diarrhoea. This study evaluated the antimicrobial ability of C. elaeagnoides leaf fractions and the isolated compound quercetin-3- O -rhamnoside against a panel of foodborne pathogens, and biofilms formed by them. The samples were also assessed for their antioxidant activity and cytotoxicity. Fractions prepared from the methanol extract of the leaves, and a bioactive compound (quercetin-3- O -rhamnoside) isolated from the ethyl acetate fraction were investigated for activity against nine reference and clinical strains of foodborne pathogens. The microdilution method was used to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the fractions and compound. The inhibition of biofilm formation and the crystal violet staining assays were used to determine the antibiofilm efficacy. The DPPH (2, 2-diphenyl-1-picrylhydrazyl) assay and the 2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) electron reduction assay were used to determine the antioxidant potential of the fractions and compound. The cytotoxicity was assessed using the 3-(4, 5-dimethylthiazolyl-2)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay against Vero African monkey kidney cells. The fractions were active against all tested organisms, with MIC values ranging from 0.03 to 1.25 mg/mL. The best MBC was 0.63 mg/mL. All the fractions and the purified compound inhibited biofilm formation of Staphylococcus aureus and Salmonella Typhimurium, with percentage inhibition values greater than 50% at 1 mg/mL. The compound had very promising antibiofilm activity against Escherichia coli 1 (ATCC 25922) with percentage inhibition of >150%. The compound and fractions had good radical scavenging potential against the DPPH and ABTS radicals. Quercetin-3- O -rhamnoside and the fractions were relatively non-cytotoxic. The ability of the fractions and compound to reduce and inhibit biofilm biomass and their promising antioxidant potential provide motivation to further investigate the use of plants to protect food products from contamination, as well as to treat infections characterized by bacterial biofilms. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2021
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14. In vitro antimicrobial effects of Hypoxis hemerocallidea against six pathogens with dermatological relevance and its phytochemical characterization and cytotoxicity evaluation.
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Mwinga, James L., Asong, John A., Amoo, Stephen O., Nkadimeng, Sanah M., McGaw, Lyndy J., Aremu, Adeyemi O., and Otang-Mbeng, Wilfred
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ANTI-infective agents , *ANTIOXIDANTS , *CAROTENES , *CELL lines , *CELL surface antigens , *COLORIMETRY , *DRUG resistance in microorganisms , *FLAVONOIDS , *GAS chromatography , *IMMUNODIAGNOSIS , *MASS spectrometry , *MEDICINAL plants , *RESEARCH funding , *SKIN diseases , *SPECTROPHOTOMETRY , *LINOLEIC acid , *PHYTOCHEMICALS , *PLANT extracts , *FREE radical scavengers , *DESCRIPTIVE statistics , *IN vitro studies , *PHARMACODYNAMICS ,THERAPEUTIC use of plant extracts - Abstract
Hypoxis hemerocallidea (commonly known as African Potato) is popular in African traditional medicine. It is used in the management of diverse ailments including burns, wounds and skin-related diseases. The current study investigated the antimicrobial effects of Hypoxis hemerocallidea against six microorganisms associated with skin diseases. In addition, the antioxidant activity, phytochemical profiles and cytotoxicity of the bulb extracts were evaluated. The antimicrobial activity of 50% methanol (MeOH) and petroleum ether (PE) extracts of Hypoxis hemerocallidea bulbs was tested against two bacterial and four fungal strains implicated in causing opportunistic skin-related diseases. Antioxidant potential of the extract was investigated via the 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging assay and β -carotene linoleic acid model. Phytochemical profiling of the 50% MeOH extract of Hypoxis hemerocallidea was done using spectrophotometric assay and Gas Chromatography-Mass Spectrometry (GC-MS). The extracts were also evaluated for cytotoxicity against African green monkey Vero kidney cell lines based on the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. Both 50% MeOH and PE extracts showed considerable inhibitory effects against all six microorganisms. The extracts were potent against Shigella flexneri and Trichophyton tonsurans with minimum inhibitory concentration (MIC) values less than 1 mg/ml. However, there was relatively poor antifungal activity against the other fungal strains. In the DPPH assay, the MeOH extract of the bulb had an EC 50 of 29.8 μg/ml while 76.91% antioxidant activity was observed in the β -carotene-linoleic acid model. The extract contained total phenolics (41 mg GAE/g) and flavonoids (10 mg CE/g). The GC-MS analysis of Hypoxis hemerocallidea bulb revealed 29 and 160 bioactive compounds for 50% MeOH and PE extracts, respectively. Based on the cytotoxicity, Hypoxis hemerocallidea had LC 50 value of 210.9 ± 18.4 and 95.5 ± 13.3 μg/ml for PE and MeOH extracts, respectively. The bulb extracts of Hypoxis hemerocallidea exhibited good antimicrobial and antioxidant activities, which could be attributed to the presence of phenolics, flavonoids and the other bioactive compounds identified through GC-MS, making it a potentially effective cosmetic plant. These findings also account for the multi-pharmacological use of Hypoxis hemerocallidea in traditional medicine, especially related to skin diseases. The plant extracts can be considered as safe based on their LC 50 values (< 20 μg/ml). However, other form of cytotoxicity studies need to be carried out on Hypoxis hemerocallidea, as well as in vivo tests, to confirm its safety and efficacy as a treatment for skin-related diseases. Image 1 [ABSTRACT FROM AUTHOR]
- Published
- 2019
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