Mycothiol disulfide reductase: A continuous assay for slow time-dependent inhibitors

Hamilton, Chris J.; Finlay, R.; Stewart, Matthew J; Bonner, Alexandra

doi:10.1016/j.ab.2009.02.015

Cited by 17 publications

(14 citation statements)

References 20 publications

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“…The enzyme reduces a symmetrical mycothiol disulfide (MSSM) into thiol mycothiol (MSH). This is a continuous cycle which helps to protect the mycobacteria cell from oxidative stress [20]. The alkaloids in the roots of R. vomitoria, may have better binding site for the mycothione reductase, hence becomes subversive substrates in the thioredox pathway of a Mycobacterium cell.…”

Section: Resultsmentioning

confidence: 99%

Antimycobacterial, antioxidant activity and toxicity of extracts from the roots of Rauvolfia vomitoria and R. caffra

Erasto¹,

Lubschagne²,

Mbwambo³

et al. 2011

Spatula DD

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AIM: This study aimed to investigate the antimycobacterial activity of total alkaloid and ethanolic aqueous extracts of Rauvolfia vomitoria and R. caffra. It further aimed to evaluate antioxidant activity and cytotoxicity effect of the extracts which would have shown high antimycobacterial efficacy. METHODS: The alkaloids from the roots of two plant species were extracted according to standard procedures. Antimycobacterial activity of the extracts was evaluated using a two fold microdilution method. The antioxidant activity of the alkaloids and ethanolic extracts was determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and reducing capacity assays. The potential cytotoxicity of the extracts was evaluated using brine shrimp toxicity assay. Comparison of alkaloidal composition of the two alkaloidal extracts was done using HPLC analysis. RESULTS: The study revealed that, alkaloid extracts from the roots of Rauvolfia species had higher antimycobacterial activity against Mycobacterium madagascariense (MM) and M. indicus pranii (MIP). The minimum inhibition concentration (MIC) values of alkaloid extracts ranged between 0.078 to 1.25 mg/ml, while the ethanolic extracts were generally moderately active against test organism. The alkaloids and ethanolic aqueous extracts of R. vomitoria exhibited high antioxidant activity. In the cytotoxicity assay, extracts did not exhibit any toxicity against brine shrimps. CONCLUSION: The alkaloids from the roots of R. vomitoria have high antimycobacterial and antioxidant activity. The alkaloids ability to inhibit the growth of two Mycobacterium strains may be associated to its antioxidant activity. The cytotoxicity of the most active extract is negligible when compared to the standard anticancer drug, this may explain why R. vomitoria is highly used in the treatment of various infectious and physiological ailments. ÖZET AMAÇ: Çalışmada Rauvolfia vomitoria ve R. caffra alkaloid ve etanolik sıvı ekstrelerinin antimikobakteriyel etkilerinin araştırılması ve ayrıca, yüksek antimikobakteriyel etki gösterecek olan ekstrelerin antioksidan ve sitotoksik etkilerinin değerlendirilmesi amaçlandı. YÖNTEM: Alkoloidler, standart prosedürlere göre iki bitkinin köklerinden ekstrakte edildi. Ekstrelerin antimikobakteriyel etkileri, iki kat mikrodilüsyon metodu kullanılarak değerlendirildi. Alkaloidlerin ve etanol ekstrelerin antioksidan etkileri 1,1-difenil-2-pikrilhidrazil (DPPH) ve indirgeyen kapasite analizleri kullanılarak saptandı. Ekstrelerin potansiyel sitotoksisitesi, tuzlu su karidesi toksisite analizi kullanılarak değerlendirildi. İki alkoloidal ekstrenin alkoloidal bileşiminin karşılaştırılması, HPLC analizi kullanılarak yapıldı. BULGULAR: Çalışmamız, Rauvolfia türlerinin köklerinden elde edilen alkaloid ekstrelerin, Mycobacterium madagascariense (MM) and M. indicus pranii (MIP)'ye karşı yüksek antimikobakteriyel etkiye sahip olduğunu göstermiştir. Alkoloid ekstrelerin minimum inhibitör konsantrasyonları (MIC), 0.078-1.25 mg/ml arasında değişirken, etanolik ekstreler, genellikle orta derece...

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Section: Resultsmentioning

confidence: 99%

Antimycobacterial, antioxidant activity and toxicity of extracts from the roots of Rauvolfia vomitoria and R. caffra

Erasto¹,

Lubschagne²,

Mbwambo³

et al. 2011

Spatula DD

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“…Furthermore, they also exhibited good electron donating ability, which implies that alkaloids may be inhibiting some redox pathways in the bacterial cell thereby slowing their growth or causing death of microbes (Hamilton, Finlay, Stewart, & Bonner, 2009). This pharmacological property adds value to the potential antimicrobial efficacy of the alkaloids from the roots of R. caffra.…”

Section: Discussionmentioning

confidence: 99%

“…This pharmacological property adds value to the potential antimicrobial efficacy of the alkaloids from the roots of R. caffra. The electron donating ability of the alkaloid is very important in the inhibition of the bacterial cell growth as the bacterial cell utilizes NADPH dependent reductase enzymes to maintain an intracellular reduced environment in the cells (Hamilton et al, 2009). The DPPH free radical scavenging activity displayed by R. caffra methanolic extract compare closely to the currently known scavenging bioorganic molecules and could indicate a potential source of natural anti-oxidants that can be formulated into commercial products.…”

Section: Discussionmentioning

confidence: 99%

Antimicrobial and Antioxidant Activity of Crude Extracts of Rauvolfia caffra var. caffra (Apocynaceae) From Tanzania

Njau¹,

Alcorn²,

Ndakidemi³

et al. 2014

IJB

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As part of an effort to search for extracts and compounds with new antimicrobial efficacy to fight against bacterial resistance, the antibacterial activity of Rauvolfia caffra var. caffra (Sond.), a plant of family Apocynaceae used in Traditional Medicine in Tanzania, was investigated. Ethanol, methanol and water extracts from leaf, stem and root barks were tested against three species of bacteria namely Escherichia coli (ATCC 25922) (Gram -ve), Staphylococcus aureus (ATCC 25923) (Gram +ve) and Enterococcus faecalis (ATCC 51299) (Gram +ve) using Agar-well diffusion assay method and minimum inhibitory concentration on Mueller-Hinton Agar plates. The extracting solvents were removed by vacuo evaporator to obtain gummy-like extracts. This was then dissolved in dimethylsulfoxide (10% DMSO). The DMSO without plant extracts was used as a negative control whereas Gentamicin® as the standard antibiotic was used as a positive control. The Zone of Inhibition (ZOI) measured in mm and Relative Inhibitory Zone Diameter (RIZD) was calculated. Results showed that R. caffra exhibited antimicrobial inhibitory activity at a range of 1.25 to 5.0 mg/ml with activity most prominent with methanol extract (ZOI of 28.33± 0.33 mm and RIZD of 95% for S. aureus; and ZOI of 26.66 ± 0.33 mm for E.coli and 19.0 ± 0.57 mm for E. faecalis at P< 0.05). To characterize further, the alkaloid from the root bark was extracted according to the standard procedure. The antioxidant activity of the alkaloids and ethanolic extracts was determined using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and reducing capacity assays. The results indicated that alkaloid fraction of the root and 80% ethanolic extracts of stem bark exhibited high antioxidant activity. The phytochemical analysis indicated that R. caffra is rich in alkaloids, anthraquinones, anthocyanoides, flavonoids, saponins, tannis and reducing sugars. This study provides supportive evidence that methanol and ethanol extracts of R. caffra can be used as herbal medicine in control of E.coli, S. aureus and E. faecalis.

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“…Enzyme kinetics on Mycothiol disulfide and Glutathione reductase An adapted method of Hamilton et al, (2009) was used to determine the enzyme inhibition potential of the M. sericea extract on glutathione (Gtr) and mycothiol disulfide (Mtr) reductases 7 . Briefly, the inhibition assay with Mtr and Gtr were carried out at 35ºC in a 96-well plate with 50 mM Hepes (pH 7.6), 0.1 mM EDTA, NADPH (70 µM), Ellman's reagent (DTNB) (100 µM), substrate GSSG and MSSM (60 µM) and varying concentrations of the extract.…”

Section: Solanum Tomentosummentioning

confidence: 99%

Antibacterial and Anticancer Activity of Ethnomedicinal Plants Used in the Jongilanga Community, Mpumalanga

Lall¹,

Mn²,

Reid³

et al. 2018

Phyto

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Seventy-four ethanolic extracts were prepared from traditionally used medicinal plants in the Jongilanga community in Mpumalanga South Africa. The aim was to determine the biological activity of the selected plants against cancer, mycobacteria species and acne. From the results, it was evident that Mundulea sericea was able to inhibit the proliferation of human melanoma cells (A375) with a fifty percent inhibitory concentration (IC50) ranging between 50 and 100 µg/ml as well as the ability to inhibit Mycobacterium tuberculosis, Mycobacterium smegmatis and Propionibacterium acnes with minimum inhibitory concentrations (MIC) of 125, 31.25 and 7.9 µg/ml respectively. This further led to the investigation of the antioxidant and anti-inflammatory activity as well as the influence of the extract on mycothiol disulphide reductase (Mtr) and glutathione reductase enzymes (Gtr) as potential targets against the above-mentioned diseases. M. sericea inhibited the COX-2 enzyme, responsible for inflammation, with an IC50 value of 10.70 ± 1.14 µg/ml, furthermore compounds previously isolated from M. sericea showed potential inhibition of COX-2 in molecular docking studies. Low radical scavenging capacity against the DPPH free radical with an IC50 value of 60.52 ± 2.40 µg/ml was obtained, however, M. sericea showed a higher affinity towards Mtr as compared to Gtr, which makes it an ideal plant for use as an antimycobacterial agent.

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Mycothiol disulfide reductase: A continuous assay for slow time-dependent inhibitors

Cited by 17 publications

References 20 publications

Antimycobacterial, antioxidant activity and toxicity of extracts from the roots of <i>Rauvolfia vomitoria</i> and <i>R. caffra</i>

Antimycobacterial, antioxidant activity and toxicity of extracts from the roots of <i>Rauvolfia vomitoria</i> and <i>R. caffra</i>

Antimicrobial and Antioxidant Activity of Crude Extracts of Rauvolfia caffra var. caffra (Apocynaceae) From Tanzania

Antibacterial and Anticancer Activity of Ethnomedicinal Plants Used in the Jongilanga Community, Mpumalanga

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Mycothiol disulfide reductase: A continuous assay for slow time-dependent inhibitors

Cited by 17 publications

References 20 publications

Antimycobacterial, antioxidant activity and toxicity of extracts from the roots of &lt;i&gt;Rauvolfia vomitoria&lt;/i&gt; and &lt;i&gt;R. caffra&lt;/i&gt;

Antimycobacterial, antioxidant activity and toxicity of extracts from the roots of &lt;i&gt;Rauvolfia vomitoria&lt;/i&gt; and &lt;i&gt;R. caffra&lt;/i&gt;

Antimicrobial and Antioxidant Activity of Crude Extracts of Rauvolfia caffra var. caffra (Apocynaceae) From Tanzania

Antibacterial and Anticancer Activity of Ethnomedicinal Plants Used in the Jongilanga Community, Mpumalanga

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Antimycobacterial, antioxidant activity and toxicity of extracts from the roots of <i>Rauvolfia vomitoria</i> and <i>R. caffra</i>

Antimycobacterial, antioxidant activity and toxicity of extracts from the roots of <i>Rauvolfia vomitoria</i> and <i>R. caffra</i>