In vitro antimycobacterial and cytotoxic data on medicinal plants used to treat tuberculosis

This article contains data on in vitro antimycobacterial activity and cytotoxicity of hydroethanolic crude extracts from five selected medicinal plant species traditionally used to treat tuberculosis in Ghanaian ethnomedicine, see “Medicinal plants used to treat TB in Ghana” [1]. The interpretation and discussion of these data and further extensive insights into drug discovery against tuberculosis from natural products of plant biodiversity can be found in “Antimycobacterial and cytotoxic activity of selected medicinal plant extracts” [2].


More specific subject area
Drug discovery against tuberculosis Type of data Tables  How data was  acquired in vitro antimycobacterial data was acquired using Microplate alamar blue assay (MABA), while cytotoxicity data was generated using MTS assay, with absorbance being read at 490 nm using Infinite M200 Pro TM  This data may provide insights for future drug development against tuberculosis. The data set can be used to guide further isolation of anti-TB compounds. This data set can be used for external validation of data acquired from similar experiments.

Data
Data on comparative antimycobacterial activity of total hydroethanolic extracts derived from five medicinal plant species is presented (Table 1). Data on in vitro cytotoxic activity of tested plant species and positive control drugs, isoniazid, rifampicin and ethambutol against MRC-5, human fetal lung fibroblast cell line (ATCC s CCL-171™) is shared in Table 2.

Collection and preparation of plant materials
The rhizomes of Zingiber officinale and the leaves of Chenopodium ambrosioides, Dissotis rotundifolia, Aloe vera var. barbadensis and Solanum torvum were collected from the eastern region of Ghana, identified and prepared for bioassays as earlier described [1,2].

Microplate alamar blue assay (MABA)
Mycobacterial strains were maintained on Lowenstein Jensen slopes, while the test inoculum was prepared in 7H9GC-tween broth, adjusted to a no. 1 McFarland tube standard, to give approximately 3.0 Â 10 8 cells and further diluted at the ration of 1:10 in the enriched broth (7H9GC-Tween) for anti-TB bioassays [2,3]. The assay was conducted as earlier described by Nguta et al. [2] and Palomino et al. [3]. Briefly, 100 μL of the enriched broth was dispensed in each well of a sterile flat-bottom 96-well plate, followed by serial two-fold dilutions of the crude extracts. The positive control drugs were prepared directly in the microtiter plate. One hundred microliters (100 μL) of the prepared inoculum was added to each well. A sterile control comprising of the medium only and a growth control consisting of cells and growth medium were also included for each experiment. Evaporation during the incubation period was minimized by addition of sterile water to all perimeter wells of the 96-well microtiter plate. The covered microtiter plates were sealed in plastic bags and incubated at 37°C under a normal atmosphere. After 7 days of incubation for M. tuberculosis H37Ra and M. tuberculosis subsp. tuberculosis, and 48 h of incubation for M. smegmatis, 30 μL of a mixture of 10% tween 80 and alamar blue solution in a ratio of 1:1 was added to each well, and the plate incubated overnight. A color change from blue to pink indicated mycobacterial growth, and the minimum inhibitory concentration (MIC) was taken as the highest dilution of the crude extract or positive control drug that    , was used to enzymatically remove the confluent layers, followed by suspension in culture medium. A light microscope (Leitz Wetzlar, Germany) was used to determine cell numbers after vital staining with trypan blue (0.4% (wt/vol); Sigma, USA).

Preparation of test extracts
Total (crude) extracts were suspended in enriched phenol free Dulbecco's modified essential medium/Ham's 12 nutrient mixture (DMEM/F12), (Gibco) at the concentration of 10 000 μg/mL and dispersed by ultrasonic vibration for 15 min. Crude extracts were stirred on a vortex for one minute before every use to ensure uniform suspension.
2.4.4. MTS assay in vitro cytotoxicity assay was performed using the Promega CellTiter 96 AQueous Non-Radioactive Cell Proliferation (MTS) assay as earlier described [2,4]. The procedure for cytotoxic evaluation was adopted from manufacturer's instructions and previously published papers ( [5,6]). Total extracts were suspended in enriched Dulbecco's modified essential medium/Ham's/12 nutrient mixture, followed by serial dilution across 96-well microtiter plates (100 μL), and incubation at 37°C with 5% carbon dioxide (CO 2 ) for a period of 24 h in a humidified CO 2 incubator. Four (4 h) hours prior to the end of each experiment, an MTS mixture (20 μL/well) was added to each of the test wells of the 96-well microtiter plate. The plates were then placed on a microwell plate reader (Tecan, Austria, GmbH), shaken for 10 s and the absorbance of the formazan product read at 490 nm after the completion of each exposure period. Each experiment was run in triplicate. For each experiment, two internal controls were set: (i) IC 100 consisting of medium only and (ii) an IC 0 consisting of cells only. Background absorbance due to the non-specific reaction between the MTS reagent and the crude extracts was deducted from exposed cell values [7].

Conflict of interest declaration
We declare no conflict of interest.