hello Nurhazwani, cell culture models can be employed to assess the possible toxicity of plant ingredients at a cellular level. I would use a range of cells and use the MTT assay and Neutral Red Assay to start as they will help determine the toxicity  (if any) of the plant extracts.  However, toxicology results from cell-based trials cannot be accurately extrapolated to humans when evaluating the safety of functional ingredients so I would approach with caution. Check the literature to see if these plants are toxic etc. 

Hi Nurhazwani,

As indicated by Dr Naim O'Sullivan also, in-vitro testing results may not be directly interpreted for the safety of a given formulation. In-vitro studies are a great starting point but ultimately, you will need to do testing on animals also (in-vivo testing) - both acute and chronic.

For in-vitro testing, the most commonly employed cytotoxicity tests are based on two major endpoints : (i) the metabolic indicators such as MTT, MTS, XTTC etc. or (ii) the cell viability/membrane indicators such as Neutral Red Uptake (NRU), Trypan Blue Exclusion etc. In my opinion you can start with MTT assay and once you have an idea on the cellular viability vs the doses of the plant extract, you can get more confirmatory data on LD50 by going for Trypan blue exclusion assay (in vitro LD50 will be the dose of extract killing 50% of the cells after given time point). Both types of tests will give you quantitative data for setting a rationale for your extended studies. Your best bet would be to use the normal or primary cell lines derived from various organs but it would not hurt to include some established cancer cell lines also. ATCC sells most of the cell lines and you can find the following links useful:

http://www.atcc.org/Products/Cells_and_Microorganisms/Human_Primary_Cells/Cell_Type.aspx

http://www.atcc.org/Products/Cells_and_Microorganisms/Cell_Lines.aspx

Under in-vivo testing, you will have to calculate the in vivo LD50 values for your extract (the dose of the extract which will kill 50% of the tested animal population being tested after a specified duration). The LD50 values will further help you in designing your acute or chronic toxicity evaluation studies for the organs of your interest. The organ specific studies may include biochemical, molecular and immuno-histopathological parameters 

Best Wishes

Subhash

Hi Wanie,

I agree with all of the points above. You can also refer to my recent preliminary research article which we used normal Human-Prostate-Cell (PN2TA) to study the properties of mushroom extract for food application.

''Antimicrobial properties and cytotoxicity of sulfated (1,3)-β-D-glucan from the mycelium of the mushroom Ganoderma lucidum''

Best wishes,

Wan

Article Antimicrobial Properties and Cytotoxicity of Sulfated (1,3)-...

Thank you Dr Naim, Dr Subhash and Dr Wan Qadr.

Yes, the in vitro study just for screening and maybe mechanism study before we proceed to in vivo.