Science Buddies: "Ask an Expert"

I am an eighth grader. I am trying to prepare for my science fair project.

I want to test alpha-amylase enzyme inhibitor properties of some ancient herbs/plant based phytochemicals. I want to find out if this will slow down the conversion of starch to glucose (like acarbose). This reaction is supported by alpha amylase enzyme which is found in the human saliva and stomach. My procedure will be in vitro or outside the body for my experiment, and I need help to develop a procedure. Would you please be able to guide me with the methods I should be using to find out inhibition properties? Would continuous enzyme assays like Spectrophotometric be the recommended method? Unfortunately, I don't have access to lab. Are there any other ways?

Another idea I have is measuring insulin activity using plant based chemicals that can act as insulin.

Best Regards,
Eight Grader Seeking Help

Hi,

This sounds like a fun project.

First of all, you need to make sure that you can get access to the phytochemicals/plants you want to test, and get the alpha-amylase. If you can get these, you can choose a starch source that you want the amylase to digest. You may want to use some ordinary corn starch that you can buy in the grocery store.

Assaying the starch digestion is usually done by chromatography, but if you search in the Science Buddies website, there is an experiment called "How Sweet It Is" about sugar in food, and this experiment measures glucose levels. It will not be as precise as chromatography, but you can use glucose strips without a lab. The protocol for that experiment would be very helpful for you to review to plan your testing. If you do a google search for "starch digestion lab," the first result is a document from Indiana University that has a protocol for a starch digestion lab that uses a chemical called Lugol's Reagent to test if starch is present. Both of these would be good resources for you to look at as you begin.

As you come up with your protocol, make sure you consider things like how you will be introducing the phytochemicals to the starch and amylase, and do some reading on how to handle the amylase.

Good luck with your project, it sounds very exciting. Please don't hesitate to ask any other questions or follow-ups!