What are nightshades? – The Hindu

What is it?

What exactly are nightshades? Simply put, they are plants, herbs, and vegetables that belong to the Solanaceae plant family. This is a plant family where nearly all members of its flora contain naturally occurring organic compounds known as alkaloids, which makes them toxic in nature.

The nightshade family consists of approximately 2700 species of plants, out of which many are used for medicinal and agricultural purposes. They are known for having star-shaped flowers with five fused petals that are symmetric in nature. The origin of the name ‘nightshade’ to this day is unclear, but it has been suggested that the plant was named because most of its members grow more effectively in the shade.

Poisonous or not?

This is a topic of discussion that holds many points of value and complexity. Why the confusion? The alkaloid compounds make them toxic, so that should immediately set the warning, shouldn’t it? Well, to put it simply, not always. If all nightshade plants were equivalent to poison, then that would mean the ‘tomato chutney’, french fries, and baingan bharta, which many of you love to eat, should be considered poisonous as well, since, believe it or not, tomatoes, potatoes, and brinjal all come from the same family.

The toxic nature of nightshade plants may seem like a complex topic, but there is an explanation: If collected and prepared properly with the right steps, some nightshade plants don’t cause harm to the body, and on the contrary, end up providing the person with many health benefits. If these nightshades are consumed in large amounts, they can prove to be toxic to humans. Let us take a simple example: the potato. If the right ones are picked and prepared, they can be consumed without consequences. However, if you find a green potato, toss it away immediately! This is one of the few times when the colour green should be seen as a negative sign! But what causes the green? What makes some nightshades poisonous? The answer to that would be solanine.

The sinister solanine

Solanine is one of the main alkaloids in nightshades. It is a toxic chemical compound known as a glycoalkaloid. It is bitter in taste and highly poisonous, even when taken in small doses. But it does help the plant in one way. Similar to how in DC comics,  kryptonite, which is Superman’s weakness (or poison, in this case), can be used as a form of defense against evil kryptonians attacking Earth, solanine is responsible for protecting the plant from external threats like pests and insects. It has pesticidal properties and is the nightshade’s natural defense.

It was first isolated from black nightshade berries in the year 1820. This chemical compound can naturally form in any part of the plant (leaves, stems, fruits, and sprouts). The normal concentration of solanine synthesised is not that harmful to human health. But there are times when normally edible nightshades like tomatoes and potatoes are faced with extreme external disturbances from the environment, and produce excess solanine content as a form of chemical defense. If these nightshades are found to have high contents of this compound, their consumption should be avoided. This can be seen in green potatoes, unripe tomatoes and eggplants.