4 Plants That Are Great for Humans

They might not be able to pull you out of
a freezing lake, or carry you from a burning building, but plants have probably saved your
life, or at least made you feel a whole lot better. That’s because, at least in the U.S., a
quarter of all prescription drugs come from substances that are found only in plants. We humans have a long history of using plants
to treat diseases. Most of those treatments were probably discovered
using blind luck — like, by people munching on random leaves and seeing how they felt. If they found one that seemed to work, the
knowledge would usually get passed around by word of mouth, but sometimes it would also
be written down. That’s how we ended up with recipes that
are about as old as writing itself — like the 5000 year old Sumerian clay slab that
lists 250 plants for preparing medicines. Of course, the recipes don’t always work,
and there are plenty of old herbal remedies that do absolutely nothing. But a few did
work — and we still use some of them in medicines today. Many of the plant-based substances people
use belong to a broad group of bitter-tasting, nitrogen-containing compounds called alkaloids. These compounds don’t seem to be strictly
necessary for plants to survive, so they probably offer evolutionary bonuses – like a defense
against anything that tries taking a bite out of it. Their names mostly end in i-n-e, and you’ve
probably already heard of some of them, like caffeine, nicotine, morphine… And a lot of them have effects on our bodies
that are pretty strong … for better or worse. Take the deadly nightshade, for example. In 2009, a woman was hospitalized from eating
just six nightshade berries, which she thought were blueberries. Ten berries could have been
fatal. One of the killer compounds in nightshade
is atropine, an alkaloid found all over the plant. But atropine also has a good side — it’s
actually on the World Health Organization’s “Model List of Essential Medicines” in
three separate places! Surgeons can use it as a sedative for short
operations, or to dilate the pupils to gain easy access to the back of the eye. And, despite being extracted from a plant
so toxic, atropine works an antidote against certain types of poisoning! Some pesticides and nerve gases overwork the
parasympathetic nervous system, and atropine can counter that deadly effect by blocking
the receptors these toxins over-activate. Other useful plant-based drugs took a lot
of hard science to make work — as in the case of an anti-malarial drug called artemisinin. The compound comes from the sweet wormwood
plant, and Youyou Tu, the chemical engineer who developed it, was awarded half of the
Nobel Prize for Medicine in 2015. Using plants to treat malaria is not a new
thing. The disease has probably killed half of all humans from the Stone Age to today,
and we haven’t beaten it yet. With so many people suffering, especially
in developing countries, it’s not surprising people turned to plants for a cure. Around the world, more than 1200 plant species
are used to treat malaria and the fever that comes with it. But only a fraction of these
have been properly tested for their effectiveness. One of the first remedies known to be genuinely
effective was quinine, an alkaloid that comes from the bark of Peruvian cinchona trees. A compound known as chloroquine, which was
based on quinine, was later developed synthetically as a safer and more potent version of the
drug. But it wasn’t long before the Plasmodium
parasite that causes malaria started showing resistance to chloroquine. So people started
looking for an alternative. Tu and her team turned to traditional remedies
from China. They scoured thousands of traditional recipes for potions and medicines that were
said to reduce fever, looking for the most promising plants. They found a clear winner. One plant — the
sweet wormwood — showed up in not just one or two, but hundreds of different recipes. Initial tests of sweet wormwood extracts on
the malaria parasite were promising, but inconsistent. Some experiments showed sweet wormwood to
be highly effective, but others only slightly. Tu thought that the variations might be caused
by differences in the way the wormwood extract was prepared, so she went back to the old
texts to find more clues. Most of the remedies suggested processing
dried leaves with boiling water, but Chinese philosopher Ge Hong, writing in the year 340
CE, had a different suggestion. He described a preparation process that used
fresh, not dried leaves, and involved extracting the juice by soaking those fresh leaves in
cold water, wringing them out, then drinking the juice straight down. Based on this account, the team developed
their own extraction method using ether, then tested it out on mice, monkeys, and finally
people. And it worked! The new-and-improved extract killed off malaria
parasites soon after they entered their host’s red blood cells, and with relatively mild
side effects. The active compound was called artemisinin after the plant it was found in. The discovery of artemisinin created a whole
new family of antimalarial drugs that are still used to treat malaria today. Then there’s diabetes, another disease that
people have been trying to treat for a long time. Uncontrolled blood sugar levels in people
with diabetes can lead to complications like nerve damage, sight problems and kidney failure. But plants have our backs on this one, too. For the estimated 400 million people who have
Type II diabetes, one of the most widely prescribed treatments is metformin, a relatively simple
molecule that’s made up of just a few nitrogen, carbon, and hydrogen atoms. The story of metformin starts with an herb
known as goat’s rue, or professor weed. It stands over a meter high, with white, blue,
or purple flowers. Professor weed has been used to manage diabetes
around the Middle East and Europe since the Middle Ages. In the late 1800s, studies found that the
plant contained high levels of an alkaloid called guanidine. When isolated, guanidine
worked great at reducing blood sugar levels in animals, but it was too toxic to use in
people. So chemists got to work, trying different
adaptations of guanidine that kept the blood sugar down, but without the whole poisoning
problem. The result was metformin. Safe, effective
and cheap to make, metformin is helping millions of people manage their diabetes. Despite its simple chemical structure and
plenty of research, we still don’t really know how metformin lowers blood sugar, or
why it’s so effective with so few side-effects. So, what thanks do the American people give
this life-saving plant? We slap it on the Noxious Federal Weed list! But, to be fair, that’s because it’s an
invasive species in the US. It’s a lot less destructive when it grows in the Middle East,
Europe and Asia. Not all plants are so common, though — in
fact, plants containing the secrets to much-needed cures may have gone extinct before we had
the chance to even name them, let alone study them. And we’ve come close to losing life-saving
plants before. In 1987, for example, a botanist named John
Burley trekked through a swamp forest in Malaysia, collecting plant samples to study back in
the lab. His travels were part of a larger mission to find new treatments for various
cancers, as well as HIV. One of these samples, tagged “Burley-and-Lee
351” didn’t kill cancer cells, but it did do an amazing job of preventing HIV from
replicating. So the collectors high-tailed it back to the
forest… only to find it gone, cut down for firewood or building. Extracts from similar
trees didn’t have the same effect, because they were slightly different species. It was only salvaged when a few trees of the
right species were found at the Singapore Botanical Gardens. The drug is called Calanolide
A, and it’s currently in Phase II clinical trials and owned by the local Malaysian government. Then there’s this pretty little thing — the
Rosy Periwinkle. It might look like something that would be
right at home in my backyard, but it’s actually native only to Madagascar – though it will
happily grow anywhere warm. The native people of Madagascar used these periwinkle plants
for all kinds of ailments. In the 1950s, researchers from Western pharmaceutical
companies studied the periwinkle and discovered that it contained some rather remarkable alkaloids. Two of these, called vincristine and vinblastine,
are used to treat certain types of cancer by stopping the cells from dividing. Vincristine has helped increase success rates
in treating kids with leukemia from just 10% in the 1960s, to well over 80% today. And vinblastine is often a core chemotherapy
component for lymphoma — a cancer of the lymphatic system — as well as testicular
cancer. All kinds of plants have amazing substances
locked away inside them. So the next time you walk past a tree or flower, give it a
pat on the leaf — assuming it’s not, like, thorny, or poisonous to the touch- anything
like that. You might look a little strange, and the plant
won’t understand, but it probably deserves it anyway. Thanks for watching this episode of SciShow,
which was brought to you by our patrons on Patreon. If you want to help support this
show, just go to patreon.com/scishow. And don’t forget to go to youtube.com/scishow
and subscribe!


  1. Ayurveda has documented many tested herbs and commination of herbs. Would really appreciate it if you can make a video on that too. Hope you do it. Just trying to spread awareness😊😊

  2. He made be right about everything else, but the metformin part, 👎. Look up the bad side effects that it produces.

  3. To know more about medicinal plants you must visit to India China or any other country is not only are using plants as medicine. Your most of the plants are native to India as well

  4. The so called modern scientists seem to know everything,yet they know little about the science our ancestors adopted to happy healthy on this planet earth.The reason for today's catastrophic state of climate change and destruction of flora and fauna squarely rests on the greedy western civilization which seems to have only one objective of destruction without understanding evidence based scientific living.Hope these mad greedy and murderous scientists supported by greedy business men are stopped as quickly.Monsanto like companies are persistent in their efforts to destroy what ever little wisdom has been left on this planet with natural organic sustainable living.

  5. The medicinal plants are not in extinction but the truth the Healers from Asia will not share the knowledge not at east a person is a family and they download it verbally to their next-generation who is destined to become a healer too. I am familiar with these for I am one of them. The reason is that some of the plants are poisonous and dangerous it can be used by another person who used it for revenge to there enemy there they are carefully handed to the chosen one.

  6. Do you really think our government want cures for serious diseases? Wouldn’t they make more money keeping disease going? It’s a business and I don’t trust them SMH

  7. Malaria is a parasite. And yet pharma insists. To cure symtoms not cause. Parasite body cleans could go for more further then u think

  8. Well nothing is natural anymore, they poisoned everything to death. Fertilize, it takes years to get that poison out of the environment

  9. The reason the pharmacological community likes to say old-fashioned remedies often have no effect whatsoever, is because they're looking for instantaneous "miracle-cures." But plants tend to work a bit slower, which may actually be more preventative, and gently corrective to the entire organism, rather than correcting an isolated dis-ease, such as eczema.
    Often, a disease manifestation may be traceable to an underlying imbalance in the entire organism. The first manifestation may be rather mild, such as an energy slump mid-afternoon. Later, the imbalance may manifest itself in more alarming ways such as slight overweight turning into obesity… and then prediabetes.
    But of course, modern medicine isn't interested in a "normal" energy slump two hours after a high-carb meal. What they are concerned about, is trying to keep the A1c under 7.5 in full-blown diabetics. In other words, they're more interested in trying to keep sick people alive, though miserable, than they are in correcting incorrect metabolization of carbohydrates, to create a healthy, long-lived population.

  10. Rosy Periwinkle is so common everywhere here. Since kids we're always told not to mess with it because it's poisonous.

  11. I think the Rosy Periwinkle is also abundant in Southeast Asia. If I'm right that's one of the few smelly little flowers in the world.

  12. 👍👍
    Metformin is used as Insulin sensitizer. Hence by increasing activity of body insulin it reduces blood sugar level.
    It should be used only under supervision of qualified doctor because it have some sides effects too like other antidiabetic agents.

  13. More than 1/4 th of the plant compounds are used to create prescription medications . Try 90-95% of medications are plant derived!

  14. Hank Green,
    4heaven's sake, will you calm down? You making me nervous just watching you hyper ventilate
    no need to compete, with what, anyway? with yourself? You can not force us to listen, no matter what you do.

  15. As a person who has not been to a doctor in 25+ yrs ( no doctors that I would trust here in the jungle )…and ONLY medicate myself with local plants and ionic silver ( that I produce ). The plants have extreme knowledge and if you listen & look…they reviel their secrets. Just the use of fresh herbs daily…can pretty much assure good health.

  16. I do herbalism as a hobby. I'm not a professional & I'm certainly not a beginner. I do however have quite a bit of experience with plant medicines & I can tell you with 100% assurance that if you have a capable herbalist, that can cure many different types of so called incurable conditions.
    I've seen a well made broad leaf plantain salve literally heal a nasty, infected, deep, cat scratch within 4 days. It did it so well that by the 4th day the wound was not even visible.
    I've seen a lady with blood pressure problems that prescription medicine wouldn't touch. But after taking a total of 4 750 mg capsules of cayenne pepper over a 2 day period, she didn't have any more blood pressure problems for several years.
    I've seen flu's cured in less than 3 days, abscesses miraculously healed, colds stopped dead in their tracks but 3 drops of a poke tincture, heart attacks stopped dead in their tracks. Herbs from a knowledgeable practioner are much better medicine that the drugs that you get from a pharmacy. Doctors are good at being mechanics for the human body & know almost nothing about actual medicine, disease prevention & nutrition herbalists do.
    Now it's true that many people turn to herbalism when they have cancer but almost invariably it's after the doctors are done giving round after round of chemotherapy which not only destroys the body's ability to fight disease but is itself a carcinogen. Most of these people die. Not because herbs don't work but because they went to the herbalist too late & after they have destroyed their immune system!

  17. just a few i think he left out aloe vera excelant for burns also muscadine hull are full of medical stuff plus the seed of muscadins contain a chemica that fits canser in our bodies muscadines contain all the good things that grapes have plus alot more red wine is good for your heart muscadines are better ps i sale muscadins

  18. Do you want to know what the most dangerous plant in the world is??… its the Japanese nuclear power plant…

    I thank you….👏👏👏

  19. If you pat a plant or otherwise show your admiration – it does understand.
    One anecdote is about a strand of potted ficus in a main walkway of a shopping centre in the US. The trees were relocated to a quiet part of the centre & started dying. They moved them back. The frequent silent admiration by people passing them thinking how beautiful they were made the plants extra strong & healthy. Removal depressed them.
    Many gardeners are aware of plant communication. I've had plants contact me in my dreams, & then met that particular plant not long after. Depends whether you're open to the communication.

  20. When I was in middle school I began to discover the incredible history of "plant hunters" who traveled the world to bring back plants that had medicinal value or horticultural interest. Some died in their pursuit of the rare and unusual plants. Medicinal plants like cinchona were so valuable that trying to acquire the plants to attempt to grow them all over the tropical world sometimes led to murder. The Chinese were very reluctant to release the tea plants to the outside world, it took decades to obtain the true variety of camellia that produces tea.
    People are still gathering plant specimens to study, few are of real value except to botanists and research scientists but some finally finish growth trials and the eventually reach your local nursery for us to enjoy.

  21. These are all relatively good for treating the diseases they are doing used to counter, but specifically metformin I have issues. It does not help diabetics, only prolong the inevitable. It lowers blood sugar temporarily but does not stop people from constantly spiking insulin and their blood sugar a lot. It fixes a symptom of diabetes but doesn’t cure it. The only real way to treat diabetes is by changing the diet. It’s caused by repeatedly spiking your insulin over a long period of time to the point where you become insulin resistant and your pancreas can’t keep up and you can’t produce enough insulin. The way to deal with diabetes permanently is not to start taking a bunch of drugs, it’s to stop spiking your insulin. Carbohydrates spike your blood sugar/insulin(they go hand in hand) a lot while protein spikes it some and fat does it almost not at all. The standard American diet(SAD) is super high carb and just by looking at the foods most people eat it’s no surprise that the US has one of the highest diabetes rates in the world. Everything we eat is either wrapped in bread, a tortilla, surrounded by pasta or some other grains. Plus plenty of high sugar fruits and starchy vegetables(ie potatoes). All of those foods spike insulin a lot and almost everyone eats stuff like it 3 times a for every meal while avoiding fat like the devil. Upwards of 70%+ of calories with most people are coming from carbs. Stuff like that always leads to insulin resistance and eventually diabetes. It’s also why everyone is so fat. The only way to truly deal with diabetes is by restricting carbs significantly(<20g per day) which will give your body a break and stop spiking insulin and blood sugar. This lets your body be able to heal its insulin resistance and eventually deal with type 2 diabetes entirely. Type 1 can be helped significantly but since type 1 means your body produces no insulin at all you will still need occasional insulin injections. Either way reducing carbs and replacing it with high quality fat is very good for you.

  22. I always loved the Rosy Periwinkle plant because it's pretty, but now I love it even more. I'm gonna remember how useful it is that everytime I see one now.

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