Plants remove cancer causing toxins from air

A ground-breaking study has revealed that plants can efficiently remove toxic gasoline fumes, including cancer causing compounds such as benzene, from indoor air.

The study was led by University of Technology Sydney (UTS) bioremediation researcher Associate Professor Fraser Torpy, in partnership with leading Australian plantscaping solutions company Ambius.

The researchers found that the Ambius small green wall, containing a mix of indoor plants, was highly effective at removing harmful, cancer-causing pollutants, with 97 per cent of the most toxic compounds removed from the surrounding air in just eight hours.

Poor indoor air quality is responsible for 6.7 million premature deaths globally, according to the World Health Organisation. Most people spend 90% of their time indoors at home, school or the workplace, so adopting new strategies to improve air quality is critical.

Ambius General Manager Johan Hodgson said the research presented new evidence into the critical role played by indoor plants and green walls in cleaning the air we breathe quickly and sustainably.

"We know that indoor air quality is often significantly more polluted than outdoor air, which in turn impacts mental and physical health. But the great news is this study has shown that something as simple as having plants indoors can make a huge difference," Mr Hodgson said.

Previous studies on indoor plants have shown they can remove a broad range of indoor air contaminants, however this is the first study into the ability of plants to clean up gasoline vapors, which are one of the largest sources of toxic compounds in buildings worldwide.

Offices and residential apartment buildings often connect directly to parking garages, either by doors or elevator shafts, making it difficult to avoid harmful gasoline-related compounds seeping into work and residential areas. Many buildings are also exposed to gasoline fumes from nearby roads and highways.

Breathing gasoline fumes can lead to lung irritation, headaches and nausea, and has been linked to an increased risk of cancer, asthma and other chronic diseases from longer term exposure, contributing to decreased life expectancy.

Associate Professor Torpy said the study results, based on measurements from a sealed chamber, had far exceeded their expectations when it came to removing gasoline pollutants from the air.

"This is the first time plants have been tested for their ability to remove gasoline-related compounds, and the results are astounding.

"Not only can plants remove the majority of pollutants from the air in a matter of hours, they remove the most harmful gasoline-related pollutants from the air most efficiently, for example, known carcinogen benzene is digested at a faster rate than less harmful substances, like alcohols.

"We also found that the more concentrated the toxins in the air, the faster and more effective the plants became at removing the toxins, showing that plants adapt to the conditions they're growing in," Associate Professor Torpy said.

Mr Hodgson said the findings confirmed feedback they'd received after installing plants in hundreds of office buildings across the nation.

"At Ambius, we see over and over again the effects plants have in improving health, wellbeing, productivity and office attendance for the thousands of businesses we work with. This new research proves that plants should not just be seen as 'nice to have', but rather a crucial part of every workplace wellness plan.

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The dark cost of being toxic

An international research team including scientists from the Max Planck Institute for Chemical Ecology in Jena has discovered that the striking orange and black wings of monarch butterflies not only send the message to predators that these butterflies are highly toxic, but that the storage of toxins and development of the colourful wings come at a cost to the butterfly's body. The team reared monarch caterpillars on their milkweed food plants that had different levels of toxins. Monarchs that had ingested high levels of toxins from their food plants as caterpillars, experienced high levels of oxidative damage after storing these toxins in their bodies, and were less conspicuous in their coloration. The study demonstrated experimentally that the storing of toxins is costly for insects that are highly specialized on their food plants.

Monarch butterflies (Danaus plexippus) feed on milkweeds of the genus Asclepias when they are caterpillars, storing the plants' cardenolide heart poisons in their bodies for their own defence. The combination of the toxins with the striking orange and black wings of the monarch is called aposematism (derived from the Greek terms apo = away and sema = signal). Hannah Rowland head of the Max Planck Research Group on Predators and Toxic Prey at the Max Planck Institute for Chemical Ecology explains: "aposematism works because predators learn that eye-catching prey are best avoided. Predators learn faster when the visual signal is always the same. Bright orange means "`'don't eat me'. But other scientists and I have repeatedly found that aposematic animals can have varying degrees of warning signal strength, and we wondered what about pale orange, or deep orange? What does this mean, and what causes the difference?"

Rowland, together with her colleague Jonathan Blount from the University of Exeter, along with their international team of scientists, tested whether the storage of the plant's toxins is costly to the butterfly's body condition. Specifically, whether the storage of toxins causes oxidative stress, whichhappens when antioxidant levels are low. Because antioxidants can be used to make colourful pigments, they tested if the amount of toxins in the monarch is related to their conspicuousness and their oxidative state.

The researchers reared monarch caterpillars on four different milkweeds of the genus Asclepias that have different toxin levels. With this, they were able to manipulate the amount of toxins ingested to subsequently measure concentrations of cardenolides, determine oxidative state, and compare the resulting wing coloration.

"Monarch butterflies that sequestered higher concentrations of cardenolides experienced higher levels of oxidative damage than those that sequestered lower concentrations. Our results are among the first to show a potential physiological mechanism of oxidative damage as a cost of sequestration for these insects," says Hannah Rowland. The scientists also found that the colour of the wings of male monarchs depended on how much cardenolides they sequestered, and how much oxidative damage this had resulted in. Males with the highest levels of oxidative damage showed decreasing colour intensity with increased toxin uptake, while males with the least oxidative damage were the most toxic and colour intense.

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Simple measures can go a long way to combating air pollution in schools

Most UK primary schools experience levels of pollution which exceed the safe levels set out by the World Health Organization, yet simple measures can cut outdoor and indoor exposure of toxins by almost half, according to a new study from the University of Surrey.

Working with a select number of London schools, researchers from Surrey's Global Centre for Clean Air Research (GCARE) investigated whether putting up a green screen along the perimeter fence of a school, installing air purifiers in classrooms, and organising school street initiatives during pick-up and drop-off hours, improved air quality of classrooms and playgrounds. These initiatives were funded by Impact on Urban Health.

The researchers found that air purifiers in classrooms reduced indoor pollution concentrations by up to 57%, and the School Streets initiative, which stops motor vehicles driving past schools at the start and end of school days, reduced particle concentrations by up to 36%. Green screens at the school boundary reduced some of the most dangerous outdoor particle levels coming from roads by up to 44%, depending on wind conditions.

Prashant Kumar, founding Director of the Global Centre for Clean Air Research (GCARE) at the University of Surrey, said:

"Everybody, especially our children, deserves to live and work where the air is as clean and safe as possible. Unfortunately, the reality is far from ideal, with many of our schools unwittingly exposing children to harmful pollutants. The problem is particularly bad at schools near busy roads.

"Our research offers hope to many who care about this issue, as the results show that taking reasonable action can make a positive difference."

Ten million students worldwide spend 30% of their daily lives at school, with 70% of this time being spent indoors. Currently, 7,000 UK schools breach the World Health Organization's air quality limits, leaving children vulnerable to respiratory diseases, affected lung and brain health, behavioural problems, and increased risk of cancer.

Kate Langford, Programme Director of the Health Effects of Air pollution programme at Impact on Urban Health, funders of the research, said:

"Every child has the right to learn in an environment that keeps them safe and healthy. But, every day, children are exposed to dangerously high levels of air pollution in and around schools.

"Our partnership with Arup, Global Action Plan and the University of Surrey has shown there are practical ways that we can protect children in and around schools and can help guide schools to implement these solutions.

"These measures now need to be combined with efforts from local authorities at regional and national levels to improve air quality and create healthier places for children to live, learn and play."

Larissa Lockwood, Director of Clean Air at Global Action Plan, said:

"Schools should be safe places of learning, not places where students are at risk of health hazards. There is no safe level of air pollution, but children are particularly vulnerable to its impacts including the development of organs and their ability to learn. Services like the London Schools Pollution Helpdesk ensure that schools have access to advice on what they can do to reduce exposure to air pollution, including the measures tested in this research. But this needs to be rolled out nationally -- all children must be protected from the health effects of air pollution in their everyday lives."

Professor Prashant Kumar concluded:

"My simple plea to decision-makers in the UK is this: simple actions speak louder than words. By giving every school resources to implement one of the measures detailed in our research, they could make a world of difference to tens of thousands of children in this country."

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A safer, greener way to make solar cells: Toxic solvent replaced

Scientists at SPECIFIC Innovation and Knowledge Centre, Swansea University, have found a way to replace the toxic, unsustainable solvents currently needed to make the next generation of solar technology.

Printed carbon perovskite solar cells have been described as a likely front runner to the market because they are extremely efficient at converting light to electricity, cheap and easy to make.

A major barrier to the large-scale manufacture and commercialisation of these cells is the solvents used to control crystallisation of the perovskite during fabrication: this is because they are made from unsustainable materials and are banned in many countries due to their toxicity and psychoactive effects.

SPECIFIC's researchers have discovered that a non-toxic biodegradable solvent called γ-Valerolactone (GVL) could replace these solvents without impacting cell performance.

GVL's list of advantages could improve the commercial viability of carbon perovskite solar devices:
 

• It is made from sustainable feedstocks
• There are no legal issues in its use around the world
• It is suitable for use in large-scale manufacturing processes
• It is non-toxic and biodegradable

Carys Worsley, who led the research as part of her doctorate, said:

"To be truly environmentally sustainable, the way that solar cells are made must be as green as the energy they produce. As the next generation of solar technologies approaches commercial viability, research to reduce the environmental impact of large-scale production will become increasingly important."

Professor Trystan Watson, research group leader, added:

"Many problems need to be resolved before these technologies become a commercial reality. This solvent problem was a major barrier, not only restricting large-scale manufacture but holding back research in countries where the solvents are banned.

We hope our discovery will enable countries that have previously been unable to participate in this research to become part of the community and accelerate the development of cleaner, greener energy."

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What makes a giant jellyfish's sting deadly?

With summer on the way, and some beaches reopening after COVID-19 shutdowns, people will be taking to the ocean to cool off on a hot day. But those unlucky enough to encounter the giant jellyfish Nemopilema nomurai (also known as Nomura's jellyfish) might wish they had stayed on shore. Now, researchers reporting in ACS' Journal of Proteome Research have identified the key toxins that make the creature's venom deadly to some swimmers.

Found in coastal waters of China, Korea and Japan, Nomura's jellyfish can grow up to 6.6 feet in diameter and weigh up to 440 pounds. This behemoth stings hundreds of thousands of people per year, causing severe pain, redness, swelling, and in some cases, even shock or death. The jellyfish's venom is a complex brew of numerous toxins, some of which resemble poisons found in other organisms, such as snakes, spiders, bees and bacteria. Rongfeng Li, Pengcheng Li and colleagues wanted to determine which of the many toxins in the jellyfish's venom actually cause death. The answer could help scientists develop drugs to counteract jellyfish stings.

The researchers captured N. nomurai jellyfish off the coast of Dalian, China, and collected their tentacles, which contain the venom. They extracted venom proteins and separated them into different fractions using chromatography. By injecting each protein fraction into mice, the team identified one that killed the animals. Autopsies revealed damage to the mice's heart, lungs, liver and kidneys. The researchers used mass spectrometry to identify 13 toxin-like proteins in this lethal fraction. Some of the jellyfish proteins were similar to harmful enzymes and proteins found in poisonous snakes, spiders and bees. Instead of any one toxin being lethal, it's likely that multiple poisons work in concert to cause death, the researchers say.

From Science Daily

Scorpion toxin that targets 'wasabi receptor' may help solve mystery of chronic pain

Black rock scorpion

Researchers at UC San Francisco and the University of Queensland have discovered a scorpion toxin that targets the "wasabi receptor," a chemical-sensing protein found in nerve cells that's responsible for the sinus-jolting sting of wasabi and the flood of tears associated with chopping onions. Because the toxin triggers a pain response through a previously unknown mechanism, scientists think it can be used as a tool for studying chronic pain and inflammation, and may eventually lead to the development of new kinds of non-opioid pain relievers.

The scientists isolated the toxin, a short protein (or peptide) that they dubbed the "wasabi receptor toxin" (WaTx), from the venom of the Australian Black Rock scorpion. The discovery came as the researchers were conducting a systematic search for compounds in animal venom that could activate, and therefore be used to probe and study, the wasabi receptor -- a sensory protein officially named TRPA1 (pronounced "trip A1") that's embedded in sensory nerve endings throughout the body. When activated, TRPA1 opens to reveal a channel that allows sodium and calcium ions to flow into the cell, which can induce pain and inflammation.

"Think of TRPA1 as the body's 'fire alarm' for chemical irritants in the environment," said John Lin King, a doctoral student in UCSF's Neuroscience Graduate Program and lead author of a study published August 22, 2019 in Cell, which describes the toxin and its surprising mode of action. "When this receptor encounters a potentially harmful compound -- specifically, a class of chemicals known as 'reactive electrophiles,' which can cause significant damage to cells -- it is activated to let you know you're being exposed to something dangerous that you need to remove yourself from."

Cigarette smoke and environmental pollutants, for example, are rich in reactive electrophiles which can trigger TRPA1 in the cells that line the surface of the body's airway, which can induce coughing fits and sustained airway inflammation. The receptor can also be activated by chemicals in pungent foods like wasabi, onions, mustard, ginger and garlic -- compounds that, according to Lin King, may have evolved to discourage animals from eating these plants. WaTx appears to have evolved for the same reason.

Though many animals use venom to paralyze or kill their prey, WaTx seems to serve a purely defensive purpose. Virtually all animals, from worms to humans, have some form of TRPA1. But the researchers found that WaTx can only activate the version found in mammals, which aren't on the menu for Black Rock scorpions, suggesting that the toxin is mainly used to ward off mammalian predators.

"Our results provide a beautiful and striking example of convergent evolution, whereby distantly related life forms -- plants and animals -- have developed defensive strategies that target the same mammalian receptor through completely distinct strategies," said David Julius, PhD, professor and chair of UCSF's Department of Physiology, and senior author of the new study.

But what the researchers found most interesting about WaTx was its mode of action. Though it triggers TRPA1, just as the compounds found in pungent plants do -- and even targets the very same site on that receptor -- the way it activates the receptor was novel and unexpected.

First, WaTx forces its way into the cell, circumventing the standard routes that place strict limits on what's allowed in and out. Most compounds, from tiny ions to large molecules, are either ingested by the cell through a complex process known as "endocytosis," or they gain entry by passing through one of the many protein channels that stud the cell's surface and act as gatekeepers.

But WaTx contains an unusual sequence of amino acids that allows it to simply penetrate the cell's membrane and pass right through to the cell's interior. Few other proteins are capable of the same feat. The most famous example is an HIV protein called Tat, but surprisingly, WaTx contains no sequences similar to those found in Tat or in any other protein that can pass through the cell's membrane.

"It was surprising to find a toxin that can pass directly through membranes. This is unusual for peptide toxins," Lin King said. "But it's also exciting because if you understand how these peptides get across the membrane, you might be able to use them to carry things -- drugs, for example -- into the cell that can't normally get across membranes."

Once inside the cell, WaTx attaches itself to a site on TRPA1 known as the "allosteric nexus," the very same site targeted by pungent plant compounds and environmental irritants like smoke. But that's where the similarities end.

Plant and environmental irritants alter the chemistry of the allosteric nexus, which causes the TRPA1 channel to rapidly flutter open and closed. This allows positively charged sodium and calcium ions to flow into the cell, triggering pain. Though both ions are able to enter when TRPA1 is activated by these irritants, the channel exhibits a strong preference for calcium and lets much more of it into the cell, which leads to inflammation. By contrast, WaTx wedges itself into the allosteric nexus and props the channel open. This abolishes its preference for calcium. As a result, overall ion levels are high enough to trigger a pain response, but calcium levels remain too low to initiate inflammation.

To demonstrate this, the researchers injected either mustard oil, a plant irritant known to activate the wasabi receptor, or WaTx into the paws of mice. With mustard oil, they observed acute pain, hypersensitivity to temperature and touch -- key hallmarks of chronic pain -- and inflammation, as evidenced by significant swelling. But with WaTx, they observed acute pain and pain hypersensitivities, but no swelling.

"When triggered by calcium, nerve cells can release pro-inflammatory signals that tell the immune system that something's wrong and needs to be repaired," Lin King said. "This 'neurogenic inflammation' is one of the key processes that becomes dysregulated in chronic pain. Our results suggest that you can decouple the protective acute pain response from the inflammation that establishes chronic pain. Achieving this goal, if only in principle, has been a longstanding aim in the field."

The researchers believe their findings will lead to a better understanding of acute pain, as well as the link between chronic pain and inflammation, which were previously thought to be experimentally indistinguishable. The findings may even lay the groundwork for the development of new pain drugs.

"The discovery of this toxin provides scientists with a new tool that can be used to probe the molecular mechanisms of pain, in particular, to selectively probe the processes that lead to pain hypersensitivity," Lin King said. "And for those interested in drug discovery, our findings underscore the promise of TRPA1 as a target for new classes of non-opioid analgesics to treat chronic pain."

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