Monday, 7 August 2017

Is your tea 100% biodegradable?

What is not to like about enjoying a nice, tasty, refreshing cup of tea but a cup of tea is more than a soothing beverage. It is a legitimate reason to take a break from work. It is a life essential. It is emblematic of all that is grand good about the Great British mind-set. There is never a bad time to have a cuppa. Making sure your cuppa tea is 100% biodegradable is more of a challenge than one might think. Here's why......


Image result for tea bagsYour beloved cup of tea is probably hiding a dark secret and much like the animal fat in £5 notes scandal, there is a bad side to your benign cup of tea, and that is plastic. Not just the plastic wrapper on the box, or the plastic pouch some teas come in, but plastic actually in the teabag itself. Let that sink in a moment – there is plastic in the teabag!

You might be wondering why there is a need for plastic to be found in teabags? Well, plastic (polypropylene to be exact) is apparently added to the paper teabag to help heat seal them during manufacture so they don’t come open in the box, or in your cup. It also means though that these tea bags aren't 100% biodegradable, which is a bit of problem.

As a lot of the information stems from a 2010 article published in the Guardian national newspaper which stated that the vast majority are only 70-80% biodegradable: 
https://www.theguardian.com/environment/2010/jul/02/teabags-biodegradeable

Image result for tea bagsTeapigs advise that all of their teabags are made from a by-product of corn starch known as Soilon. The box that they are sold in does appear to contain some plastic though, so if that is an issue then this may not be your solution.


Taylors of Harrogate (who make Yorkshire Tea )advise that they are working with their supplier of teabag paper to develop a paper that is 100% plant-based, but right now our tea bags do contain polypropylene as part of the fibres.

Twinings have several different types of teabags available on the market. They advise that their standard teabags, used for Earl Grey and English Breakfast, to name a couple, and many of our infusions and Green teas are produced from a natural plant based cellulose material and contain no plastic in the fibres. However, these teabags are “heat sealed” tea bags, and so the paper also has a very thin film of polypropylene, a plastic, which enables the two layers of the tea bags to be sealed together.

Related imageMeanwhile their ‘string and tag with sachet’ tea bags, also contain a thin layer of plastic polyethylene to help seal up the sachets. The only Twinings product that does not contain any plastic is their pyramid teabag range – whereby the material is derived from maize starch and is fully biodegradable and compostable. Rather annoyingly though, many of their pyramid tea bags seem to come in plastic bags rather than boxes.


Pukka Tea advise that their teabags do not contain polypropylene or any other plastic – their teabag is sewn shut by machine with cotton thread. They further mention that their teabag paper is made of a blend of natural abaca (a type of banana) and plant cellulose fibres, and their supply of tea bag paper is also totally chlorine free and unbleached. They are staple-free and 100% biodegradable and/or recyclable. The tea bag strings are made from 100% organic, non-GMO, un-bleached cotton. Each teabag is individually packaged though (possibly in plastic), so the one downside is that there is a bit of waste from one box of tea .

PG Tips say their “teabags are made with 80% paper fibre which is fully compostable along with the tea leaves contained in the bag. The remaining packaging includes a small amount of plastic which is not fully biodegradable: this is needed to create a seal to keep the tea leaves inside the bag“. However, they didn't have the information to state whether or not this was polypropylene.

Tetley also say their round and square teabags are made with 80% paper fibre, and 20% thermoplastic. Their string & tag teabags are plastic-free but are used mostly in their catering range for individually wrapped tea bags. They advise that Tata Global Beverages has ongoing continuous improvement and environmental awareness and are working towards more sustainable and biodegradable solutions for all their products. They also advised that ripping ripping the bag and dispersing the contents should help the composting process.

Typhoo, and Clipper declined to comment. 

Related image
So whilst Teapigs, Pukka Tea, Twinings Pyramid tea bags and Tetley’s catering range are plastic free, in pretty much all cases the packaging is not. The teas are also on the more expensive side, perhaps best as a infrequent treat but may be a little pricey to enjoy as your everyday cup of tea. Especially if you have a  chronic tea habit.


If you are keen to enjoy your tea without the added plastic the other option is to switch to loose leaf tea. I’ve been hunting down some handy accessories that might come in handy if you choose to do so:

Plastic-Free Tea Alternatives

    Image result for loose leaf tea and teapot
  • Reusable Tea Bags (£7.98 for 5) (or make your own)
  • Tea Ball Infuser (£3.25)
  • A pretty fairtrade mug (£9.95)
  • A cheery teapot (£24.95) with infuser basket so no need for additional tools or tea leaves floating in your tea.

References

  1. http://moralfibres.co.uk/is-there-plastic-in-your-tea/
  2. Most UK teabags not fully biodegradeable, research reveals (Guardian article 2010)


Saturday, 1 July 2017

The dark side of melatonin

Image result for melatonin pillsTwenty-one years ago, MIT neuroscientist Dr. Richard Wurtman introduced melatonin as a new solution to sleep problems. His lab patented supplements in hopes of curing insomnia in the older population, whose melatonin receptors calcify with age.

“Researchers say pills of the natural hormone...will bring on slumber quickly without the addictive effects of drugs,” the New York Times reported at the time. In the same article, Judith Vaitukaitis, then director of the National Center for Research Resource, said the hormone “offered hope for a natural, non-addictive agent that could improve sleep for millions of Americans.”

Wurtman himself wasn’t quite so cavalier. In that same article, he warned, “People should not self-medicate with melatonin.”

Nonetheless, melatonin was a hit. In the last two decades, the all-natural sleep aid has earned a spot in medicine cabinets across the country. Inexpensive, easily accessible, naturally occurring and considered safe, melatonin appeals to the those who’d rather avoid prescribed pills. Naturopaths, chronic insomniacs, shift-workers and frequent fliers pop milligrams of melatonin without thinking twice.

According to the National Center for Complementary and Integrative Health, nearly 1.3 million American adults reported taking melatonin in February, 2015. Parents are even handing it out to their kids — 419,000 as of February — believing melatonin to be a harmless, naturally produced hormone.

Image result for melatonin pills
Melatonin is indeed naturally produced, but the hormone is one of the murkiest supplements on the market, unsubstantiated by incomplete and developing research. Only in the U.S. is melatonin available over-the-counter as a dietary supplement, and long-term usage can alter natural hormone levels and even sabotage sleep. Given to children, its potential side effects are even more concerning.

The Real Sandman
Melatonin, secreted by the pineal gland, is the messenger that announces bedtime to our brains. Darkness stimulates its release into the bloodstream; light inhibits it. Once released, it binds to hormonal receptors located in the brain’s suprachiasmatic nuclei — a cluster of nerves that regulates the body’s internal clock and circadian rhythms — and travels into cerebrospinal fluid and the bloodstream.

Our bodies naturally produce “endogenous” melatonin (or, “growing or originating from within an organism”). What ends up on pharmacy shelves in synthesized “exogenous” melatonin — growing or originating from outside an organism. Its most common application is that of sleep aid; users are told to take their dose directly before bedtime, when endogenous levels are already on the rise. Frequent fliers swear by its effectiveness in recovering from jet lag recovery, saying the hormone helps reset their biological clock in a new time zone.

Studies also suggest melatonin can help prevent sleep disorders in children suffering from ADHD and autism (though its use in kids remains controversial).

Image result for melatonin pills
The FDA classifies melatonin as a dietary supplement. Dr. Wurtman sees this as a marketing ploy to circumvent the bureaucratic web of research and patents that typically burden the process of bringing drugs and hormones to market.

And that’s where the problems arise.

A Dosing Problem
Given the lack of apparent side effects, it may seem harmless to label melatonin as a dietary supplement. But the classification matters for consumers, because the FDA doesn’t require supplements to include warnings of overdose risks on their labels, as is mandatory for drugs and hormones.

Perhaps even riskier, the classification allows companies to sell melatonin in varying dosages.

In 2001, researchers at MIT concluded that the correct dosage for melatonin falls between .3 and 1 mg. Yet, walk down the pharmacy aisle and you’ll see stacks of sleep aids packing as 10 times that amount.

It’s easy to take too much, and most of melatonin’s side effects are the result of just that. While there’s no evidence that too much melatonin could be fatal, or even remotely life-threatening, exceeding the proper dosage can upset the body’s natural processes and rhythms.

“With some hormones, if you take too much you can really put your body in danger,” says Dr. Wurtman. “With melatonin, you’re not in danger, but you’re also not very comfortable. It won’t kill you, but it’ll make your life pretty miserable.”

And, despite common perception, melatonin can cause next-day drowsiness, according to Michael Grandner, a sleep researcher at the University of Pennsylvania.

More importantly, melatonin is a hormone. With children, according to Grander, it can affect puberty, disrupt menstrual cycles and impede normal hormonal development.  

Excess melatonin can also induce hypothermia, as body temperatures reduce during melatonin release, and stimulate overproduction of the hormone prolactin, which can cause hormonal problems and even kidney and liver issues in men.

The Insomnia Clause
When used occasionally and at the correct time, melatonin is a fine means of encouraging sleep. But, ironically, with prolonged use, it can actually amplify insomnia. Having too much melatonin in the system, the theory goes, overwhelms the receptors, changing how a patient reacts to the hormone — whether it’s endogenous or exogenous.

According to Dr. Wurtman, melatonin supplements may work at first, but soon “you’ll stop responding because you desensitize the brain. And as a consequence, not only won’t you respond to the stuff you take…you won’t respond to the stuff you make, so it can actually promote insomnia after a period of time.”

Mauricio Farez, an Argentinian sleep researcher, has similar reservations. “I have some issues, in terms of the pharmacology, and…it’s really hard to have stable levels of the drug in our blood.”

Grandner agrees. “Taking melatonin for an extended period of time your body may acclimate and re-adjust and produce less over time which will work against you.”

When it comes down to it, taking melatonin to fall asleep sooner doesn’t even work. “When it’s nighttime and melatonin levels are high,” says Dr. Wurtman “taking melatonin supplements is like putting a drop of water into an empty bucket; when it’s daytime, it’s like putting a drop of water into a full bucket.”

This doesn’t mean melatonin is without potential benefits. Farez wants to see more research on its immunologic potential, as his most recent study suggests melatonin could play a role in managing multiple sclerosis. It’s also widely used to fight certain types of cancer, as it combats tumour cells.

Both Farez and Wurtman believe melatonin’s potential benefits outweigh the drawbacks. But that’s largely in a clinical, controlled environment under professional supervision. Allowing melatonin to sit on our shelves, unregulated and sold as freely as aspirin, is a problem waiting to happen.

How safe is melatonin to take regularly for sleep problems? Are there more risks for children versus adults?

There’s a dearth of safety data for melatonin, but there are a number of potential concerns, especially for children.

“I think we just don’t know what the potential long-term effects are, particularly when you’re talking about young children,” said Dr. Judith Owens, director of the Center for Pediatric Sleep Disorders at Boston Children’s Hospital. “Parents really need to understand that there are potential risks.”



The pineal gland in the brain ramps up production of the hormone melatonin in the evening, as light fades, to encourage sleep, and it turns down production in the early morning hours. Synthetic forms of the hormone are also sold as a dietary supplement; because melatonin is found in some foods, like barley, olives and walnuts, it is regulated as a nutritional supplement rather than a drug, as most other hormones are.

In adults, studies have found melatonin to be effective for jet lag and some sleep disorders. It is also hugely popular as a sleep aid for children and can be useful for sleep disorders among those with attention-deficit disorders or autism, Dr. Owens said. “I rarely see a family come in with a child with insomnia who hasn’t tried melatonin,” she said. “I would say at least 75 percent of the time when they come in to see us” at the sleep clinic, “they’re either on melatonin or they’ve tried it in the past.”

While short-term use of the hormone is generally considered safe, it can have side effects, including headaches, dizziness and daytime grogginess, which could pose a risk for drivers. Melatonin can also interfere with blood pressure, diabetes and blood thinning medications.

Less is known about this potent hormone’s effects in children. Some research suggests it could, at least in theory, have effects on developing reproductive, cardiovascular, immune and metabolic systems.

Related imageIf you do turn to melatonin, Dr. Owens says, do so under the guidance of a health care professional and buy melatonin from a reputable source. “Pharmaceutical grade” melatonin, she said, may have more precise dosing levels than off-the-shelf brands. A study published in November in the Journal of Clinical Sleep Medicine found that 71% of melatonin samples were more than 10% off the stated dose, with some lots containing nearly five times the listed dose.

There are of course, number of more natural, herbal and holistic approaches to sleep problems. read my previous post if you want more information about natural alternatives if you want to avoid exogenous melatonin altogether: http://yaso-shan.blogspot.co.uk/2013/10/a-good-nights-sleep.html

References

  1. https://well.blogs.nytimes.com/2017/01/06/is-the-sleep-aid-melatonin-safe-for-children-and-adults/?_r=0
  2. http://www.huffingtonpost.com/van-winkles/the-dark-side-of-melatoni_b_8855998.html

Saturday, 3 June 2017

Examining the Madasgar periwinkle

The Scientific World Journal recently published a review article addressing the two ‘faces’ of the Madagascar Periwinkle (Catharanthus roseus or Vinca rosea): lovely garden ornamental and important medicinal plant.

One of the major medical breakthroughs of the last century utilises compounds derived from a popular ornamental plant found in gardens and homes across the world, the Madagascar periwinkle. This tender, perennial plant grows as a herb or a subshrub, sprawling along the ground or standing erect up to a metre in height. The attractive white or pink flowers comprise five petals spreading from a long, tubular throat, while the leathery, dark green leaves are arranged in opposite pairs. Each fruit is formed of two narrow, cylindrical follicles which house.

With a long history of both ornamental use in gardens and medicinal use in Ayurvedic and traditional Chinese medicine, the periwinkle exemplifies the advantages of exploring herbal traditions for important modern health benefits.  The plant now is considered endangered in some areas, and has also been controversial due to the facts that there have been patents on chemotheraphy drugs derived from C. roseus.

In particular, the plant is known for vinblastine and vincristine, which are TIAs or terpenoid indole alkaloids. Both vinblastine and vincristine are on the World Health Organization’s list of essential medicines as important anti-cancer medications used in treatment of Hodgkin’s lymphoma and leukemias. As well, over 100 other indole alkaloids have been isolated from the plant, although at present only five are being marketed. The isolation of these medications from the plant is time-consuming and costly; they are now generally synthesized in the laboratory.

The authors comment that “previously published reviews on MP [Madagascar periwinkle] mostly concentrate on the pharmaceutical and chemical compounds of the herb”.  Thus, the presentation of other aspects of the plant are useful. C. roseus is drought and heat tolerant, and can thrive in both shade  and/or sun, in various habitats, and is generally hardy.


Africa’s gift to the world
Scientists looking for potential new drugs in plants can take various routes along the path to drug discovery. All the plants in a specified region can be collected and their extracts tested – or screened – against various whole organisms, cells or purified proteins in the hope of finding new biologically active compounds, which might one day lead to new drugs. An alternative approach called ethnobotany, selects plants for screening based on their folkloric use in one or more traditional societies. Plants within the same species often contain similar compounds, and therefore another more targeted approach is to probe plants related to those already known to contain bioactive chemicals.


Regardless of how it is done, searching for new drugs in plants is tedious, time consuming and expensive. In a complete turnaround from 20 years ago, only a small number of pharmaceutical companies now continue with active research programmes in medicinal plant chemistry. But no matter which route in drug discovery is taken, serendipitous discoveries often play a part along the way.

A beautiful pink flower from the island of Madagascar off the coast of east Africa called the Madagascar periwinkle (Catharanthus roseus), also known as the rosy periwinkle, has long been used by traditional medicinal healers for treating diabetes. In the 1950s, this attracted the attention of western natural product chemists searching or biologically active compounds in plants and consequently the periwinkle’s anti-cancer properties were discovered. Further research led to isolation of two biologically active chemical substances produced naturally in the plant – vincristine and vinblastine – and to their identification as anti-cancer agents. These compounds have both been used as chemotherapy drugs since the early 1960s.

Today, both are included in the World Health Organization’s list of minimum medicine needs for a basic healthcare system for both adults and children. Vincristine is used against various blood and solid cancers including acute lymphoblastic leukaemia and Hodgkin lymphoma. Vinblastine is most often used in bladder cancer treatment but is also effective against other blood and solid cancers including Hodgkin lymphoma. Both are frequently used in combination with other chemotherapy drugs.

The route to discovery
The Madagascar periwinkle is a tropical perennial often grown as an annual in temperate climates. It is a member of the dogbane family (Apocynaceae). The Madagascar periwinkle was first named Vinca rosea by the great Swedish botanist Carolus Linnaeus in the 1750s, but was reclassified and placed in the genus Catharanthus in 1834.

It took many more years before the full benefits of this plant were realised. The first chemistry and drug trials were not conducted until the 1950s. During this period, the large US pharmaceutical company Eli Lilly was testing hundreds of plant extracts a year for biological activity in the hope of finding a lead to the development of a new drug. Gordon Svoboda (1922–1994) added the Madagascar periwinkle to the list of the company’s research subjects based on his recollection of reports of the use of periwinkle products for the treatment of diabetes in the Philippines during the second world war. In December 1957, an extract of the plant was submitted for biological testing. Gordon learned in January 1958 that the extract exhibited very high potency in anti-cancer tests.

At the same time and independently of work at Eli Lilly, two research scientists, Robert Noble (1910–1990) and Charles Beer (1915–2010) at the University of Western Ontario in Canada, discovered that extracts of the Madagascar periwinkle destroyed white blood cells. Results of their research on the discovery of novel anti-cancer activity were presented in March 1958 at a research symposium at the New York Academy of Sciences. The research paper had been submitted to the conference at the last minute by invitation of the conference organiser, who recognised the importance of their findings and found a slot for them to present. However, the symposium ran late and the Canadians presented their findings at midnight. The audience had dwindled to just a few listeners – most of whom were researchers from Eli Lilly.

At the time the Canadians’ paper was presented in the spring of 1958, neither research group knew of each other’s work on the same plant. While the two groups were looking for anti-diabetic effects both had observed that their respective plant extracts lowered white blood cell counts in laboratory animals. Both teams deduced that since leukaemia involves a proliferation of white blood cells, an agent that reduced the number of white blood cells might have potential value in leukaemia therapy.

At the meeting Charles reported he had isolated the first active compound, which he named vinblastine, from an extract of the plant. Needless to say, the Eli Lilly research team was extremely interested in Charles’ work and a formal collaboration between the Eli Lilly and the Canadian researchers was soon established. This collaboration led to the rapid identification, development and advancement of two closely related drugs from the periwinkle’s extract: vincristine and vinblastine.

One of the challenges that had to be overcome during the race to market was to secure sufficient quantities of compounds. The extraction of just one gram of vinblastine requires 900 kg of dried leaves. Eli Lilly was forced to move away from dependence on erratic supplies of widely scattered plants in the wild to large scale farm cultivation.

In 1961, vincristine was approved by the US Food and Drug Administration (FDA) as a chemotherapeutic agent for the treatment of Hodgkin lymphoma. Vinblastine gained acceptance from the FDA two years later in 1963. Approval of both drugs followed quickly thereafter in the UK and other countries worldwide.

Phytochemistry
Vincristine and vinblastine are both alkaloids, a group of naturally-occurring chemical compounds found commonly in plants that almost always contain at least one basic nitrogen atom in a cyclic ring of carbon and hydrogen atoms. Extracts of the Madagascar periwinkle have been found to contain up to 70 different alkaloids. Many alkaloids have been found to have pharmacological effects in humans, and as a consequence are widely used for medication or as recreational drugs. Examples include the local anaesthetic and stimulant, cocaine; the stimulants, caffeine and nicotine; the analgesic, morphine; and the anti-malarial drug, quinine.

Vinblastine

Due to the presence of a basic nitrogen atom, alkaloids can be purified from crude plant extract samples by a combination of acid-base extraction and liquid-liquid partitioning between an aqueous solvent (in this case dilute acid) and an immiscible organic solvent (such as dichloromethane). Once this periwinkle was selected, research was undertaken to find organic solvents that could first dissolve the alkaloids in order to separate them from the plant material. Subsequent isolation and the use of refined chromatographic techniques led to the separation of pure samples of vincristine and vinblastine.

Vincristine and vinblastine contain many functional groups familiar to the student of organic chemistry: carbonyl groups, hydroxyl groups, carboxylic groups, aromatic rings and an indole ring. When finally all the pieces are fitted together, structurally and chemically, both molecules are complex.

Vincristine and vinblastine have similar biological and chemical properties as their chemical structures are very closely aligned. In fact, vincristine and vinblastine are so similar they differ by only one carbonyl group, present in the form of an aldehyde functional group in the former, compared with a methyl group in the same location in the latter.

Tens of thousands of cancer patients, especially those suffering from leukaemia and lymphomas, have benefited from the drugs derived from a remarkable medicinal plant, the Madagascar periwinkle – known to many in tropical climates as a weed and to western gardeners as an easy-to-grow ornamental. Serendipity led to an educated guess and the hunch turned out to be correct. This tiny plant from Madagascar became one of Africa’s great gifts to humanity.

Further reading

  1. R Cooper and J J Deakin, Botanical miracles: chemistry of plants that changed the world. CRC Press, 2016
  2. J Duffin, Pharm. Hist., 2002, 44, 64; J Duffin, Pharm. Hist., 2002, 44, 105
  3. Naghmeh Nejat, Alireza Valdiani, David Cahill, Yee-How Tan, Mahmood Maziah, Rambod Abiri. Ornamental Exterior versus Therapeutic Interior of Madagascar Periwinkle (Catharanthus roseus): The Two Faces of a Versatile Herb. ScientificWorldJournal. 2015; 2015: 982412. Published online 2015 Jan 15. doi:  10.1155/2015/982412 PMCID: PMC4312627
  4. Baskaran, K. K., Kulkarni, R. N., Kumar, S. S. and Sreevalli, Y. Y. 2001. The mechanism and inheritance of intraflower self-pollination in self-pollinating variant strains of periwinkle. Plant Breeding. 120: 247-250.
  5. Foster, S. 2010. From Herbs to Medicines: The Madagascar Periwinkle's Impact on Childhood Leukemia: A Serendipitous Discovery for Treatment. 347-350 in Simon, J., Cooper, R., and Hughes, K., editors. Alternative & complementary therapies; a new bimonthly publication for health care practitioners.
  6. International Wildlife. 2000. . Accessed 7 Mar 2011.
  7. National Tropical Botanical Garden. 2011. . Accessed Mar 29 2011.
  8. Pennisi, E. 1992. Bacteria turns roots into chemical factories. Science News. 197:366-368
  9. PLANT OF THE WEEK. . Accessed 10 April 2011.
  10. Swerdlow, J. L. 2000. Nature's Rx. National Geographic. 197:98.
  11. USDA, Natural Resources Conservation Services, Plants Database, 2011. .  Accessed 21 Mar 2011.