History repeating itself: using the medicine of the past to find the treatments of the future

With the vast number of medical studies that are reported every week, it can feel as though researchers are on a steady and direct march onward into the future, discovering new things about diseases and new forms of treatment day-by-day.

What lessons are left to learn from historical medical practices considering the progress that has been made by medicine over the past few decades?

Occasionally, though, a story will emerge where researchers revisit medicine that has long since been abandoned by the establishment and consigned to the murky depths of the past. When these stories occur, they often capture the imagination.

At the start of this month, researchers from the University of Nottingham in the UK may have a discovered a potential new treatment for methicillin-resistant Staphylococcus aureus (MRSA) in an unlikely source: a 1,000-year-old medieval manuscript.

The eye infection remedy that the researchers found in Bald's Leechbook, a book containing a collection of Anglo-Saxon remedies for a variety of ailments, was as effective if not better at killing MRSA than conventional antibiotics.

As stated before, this kind of discovery is not an isolated incident. Over the past year, MNT have reported on a number of similar studies in which researchers have found inspiration for future treatments and approaches in the medicine of the past.

Why is it that history consistently offers the present and future new ideas for avenues of research, especially when our collective understanding of the human body and health has progressed so far over the past 1,000 years? In this Spotlight feature, we attempt to find out.

Ebola virus and historical precedence

The Ebola crisis that dominated world news last year produced two papers that looked to the past as a way of remedying the present.

When two American missionaries contracted the Ebola virus, an experimental drug untested on humans known as ZMapp was administered. Following this treatment, the missionaries made what was referred to as a miraculous recovery from the disease that has a case fatality rate of around 90%.

In the Annals of Internal Medicine, some researchers stated that development of the ZMapp treatment had much in common with methods of treating illness that were developed toward the end of the 19th century, inspired by the work of luminary microbiologists such as Louis Pasteur and Robert Koch.

ZMapp was created by collecting antibodies formed in the blood of mice after exposing them to fragments of the Ebola virus, mirroring the technique of passive serotherapy that was originally used to treat diseases such as pneumonia and meningitis.

One team of researchers chose to look even further back into history to find ways of dealing with the Ebola virus. Dr. Igor Linkov, a visiting professor of the Ca Foscari University, Italy, and colleagues believe that 14th century Venice holds many lessons on how to deal with such a crisis.

Forms of infection control utilized in 14th century Venice could be used to inform management of the Ebola virus.

In 1347, the city became the epicenter of a plague epidemic. 

After initial attempts to fight the disease with prayer and ritual, the Venetians eventually responded by instigating what experts have termed "resilience management."

Although they did not understand the disease itself, the authorities introduced a system of inspection, quarantine stations on nearby islands and the wearing of protective clothing. 

These measures helped Venice to remain prosperous even after the initial devastation wrought by the plague.

Resilience management can be a guide to dealing with the current Ebola outbreak in Africa, and others like it, as well as other issues like population growth and the impacts of global climate change.

Similar to what the officials of Venice did centuries ago, approaching resilience at the system level provides a way to deal with the unknown and unquantifiable threats we are facing at an increasing frequency.

This example illustrates one simple reason researchers might be inclined to examine the past to treat diseases of the future: historical precedence. The parallels between the epidemics faced by 14th century Venice and present day West Africa are numerous enough to suggest that one or two lessons learned then may still be applicable. Here, history is repeating itself.

Lost knowledge

The example of the medieval eye remedy explains why discoveries can be made using historical sources many years after they were first recorded. In the case of Bald's Leechbook, the knowledge contained within was only made accessible after the manuscript was translated.

The recipe was chosen to be tested by the researchers because the recipe contained ingredients such as garlic that are currently being studied by others for their antibiotic potential.

Researchers believe modern research into disease can benefit from past responses and knowledge, which is largely contained in nonscientific writings. But the potential of these texts to contribute to addressing the challenges cannot be understood without the combined expertise of both the arts and science."

Manuscripts such as Bald's Leechbook contain recipes that are designed to treat ailments that researchers can now identify as bacterial infections affecting areas of the body such as the eyes, skin, throat and lungs.

Given that these remedies were developed well before the modern understanding of germ theory, this poses two questions. How systematic was the development of these remedies? And how effective were these remedies against the likely causative species of bacteria?

As well as satisfying a particular curiosity by exploring how people in Medieval times approached medicine, the team from the University of Nottingham describe another factor that drives this form of research.

"There is a pressing need to develop new strategies against pathogens because the cost of developing new antibiotics is high and eventual resistance is likely," explains study leader Dr. Freya Harrison, from the School of Life Sciences.

This truly cross-disciplinary project explores a new approach to modern health care problems by testing whether medieval remedies contain ingredients which kill bacteria or interfere with their ability to cause infection.

Forms of medicine used in the past may have successfully treated certain forms of disease, even if those who administered these treatments were unaware how they worked - much like the authorities of 14th century Venice implementing resilience management. Today, researchers can analyze treatments that were used with success hundreds of years ago and explore the mechanisms behind them.

Re-evaluating traditional medicine

This appraisal of historical medicine is not limited to forms of treatment that may have been previously lost to the past. Researchers are regularly assessing traditional medicine or individual components of folk remedies used for hundreds of years within specific cultures.

A paper published in EMBO Reports examines whether ancient medical knowledge can lead researchers to new drug combinations. 

Since our earliest ancestors chewed on certain herbs to relieve pain, or wrapped leaves around wounds to improve healing, natural products have often been the sole means to treat diseases and injuries.

In recent decades, natural products have taken a secondary role in drug discovery and development, but the authors of the paper suggest that over the last few years, attitudes toward natural products have changed:

"The modern tools of chemistry and biology - in particular, the various '-omics' technologies - now allow scientists to detail the exact nature of the biological effects of natural compounds on the human body, as well as to uncover possible synergies, which holds much promise for the development of new therapies against many devastating diseases, including dementia and cancer."

Roseroot is a herb that has been used in traditional European folk medicine for over 3,000 years. A recently conducted study has suggested it could be a potential treatment option for depression by stimulating the receptors of neurotransmitters in the brain that are associated with mood regulation.

The herb has been used in traditional medicine to promote work endurance, increase longevity and promote resistance to a number of health conditions including fatigue and depression.

 Although this form of therapy is slowly growing more prominent, the practice of using human stool to treat illness can be traced all the way back to 4th century China.

Literature of this era - perhaps similar to Bald's Leechbook - makes reference to stool being used to treat food poisoning and diarrhea. Evidence of the practice exists throughout history up until World War II, when German soldiers stationed in Africa observed that a Bedouin remedy involving the consumption of camel dung was effective in treating bacterial dysentery.

Also found in traditional Chinese medicine is honeysuckle, frequently consumed in the form of tea. Last year, researchers identified a molecule within the plant that directly targets a family of viruses that includes Spanish flu and avian flu.

By discovering what elements of traditional medicine have curative properties, researchers can develop new forms of treatment that may be effective where the efficacy of current forms of treatment is slowly lessening.

Old solutions for new problems

Many health professionals are concerned that we are approaching - or indeed have reached - a postantibiotic era. Antimicrobial resistance is an urgent issue that many researchers are spending considerable amounts of time and energy into addressing.

Present day research into disease can benefit from the insight of the past.

More and more microbial pathogens are adapting and evolving in ways that render them resistant to the antimicrobial drugs that had redefined health care in the 20th century.

Antibiotics transformed the very practice of medicine. 

By the late 1980s and early 1990s, however, in the wake of the AIDS epidemic, increasingly identified antibiotic resistance, public health retrenchment, and increasing globalization, such initial optimism had given way to fears regarding 'emerging infections' and a 'world out of balance.'

A time is approaching where the solutions that have been so effective for so long are no longer able to protect people from disease. As this time draws nearer, scientists need to be developing new strategies of dealing with illness.

In the pre-antibiotic era, such strategies were used out of necessity. It is not surprising that, as a result, many researchers are looking to the past and revisiting previously used methods with a fresh eye in order to create new forms of treatment.

Yes, there is evidence of history consistently repeating itself, but it is equally true that new challenges will also present themselves. By combining hindsight and new breakthroughs in scientific knowledge, researchers may already have the materials to solve these challenges at their disposal.

It could simply be a matter of looking in the right place, or time.

References:

1.  Natural products and drug discovery. Can thousands of years of ancient medical knowledge lead us to new and powerful drug combinations in the fight against cancer and dementia?, Hong-Fang Ji, et al., EMBO Reports, published online March 2009.
2.  Serotherapy for Ebola: back to the future, Scott H. Podolsky, Annals of Internal Medicine, doi:10.7326/M14-1810, published 11 August 2014.
3.  Springer news release, accessed 10 April 2015.
4.  University of Nottingham news release, accessed 10 April 2015.