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Science behind herbal ‘cures’ for COVID-19


*Guava gets patent as anti-coronavirus agent
*UI recommends asthma plant for treating virus
*Sunshine reduces cases, deaths from infection
*WHO considers Artemisia annua as treatment

As Nigeria and indeed the rest of the world grapple with the novel coronavirus, scientists are churning out traditional ‘cures’ for the dreaded disease. Top on the list of the new breakthroughs are: an extract of guava (Psidium guajava) leaves and stems gets patent for containing coronavirus; University of Ibadan researchers recommend Euphorbia hirta (asthma plant) for treating virus; study finds people with low levels of sunshine vitamin may be more likely to catch and die from COVID-19 infection; and the World Health Organisation (WHO) has announced that medicinal plants such as Artemisia annua are being considered as possible treatments for COVID-19 and should be tested for efficacy and adverse side effects.

Guava as anti coronavirus agent
Guava (Psidium guajava) has obtained a patent with number, JP 2005-314316 A, as anti-Severe Acute Respiratory Syndrome (SARS) Coronavirus agent. The patent is titled “Anti-SARS coronavirus agent and product containing anti-SARS coronavirus agent.”

The Taiwanese patent applied by Japanese inventors from a Japanese company (POKKA Corp.) claims using extract from Psidium Guajava Linn’s leaves or stems and ascorbic acid as a treatment for SARS. No compound structure was specified.

The present invention relates to an anti-SARS coronavirus agent and a product containing an anti-SARS coronavirus agent. SARS (Severe Acute Respiratory Syndrome) is an infectious disease caused by the SARS virus recently discovered as a new coronavirus. Major symptoms include respiratory symptoms such as fever above 38 ° C., cough, shortness of breath, and difficulty breathing. Symptoms such as diarrhea, headache, chills, loss of appetite, general malaise, and consciousness may be observed. At present, an effective curative treatment for SARS has not been established, and symptomatic treatment is the center.


According to the patent, “the present invention is based on the finding that the combination of guava extract and ascorbic acid has an excellent anti-SARS coronavirus action as a result of intensive studies by the present inventors…

“The anti-SARS coronavirus agent according to this embodiment contains a guava extract extracted from guava (Psidium guajava) using a specific extraction solvent and ascorbic acids as active ingredients.”

Also, guava is one of the active ingredients in Prof. Maurice Iwu’s proposed cure for the novel coronavirus. Iwu told The Guardian the drug is already a National Agency for Food and Drug Administration and Control (NAFDAC) listed product which we want to subject to clinical evaluation against COVID-19.

The clinical trial titled: “Efficacy and safety of IHP Detox Tea (a special blend of Andrographis paniculata, Garcinia kola and Psidium guajava) for treatment of Corona virus disease 2019 (COVID-19): a pilot placebo-controlled randomized trial”.
Why UI recommends asthma herb for COVID-19 treatment

Also, researchers from the University of Ibadan (U.I.) have provided explanations why they recommend Euphorbia hirta (commonly asthma plant) for the treatment of COVID-19.

A research group in the University of Ibadan is exploring the benefits of Euphorbia hirta and similar plants for the cure of chronic flu and other respiratory diseases including COVID-19.

Contributing to the study on medicinal efficacy of the plant in different ways are: Prof. Ademola Ladele (Agricultural Extensionist); Prof. Rasheed Awodoyin (Weed Ecologist); Professor Olaniyi Babayemi (Animal Scientist), Professor Olapeju Aiyelaagbe (Chemist); Dr. Okhiomah A. Abu (Animal Scientist); Dr. Olugbenga AdeOluwa (Organic Agriculturist); Dr. Olajumoke Oke Fayinminnu (Toxicologist); Dr. Funmilayo Adebiyi (Animal Scientist); Dr. Idayat Gbadamosi (Ethnobotanist) and Dr. Joseph Badejo (Cardiovascular Pharmacologist).

The University of Ibadan researchers wrote: “The plant may be a handy first-aid treatment as tea for people experiencing dry cough, respiratory failure, fever and diarrohea which are some of the symptoms of COVID-19 infection. Using the plant may thus help the patients to breath with ease and remove the need for a ventilator for mild cases. There is no evidence yet that Euphorbia hirta can cure coronavirus, but it can be useful in mitigating some of the symptoms like fever, cough and respiratory challenges.”


Euphorbia hirta is reported to contain triterpenes, phytosterols, tannins, polyphenols, flavonoids, essential oil, alkaloids, saponins, amino acids and minerals. Quercitrin, a flavanoid glycoside isolated from the herb showed anti-diarroheal activity.

Researchers across the world, including the University of Ibadan, Nigeria, have reported extensively on medicinal properties of this humble but wonderful plant.

“In Benin (Nigeria), the plant is pounded, mixed with palm oil and licked to treat any form of cough. Traditionally in Nigeria, a handful (50 gm) of fresh leaves steeped in four cups (one litre) of water, bring to boil, live boiling for three- four minutes and taken as tea for two- three times a day softens dry cough to release mucus as phlegm, which will clear airways and nasal chambers experienced by someone suffering from chronic flu. If in powder form, steep two teaspoonfuls in one cup (250 ml) of boiled water, live to extract for 15 minutes and drink three- five times a day. It is a powerful herb and must be used with care. It is reported to have anti-fertility activity. Use for short period of time ranging from one- three days, and not more than seven days at a time. If it must be repeated take a seven-day recess. Not recommended for expectant and nursing mothers, and small children.”

Sunshine vitamin ‘cure’ for COVID-19
A preliminary study has found tentative evidence suggesting low levels of vitamin D may make it more likely an individual will die after contracting coronavirus. The study was published on pre-print site Research Square.

The research compared average levels of vitamin D across 20 European countries with COVID-19 infection rate and mortality. It revealed a convincing correlation where countries with low vitamin D levels were also the countries with highest mortality and COVID-19 infection rates.


The study has not yet been peer-reviewed and scrutinised by other scientists and is unable to prove vitamin D is the reason behind this link. However, the scientists from Queen Elizabeth Hospital Foundation Trust and the University of East Anglia write in their study: “We believe, that we can advise Vitamin D supplementation to protect against SARS-CoV2 infection.” This finding backs up a separate study which also found vitamin D may improve a person’s chance of recovery after contracting the coronavirus.

A ten-week trial from the University of Granada is currently ongoing after a recent study by Trinity College Dublin found adults who took Vitamin D supplements saw a 50 per cent fall in chest infections.

The latest study used pre-existing data on vitamin D levels, including from a comprehensive 2019 study led by Paul Lips, Professor Emeritus of internal medicine at Vrije Universiteit Amsterdam.

This previous study collected data on vitamin D levels of populations across Europe and the Middle East. The study involved taking vitamin D measurements of thousands of individuals.

The latest study on the vitamin’s effectiveness against COVID-19 narrowed this data to 20 countries, to negate any interfering factors, such as a country’s latitude.

The average amount of vitamin D in serum samples was (56 nmol/l), with anything below 30nmol/l deemed ‘severely deficient’. The latest study took the existing database of vitamin D levels and found worryingly low levels of vitamin D in the elderly, a demographic more at risk of dying after contracting the coronavirus.

“[The study shows levels of] vitamin D of 26nmol/L in Spain, 28 nmol/L in Italy and 45 nmol/L in the Nordic countries, in older people,” the researchers write.


“In Switzerland, mean vitamin D levels are 23(nmol/L) in nursing homes and in Italy 76 per cent of women over 70 years of age have been found to have circulating levels below 30nmol/L.

“These are countries with high number of cases of COVID–19 and the ageing people is the group with the highest risk for morbidity and mortality with SARS-Cov2.”

Vitamin D can make its way into the human body either through certain foods, such as fish and mushroom, or can be produced by skin cells when exposed to sunlight.

A simple statistical analysis, called a t-test, was then performed on the two sets of data to determine any relationship, which unearthed the correlation between deaths and vitamin D levels.

“The most vulnerable group of population for COVID-19 is also the one that was the most deficit in vitamin D,” the researchers conclude in their preliminary report.

Also, health experts have provided explanations on why getting just 10 minutes of sunshine every day could make you less vulnerable to COVID-19 – with low vitamin D levels increasing the risk of lung infections.

An Australian health expert has revealed that stepping out in the sun for just 10 minutes per day can greatly reduce the risk of dying with COVID-19.
Skin cancer researcher, Dr. Rachel Neale, said that having low levels of vitamin D, which the skin produces when exposed to sunlight, increases your chance of getting a respiratory infection – which can be fatal if one also has the coronavirus.

“Now, more than ever, is not the time to be vitamin D deficient,” Dr. Neale told The Australian. “It would make sense that being vitamin D deficient would increase the risk of having symptomatic COVID-19 and potentially having worse symptoms. And that’s because vitamin D seems to have important effects on the immune system.”

Last year, Neale found that people with low levels of vitamin D are almost twice as likely as those with high levels of vitamin D of developing acute respiratory infections.

According to the study of 78,000 patients, people with vitamin D deficiencies were more likely to be sicker for longer. Neale said she sits in the Brisbane sun for five to 10 minutes everyday to stimulate her body’s production of vitamin D.

The doctor does not take vitamin D tablets, as she believes time in the sun provides more benefits – but accepts they are useful for people who can’t leave their home.


WHO supports scientifically proven traditional medicines for COVID-19
Also, the WHO has broken its silence on the array of scientifically based herbal cure claims for COVID-19. The WHO said medicinal plants such as Artemisia annua are being considered as possible treatments for COVID-19 and should be tested for efficacy and adverse side effects. “Africans deserve to use medicines tested to the same standards as people in the rest of the world. Even if therapies are derived from traditional practice and natural, establishing their efficacy and safety through rigorous clinical trials is critical,” it noted.

The WHO, in a statement, said: “As efforts are under way to find treatment for COVID-19, caution must be taken against misinformation, especially on social media, about the effectiveness of certain remedies. Many plants and substances are being proposed without the minimum requirements and evidence of quality, safety and efficacy. The use of products to treat COVID-19, which have not been robustly investigated can put people in danger, giving a false sense of security and distracting them from hand washing and physical distancing which are cardinal in COVID-19 prevention, and may also increase self-medication and the risk to patient safety.

“WHO welcomes every opportunity to collaborate with countries and researchers to develop new therapies and encourages such collaboration for the development of effective and safe therapies for Africa and the world.”

The WHO said it welcomes innovations around the world including repurposing drugs, traditional medicines and developing new therapies in the search for potential treatments for the novel coronavirus (COVID-19).

The WHO said it recognises that traditional, complementary and alternative medicine has many benefits and Africa has a long history of traditional medicine and practitioners that play an important role in providing care to populations.


African governments through their Ministers of Health adopted a resolution urging Member States to produce evidence on the safety, efficacy and quality of traditional medicine at the Fiftieth Session of the WHO Regional Committee for Africa in 2000. Countries also agreed to undertake relevant research and require national medicines regulatory agencies to approve medicines in line with international standards, which include the product following a strict research protocol and undergoing tests and clinical trials. These studies normally involve hundreds of people under the monitoring of the national regulatory authorities and may take quite a few months in an expedited process.

The WHO said it is working with research institutions to select traditional medicine products, which can be investigated for clinical efficacy and safety for COVID-19 treatment. In addition, the Organisation said it would continue to support countries as they explore the role of traditional health practitioners in prevention, control, and early detection of the virus as well as case referral to health facilities.

The WHO said it has been working with countries, over the past two decades, to ensure safe and effective traditional medicine development in Africa by providing financial resources and technical support. The WHO said it has supported clinical trials, leading 14 countries to issue marketing authorization for 89 traditional medicine products, which have met international and national requirements for registration. Of these, 43 have been included in national essential medicines lists. These products are now part of the arsenal to treat patients with a wide range of diseases including malaria, opportunistic infections related to Human Immuno-deficiency Virus (HIV), diabetes, sickle cell disease and hypertension. It said almost all countries in the WHO African region have national traditional medicine policies, following support from WHO.


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