The initial antibiotics all were are antibacterial compounds derived from plant sources. The first antibiotic that has been industrially produced, penicillin, is a compound extracted from the penicillum mold.
By and large, plants depend much more on chemical defenses against diseases then do animals, including humans. And plants, just like animals, are infected, and rendered ill, by both bacteria and viruses.
Just as they have antibacterial compounds, many plants also have some antiviral chemicals in their arsenal of defenses against disease. These antiviral phytochemicals typically are not effective against all viruses, not in the concentrations at which they are present, and neither for the living plant against those viruses that infect it, nor for the use as herbal medications against human viruses, not in the amounts typically consumed of herbal medications.
But herbal antivirals have a substantial advantage when compared to the huge number of chemical antivirals: they can confer an antiviral benefit without otherwise doing harm.
Let’s be clear about this: the world is full of synthetic antivirals: bleach, caustic acid, arsenic, and practically every chemical poison kills viruses. They also kill humans that are treated with this kind of "antivirals". The point is: we want to find antivirals that are not otherwise unhealthy to the humans treated with them.
The big advantage of herbal antivirals is that (as all living organisms are connected through evolution and environmental adaptation) they are something that has been around in the natural environment of mankind and their evolutionary ancestors for millions of years. Thus, there is a far increased probability that some of the relationships between plants and ill animals, including humans, are symbiotic.
And yes, on the evolutionary timetable, the use of herbs to treat physical states of discomfort reaches back for further than the time of the first hominids. Primates, and even less developed animals, do add certain plants to their diet not for the purposes of food intake but for "medical" applications (as this may not be commonly known, we have included a source on the use of herbal medications by wild animals at the end of this article).
Among all plants that have been tested for a possible antiviral use in the treatment of humans, phyllanthus species, especially phyllanthus urinaria, has yielded the most promising results. Her just a few quotes from the abstract of scientific articles.
In their abstract on a systematic review of the scientific literature (Antivir Ther. 2003 Apr;8(2):77-90.), K.W. Martin and E. Ernst (Peninsula Medical School, Universities of Exeter & Plymouth, Exeter, UK) specifically mentioned the prominent position held by Phyllanthus plants in the ongoing research for antiviral extracts from plants. They stated:
"BACKGROUND AND AIMS: Many antiviral compounds presently in clinical use have a narrow spectrum of activity, limited therapeutic usefulness and variable toxicity. There is also an emerging problem of resistant viral strains. This study was undertaken to examine the published literature on herbs and plants with antiviral activity, their laboratory evaluation in vitro and in vivo, and evidence of human clinical efficacy. METHODS: Independent literature searches were performed on MEDLINE, EMBASE, CISCOM, AMED and Cochrane Library for information on plants and herbs with antiviral activity. There was no restriction on the language of publication. Data from clinical trials of single herb preparations used to treat uncomplicated viral infections were extracted in a standardized, predefined manner. RESULTS: Many hundreds of herbal preparations with antiviral activity were identified and the results of one search presented as an example. Yet extracts from only 11 species met the inclusion criteria of this review and have been tested in clinical trials. They have been used in a total of 33 randomized, and a further eight nonrandomized, clinical trials. Fourteen of these trials described the use of Phyllanthus spp. for treatment of hepatitis B, seven reporting positive and seven reporting negative results. The other 10 herbal medicines had each been tested in between one and nine clinical trials. Only four of these 26 trials reported no benefit from the herbal product. CONCLUSIONS: Though most of the clinical trials located reported some benefits from use of antiviral herbal medicines, negative trials may not be published at all. There remains a need for larger, stringently designed, randomized clinical trials to provide conclusive evidence of their efficacy."
The antiviral effects of phyllanthus urinaria go hand in hand with a protective effect phyllanthus urinaria has on liver cells. In Chinese and Indian traditional medicine, phyllanthus urinaria has been used in the treatment of liver problems long before it has been known that hepatitis is a liver disease caused by viruses. The plant compounds that are responsible for the liver-protective benefits of phyllanthus urinaria have since been identified. S. Zhou reported on the liver-protective effect in a Medline-cited scientific article under the headline "Mechanism of protective action of Phyllanthus urinaria L. against injuries of liver cells". The abstract of his work:
"It has been found out that the carbon tetrachloride (CCl4)-induced increase of serum glutamic-pyruvic transaminase (ALT) and elevation of MDA in liver of mice are significantly lowered by Phyllanthus urinaria in vivo, and the coincubation of isolated rat hepatocytes with Phyllanthus urinaria in vitro significantly inhibits CCl4-induced decrease of mobility of membrane of liver cells and increase of intracellular free Ca2+ ([Ca2+]i) concentrations of liver cells. These results suggest that the anti-lipid peroxidation effect and protective action of membrane of Phyllanthus urinaria may be related to its protective action against CCl4-induced liver injuries."
In a project for the 2003 California State Science Fair, Erik Toh examined the use of Phyllanthus urinaria in the treatment of hepatitis B.
"Hepatitis B is one of the major diseases inflicting the human population. Conventional treatment with interferon-alpha is very expensive and has many serious side effects. Alternative herbal medicine using extracts of Phyllanthus niruri (amarus) and Phyllanthus urinaria has been reported to be effective against hepatitis B and other viral infections. The purpose of this study is to quantitatively determine the antiviral effect of these herbs in a well defined in vitro system. Methods/Materials: Antiviral activity induced by the herbal extract was measured as inhibition of the cytopathic effect (CPE) which normally results from infection of untreated MDBK cells with vesicular stomatitis virus (VSV).
Aqueous extract of P. urinaria (prepared from dried herbs) and P. niruri were serially titrated and their activities were compared to a positive control, interferon-alpha2b… Conclusions/Discussion: A cell-based assay has been developed to examine the antiviral effect of herbal extracts from the genus Phyllanthus. Aqueous extracts of P. niruri and P. urinaria protect MDBK cells from viral infection. In addition, they do not display cytotoxicity in uninfected normal cells. These findings support clinical studies by others that regular intake of these herbal supplements may be beneficial for chronic hepatitis B patients."
As mentioned initially, the use of herbal medications to treat physical discomfort is older than mankind. Wild primates, and even lesser animals, also use certain plants to treat their illnesses.
Medicinal Plant Use by Animals
by Jennifer A. Biser
Pausing only to wipe the feverish sweat from her brow, the WaTongwe woman finishes crushing a few leaves and stems a fellow tribe member brought her from the mujonso, or "bitter leaf," tree… Grimacing in anticipation of the liquid's foul taste, she holds her nose and gulps down the bitter elixir, hoping this reliable remedy will rid her of the intestinal pain that's plagued her for days.
Nearby, in Tanzania's Mahale Mountains National Park, a lethargic chimpanzee suffering from diarrhea and malaise slowly pulls a young shoot off a small tree called Vernonia amygdalina. She peels away the shoot's bark and leaves with her teeth, and begins chewing on the succulent pith. Swallowing the juice, she spits out most of the fibers…
Recovered within 24 hours, both of these females resume business as usual. They were both suffering the effects of an intestinal parasite infection. And, in case you haven't guessed, they both ate from the same tree…
"The probability that animals may have something to teach us about the medicinal use of plants is quite high," says primatologist Michael Huffman at the Kyoto University of Japan. Actually, the idea's hardly been ignored. In fact, an entirely new field, sometimes called "zoopharmacognosy", has evolved from the onslaught of diverse research on self-medicative behavior in animals…
European starlings (Sturnus vulgaris) face serious pressure from pathogens and parasites. Studies by biologist Larry Clark show that by lining their nests with select fresh vegetation, these birds are protecting themselves from a myriad of possible infections. Wild carrot (Dauscus carota), for example, kills fowl mites in starling nests... The carrot contains the steroid B-sitosterol, a compound that repels mites and inhibits their egg-laying abilities. This compound is also found in leaves of the margosa tree (Azadirachta indica), from which house sparrows often gather material to line their nests, and which some Native Americans employ as a tick repellent…
According to World Wildlife Fund scientist Holly Dublin, African elephants (Loxodonta africana) seek a particular species of tree, possibly to induce labor. Dublin followed a pregnant elephant for more than a year in East Africa, and observed that the elephant followed a strictly uniform diet and pattern of daily behavior until near the end of gestation. At that time, the elephant walked 17 miles in one day--many more than her usual three--and ate a tree of the Boraginaceae family from leaves to trunk! Four days later she gave birth to a healthy calf. Dublin found that Kenyan women brew a tea from the leaves of this tree to induce labor. She believes this is more than just coincidence…