Adalah masyarakat Cina terutama Taiwan yang memulai menyadari kehebatan dan melakukan pengembangan kemanfaatan daun pohon yang bernama ilmiah Vernonia amygdalina. Penamaan Nan Fei Shu (nan itu berarti selatan) tidaklah menunjukkan tempat absolut dari bagian benua afrika, melainkan letak relatif dari cina; bumi di selatan cina, maksudnya.
Entah kapan dan oleh siapa tanaman ini bisa sampai ke negeri cina. Belum bisa dipastikan kebenaran cerita bahwa daun ini sudah dimanfaatkan kaisar dan kalangan istana jaman cina kuno dulu. Saya berpikir bahwa informasi yang diketoktularkan secara copy-paste itu bersifat hoax. Jelas menyebarnya pohon yang dalam bahasa Inggris bernama bitter leaf ini tidak ada hubungannya dengan hadist "belajarlah walau pun sampai ke negeri cina," sebab kelihatannya dalam hal pemanfaatan pohon ini sebagai obat, justru masyarakat cina belajar pada orang afrika yang dulu-dulunya belajar dari monyet tidak berbuntut. Betul sekali, adalah simpanse, jenis kera cerdas yang bisa main film, yang memberikan inspirasi kepada manusia afrika, ihwal kemujaraban khasiatnya.
Daun afrika bukanlah makanan sehari-hari bagi simpanse. Seperti juga kita, simpanse mungkin tidak suka rasa pahit yang luar biasa ini. Namun begitu, jika terkena infeksi, simpanse mencari dan memakan daun dari perdu yang tingginya bisa mencapai 5 meter ini. Di jaman masih banyak orang belajar dari alam, dan peka terhadap fenomena alam sekitarnya, wajar jika ada orang-orang bijak dan kritis menangkap perilaku monyet hitam lucu ini dalam mengobati diri jika terserang sakit. Dari situ kemudian manusia mencoba membongkar rahasia dibalik keampuhan daun afrika dalam mengobati penyakit infeksi oleh sebab cacing, plasmodium malaria, bakteri, dan jamur.
Sekarang, daun afrika telah menyebar ke seantero dunia. Awalnya disosialisasikan oleh biarawati dan gerakan sosial lainnya. Produknya telah mencapai benua amerika dan dipasarkan melalui amazon[dot]com. Di Indonesia diperkirakan masuk pada awal tahun 2000-an. Daun afrika pertama ditanam di pulau Jawa pada 2008 di Bogor.
Pemanfaatan daun afrika sebagai obat herbal berbentuk kapsul atau teh herbal, tampaknya merupakan trend yang terbangun di luar afrika. Aslinya di afrika, daun ini umumnya diolah menjadi beragam produk kuliner.
Daun afrika dalam sup Nigeria
Berikut ini saya tempel sebuah artikel dari Tanzania, Afrika Timur:
Observations of chimpanzees' feeding behavior in Tanzania, East Africa, have led to the discovery of medicinal properties and other potential applications for two types of plants. This type of study, involving the ways animals use plants, is referred to as zoopharmacognosy, a term coined in 1992 from Greek roots: zoo- = animal; pharma- = a drug or poison; and -cognosy = to recognize.
While conducting such a study in Tanzania's Gombe National
Park, Harvard University graduate student Richard Wrangham noticed chimps
selecting and eating the leaves of Aspilia sp. (Other scientists have since
studied chimps in other areas, including the Mahale Mountains.) The three main
species selected were A. mossambicensis, A. pluriseta, and A. rudis. Other
researchers noticed chimps selecting and eating the pith of Vernonia
amygdalina. In both cases, these were obviously not appealing food choices for
the chimps because they grimaced when swallowing the leaves, and the pith is
known to be very bitter.
Interestingly, it was noted that not all chimps practiced
"whole leaf swallowing" and "bitter pith chewing," as
scientists now refer to those practices. Furthermore, Michael Huffman of the
Primate Research Institute at Kyoto University noted that the chimps practicing
these behaviors were in poorer health than the others. Specifically, they
seemed depressed and despondent, tended to separate themselves from the group,
and had diarrhea. This observation led to the hypothesis that Aspilia and
Vernonia were consumed in response to illness, possibly parasitic infestation.
In 1989, Huffman and his collaborators tested this hypothesis by collecting and
analyzing fecal samples and documenting chimp activity for as many individuals as
possible. Fecal analysis revealed that chimps practicing whole leaf swallowing
and/or bitter pith chewing were in fact suffering from single or multiple
parasitic infections.
Vernonia pith was examined via bioassay, a technique in
which living material in a system is tested for biological activity. The tests
showed antiparasitic activity against microorganisms that infect both chimps
and humans. Further analysis of the bitter pith revealed chemicals categorized
as sesquiterpene lactones and steroid glycosides, both of which are known for
their bioactivity. Specifically, vernonioside B1 and vernoniol B1, two
compounds isolated from the pith of Vernonia, suppressed movement and
egg-laying activity in bioassays of Schistosoma japonicum, a parasitic worm. Thus,
apparently the chimps were selecting Vernonia for its chemical constituents.
A different mode of action was found for Aspilia. When the
fecal samples of chimps consuming those leaves were analyzed, not only did the
feces contain a stable number of parasites during Aspilia consumption, but the
parasitic worms (Oesophagostomum stephanostomum) were still very much alive.
Obviously, consuming the plant had suppressed neither the movement nor the
egg-laying activity of the parasitic worms. However, the analysis also revealed
that Aspilia leaves not only remained whole and undigested, but were curiously
folded like accordions--a characteristics that turned out to have a function:
O. stephanostomum attach their suckers to the intestine's mucous lining, where
they extract nutrients from the host. In this case, the intestinal worms were
firmly stuck to the surface of the leaves (which are known to have a high
concentration of trichomes, or hairs) and caught between the accordion-like
folds! Clearly this was a physical removal of the parasites as the roughness of
the leaf surface seemed to dislodge the worms from the animal's intestinal
lining.
Aspilia is a dicot in the Compositea or Asteraceae family,
and its distribution includes tropical America, Africa, and Madagascar.
Although leaf swallowing basically results in the physical removal of
intestinal worms, additional research into the chemical composition of
Aspilia's parts other than the leaves has indicated the production of a red oil
called thiarubrine-A. This chemical has been found to inhibit the growth of
many disease-causing agents, specifically parasitic worms, microorganisms, and
other intestinal parasites.
Vernonia is also in the Asteraceae family, with a similar
distribution to that of Aspilia. Its sesquiterpene lactones have demonstrated
anti-tumor activity, and the Vernonia chemicals (vernoniosides) of the pith
have proven effective against drug-resistant malarial parasites, which are very
common within the range of this plant.
Although the chimpanzees pointed the way to Aspilia and
Vernonia, plants overlooked in the past, additional research has revealed that
Aspilia and Vernonia have been part of Tanzanian folk medicine for hundreds of
years. The WaTongwe traditionally use Vernonia for stomachaches and several
parasitic infections. A. latifolia has been reported to stop bleeding by
inducing clot formation. The leaves of Vernonia are highly toxic and apparently
avoided by the chimps; however, after soaking the leaves in water and cooking
them, local people use them in soup and stew as a strength-giving tonic. They
also widely use Vernonia to treat parasites and other ailments in themselves
and their livestock, indicating potential agricultural applications for other
countries. Additionally, it is documented that Vernonia is used locally as an
insecticide.
Apparently we can learn much from watching our neighbors on
planet Earth!
