Anti-HIV and anti-cancer drugs derived from Borneo rainforest progressing to final development stagesmongabay.com
June 29, 2009
Calanolide, an anti-HIV drug derived from the Bintangor or Calophyllum tree, is now in the clinical trial stage, said Deputy Chief Minister Tan Sri Dr George Chan, speaking to reporters in Miri, Sarawak at the launch of the official website for the Borneo Research Council Conference 2010.
Dr Chan said that samples of the anti-cancer drug Silvestrol were sent to the National Cancer Institute in the United States for testing.
Rainforest plants have long been recognized for their potential to provide healing compounds. Indigenous peoples of the rainforest have used medicinal plants for treating a wide variety of health conditions while western pharmacologists have derived a number of drugs from such plants.
However, as forests around the world continue to fall -- the Brazilian Amazon and Indonesia together have lost more than 120,000 square miles of forest in the past decade -- there is a real risk that pharmaceutically-useful plants will disappear before they are examined for their chemical properties. Increasingly, it is becoming a race against time to collect and screen plants before their native habitats are destroyed. One near miss occurred recently with a compound that has shown significant anti-HIV effects, Calanolide A.
Calanolide A is derived from Calophyllum lanigerum var austrocoriaceum, an exceedingly rare member of the Guttiferae or mangosteen family. Samples of Calophyllum lanigerum var austrocoriaceum were first collected in 1987 on a National Cancer Institute (NCI)-sponsored expedition in Sarawak. Once scientists determined that Calophyllum lanigerum var austrocoriaceum showed activity against HIV, researchers returned to the original kerangas forest near Lundu (Sarawak, Malaysia) to gather more plant matter for isolating the active compound. The tree was gone -- likely felled by locals for fuelwood or building material. The disappearance of the tree lead to mad search by botanists for further specimen. Good news finally came from the Singapore's Botanical Garden which had in its possession several plants collected by the British over 100 years earlier. Sarawak banned the felling and export of Calophyllum shortly thereafter.
Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs) are a class of anti-HIV drugs that prevent healthy T-cells in the body from becoming infected with HIV. Approved NNRTIs include Viramune® (nevirapine) from Boehringer Ingelheim, Sustiva® (efavirenz) from Bristol-Myers Squibb, and Rescriptor® (delavirdine) from Pfizer. Most NNRTIs dramatically reduce viral load soon after the first dose is taken, but Calanolide A, for reasons that are not yet known, seems to have a delayed effect.
Due to the low prevalence of Calanolide A in Calophyllum lanigerum var austrocoriaceum (only 0.05% can be extracted from the twigs and leaves) Sarawak MediChem Pharmaceuticals, has developed and patented a process for the total synthesis of (+)-Calanolide A. Calanolide A is currently in clinical trials but is not yet approved by the FDA for use outside of clinical trials.
A related species, Calophyllum teysmannii var. inophylloide, produces a compound (Costatolide) that also exhibits activity against HIV. Costatolide, now known as (-)-Calanolide B, is present in the latex so that tree need not be felled in order to collect the compound. Calanolide B is in preclinical testing with the National Cancer Institute.
Should either drug prove a commercial success, it would bolster the argument that standing rainforests have the potential to generate benefits beyond timber and agricultural land.
An interview a shaman in the Amazon rainforest
(07/28/2008) Deep in the Suriname rainforest, an innovative conservation group is working with indigenous tribes to protect their forest home and culture using traditional knowledge combined with cutting-edge technology. The Amazon Conservation Team (ACT) is partnering with the Trio, an Amerindian group that lives in the remote Suriname-Brazil border area of South America, to develop programs to protect their forest home from illegal gold miners and encroachment, improve village health, and strengthen cultural ties between indigenous youths and elders at a time when such cultures are disappearing even faster than rainforests. In June 2008 mongabay.com visited the community of Kwamalasamutu in Suriname to see ACT's programs in action. During the visit, Amasina, a Trio shaman who works with ACT, answered some questions about his role as a traditional healer in the village.
Colorful insects help search for anti-cancer drugs
(07/07/2008) Brightly-colored beetles or caterpillars feeding on a tropical plant may signal the presence of chemical compounds active against cancer and parasitic diseases, report researchers writing in the journal Frontiers in Ecology and the Environment. The discovery could help speed drug discovery.
Amazon rainforest children to get medicinal plant training from shamans
(11/21/2007) The Amazon conservation Team (ACT) -- a group using innovative approaches to preserving culture and improving health among Amazonian rainforest tribes -- has been awarded a $100,000 grant from Nature's Path, an organic cereal manufacturer. The funds will allow ACT to address one of the most pressing social concerns for Amazon forest dwellers by expanding its educational and cultural "Shamans and Apprentice" program for indigenous children in the region.
70% of new drugs come from Mother Nature
(03/20/2007) Around 70 percent of all new drugs introduced in the United States in the past 25 years have been derived from natural products reports a study published in the March 23 issue of the Journal of Natural Products. The findings show that despite increasingly sophisticated techniques to design medications in the lab, Mother Nature is still the best drug designer.
Medicinal value of chocolate explored by scientists
(02/09/2006) The cocoa plant (Theobroma cacao) holds tremendous potential to impact public health and improve the socioeconomic and ecological landscape of the countries where it's grown, according to leading world scientists who convened at the National Academies today to examine the latest scientific advances in cocoa research.
How did rainforest shamans gain their boundless knowledge on medicinal plants?
(05/14/2005) For thousands of years, indigenous people have extensively used rainforest plants for their health needs -- the peoples of Southeast Asian forests used 6,500 species, while Northwest Amazonian forest dwellers used 1300 species for medicinal purposes. Perhaps more staggering than their boundless knowledge of medicinal plants, is how shamans and medicinemen could have acquired such knowledge. There are over 100,000 plant species in tropical rainforests around the globe, how did indigenous peoples know what plants to use and combine especially when so many are either poisonous or have no effect when ingested. Many treatments combine a wide variety of completely unrelated innocuous plant ingredients to produce a dramatic effect.