Rainforests are famous for their lush canopies and extraordinary biodiversity, but the sheer complexity of life that thrives in this biome means that we still know very little about it. Traditional healers from these regions have a robust knowledge of local fauna and associated medicinal applications, but pharmacological and biochemical medical researchers still lack a comprehensive understanding of the variety of species that populate rainforest regions around the globe.
It is estimated that we have only formally studied less than 5% of rainforest plant life for medicinal use, although in some regions, it is estimated that local indigenous communities can identify nearly 40% of local fauna.1,2,3,4,5 Despite the minimal practical research on these plants, several conventional medicines have been derived from fauna found in the Amazon rainforest in South America.
Quinine (Cinchona bark)
Perhaps the most well-known medicine with its roots in the rainforest, quinine is extracted from the bark of the cinchona tree and is used to treat malaria, lupus, arthritis, and malaria-like parasitic infections. Bark extracts from this tree have been used to treat malaria from as early as the 1600s. Although more effective anti-malaria drugs exist now, Quinine continues to be listed on the WHO Model List of Essential Medicines (EML) owing to its varied utility and efficacy for life-threatening complications.
Vincristine/Vinblastine (Catharanthus roseus)
Like quinine, vincristine and vinblastine hold positions on the WHO’s EML owing to their ability to disrupt the development of cancer cells and treat myriad cancers. These chemotherapeutic drugs were originally derived from Catharanthus roseus, or the Madagascar periwinkle, but this plant has served medicinal purposes long before this use was discovered in the laboratory. Local populations have historically used extracts from the roots and shoots to treat lymphoma, muscle pain, and diabetes as well as being applied to stimulate the central nervous system for a variety of ailments.
Tubocurarine (Chondrodendron tomentosum)
Though rarely used today, tubocurarine was originally used by anesthesiologists as a safer alternative to traditional anesthetics such as extremely high doses of ether. This naturally occurring compound is derived from curare, a bark secretion from the climbing plant Chondrodendron tomentosum.
Previous medical research on these compounds has saved millions of lives, and many researchers urge the further study of rainforest fauna—particularly plants used by indigenous tribes to treat ailments like nausea, depression, chronic pain, and fevers—owing to the high likelihood of usefulness for promoting human health.
Barriers to medicinal plant research
Although there is significant pharmaceutical and academic research interest in the applicability of medicinal plants to conventional medicine, researching potential medicines is a long, complicated, and arduous process. Beyond these basic limitations, however, there is one major threat to the future of medicine: the loss of rainforests.
Biodiversity loss and its impact
Biodiversity is important for many reasons—maintaining ecosystem equilibrium, promoting soil and air health, supporting regional recovery from natural disasters, to name a few—but its significance to medical research and indigenous medicinal traditions cannot be overstated.6,7,8 Nearly 80% of the global population relies nearly entirely on plant-based medicines for primary health care,9 and approximately 120 chemical compounds are extracted from fewer than 100 plants for medicinal use around the world.10 It has been reported that over 50% of prescription drugs were first derived from plant-based compounds.11
Even medicinal plants that have not been used to create laboratory drugs are widely applied and prescribed in several parts of the world. Considering how much we have done with how little we have studied these plants, the loss of a single species could mean the loss of a life-saving treatment.
Rainforest loss threatens medical research that relies on other ecosystems as well. The Earth’s biomes are interdependent, meaning that imbalance in certain ecosystems can cause massive disruptions in others. Global loss of biodiversity directly impacts the availability and sustainability of medicinal rainforest plants. The protection of rainforests and promotion of medicinal research in these regions is vital to maintaining and producing accessible, sustainable, and life-saving medicines.