feed on contain lipophilic alkaloid toxins, and the toxins are then absorbed by the frog and used as a defense mechanism. These frogs cannot produce the toxins by themselves thus receive them from an exogenous source or a source that is not produced within themselves. Proteomic profiling has revealed that the livers of these frogs produce high levels of specialized proteins like saxiphilin that may be involved in alkaloid sequestration. Ingesting lipophilic alkaloids causes a dramatic increase in saxiphilin expression in the skin and liver of the frog. Saxiphilin protein is likely involved in helping to transport the alkaloids from the digestive tract to the skin, where they are used in defense. O. sylvatica can sequester alkaloids in just 4 days compared to weeks in some other dendrobatid species such as the golden poison frog. There is ongoing research investigating how O. sylvatica is able to sequester and use alkaloid toxins, as well as how its consumption of such toxins alter its molecular physiology related to metabolic functions. After ingestion, the frog’s intestinal lining is designed to prevent passive absorption of toxins. Instead, as these toxins are small and lipophilic, they are transported through the blood via carrier proteins, and the lymph via chylomicrons. How exactly the toxins are able to arrive at the skin and be stored in granules is yet unknown, but researchers hypothesize this process likely involves coordination between various tissues and transport systems. Toxins While O. sylvatica harvests toxins from its diet for defensive use, its body must also strike a balance between usage and metabolism to prevent the organism from poisoning itself due to an overabundance of toxins. As such, proteomic profiling studies have found varying degrees of upregulation and downregulation of different metabolic-related proteins in these frogs, compared to non-toxic controls. Some drug-metabolizing proteins are found to be decreased, such as nicotinamide N-methyltransferase, found to detoxify xenobiotics, and cytochrome P450s, which are involved in small molecule metabolism. Meanwhile, others are increased, such as glutathione S-transferase kappa 1. There have also been a host of proteins found to be upregulated in expression that may play a role in alkaloid transport. ApoA4 is an apolipoprotein that could also function as an alkaloid transporter. The complement system is also found to be more active, especially the C3 protein, which may enhance alkaloid absorption. Parallels have been drawn with CVF, the cobra venom factor that is activated by