Metanephrine (metadrenaline) is a metabolite of epinephrine (adrenaline) created by the action of catechol-O-methyl transferase on epinephrine. It is a commonly occurring, pharmacologically and physiologically inactive metabolite of epinephrine. The measurement of plasma free metanephrines is considered to be the best tool in the diagnosis of pheochromocytoma, a rare kind of adrenal medullary neoplasm. In adrenal chromaffin cells, leakage of norepinephrine and epinephrine from storage granules leads to the substantial intracellular production of the O-methylated metabolite metanephrine. In fact, the adrenals constitute the single largest source out of any organ system including the liver for circulating metanephrine. In humans, about 93 percent of circulating metanephrine is derived from catecholamines metabolized within adrenal chromaffin cells.

TETRAHYDROPALMATINE, (+)- is an alkaloid found in the plants of the Carydalis species. Tetrahydropalmatine (THP) has two enantiomers with different effects on the brain dopaminergic system. Dopamine (DA) content reduction in the rat striatum induced by d-THP is much more dose-dependent. At a small dose, d-THP predominantly reduced the DA level but left serotonin and noradrenaline level unaffected. d-THP is probably a DA depletor. There were stereoselective differences between the two THP enantiomers on the activity of cytochrome P450 (CYP450) isozymes, i.e., d-THP had the potential to inhibit the activities of CYP2D6 and CYP1A2 isozymes, while l-THP inhibited CYP1A2 isozyme and induced CYP3A4 and CYP2C9 isozymes. The plasma levels of l-THP were always higher than those of d-THP in rats.

Coptisine (COP), a protoberberine alkaloid, is widely found in Chinese medicinal plants (family Berberidaceae, Ranunculaceae and Papaveraceae). It is reported that COP has a wide range of pharmacological and biological activities, including antibacterial, hypoglycemic, anti-tumorigenic, and gastric-mucous membrane protection. Considerable attention has been focused on its activity against central nervous system disorders, such as improving the symptoms of Alzheimer’s disease and even preventing its onset, by exerting antidepressant effects as a potent type A monoamine oxidase inhibitor. Coptisine was found to be an efficient uncompetitive Indoleamine 2,3-dioxygenase inhibitor. Coptisine is a potent inhibitor of human organic cation transporters.

Retrorsine (RTS) is a naturally occurring pyrrolizidine alkaloid (PA), isolated from Senecio retrorsus of South African origin. Retrorsine is a hepatotoxic Pyrrolizidine alkaloid which specifically inhibits the proliferation of hepatocytes and subsequently induces liver injury. The toxic effect of PAs has received plentiful clinical attention, yet the understanding of the mechanism of Retrorsine-induced hepatotoxicity is still limited. It has been reported that the CYPs mediated bioactivation is necessary for the toxicity of PAs and that CYP3A4 is the major isoform involved in the metabolism of Retrorsine. Together withCYP3A4, Organic cation transporter 1 mediates the liver-specific uptake of Retrorsine and plays an important role in RTS-induced hepatotoxicity. Retrorsine impairs liver regeneration after partial hepatectomy, not only by an S or G2/M phase block but also by a block located before the G1/S transition of the cell cycle. Treatment of rats with retrorsine, a pyrrolizidine alkaloid, results in a series of chronic and progressive hepatic lesions, including a long-lasting block in the cell cycle.

Fenamiphos is an organophosphate insecticide and nematicide used for the control of nematodes and sucking insects (including aphids and thrips) on food and non-food crops, and for the control of nematodes in the turf. Fenamiphos blocks the enzyme acetylcholinesterase in the target pests. Fenamiphos is a highly toxic poison that acts by inhibiting cholinesterase (ChE) enzymes in the blood and central and peripheral nervous systems. Inhibition of plasma cholinesterase activity is the most sensitive toxicological endpoint in acute and short-term studies on experimental animals. Fenamiphos is applied on a variety of plants such as tobacco, turf, bananas, pineapples, citrus, and other fruit vines, some vegetables, and grains. In Brazil, this pesticide has been extensively used in tomato crop at planting and also in melon.

Glucosamine is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of the polysaccharides chitosan and chitin, which compose the exoskeletons of crustaceans and other arthropods, as well as the cell walls of fungi and many higher organisms. Glucosamine is one of the most abundant monosaccharides. It is produced commercially by the hydrolysis of crustacean exoskeletons or, less commonly, by fermentation of a grain such as corn or wheat. Oral glucosamine is a dietary supplement and is not a pharmaceutical drug. It is illegal in the US to market any dietary supplement as a treatment for any disease or condition. Glucosamine is marketed to support the structure and function of joints, and the marketing is targeted to people suffering from osteoarthritis. Commonly sold forms of glucosamine are glucosamine sulfate, glucosamine hydrochloride, and N-acetylglucosamine. Of the three commonly available forms of glucosamine, only glucosamine sulfate is given a "likely effective" rating for treating osteoarthritis. Glucosamine is often sold in combination with other supplements such as chondroitin sulfate and methylsulfonylmethane. Glucosamine, along with commonly used chondroitin, is not routinely prescribed to treat people who have symptomatic osteoarthritis of the knee, as there is insufficient evidence that this treatment is helpful. One clinical study over three years showed that glucosamine in doses of 1500 mg per day is safe to use. Glucosamine with or without chondroitin elevates the international normalized ratio (INR) in individuals who are taking the blood thinner, warfarin. It may also interfere with the efficacy of chemotherapy for treating cancer symptoms. Adverse effects may include stomach upset, constipation, diarrhea, headache, and rash. There are case reports of people who have chronic liver disease and a worsening of their condition with glucosamine supplementation. Glucosamine is naturally present in the shells of shellfish, animal bones, bone marrow, and fungi. D-Glucosamine is made naturally in the form of glucosamine-6-phosphate, and is the biochemical precursor of all nitrogen-containing sugars. Specifically in humans, glucosamine-6-phosphate is synthesized from fructose 6-phosphate and glutamine by glutamine—fructose-6-phosphate transaminase as the first step of the hexosamine biosynthesis pathway. The end-product of this pathway is uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), which is then used for making glycosaminoglycans, proteoglycans, and glycolipids. As the formation of glucosamine-6-phosphate is the first step for the synthesis of these products, glucosamine may be important in regulating their production; however, the way that the hexosamine biosynthesis pathway is actually regulated, and whether this could be involved in contributing to human disease remains unclear.

Tetramethrin is a synthetic pyrethroid based on the natural counterpart found in chrysanthemum flowers but more stable and longer lasting. Amongst one of the most widely used insecticides, Tetramethrin is a fast acting neurotoxin used against most flying and crawling insects. It is often used in combination with other active ingredients to create a multi-action pesticide. Tetramethrin was found to inhibit various ABC and SLC drug transporters, including multidrug resistance-associated protein(MRP) 2, breast cancer resistance protein (BCRP), organic anion transporter polypeptide (OATP) 1B1, organic anion transporter (OAT) 3, multidrug and toxin extrusion transporter (MATE) 1, organic cation transporter (OCT) 1 and OCT2.

Oxymatrine is one of the key components extracted from Sophora flavescens, a leguminous plant grown in China, Japan, and some European countries. It has attracted much attention because of its low toxicity and side effects. Extensive research over the past decades have revealed various important pharmacological activities of oxymatrine under in vitro and in vivo conditions, including anti-inflammation, immunoregulatory, antihepatitis virus infection, antihepatic fibrosis, antianaphylaxis, and other immune regulation. Oxymatrine has been extensively studied for their cancer chemopreventive potential against various cancers, for instance, human pancreatic cancer, gastric cancer, breast cancer, lung cancer, osteosarcoma, and leukemia. However, the precise mechanisms underlying the anticancer activity of oxymatrine are largely unknown.