Ambenonium is a cholinesterase inhibitor with all the pharmacologic actions of acetylcholine, both the muscarinic and nicotinic types. It was marketed under the brand name Mytelase, but was withdrawn from the market in the United States in 2010. Ambenonium, similar to pyridostigmine and neostigmine, is used for the treatment of muscle weakness and fatigue in people with myasthenia gravis.Ambenonium exerts its actions against myasthenia gravis by competitive, reversible inhibition of acetylcholinesterase. The disease myasthenia gravis occurs when the body inappropriately produces antibodies against acetylcholine receptors, and thus inhibits proper acetylcholine signal transmission (when acetylcholine binds to acetylcholine receptors of striated muscle fibers, it stimulates those fibers to contract). Ambenonium reversibly binds acetylcholinesterase at the anionic site, which results in the blockage of the site of acetycholine binding, thereby inhibiting acetylcholine hydrolysis and enhancing cholinergic function through the accumulation of acetycholine at cholinergic synpases. In turn this facilitates transmission of impulses across the myoneural junction and effectively treats the disease.

Mepenzolate is a postganglionic parasympathetic inhibitor. It decreases gastric acid and pepsin secretion and suppresses spontaneous contractions of the colon. It specifically antagonizes muscarinic receptors. Mepenzolate is marketed under the brand name CANTIL. CANTIL is indicated for use as adjunctive therapy in the treatment of peptic ulcer. It has not been shown to be effective in contributing to the healing of peptic ulcer, decreasing the rate of recurrence, or preventing complications.

Tridihexethyl is a synthetic anticholinergic agent which was marketed under the brand name Pathilon as an adjunct in the treatment of peptic ulcer disease. However, it is no longer available in the US market. Tridihexethyl may block all three types of muscarinic receptors including M-1 receptors in the CNS and ganglia, M-2 receptors in the heart, and M-3 receptors. The muscarinic acetylcholine receptors mediate various cellular responses including inhibition of adenylate cyclase, the breakdown of phosphoinositides, and modulation of potassium channels through the action of G proteins. Tridihexethyl inhibits vagally mediated reflexes by antagonizing the action of acetylcholine. This, in turn, reduces the secretion of gastric acids in the stomach. Tridihexethyl was also examined for effect on patients with acquired nystagmus where four out of six patients showed improvement, but due to the profile usage of Tridihexethyl to treat nystagmus was limited.

Quercetin is a unique bioflavonoid that has been extensively studied by researchers over the past 30 years. Quercetin, the most abundant of the flavonoids (the name comes from the Latin –quercetum, meaning oak forest, quercus oak) consists of 3 rings and 5 hydroxyl groups. Quercetin is a member of the class of flavonoids called flavonoles and forms the backbone for many other flavonoids including the citrus flavonoids like rutin, hesperidins, Naringenin and tangeritin. It is widely distributed in the plant kingdom in rinds and barks. The best described property of Quercetin is its ability to act as antioxidant. Quercetin seems to be the most powerful flavonoids for protecting the body against reactive oxygen species, produced during the normal oxygen metabolism or are induced by exogenous damage [9, 10]. One of the most important mechanisms and the sequence of events by which free radicals interfere with the cellular functions seem to be the lipid peroxidation leading eventually the cell death. To protect this cellular death to happen from reactive oxygen species, living organisms have developed antioxidant line of defense systems [11]. These include enzymatic and non-enzymatic antioxidants that keep in check ROS/RNS level and repair oxidative cellular damage. The major enzymes, constituting the first line of defence, directly involved in the neutralization of ROS/RNS are: superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) The second line of defence is represented by radical scavenging antioxidants such as vitamin C, vitamin A and plant phytochemicals including quercetin that inhibit the oxidation chain initiation and prevent chain propagation. This may also include the termination of a chain by the reaction of two radicals. The repair and de novo enzymes act as the third line of defence by repairing damage and reconstituting membranes. These include lipases, proteases, DNA repair enzymes and transferases. Quercetin is a specific quinone reductase 2 (QR2) inhibitor, an enzyme (along with the human QR1 homolog) which catalyzes metabolism of toxic quinolines. Inhibition of QR2 in plasmodium may potentially cause lethal oxidative stress. The inhibition of antioxidant activity in plasmodium may contribute to killing the malaria causing parasites.

Propantheline is an antimuscarinic agent used for the treatment of excessive sweating (hyperhidrosis), cramps or spasms of the stomach, intestines (gut) or bladder, and involuntary urination (enuresis). It can also be used to control the symptoms of irritable bowel syndrome and similar conditions. Propantheline is one of a group of antispasmodic medications which work by blocking the action of the chemical messenger acetylcholine, which is produced by nerve cells, to muscarinic receptors present in various smooth muscular tissues, in places such as the gut, bladder, and eye. Normally, the binding of acetylcholine induces involuntary smooth muscular contractions. Varying degrees of drying of salivary secretions may occur as well as decreased sweating. Ophthalmic side effects include blurred vision, mydriasis, cycloplegia, and increased ocular tension. Other reported adverse reactions include urinary hesitancy and retention, tachycardia, palpitations, loss of the sense of taste, headache, nervousness, mental confusion, drowsiness, weakness, dizziness, insomnia, nausea, vomiting, constipation, bloated feeling, impotence, suppression of lactation, and allergic reactions or drug idiosyncrasies including anaphylaxis, urticaria and other dermal manifestations.

Oxyphenonium bromide is a quaternary ammonium anticholinergic agent, which was used under brand name antrenyl, to relieve visceral spasms and as an adjunct in the treatment of peptic ulcer. In addition, Oxyphenonium inhibits gastrointestinal propulsive motility and decreases gastric acid secretion and controls excessive pharyngeal, tracheal and bronchial secretions. Action is achieved via a dual mechanism: a specific anticholinergic effect (antimuscarinic) at the acetylcholine-receptor sites and a direct effect upon smooth muscle. Oxyphenonium bromide also been used in the form of eye drops for mydriatic effec

Levonordefrin acts as a topical nasal decongestant and vasoconstrictor, most often used in dentistry. It is administered in a pre-mixed solution with local anesthetics, such as mepivacaine or procaine.

Evans Blue (EBD) is an azo dye which has a very high affinity for serum albumin. It can be useful in physiology in estimating the proportion of body water contained in blood plasma. Evans Blue Dye is widely used to study blood vessel and cellular membrane permeability as it is non-toxic, it can be administered as an intravital dye and it binds to serum albumin – using this as its transporter molecule. The EBD–albumin conjugate (EBA) can be: (i) identified macroscopically by the striking blue colour within tissue; (ii) observed by red auto-fluorescence in tissue sections examined by fluorescence microscopy; and (iii) assessed and quantified by spectrophotometry for serum samples, or homogenised tissue. has recently been utilised in mdx mice to identify permeable skeletal myofibres that have become damaged as a result of muscular dystrophy. EBD has the potential to be a useful vital stain of myofibre permeability in other models of skeletal muscle injury and membrane-associated fragility. Evans Blue is a potent inhibitor of L-glutamate uptake into synaptic vesicles. It also inhibits AMPA and kainate receptor-mediated currents (IC50 values are 220 and 150 nM respectively). P2X-selective purinoceptor antagonist.

Hexamethonium is a nicotinic cholinergic antagonist. It was used to treat hypertension, but has never been approved and was discontinued because of the non-specified treatment. When this drug tried to use in medical study via inhalation, one of the volunteer died, the death has been described as “particularly disturbing ”because it was a healthy volunteer who had no thing to gain by taking part in the study. This volunteer participated in a study designed to provoke a mild asthma attack in order to help doctors discover the reflex that protects the lungs of healthy people against asthma attacks. Hexamethonium is poorly absorbed from the gastrointestinal tract and does not cross the blood-brain barrier. Now it is widely used a research tool.

Tubocurarine, a naturally occurring alkaloid, is used to treat smoking withdrawl syndrom. Tubocurarine, the chief alkaloid in tobacco products, binds stereo-selectively to nicotinic-cholinergic receptors at the autonomic ganglia, in the adrenal medulla, at neuromuscular junctions, and in the brain. Two types of central nervous system effects are believed to be the basis of Tubocurarine's positively reinforcing properties. A stimulating effect is exerted mainly in the cortex via the locus ceruleus and a reward effect is exerted in the limbic system. At low doses the stimulant effects predominate while at high doses the reward effects predominate. Intermittent intravenous administration of Tubocurarine activates neurohormonal pathways, releasing acetylcholine, norepinephrine, dopamine, serotonin, vasopressin, beta-endorphin, growth hormone, and ACTH. Tubocurarine competes with acetylcholine for post-synaptic nicotinic NM receptors and blocks them.