Cinnamic acid is a polyphenol found in cinnamon oil and used in commercial flavorings. Recent studies have shown the pharmacological properties of cinnamic acid and its derivatives, including hepatoprotective, anti-oxidant, and anti-diabetic activities. In preclinical studies cinnamic acid demonstrated to be a promising candidate for the treatment ob obesity and diabetes. The mechanism of action of cinnamic acid in obesity is explained by its ability to inhibit lipases and ACE (angiotensin-converting enzyme). However, there are several hypotesis regarding the effect of cinnamic acid in diabetes: cinnamic acid enhances glucose-induced insulin secretion, prevents palmitic acid-induced lipotoxicity, inhibits palmitic acid-induced alteration of lipogenic gene and protein expression (AMPK, SREBP-1c, FAS, ACC), inhibits DPP IV, exhibits an additive effect on the uptake of glucose, stimulates adiponectin secretion, etc.

CAPOZIDE (captopril and hydrochlorothiazide tablets, USP) for oral administration combines two antihypertensive agents: captopril and hydrochlorothiazide. The mechanism of action of captopril has not yet been fully elucidated. Captopril prevents the conversion of angiotensin I to angiotensin II by inhibition of ACE, a peptidyldipeptide carboxy hydrolase. Hydrochlorothiazide belongs to thiazide class of diuretics. It reduces blood volume by acting on the kidneys to reduce sodium (Na+) reabsorption in the distal convoluted tubule. CAPOZIDE (captopril and hydrochlorothiazide tablets, USP) is indicated for the treatment of hypertension. The blood pressure lowering effects of captopril and thiazides are approximately additive. Major side effects are: Black, tarry stools; chest pain; chills; cough; fever; painful or difficult urination; shortness of breath; sore throat; sores, ulcers, or white spots on lips or in mouth; swollen glands; unusual bleeding or bruising; unusual tiredness or weakness. It has been reported that indomethacin may reduce the antihypertensive effect of captopril, especially in cases of low renin hypertension. Captopril’s effect will be augmented by antihypertensive agents that cause renin release. For example, diuretics (e.g., thiazides) may activate the renin-angiotensin-aldosterone system.

Delapril is a lipophilic nonsulfhydryl angiotensin-converting enzyme (ACE) inhibitor, which has been shown to exert potent ACE inhibitory activity and is marketed as an antihypertensive drug. Delapril has been shown to exist in solution as a mixture of s-cis and s-trans conformational isomers, as a result of restricted rotation about the amide bond.

Zofenopril is an inhibitor of Angiotensin Converting Enzyme (ACE), which is approved in Europe for the treatment of hypertension and acute myocardial infarction.

Imidapril (Tanatril), through its active metabolite imidaprilat, acts as an ACE inhibitor to suppress the conversion of angiotensin I to angiotensin II and thereby reduce total peripheral resistance and systemic blood pressure (BP). In clinical trials, oral imidapril was an effective antihypertensive agent in the treatment of mild to moderate essential hypertension. Some evidence suggests that imidapril also improves exercise capacity in patients with chronic heart failure (CHF) and reduces urinary albumin excretion rate in patients with type 1 diabetes mellitus. Imidapril was well tolerated, with a lower incidence of dry cough than enalapril or benazepril, and is a first choice ACE inhibitor for the treatment of mild to moderate essential hypertension.

Temocapril is a prodrug-type angiotensin-I converting enzyme (ACE) inhibitor not approved for use in the United States but is approved in Japan and South Korea. Temocapril can also be used in hemodialysis patients without risk of serious accumulation.

Cilazapril (Vascace and Dynorm are brand names in a number of European countries) is an angiotensin converting enzyme (ACE; kininase II) inhibitor. It competes with angiotensin I for binding at the angiotensin-converting enzyme, blocking the conversion of angiotensin I to angiotensin II. Cilazapril is a prodrug that is hydrolyzed after absorption to its main metabolite cilazaprilat. The half-life (30–50 hours) of cilazapril allows for once daily dosing unless the hypertension is severe. Cilazapril is used for the treatment of hypertension, congestive heart failure, post-myocardial infarction, and some other indications. Adverse events were mostly observed within the first 8-16 weeks of treatment, with headache, dizziness, fatigue, nausea, cough and chest pain being the most frequent.

Racecadotril (acetorphan) is an oral enkephalinase inhibitor for use in the treatment of acute diarrhea. Racecadotril reduces hypersecretion of water and electrolytes into the intestinal lumen, by preventing the degradation of endogenous enkephalins. Treatment with racecadotril reduces the incidence and duration of acute diarrhea and reduces diarrhea-associated symptoms compared with placebo in adults. Racecadotril treatment also results in significant reductions in stool output compared with placebo in infants and young children aged 2 months to 4 years with acute diarrhea. Both rotavirus-negative and rotavirus-positive infections appear to respond to treatment in the pediatric populations investigated for this infection. Racecadotril shows similar or slightly reduced efficacy to loperamide in the treatment of diarrhea in adults and children aged up to 10 years. However, in comparative trials, racecadotril was associated with fewer adverse events than loperamide, in particular, post-treatment constipation. Racecadotril is available in France (where it was first introduced in ~1990) and other European countries (including Germany, Italy, the UK, Spain and the Czech Republic) as well as most of South America and some South East Asian countries (including China, India and Thailand), but not in the United States.

Omapatrilat is an antihypertensive agent that inhibits both neprilysin (neutral endopeptidase, NEP) and angiotensin-converting enzyme (ACE). The drug was developed for possible use in heart failure and hypertension, but was not approved by the FDA due to angioedema safety concerns.