Arnica is a perennial herb native to the mountainous regions of Europe and southern Russia and belong to the Asteraceae family. Arnica flowers contain helenanolide-type sesquiterpene lactones, flavonoids (isoquercetin, astragalin, etc.), volatile oils, and coumarins. Goethe recommended it for coronary heart disease and acute treatment of angina pectoris. Although Arnica can improve coronary circulation in much the same manner as Crataegus, it has a more rapid onset of action. Therefore, Arnica is preferred for acute and Crataegus for long-term treatment of coronary heart disease [7–9, 13, 14] (Fig. 1.2).

Astragalus is a small shrub native to temperate regions of the northern hemisphere and belongs to the Fabaceae family. Use of Astragalus roots is very old and well known in traditional Chinese medicine, employed principally as a tonic and for the treatment of diabetes and kidney diseases. Astragalus root contains a series of cycloartane triterpene glycosides named astragalosides I to VII. Several saponins based on the oleanane skeleton have also been reported. Astragalus saponins demonstrated a positive inotropic action, improving walking distance and quality of life in patients with chronic heart failure. Oral administration of extracts of the root countered the rise in blood pressure and plasma renin activity in a hypertensive model. Astragaloside IV improved homocysteine-induced endothelial dysfunction in rat aortic rings via antioxidant activity and exhibited vasodilatory effects. Oral administration of Astragalus has an inhibitory effect on left ventricular hypertrophy induced by pressure overload in rats. After acute myocardial infarction, there is an anti-free radical effect and amelioration of left ventricular function. Astragalus increases the survival rate and improves some abnormal electrophysiological parameters in acute viral myocarditis. Routine therapy combined with oral administration of Astragalus in these patients significantly enhanced immune parameters compared with patients receiving routine therapy alone. Heart mitochondria are also protected by toxic insult experimentally produced with daunorubicin [13, 15–18] (Fig. 1.3).

Berberine is a quaternary ammonium salt derived from protoberberine, and belongs to the isoquinoline alkaloid family. This molecule is found in the roots, rhizomes, stems, and bark of plants such as Berberis aquifolium and vulgaris, Hydrastis canadensis, Xanthorhiza simplicissima, Tinospora cordifolia, and Eschscholzia californica. A detailed review concluded that berberine possesses a range of cardiovascular properties, including positive inotropic, negative chronotropic, anti-arrhythmic, and vasodilatory activities. In experiments, berberine prevented the development of pressure overload induced by left ventricular hypertrophy in vivo after aortic banding. Oral administration of 10 mg/kg decreased left ventricular, diastolic pressure, and plasma levels of adrenaline and noradrenaline. In a rat model of hypertension, 5–10 mg/kg of berberine improved cardiac contractility and inhibited left ventricular remodeling and global myocardial fibrosis. Such effects might be partially associated with increased nitric oxide and cAMP in left ventricular tissue. Berberine inhibits platelet aggregation and adhesiveness and levels of thromboxane B2, and these could be the important factors behind the anti-ischemic activity of berberine.

Recent research focused on the cholesterol-lowering activity of berberine mediated by the upregulation of hepatic LDL receptor expression and inhibition of cholesterol and triglyceride synthesis. Oral administration of berberine to hyperlipidemic hamsters for 10 days resulted in 26 and 42% decreases in total cholesterol and LDL cholesterol respectively. Human studies seem to demonstrate that berberine might benefit the integrity and function of vascular endothelial cells by improving protective mechanisms: increasing the production of NO and enhancing resistance to hyperglycemia-induced injury [7, 8, 19].

Green tea is produced from leaves of Camellia sinensis, an evergreen shrub native to Eastern Asia from Teaceae family. Green tea is the dried leaf component, whereas black tea is produced by a complex wilting and fermentation process. Tea leaves contain varying amounts of polyphenols (most of which are catechins) in addition to smaller quantities of caffeine, theanine, theobromine, theophylline, and phenolic acids. Evidence from clinical trials suggests that green tea might play a role in metabolic syndrome because it may have an impact on body weight, glucose homeostasis, and other cardiovascular risk factors. Green tea helps to reduce the oxidation of low-density lipoproteins, improving cholesterol profiles, reducing platelet aggregation, and finally antagonizing atherosclerosis [7, 8, 19–22] (Fig. 1.4).

Guggul is a small shrub that is widely distributed in India and adjacent dry regions from the Burseraceae family. The gum has been used in Indian medicine for centuries as a cardiac tonic, and as a weight-reducing and anti-inflammatory agent.

The dry gum resin obtained from the bark of the tree downregulates the expression of all inflammatory mediators. Research shows that the resin of the guggul tree contains ketonic steroid compounds called guggulsterones and these have the ability to reduce the cholesterol-containing plaque. Guggul also helps to increase the metabolic rate of the body and thus is useful for weight loss.

Guggul, in animal experiments, was as effective as phenylbutazone and ibuprofen in acute and chronic inflammation. A study in 200 patients with ischemic heart disease demonstrated an improvement on electrocardiography and a decrease in episodes of dyspnea and chest pain. Guggul increases fibrinolytic activity and decreases platelet adhesiveness, but the most interesting activity is the improvement of hypothyroid conditions and an increase in triiodothyronine levels. In most studies, the use of guggul leads to a reduction in total cholesterol and HDL. Globally, guggul is considered an important natural remedy for preventing coronary heart disease [23, 24].

Lily of the valley is an herbaceous perennial plant native to the forests of Northern Hemisphere of the Asparagaceae family (previously classified in the Liliaceae family). The aerial parts contain cardenolides and glycosides whose potency is not comparable to that of Digitalis and is also weaker than that of Scilla. Hence Convallaria is mainly used in patients with mild heart failure. The main advantage of Convallaria is its rapid onset of effects and the only remote risk of accumulation of glycosides. Furthermore, the glycosides in Convallaria do not affect the nerve impulse conduction system of the heart; thus, there is no risk of arrhythmias. This plant is therefore very well suited for the treatment of heart failure associated with bradycardia. Crataegus complements Convallaria in the case of an “aging heart.” We can classify lily of the valley as a cardiosedative remedy, well suited to the treatment of functional heart disorders [25].

Hawthorn is a spiny tree native to temperate regions in the Northern Hemisphere belonging to Rosaceae family. The use of this herb for the treatment of heart problems dates back to 1800, but the ancients probably knew already the virtues of this plant that they not casually named Crataegus: in the Greek language krátos means strength and this suggests that this plant might give the body energy through the enhancement of heart activity. Today, hawthorn is an official drug in the pharmacopoeias of Brazil, China, Czechoslovakia, France, Germany, Hungary, Russia, and Switzerland. As a measure of its incredible popularity, it is an ingredient in 213 commercial European herbal formulas, mostly for cardiovascular system.

For many years, it has been suggested that hawthorn could be used as an alternative therapy for various cardiovascular diseases, such as angina, hypertension, hyperlipidemia, arrhythmia, and initial congestive heart failure. Besides the antioxidant, positive inotropic, anti-inflammatory, and anticardiac remodeling effects and other cardiovascular protective effects of the hawthorn, active ingredients have been demonstrated in various in vivo and in vitro experiments.

The constituents of hawthorn are:

In any case, the research confirms that the overall effect of the extract as a whole is more significant than that of its individual constituents.

Many experimental studies in animals have confirmed that Crataegus increases coronary blood flow, inhibiting cAMP. Several studies also documented stimulation of myocardial contractility, through a different mechanism to that of Digitalis, indirectly improving myocardial energy metabolism through mitochondrial activation. This also explains why hawthorn requires a much longer period than Digitalis to take effect and why myocardial reactivity must exist so that the herbal drug can take effect.

It has been verified pharmacologically that Crataegus regulates heart rhythm and standard extracts of the plant demonstrated positive chronotropic and dromotropic effects in addition to negative bathmotropic effects. Crataegus increases myocardial tolerance to oxygen deficiency. An increase in cardiac volume, a reduction of peripheral vascular resistance, and an increase in cardiac performance have also been documented in various studies on animals.