**3.11. Lauraceae –** *Persea americana* **Mill.**

Many bioactive compounds have been identified in leaves, seeds, and trunk resin of *H. courbaril*, including flavonoids, terpenoids, phenolic acids, steroids, and coumarins [124, 125]. Some of these compounds have been related to the myorelaxant, anti-inflammatory, and antimicrobial effects including activity against dengue virus type-2 observed in pharmacological studies with *H. courbaril* preparations [124, 126, 127]. In Suriname, the stembark is used to prepare a tea that would treat a similar variety of ailments as well as hypertension [45]. Whether the latter activity may be associated with vasodilation following relaxation of the smooth muscles

The tamarind *T. indica* is probably indigenous to tropical Africa where it grows in the wild. It has been cultivated for centuries on the Indian subcontinent, and has been introduced in South America including Suriname by Spanish and Portuguese colonists in the sixteenth century. The fruit is a pod with a hard, brown shell that contains up to 12 seeds surrounded by a sweet and sour pulp that is used in cooking, to flavor foods, in refreshing drinks, and as a key

Preparations from *T. indica* leaves, seeds, fruits, and roots are extensively used in folk medicine, among others, for treating abdominal discomfort, microbial and parasitic infestations, as an aphrodisiac, and against hypertension [48, 128, 129]. These parts of the plant contain various phenolic compounds, terpenes, sugars, as well as mucilage and pectin [128, 129]. Some of these constituents have been associated with, among others, antioxidant, anti-hyperlipidemic,

Furthermore, an aqueous tamarind seed extract produced a decrease in blood pressure, heart rate, as well as serum LDL, cholesterol, and HDL levels in streptozotocin-induced diabetic and hypertensive rats [131]. As well, administration of the dried and pulverized fruit pulp led to a decrease in diastolic blood pressure as well as total cholesterol and LDL-cholesterol levels in human subjects [132]. The blood pressure-lowering effects of the *T. indica* preparations have

[126] including those in the blood vessel walls remains to be determined.

**Figure 5.** Fabaceae – *Hymenaea courbaril* L. (from: https://goo.gl/images/ePJjyr).

and cardioprotective effects of the plant in laboratory models [130].

**3.10. Fabaceae –** *Tamarindus indica* **L.**

170 Herbal Medicine

ingredient of Worcestershire sauce.

The avocado tree *P. americana* probably originates from Central America and the western parts of South America and was presumably domesticated as early as 5000 BC. Today, avocados are a successful cash crop with a high commercial value. Avocado is mostly eaten raw; (prolonged) cooking makes it inedible, causing a chemical reaction that confers a bitter taste to it. It is an ingredient of many servings and dishes and is often used in vegetarian cuisine as a substitute for meats because of its relatively high content of monounsaturated fats [135]. The rather expensive oil extracted from avocados is mostly used for salads or dips and in cosmetics and toiletries [136].

The stem bark, fruits, seeds, and leaves of *P. americana* are used in traditional medicine in Africa, the West Indies, as well as South and Central America including Suriname for treating, among others, menstrual problems, gastrointestinal ailments, bronchitis, diabetes mellitus, hypercholesterolemia, and hypertension [45, 46, 49, 52, 55, 137, 138]. Pharmacological evaluations with animal models provided some support for these ethnopharmacological claims [139]. These effects may partially be associated with the aliphatic acetogenins, terpenoid glycosides, furan ring-containing derivatives, flavonoids, and coumarins in various parts of the plant [140].

Evidence for an antihypertensive effect of *P. americana* leaf and seed preparations came from the relaxing effects they produced in isolated guinea pig atrial muscle strips, rat portal veins, and rat thoracic aortic rings precontracted with noradrenaline [141] and the blood pressurelowering effects they produced in laboratory animals [141–143].

The mechanisms responsible for these effects may involve vasorelaxation by substances that inhibit Ca2+ influx and stimulate the synthesis and release of endothelium-derived relaxing factors and vasoactive mediators [144], modulation of ACE activity [145], and/or lowering of total cholesterol, triglycerides, VLDL, and/or LDL [143, 145, 146]. However, a clinical study found no benefit with respect to body weight, BMI, and percentage body fat, and no difference in serum lipids, fibrinogen, blood flow, or blood pressure when avocados were substituted for mixed fats in an energy-restricted diet [147].
