**3.2. Anacardiaceae –** *Mangifera indica* **L.**

The mango tree *M. indica* is indigenous to Bangladesh, India, and Pakistan where it is found in the wild. It has been domesticated in India around 2000 BC, and many cultivated varieties have been produced in other tropical countries including Suriname. Both sour, unripe, and sweet, ripe mangoes are widely used in cuisine, among others, in chutneys, curries, pickles, or side dishes, and to prepare juices, smoothies, nectars, jams, and as a flavoring in ice creams, sorbets, fruit bars, and pies.

**Figure 2.** Acanthaceaea – *Ruellia tuberosa* L. (from: https://goo.gl/images/vk862o).

Preparations from flowers, unripe fruits, stone, leaves, stembark, and roots of *M. indica* also have many traditional medicinal uses, among others, to treat certain parasitic infections, uterus disorders, gastrointestinal problems, and syphilis; strengthen the blood vessels; cure varicose veins; and lower an elevated blood pressure [46, 62–64]. Several of these properties have been attributed to a number of bioactive substances in leaves and stem bark of the plant including the polyphenolic compound mangiferin [65]. This compound also displayed notable blood pressure-lowering effects in *in vitro* models and laboratory animals [66].

complex I, thereby shutting down cellular respiration [69]. These compounds have been associated – although not conclusively – with the unusually high incidence of atypical parkinsonism in the Caribbean island of Guadeloupe where relatively large amounts of *A. muricata* fruits as well as infusions and decoctions from the leaves of the plant are consumed [70]. Nevertheless, all parts of *A. muricata* are extensively used – also in Suriname – as traditional medicines against a wide diversity of conditions, among others, insomnia; nervousness, anxiety, and depression; a hangover; epilepsy; parasitic and helminth infections; diabetes mellitus; cancer; and hypertension [45, 48, 49, 55, 71]. Pharmacological studies with preparations from leaves, bark, and roots of the plant have indeed shown sedative, anxiolytic, smooth muscle-relaxant, antispasmodic, and antihypertensive effects [71–73]. Some of these effects may be attributed to the presence in the plant of bioactive constituents such as alkaloids, fla-

Plant-Based Ethnopharmacological Remedies for Hypertension in Suriname

http://dx.doi.org/10.5772/intechopen.72106

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Indications for an antihypertensive effect were provided by the decrease in blood pressure in normotensive Sprague-Dawley rats which were intravenously treated with an aqueous leaf extract of *A. muricata* [74]. Furthermore, the extract decreased the phenylephrine-induced contractions of isolated rat and guinea pig aortic rings [74, 75], and relaxed the contractions

These findings suggest that the hypotensive effects of the *A. muricata* leaf extract may involve vasodilation mediated through peripheral mechanisms involving antagonism of Ca2+ [74]. This effect has been attributed to alkaloids such as coreximine, anomurine, and reticulin, and

However, in light of the affinity of both crude extracts and isoquinoline alkaloids isolated from *Annona* species to 5-HT1A receptors *in vitro* [72], and the well-known decreasing effect of 5-HT1A receptor agonists on blood pressure and heart rate [76], it is also possible that the antihypertensive effect of these plants occurs through a central mechanism that causes peripheral

The celery *A. graveolens* (**Figure 4**) originates from the Mediterranean region, but many cultivars are now grown throughout the world. This plant has been cultivated since ancient times, initially only for its medicinal qualities, but later also as a vegetable to counter the salt-sickness of winter diets based on salted meats without green vegetables. Today, *A. graveolens* stalks, leaves, and hypocotyl are eaten raw or as an ingredient in salads, cooked as a vegetable, or as

*A. graveolens* seeds – which are in fact very small fruits – yield a valuable volatile oil that is used in perfumes and, when ground and mixed with salt, to produce celery salt for enhancing the flavor of, for instance, Bloody Mary cocktails [77]. However, celery seeds contain relatively high levels of the phenylpropene apiole that can cause abortion – sometimes with fatal consequences [78] – as well as liver and kidney damage [79] and severe allergic reactions

while apparently blocking Ca2+ channels [74].

vonol triglycosides, phenolics, and essential oils [71].

some essential oil components such as β-caryophyllene [74].

a flavoring – either fresh or dried – in soups, stews, and pot roasts.

including potentially fatal anaphylactic shock [80].

of isolated rat aortic rings caused by high K<sup>+</sup>

vasodilation and stimulates the vagus nerve.

**3.4. Apiaceae –** *Apium graveolens* **L.**

The apparent antihypertensive effect of *M. indica* preparations and constituents may be attributed to at least two mechanisms, namely the induction of vasodilation and the stimulation of diuresis. Indications for the former possibility are provided by the inhibition of noradrenalineinduced contractions of mesenteric arteries isolated from spontaneously hypertensive rats by a *M. indica* stem bark extract (called 'Vimang' from 'vida del mango' meaning 'life of the mango') [62]. Support for the second possibility comes from the diuretic effect of 'Vimang' in laboratory rats [67].

#### **3.3. Annonaceae –** *Annona muricata* **L.**

The exact origin of the soursop or graviola *A. muricata* (**Figure 3**) is unknown, but it is believed to be native to the Caribbean and the tropical regions of the Americas. It is now widely cultivated for its fruit, the pulp of which contains substantial amounts of vitamin C, vitamin B1, and vitamin B2 and is used to make fruit juice drinks, smoothies, as well as candies, sorbets, and ice cream flavorings. Relatively recently, *A. muricata* fruit and graviola capsules have been promoted as an alternative treatment for cancer. However, there is no medical evidence for such an activity, even though preclinical studies have shown cytotoxic effects of *A. muricata* extracts against cultured cancer cells [68].

Importantly, *Annona* species including *A. muricata* are a rich source of annonaceous acetogenins such as annonacin and annonamine, potent neurotoxins that inhibit mitochondrial

**Figure 3.** Annonaceae – *Annona muricata* L. (from: https://goo.gl/images/K9WNHr).

complex I, thereby shutting down cellular respiration [69]. These compounds have been associated – although not conclusively – with the unusually high incidence of atypical parkinsonism in the Caribbean island of Guadeloupe where relatively large amounts of *A. muricata* fruits as well as infusions and decoctions from the leaves of the plant are consumed [70].

Nevertheless, all parts of *A. muricata* are extensively used – also in Suriname – as traditional medicines against a wide diversity of conditions, among others, insomnia; nervousness, anxiety, and depression; a hangover; epilepsy; parasitic and helminth infections; diabetes mellitus; cancer; and hypertension [45, 48, 49, 55, 71]. Pharmacological studies with preparations from leaves, bark, and roots of the plant have indeed shown sedative, anxiolytic, smooth muscle-relaxant, antispasmodic, and antihypertensive effects [71–73]. Some of these effects may be attributed to the presence in the plant of bioactive constituents such as alkaloids, flavonol triglycosides, phenolics, and essential oils [71].

Indications for an antihypertensive effect were provided by the decrease in blood pressure in normotensive Sprague-Dawley rats which were intravenously treated with an aqueous leaf extract of *A. muricata* [74]. Furthermore, the extract decreased the phenylephrine-induced contractions of isolated rat and guinea pig aortic rings [74, 75], and relaxed the contractions of isolated rat aortic rings caused by high K<sup>+</sup> while apparently blocking Ca2+ channels [74]. These findings suggest that the hypotensive effects of the *A. muricata* leaf extract may involve vasodilation mediated through peripheral mechanisms involving antagonism of Ca2+ [74]. This effect has been attributed to alkaloids such as coreximine, anomurine, and reticulin, and some essential oil components such as β-caryophyllene [74].

However, in light of the affinity of both crude extracts and isoquinoline alkaloids isolated from *Annona* species to 5-HT1A receptors *in vitro* [72], and the well-known decreasing effect of 5-HT1A receptor agonists on blood pressure and heart rate [76], it is also possible that the antihypertensive effect of these plants occurs through a central mechanism that causes peripheral vasodilation and stimulates the vagus nerve.
