**3.1. Acanthaceaea –** *Ruellia tuberosa* **L.**

**Family Plant species**

162 Herbal Medicine

Caricaceae *Carica papaya* L.

Cucurbitaceae *Cucumis sativus* L.

Fabaceae *Hymenaea courbaril* L.

Fabaceae *Tamarindus indica* L.

Lauraceae *Persea americana*

Malvaceae *Gossypium* 

Malvaceae *Hibiscus sabdariffa* L.

Meliaceae *Azadirachta indica*

Oxalidaceae *Averrhoa bilimbi* L.

action.

loksi)

Mill.

(Tamarind; tamarinde)

Fabaceae *Desmodium* 

**(Vernacular name in English; Surinamese)**

(Papaya; papaya)

*adscendens* (Sw.) DC.

(West Indian locust;

(Avocado; advocaat)

*barbadense* L. (Sea island cotton; redi katun)

(Roselle; syuru)

(Bilimbi; birambi)

A. Juss. (Neem; nim)

(Cucumber; komkommer)

(Beggar lice; toriman)

**Preclinical evidence**

**Clinical evidence** **Presumed key active constituent(s)**

Yes No Unknown Vasodilation;

No No Unknown Vasodilation

No No Unknown Unknown

Yes No Unknown Sympatico-

Yes No Unknown Vasodilation;

Yes No Unknown Vasodilation

flavonoids

nimbinin

Yes No Unknown Vasodilation;

Yes No Polyphenolics,

Yes No Azadirachtin,

**Table 2.** Preclinical and clinical evidence for blood pressure-lowering activity of 15 commonly used plants in Suriname for treating hypertension, the presumed key active constituent(s) in these plants, and their presumed mechanism of

Yes Yes Unknown Stimulated diuresis

**Presumed mechanism of action**

inhibition; decreased blood lipid levels

decreased blood lipid levels

Vasodilation; stimulated diuresis; decreased blood lipid levels

Vasodilation

decreased cardiac output; stimulated

diuresis

stimulated diuresis

The minnie root *R. tuberosa* (**Figure 2**) is probably native to Central America but has spread to various other tropical regions in South America as well as South and South east Asia. Both the English vernacular name 'cracker plant' and the Surinamese vernacular name *watrakanu* ('water canon') are probably derived from the loud crack emitted when the ripe fruits in a pod with seven to eight seeds burst open on contact with water, hurdling the seeds away. The whole plant, the leaves, and/or the roots are used in various traditional medicinal systems including those in Suriname as an antidiabetic, antipyretic, analgesic, diuretic, antihypertensive, gastroprotective, anthelmintic, antigonorrheal, antioxidant, blood-purifying, and abortifacient agent [46, 48, 49, 55, 56]. Some of these activities were supported by the results from pharmacological studies [57, 58] and could be associated with certain alkaloids, triterpenoids, saponins, sterols, and flavonoids in the plant [59].

So far, no formal experimental evaluations on the presumed antihypertensive activity of *R. tuberosa* have been reported. However, crude extracts from the leaves of the closely related species *R. patula* and *R. brittoniana* as well as n-butanolic extracts and the aqueous layers of both plant extracts displayed cardiotonic effects in isolated rabbit hearts [60]. More importantly, a preparation from *R. patula* elicited a clear blood pressure-lowering effect in pentothal sodium-anesthetized rats [61]. This effect may be attributed, at least partially, to the blood lipid-lowering actions of *Ruellia* preparations [57, 58].
