The term spice is often associated with hotness and pungency; in reality, though, only a few plants are suited to transmit a pungent quality to the food. Furthermore, it is worth noting that the prototype of all hot spices, chile, originates from the New World, and thus, was not available in Europe, Asia and Africa until the 16th century, although today, foods of all continents cannot be imagined without it.
Hwentea has been used as a pepper substitute in Europe, but with regular imports of black pepper from India starting in the 16th century, it mostly disappeared. In later times, hwentea was only traded as a pepper substitute (or surrogate) in times of war and short supply. Hwentea also has the same function that is used as a spice. In the olden days, hwentea was used as a traditional medicine and for food.
In West African cookbooks (Cameroon), the spice is referred to as kieng. In its origin, it has been found that hwentea has its root in tropical Africa (Ethiopia to Ghana), where both the species X. aethiopica and X. striata are used for local cooking. In South America, X. aromatica (burro pepper), has found similar applications among Brazilian Indios.
The name Xylopia is a compression from Greek xylon pikron [ξύλον πικρόν] bitter wood, aethiopica refers to the origin of the tree (though most of it grows in Ghana). Hwentea fruits look rather like small, twisted bean pods. They are dark brown, cylindrical, 2.5 to 5 cm long, and 4 to 6 mm thick; the contours of the seeds are visible from the outside. Each pod contains 5 to 8 kidney-shaped seed grains of approximately 5 mm in length. The hull is aromatic, but not the grain itself. Hwentea belongs to the family Annonaceae (custard apple family). Hwentea is often smoked during the drying process which results in an attractive smoky–spicy flavour.
Apart from being called hwentea in Ghana, names such as Negro Pepper, Grains of Selim, African grains of Selim, Moor pepper, Kani pepper, Senegal pepper, African Black Pepper, Ethiopian Pepper, etc. are attached to Xylopia aethiopica.
Ekong and Ogan (1968), became the first researchers to report on the chemical composition of Xylopia aethiopica. Several diterpenes from the bark, fruits and pericarp of the plant have been reported. Four studies (Faulkner et al. 1985; Rabunmi and Pieeru, 1992; Harrigan et al. 1994, Ekundayo 1989) published a review of the volatiles in several Annonaceae species among which includes Xylopia aethiopica, and reported that they consist mainly of mono and sesquiterpenoids with typical constituents being a- and b-pinene, myrcene, p-cymene, limonene, linalool, and 1,8-cineole.
Lately, two new sesquiterpenes, elemol and guaiol (among other terpenes), were found in the essential oil of the fruit from the Republic of Benin (Ayedoun et al. 1996) while Jirovetz et al. (1997) gave a semblance of the aroma note from the essential oil in the fruit of Xylopia aethiopica from Cameroon.
Fast forward, another study by Tairu et al. (1999) reported that hwentea essential oil has been found to contain (2 to 4.5 percent) β-pinene, 1,8-cineol, α-terpineol, terpinene-4-ol, paradol, bisabolene, and other terpenes. Another study found that linalool (E)-β-ocimene, α-farnesene, β-pinene, α-pinene, myrtenol, and β-phellandrene. Others, such as traces of vanillin and 3-ethylphenol, were also found.
Among the non-volatile constituents, tetracyclic diterpenes of the kaurane type have been identified; the kaurane structures are based on a tetracyclo [18.104.22.168.0] hexadecane skeleton. Kauranes and the structurally similar kolavanes and trachylobanes also appear in the bark. (Phytochemistry, 21, 1365, 1982), (Phytochemistry, 36, 109, 1994)
The essential oils of the stem bark (0.85 percent) and the leaves (0.5 percent) of X. aromatica have also been investigated. The bark oil consists mainly of α-pinene, trans-pinocarveol, verbenone, and myrtenol and differs remarkably from the leaf oil (spathulenol, cryptone, β-caryophyllene, and limonene) (Planta medica, 60, 282, 1994.
Hwentea – ccience
Two recent studies by (Macedo et al. 2020; Osafo et al. 2018) found that hwentea is anti-inflammatory, and hence, can interfere with conventional inflammatory targets. Additional two animals and one in vitrol studies (Nwozo et al. 2011; Mohammed and Islam, 2017; Moukette et al. 2015) also found that hwentea is loaded with antioxidants. Another study by Babarinde and Adegoke (2015) found that tomatoes infused with hwentea at 4 & 5 percent levels significantly retained the qualities evaluated.
Arthritis and pain
One animal study by Obiri et al. (2014) evaluates the anti-arthritic effects of a 70 percent aqueous ethanol extract of the fruit of Xylopia aethiopica in a chronic inflammatory model. Extract of 100, 300 and 600 mg /kg was used. The study found that hwentea suppresses joint inflammation and destruction in arthritic rats.
Another study by Ameyaw et al. (2014) also found that hwentea can be used in the management of pain disorders including headache and neuralgia. Two studies (Woode et al. 2012; Woode et al. 2016) on animals’ findings establish the analgesic properties of the ethanol fruit extract of hwentea in musculoskeletal pain.
Glaucoma and eye health
One important clinical trial by Igwe et al. (2003) conducted on visually impaired volunteers found that hwentea is a safer spice that can be exploited in the management of exophoria and raised intraocular pressure (glaucoma) in instances where the efficacy of the older conventional drugs is insufficient. Exophoria is an eye condition that affects binocular vision and eye alignment. A person with exophoria will experience one of their eyes drifting outwards, and their eyes will have difficulty working together. This study was conducted on humans; hence, it is good news for glaucoma or those with eye problems.
Blood sugar and cholesterol
Two studies (Mohammed et al. 2016; Mohammed and Islam, 2017) examined the anti-diabetic effects of hwentea in rats and found that hwentea is effective in lowering blood sugar and other metabolic diseases.
Another animal study by Nwozo et al. (2011) also found that hwentea is effective in lowering blood sugar and cholesterol. How hwentea can lower blood sugar is what we do not know. However, one study by Mohammed et al. (2021) found that a compound in hwentea, called oleanolic acid, is responsible for the antidiabetic action of hwentea fruit.
Antimicrobial and antibacterial
One animal study by Tamfu et al. (2020) shows that hwentea can be used to manage food-borne infections. However, another previous study by Fleischer et al. (2008) found no effect of hwentea against bacteria.
One study by Bakarnga-Via et al. (2014) investigated the antineoplastic activity of essential oils from fruits of these plants growing in Chad and Cameroon. Antineoplastic drugs are medications used to treat cancer. Other names for antineoplastic drugs are anticancer, chemotherapy, chemo, cytotoxic, or hazardous drugs. These drugs come in many forms, including liquids or pills. The researchers investigated the ability of hwentea essential oils on breast cancer and found that essential oils from fruits of hwentea have shown acceptable antineoplastic potency, and might be investigated further in this regard.
Another previous study by Choumessi et al. (2012) aims to characterise the effects of extracts of this plant on cancer cells and found its potency. A recent study by Ribeiro et al. (2021) also found that hwentea is often referred to as an anticancer ingredient in Africa, and this supports their assertion. However, more studies are needed on humans.
One study by Adaramoye et al. (2010) investigated the effects of hwentea fruit extract on oxidative stress in the brains of rats and found that it is beneficial. Another study by Biney et al. (2016) also found that hwentea has antidepressant potential.
One study by Iwuanyanwu et al.(2010) examined the effect of hwentea on liver health and found that it may be protective against liver damage in rats.
Though Hwentea is safe. One experimental study on animals by Ehigiator and Adikwu (2020) showed that the use of hwentea may be detrimental to male reproduction function. The researchers used 200-800 mg/kg of hwentea extract daily for 15, 30, and 60 days. So, moderation is key for men, especially those seeking children.
In conclusion, animal and in vitro studies have shown that hwentea supports the brain, controls blood sugar, and manages cholesterol, as well as blood pressure. An animal study also proved that it is an anticancer drug; and a good support for the liver, glaucoma, and the eye in general. It can treat schistosomiasis, arthritis and pain management. Finally, it is loaded with antioxidants.
Prof. Nyarkotey has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations to justify his write-ups. My articles are for educational purposes and do not serve as Medical advice for Treatment. I aim to educate the public about evidence-based scientific Naturopathic Therapies.
The author is a Professor of Naturopathic Healthcare and President of Nyarkotey College of Holistic Medicine & Technology (NUCHMT)/African Naturopathic Foundation. E-mail: [email protected].
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