What is allspice

Even though its name suggests a mixture of spices, allspice is a single berry from the Jamaican bayberry tree. Allspice, also called pimenta, Jamaica pimenta, Jamaican pepper, Pimento Berries or Newspice ¹⁾. The name “allspice” was coined as early as 1621 by the English, who thought it combined the flavor of cinnamon, nutmeg, and cloves. Allspice has an aroma similar to a mixture of nutmeg, cinnamon and cloves ²⁾. Allspice is the dried fruit of the Pimenta dioica plant. A native plant from the Caribbean island Jamaica, Pimenta dioica belongs to the family Myrtaceae. Unlike the common black peppercorns which are fruits from a tropical vine (Piper nigram, L) which is the native of South Asia, Pimenta is a typical Evergreen tree with a height of 22 ft. Occasionally the trees grow up to 43 feet tall with light gray bark and dark green leaves (4–8 cm long). Small whitish flowers grow on the allspice tree in the summer that produces the berries. The berries are picked while still green and unripe and are traditionally dried in the sun. The berries (Allspice) become brown when they’re dried and look like large, brown, smooth peppercorns. Allspice was originally native to the tropical forests of South and Central America, southern Mexico and the West Indies. Allspice is grown commercially in Mexico, Honduras, Trinidad, Cuba and in Jamaica. Commercial Allspice is also obtained from the fruits of another related species, Pimenta racemosa (Myrtacea, L) mostly found in Central America. However, the fruits are larger and are known to be less aromatic. Jamaica is also the world’s largest producer of allspice and Jamaican allspice is renowned for being of exceptional quality because it contains a higher level of essential oils, which give it more flavor than Allspice grown in other Caribbean islands or in Central America ³⁾. Pimenta trees are dispersed around the world with Allspice spelled in over 50 languages from Arabic to Vietnamese.

The whole allspice fruits have a longer shelf life than the powdered product, and produce a more aromatic product when freshly ground before use. Whole, allspice is used in poached fish stock, vegetable and fruit pickles and for wild game. Ground, allspice is found in spice cakes, puddings, cookies, gravies, BBQ sauce and is a key ingredient in Caribbean jerk dishes. It is also often used in German sausages and is so common in English baking that it’s sometimes known as English Spice. Sometimes allspice is used as a partial replacement for black pepper in frankfurters and some smoked products ⁴⁾.

Allspice can also be found in essential oil form. Allspice contains a small amount of eugenol, the essential oil that gives cloves their strong, distinct flavor. Since eugenol is both warming and anti-microbial, Russian soldiers in the Napoleonic War of 1812 put allspice in their boots to help keep their feet warm and alleviate odor. This practice carried into the men’s cosmetic industry, so that today the scent of allspice is often found in men’s colognes.

Allspice fresh leaves are used where available. They are similar in texture to bay leaves, thus are infused during cooking and then removed before serving. Unlike bay leaves, they lose much flavor when dried and stored, so do not figure in commerce. The leaves and wood are often used for smoking meats where allspice is a local crop.

Figure 1. Allspice

Figure 2. Allspice berries

What is allspice used for

Non-medicinal use of Allspice

Whole or powdered Allspice is sold in the grocery stores throughout the world and is used in the cuisines of Middle East and Central America as well in European pastries. In Caribbean cuisines, Allspice is the most important spice and used extensively, it’s used in Jamaican jerk seasoning, in mole sauces and pickling. The meats that are seasoned with Allspice are then cooked over a P. dioica wood fire. Jamaicans also soak the berries in rum to make a special liqueur. In other countries Allspice is used mostly in baking desserts such as pumpkin pies, banana bread spice cake, bread pudding and gingerbread. In the British isles, Allspice is added in stews, sauces and for flavoring pickled vegetables.

The essential oil extracted from Allspice have typical aroma of a combination of pepper, nutmeg, clove and cinnamon. The scented oil from Allspice have been used in perfumery, candle making and in other cosmetic manufacturing. Similarly, scents extracted from fresh or dried leaves of Pimenta are also known to impart stimulating effect with the mildly spicy aroma. In recent years, in societies’ drive for natural alternatives to pesticides and fungicides, the extracts of Pimenta leaves have been used as food fumigant to preserve freshness and sterility of meat and poultry products ⁵⁾. In similar areas where synthetic pesticides are used like the wood protection and plant disease treatments, Allspice essential oils also have been substituted as a natural alternate for pesticides and fungicide ⁶⁾.

Allspice Medicinal Uses

Traditional Folk Medicine

All parts of Pimenta dioica are used in Folk medicine, the kind of medicine developed over centuries by empirical and in often times by anecdotal evidences and other approaches. In Caribbean, there is a long history of using Allspice berries for folk healing. Jamaicans also drink hot tea with Allspice for colds, dysmenorrhea (menstrual cramps) and dyspepsia (upset stomach) ⁷⁾. Costa Ricans are known to use Allspice to treat dyspepsia and diabetes. Guatemalans are known to apply crushed Allspice berries to bruises, sore joints and for myalgia (muscle ache). In Cuban medicine, Allspice along with other herbal mixtures is used to relieve indigestion. Not only used in the areas where Allspice originated from, its use has been incorporated in the Indian traditional medicine, the Ayurveda.

Allspice use in Ayurveda, which has been developed over the last two millennia, has likely originated from European colonization and subsequent use of it in Portuguese and the English populace in India. Its use includes use to relieve respiratory congestion and assorted odontalgia (toothache). In Europe, anecdotal uses of Allspice extract for dyspepsia and as purgative exist. The use of Allspice in folk medicine was also followed by its incorporation in the British Pharmacopoeia of 1898, especially of pimento oil and pimento water. Oil of pimento, however, was deleted from the British Pharmacopeia of 1914. The British Pharmacopeia Codex supposedly still retained pimento water ⁸⁾. In modern herbal medicine, Allspice extract has been used for neuralgic pain. Allspice essential oil, when added to massage oils and baths, is known to promote circulation so as to relieve pain from muscle cramps and strains. Also, it is used for headache, to combat stress and depression and to overcome fatigue because of its comforting scent. Allspice blends well with ginger, lavender and other spices, making it diversified when it comes to the choices for aromatherapy.

The reason why Allspice is used for treating indigestion might be due to the abundance of the common polyphenol, Eugenol, in Allspice, which is known to stimulate digestive enzymes ⁹⁾. Furthermore, it has been shown that Eugenol has analgesic effect in neuralgia; it is often used as anesthetic by dentists ¹⁰⁾. Eugenol could potentially contribute to the anti-inflammatory function associated with Allspice in traditional medicine. The widespread and diverse uses of Allspice, the leaves and barks of Pimenta have stimulated several studies in the last two decades on systematic investigations of the potential evidence-based medical use of Pimenta. Although, most uses of Allspice as folk medicine are inherited from ancestors among different cultures, more scientific studies have been carried out for a systematic assessment of its active components from leaves, bark and berries of Pimenta and to delineate potential medicinal values of chemicals enriched or isolated from Pimenta dioica.

Allspice Potential Health Benefits

Most of the chemical extractions of allspice have been reported for its leaves and berries. To date, the most common ingredients tested are polyphenols, lignins and terpenoids. Interestingly, none of the characterized compounds isolated is an alkaloid. Table 1 lists the main well characterized compounds isolated to date from allspice. It should be noted however, other than the chemicals isolated from fresh leaves of Pimenta dioica, many of the compounds reported to be in Allspice could potentially be from other known species that produce Allspice, Pimenta racemosa, as commercial Allspice (both berries and powdered form) is a mix of berries from either species. Table 1 highlights compounds that have shown significant medicinal potential as validated by controlled studies involving either biochemical experiments or control animals studies. The biological properties exhibited by Allspice extracts can be loosely classified as oxygen scavenges (antioxidants), vasodilators (antihypertensive) and antiproliferative agents with potential for application in cancer chemoprevention and therapies.

Table 1. Potential Pharmaceutical Products in Allspice (Pimenta dioica)

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Antioxidant Activities

Oxygen free radicals like Reactive Oxygen Species (ROS), hydroxyl radical, as well as Reactive Nitrogen Species are products of normal cellular metabolism, but their overproduction causes biological damage, the oxidative stress. Oxidative stress cause damage to DNA, proteins and lipids, and has been widely implicated in various pathological conditions involving cancer, neurological disorders, cardiovascular disease, diabetes, aging and other chronic and fatal diseases. Recently, there have been intensive researches about the antioxidant properties of natural dietary agents because of the free radical scavenging ability shown by the whole extract of plants and the components out of it. Examples of compounds derived from common dietary sources include resveratrol from grape seeds, green tea catecholamine such as (−)-epigallocatechin-3-gallate (EGCG) and the common, ascorbic acid. In addition, recently it has been shown that some commonly used herbs and spices are also rich in antioxidants, may even outperform those fruit and vegetables when compared in equivalent consumable quantities. Allspice is known for its antioxidant activities ²⁶⁾ and many compounds that have antioxidant activities have been isolated and characterized. The ethyl acetate extract of Allspice which contained polyphenols show strong antioxidant activities and free radical-scavenging activity against 1,1diphenyl-2-picrylhydrazl (DPPH) radical ²⁷⁾. Many already known compounds are isolated from leaves and berries of Pimenta Dioica, with antioxidant properties, such as Eugenol ²⁸⁾, Quercetin ²⁹⁾, Gallic acid ³⁰⁾ and others.

Extracts of Pimenta Leaves Have Hypotensive Effect

Known as folk remedy used for treatment of high blood pressure, obesity and digestion problem in Central America, as well as treatment for menstrual cramps and abdominal pain in Caribbean culture, cardiovascular effects of Pimenta dioica were investigated. Hypotensive action which is shown by decreased blood pressure level was confirmed by giving Sprague-Dawleyrats intravenous administration of aqueous extract of Pimenta Dioica ³¹⁾. Further, it has been reported that the allspice leaf extract has central nervous system (CNS) depressant effect at the same time. Analgesic and hypothermic effects were also observed with no significant changes in heart rate, body weight and no other abnormalities. Importantly, it is mentioned that aqueous fraction of Allspice generated greater hypotensive effect than the ethanol extract of identical doses. Another study using Spontaneously Hypertensive Rats also showed the aqueous extract of Allspice, which outperforms than the ethanol counterpart, causes depression of the CNS in a dose-dependent manner, but it didn’t produce significant changes in blood pressure ³²⁾. It is also noted that the hypotensive action was not mediated through cholinergic, alpha or beta adrenergic receptors and the extract may have vasorelaxing activity.

Menopause Treatment

Menopause symptoms affect about 70% of women approaching menopause with hormone replacement therapy (HRT) as the standard treatment. Interestingly, in south and Central America, women typically experience menopause earlier than the U.S. counterparts, however, they tend less to use hormone replacement therapy and they perceive the menopausal period quite positively. Epidemiology studies have shown that cultural and dietary influences may have an effect on the menopausal transition; women from Maya or Costa Rica have more plant-based dietary as well as use more herbal medicines in daily life. A study shown that the methanol extract of allspice acts as partial agonist/antagonists by enhancing estradiol-stimulated pS2 mRNA expression but reducing progesterone and PTGES mRNA expression with estrogen ³³⁾. Along with several other plants extracted studied, this might be one of the mechanisms by which herbal extracts used by South American women alleviates menopausal symptoms.

Cancer

Most, if not all studies reported on antiproliferative activities of Pimenta extracts and purified compounds from Allspice have been in vitro, no studies to date has reported studies on animal models of human cancers. Since chronic inflammation is implicated in many cancers including colorectal, breast and prostate cancer, consuming Allspice or other parts of Pimenta dioica should provide a diet with strong antioxidant source. Consequently, there could be beneficial effect on cancer incidence and or mortality, at least from cancers that are directly implicated due to inflammation. However, few studies have been reported that estimates the type, quantity and potential implication of such a diet in countries that are known to use Allspice extensively. The epidemiological data on cancer incidence and mortality among countries in Caribbean basin is not low but high ³⁴⁾. On the other hand, cancer incidence in Mediterranean countries and in regions that consumes Mediterranean diet rich in Olive oil, green and red vegetable and lower amount of red meats has a lower incidence and mortality of these diseases. This discrepancy between Caribbean countries and Mediterranean countries may be due to many factors. Briefly, there is limited scope in sequestering the contribution of a single dietary factor for changes in cancer incidence in a population. A diet rich in Allspice may also be rich in other antioxidants from sources such as citrus fruits, paprika, turmeric (a source of curcumin), green pepper (capsaicin), cinnamon and other source. Population in the Indian subcontinent has lower risk of colorectal, breast and prostate cancers ³⁵⁾. However, whether this is due to diet or other factors is not clear at this time. On the other hand, limited implication of antioxidant rich Allspice or Pimenta products on cancer incidence in Caribbean countries may be attributed to the method and form of its consumption. Clearly, consumption of Allspice in beef jerky, Jamaican rum is unlikely to have cancer protection effect in population that extensively consumes these products. Red meat and charbroiled food are associated with increased clinical incidence of breast and prostate cancers ³⁶⁾, ³⁷⁾.

Due to the relatively large number and content of aromatic and antioxidant compounds present in Allspice, several groups have attempted to isolate and characterize potential anti-tumor agents in Allspice and Pimenta leaves. The lack of fresh leaves and potential for alteration in content due to the soil conditions in places where Pimenta trees are grown, limited number of studies have been carried out on leaves versus that of Pimenta berries. Assessment of the anti-tumor activities of Pimenta leaf extract or Allspice extracts have used primarily in vitro cell (test tube studies) proliferation assays on normal and tumor cells. It has been reported that polyphenols isolated from the methanol extract of Pimenta dioica leaves remarkably inhibit the cell growth of Hep-G2 and HCT-116 cells with less effect on MCF-7 cells ³⁸⁾. Further, studies have shown pro-proliferation effect on non-tumorigenic cells such as 1301 and RAW 264.7 cells ³⁹⁾. However, there is indirect evidence that compounds that show antiproliferative activities are present in polyphenols isolated from Allspice. This include Eugenol, Quercetin, pedunculigan and Gallic acid, See Figure 3 all of which exhibit pro-apoptotic and antiproliferative activities on many established human tumor cell lines, including breast cancer cell lines, MCF-7 and MB231 ⁴⁰⁾, prostate cancer cell lines PC-3 and LNCaP ⁴¹⁾.

Figure 3. Common phenolic compounds isolated from Allspice

Note: Structures of common phenolic compounds isolated from Pimenta dioica with anti-proliferative activities. A. Eugenol: 4-Allyl-2-methoxyphenol;B. Quercetin: 2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one);C. Gallic acid: 3,4,5-trihydroxybenzoic acid; D. Ericifolin: Eugenol 5-0-b-(6′-O-galloylglucopyranoside).

[Source ⁴²⁾]

Potential Pharmaceutical Products in Allspice (Pimenta Dioica)

Eugenol

The most important component isolated from Allspice with strong antioxidant activity is Eugenol which composes 60–90% of the essential oil extracted from Allspice berries. The principal source of Eugenol however, is Clove oil. Eugenol is a phenyl propene and several studies have reported its pharmacological activities ⁴³⁾. Historically, many natural products are used against microbial infections and many compounds have been found to play a role in the antibacterial activity. Likewise, it is shown that Eugenol inhibits the growth of many different pathogens ⁴⁴⁾ as well as has synergistic effect with known antibiotics ⁴⁵⁾. Similarly, Eugenol has also been evaluated to show the antifungal activity against Candida albicans thus shed a light on the combination therapy for treating Candidiasis ⁴⁶⁾. Eugenol is also well known for its anti-inflammatory activity ⁴⁷⁾ and antioxidant effect ⁴⁸⁾. The anti-inflammatory effect was investigated on lipopolysaccharide (LPS) induced activated macrophages, to which Eugenol has inhibitory effect on its COX-2 production as well as NF-KB pathway activation, which are characteristics for inflammation ⁴⁹⁾. Radical-scavenging against 1,1′-diphenyl-2-picrylhydrazyl (DPPH) assays were used to test the anti-oxidant effect of Eugenol and showed promising results ⁵⁰⁾.

More importantly, Eugenol has been shown to have antiproliferative effect and induce apoptosis in various cancer cell lines. On HeLa cells (cervical cancer), Eugenol showed selective cytotoxicity compared to normal mammalian cells. In addition, combination with an established chemotherapy drug, gemcitabine yields better growth inhibition effect with apoptosis induction ⁵¹⁾. ROS production dependent apoptosis was found in Eugenol treated human erythroleukemia model HL-60 cells ⁵²⁾. The anti-proliferative effect of Eugenol as well as its isomer isoeugenol was also shown in melanoma cells using xenograft model ⁵³⁾ and epidermoid carcinoma A431 cells ⁵⁴⁾. By using xenograft model, Eugenol was implicated in reducing tumor size and inhibition of metastasis, while cell cycle blockage seemed to be the mechanism in the A431 cells.

Quercetin

Quercetin is a dietary polyphenol which is found in many foods that are consumed daily, it is also isolated from Allspice berries, although in a very limited portion ⁵⁵⁾. The pharmacological properties of Quercetin have been extensively documents. Briefly the results revealed the pluripotent activities of Quercetin such as antiviral, anti-inflammatory and anti-cancer effects. Quercetin has been reported to have antiviral effect against different types of virus ⁵⁶⁾, also shown protective effect for cardiovirus infected mice ⁵⁷⁾. And the mechanisms for anti-inflammatory effect of Quercetin lie in down-regulation of NF-KB pathway ⁵⁸⁾, inhibition of inflammatory cytokines expression ⁵⁹⁾ and affecting inflammatory gene expression ⁶⁰⁾.

A large portion of the health benefit studies of Quercetin focus on its anti-cancer potentials and it showed that Quercetin works through various mechanisms. DNA damage rescue and preventions is believed to be the mechanism behind tumorigenesis prevention, and Quercetin was shown to prevent DNA damage as well as increase DNA repair at lower dosages ⁶¹⁾. However, Quercetin might have pro-oxidant effect which causes cellular damage when administered in high dosage ⁶²⁾. Although the pro-oxidant effects are not welcomed for the healthy cells, it actually enabled Quercetin to work like cytotoxic drug against cancer cells under higher dose. For example, it is known that Quercetin induces apoptosis in many cancer cell lines when treated at 40–50μM or higher concentration ⁶³⁾. Anti-proliferation as well as apoptosis induction happens in both p53 dependent and independent pathways ⁶⁴⁾. In addition to the classic apoptosis pathways, Quercetin seems to exert more ways to facilitate the induction of cancer cell death. One potential strategy is by modulating the expression of chaperone protein such as HSP70, HSP27 ⁶⁵⁾ and HSP90 ⁶⁶⁾. One important issue about Quercetin is its absorption and metabolism; it was shown that both the glycoside type of Quercetin, i.e. the aglycon and the parental compounds can be absorbed at multiple sites in the human body. And the anti-oxidant effect was significant when higher dosage of Quercetin is administered in the animal, with which to reach a pharmacologically achievable serum concentration of Quercetin ⁶⁷⁾.

Although Quercetin doesnot seem to be the major component of Allspice, Quercetin does perform a strong anti-oxidant effect ⁶⁸⁾. Its potent ROS scavenging function which allows for reducing DNA damage may powerfully contribute to the potential anti-cancer effect of Allspice or Pimenta extracts as well as the potential benefit associated with their consumption.

Gallic Acid

Gallic acid (3,4,5-trihydroxybenzoic), which belongs to the phenolic acid family, is distributed among a variety of plants, foods and remedies. Similarly, Gallic acid has been shown to have antiviral effect ⁶⁹⁾. The anti-cancer effect of Gallic acid seems very general throughout many types of cancers. Towards prostate cancer, gallic acid induces ROS-dependent apoptosis in LNCaP cells ⁷⁰⁾, inhibits invasion of human prostate PC3 cells by modulating MMP-2 and -9 ⁷¹⁾, induces cell cycle arrest and apoptosis in DU145 cells ⁷²⁾ and is able to decrease tumor growth and micro vessel density in a xenograft model ⁷³⁾. In addition, gallic acid showed anti-cancer potential against both Estrogen Receptor (ER) positive MCF-7 cells as well as ER negative MB-231 models ⁷⁴⁾. Besides solid tumors, gallic acid is also reported to be effective in inhibiting growth and inducing apoptosis in lymphoma cells ⁷⁵⁾ and inhibiting invasion of human melanoma cells ⁷⁶⁾. The anti-oxidant property of Gallic acid is also beneficial in animal model of Parkinson’s disease ⁷⁷⁾.

Ericifolin

Ericifolin, Eugenol 5-O-galloylglucoside, was first isolated from leaves extract of Melaleuca ericifolia ⁷⁸⁾, whose oil showed antimicrobial and anti-inflammatory activities ⁷⁹⁾. With very preliminary studies about Ericifolin, it was found out that it poses antibacterial activity ⁸⁰⁾. Scientists have purified Ericifolin from Aqueous Allspice Extract (AAE) that shows strong antiproliferative, pro-apoptotic, pro-autophagy and anti-androgen receptor activities. Preliminary studies using the Aqueous Allspice Extract (AAE) showed strong and specific activity against prostate cancer cell proliferation and induced multiple anti-tumor activities including apoptosis, cell cycle arrest, and repression of androgen receptor transcription and tumor growth inhibition. The purified Ericifolin showed key biological functions of Aqueous Allspice Extract in cell culture studies ⁸¹⁾. Further studies are underway in the laboratories to fully illustrate its potential.