Cardamom, belonging to the family of Zingiberaceae, is obtained from the seeds of Elettaria cardamomum Maton and it is mostly cultivated in southern India, Sri Lanka, Tanzania and Guatemala. The genus consists of about six species. Only E. cardamomum Maton occurs in India and this is the only economically important species. It is highly valued from ancient times, because of its very pleasant aroma and taste and it referred as the ‘Queen of Spices’.
The major use of cardamom is culinary purpose for flavoring food. It is also used in medicine as an aromatic stimulant, carminative and flavoring agent. Cardamom was used by ancient Greeks and Romans and also recommended by the Apicius, a famous Roman empire to counteract over indulgence
Types of cardamom
(i) Small green cardamom (Eletteria cardamomum)
(ii) Large red/black cardamom (Amomumsubulatum Roxb)
Phytochemical analysis of the cardamom methanol extract was carried out to test for the presence of flavonoids, amino acids, saponins, alkaloids, phenols, tannins, terpenoids, quinone and glycoside as per the following protocols:
(i) Test for flavonoid: Test solution was treated with 10% NaOH. Formation of greenish brown color indicates the presence of flavonoids (Edeoga et al., 2005).
(ii) Test for free amino acids: Test solution when boiled with 0.2% ninhydrin solution, formation of purple colour indicates the presence of free amino acids (Khandelwal et al., 2001).
(iii) Test for saponin (Froth test): Test solution when added to water and shaken well, formation of frothing indicates the presence of saponin (Aiyelaagbe et al., 2009).
(iv) Test for alkaloid: 1ml of test solution when treated with 1ml of Hagger’s reagent, formation of yellow colour precipitate indicates the presence of alkaloid (Obadoni et al., 2001).
(v) Test for phenols: Test solution was treated to alcohol and ferric chloride formation of greenish yellow colour indicates the presence of phenols (Khandelwal et al., 2001).
(vi) Test for tannin: Test solution treated with 20% boiled water and 0.1%FeCl3, formation of brownish green colour indicates the presence of tannin (Edeoga et al., 2005).
(vii) Test for terpenoids: Test solution was treated with chloroform and conc. H2SO4, formation of orange colour indicates the presence of terpenoids (Edeoga et al., 2005).
(viii) Test for quinones: If test solution when treated with HCl gives red precipitate, it indicates the presence of quinine (Khandelwal et al., 2001).
(ix) Test for glycoside: five milliliter of test sample when treated with 2 ml of glacial acetic acid containing few drops of FeCl3 and 1ml H2SO4 added, a brown layer at interfere indicates glycoside (Aiyelaagbe et al., 2009).
Medicinal and Pharmacological Uses
Cardamom possesses the following medicinal properties: antiseptic (pulmonary), antispasmodic (neuromuscular), aphrodisiac, expectorant, anthelminthic, antibacterial (variable), cephalic, cardiotonic, diuretic, emmenagogue, sialogogue and stomachic.
Oxidative stress is a chief factor for induction of several chronic and degenerative diseases such as diabetes, cancer, immune dysfunction and Parkinson’s (Haliwell, 2000; Metodiewa and Koska, 2000). Antioxidants are natural or synthetic compounds that can be used for prevention of free radical formation through scavenging and suppression of chronic and degenerative diseases (Haliwell, 2000). Currently, there is an increasing interest towards natural antioxidants from herbal sources (Larson, 1988; Velioglu et al., 1998). Cardamom capsules and seeds are rich sources of antioxidant substances that neutralize free radicals by preventing oxidation of other components.
Nair et al. (1998) reported that cardamom capsules have a moderate level of natural antioxidant properties owing to the presence of phenol compounds such as quercetin, kaempferol and luteolins. Natural antioxidants are thought to be safer than synthetic forms (Saeed et al., 2014). Like phytonutrients and vitamins, EO of cardamom acts as an antioxidant and helps scavenging free radicals, thus reducing cellular ageing (Nanasombat and Wimuttigosol, 2011; Saeed et al., 2014).
However, some of the studies of antioxidant activity based on chemical tests including DPHH assays no longer have pharmacological relevance. Their potential under in vitro and in vivo conditions need to studied for these effects to be considered clinically relevant (Harnly, 2017).
The essential oil of cardamom capsules in in vitro studies showed anticarcinogenic effects by inhibiting damage to adult DNA by aflatoxin B1 in a microsomal enzyme intermediated reaction (Hashim et al., 1994). This might be due to bioactive components present in the essential oil that have potential anticancer roles. Cardamom oil increased the glutathione transferase and acid-soluble sulfhydryl activities and arbitrates the oxidation and detoxification of xenobiotics (Banerjee et al., 1994). Bhattacharjee et al. (2007) reported that the constituents of phytochemicals of CEOs such as 1, 8-cineole and limonene demonstrated a protective role against cancer development. Further they said aqueous cardamom extract could improve the activity of the detoxifying enzyme glutathione S-transferase and reduce lipid peroxidation.
Elguindy et al. (2018) stated that oral administration of CEO at doses of 100 and 200 mg/kg/day for 26 weeks significantly decreased serum creatinine and urea, and LDH activity in diethylnitrosamine (DENA) induced oxidative stress in rats. Only a few studies have investigated the anticancer potential of cardamom extracts and CEO, and these were conducted in animal models, not in humans. Hence, future investigations should be focused on the bioactivity of CEO in various clinical studies with humans.
Al-Zuhair et al. (1996) have shown that cardamom oil administered at 175 and 280 μl/kg of body weight inhibited the growth of carrageenan-induced paw edema in rats by 69.2% and 86.4%, respectively. The anti-inflammatory activity of cardamom oil is comparable to that of indomethacin (indometacin).
The petroleum ether soluble extract from Elettaria cardamomum seeds was screened for aspirin-induced anti-ulcerogenic activity in rats. The petroleum ether soluble extract inhibited lesions by nearly 100% at 12.5 mg/kg.
Skin-penetration Enhancing Activity
The essential oils have good skin permeation activity for certain drugs. Distract the structural order of the skin and thus increasing the diffusion capacity of the active components by the lipid intercellular pathway, due to interaction of oils with the lipids of the horny layer of the skin. An in vitro study on the permeation of estradiol through hairless mouse skin was studied by Monti et al. (2002), studies show that complex terpenes are responsible for the enhancement of transdermal permeation for moderately lipophilic drugs like estradiol. Permeation of indomethacin showed that permeation was significantly enhanced after pretreatment with cardamom oil, due to the presence of cyclic monoterpenes from Elettaria cardamomum
Well diffusion method revealed various degree of sensitivity by the test microorganisms against carda-mom extract. Well diffusion method had demonstrated EPEC (20.3 mm zone of inhibition as compared to 26 mm zone of inhibition for positive control i.e. streptomycin) as the most sensitive organism for the cardamom extract followed by B. pumilus (19 mm zone of inhibition as compared to 25 mm zone of inhibition for positive control i.e. streptomycin). Moderate resistance was exhibited by L. monocytogenes (18.5 mm zone of inhibition as compared to 22 mm zone of inhibition for positive control i.e. streptomycin) and E. coli (16.5 mm zone of inhibition as compared to 20 mm zone of inhibition for positive control i.e. streptomycin). All experiments were performed in triplicate and the inhibition zone was calculated as mean (n＝3).
Antidote to snake venom
Reportedly, the spice is also used as an antidote for both snake and scorpion venom.
The components in the volatile oil, e.g. 1,8-cineole,terpinene, terpiniol, sabinine, α-pinene and limonene, act as a tonic for the heart and liver, an appetizer, promote the elimination of bile and help reduce congestion of the liver.
Cardamom capsule extracts considerably enhanced the cytotoxic effects of natural killer cells and indicated their anticancer potential (Majdalawieh and Carr, 2010). According to Raksamiharja et al. (2012), CEO enhanced the amount of lymphocyte, CD4+ and CD8+ in doxorubicin treated rats in a dose dependent manner. Additionally, Elguindy et al. (2016) reported that cardamom essential oil or geraniol (200 mg/kg) decreased the level of TNF, IL-1 and NF-κB in diethylnitrosamine induced rats. These researchers also showed that CEO was an immune stimulant agent for chemotherapy. Even though the safety of cardamom extracts and CEO was indicated, the use of cell lines based only on in vitro assays limits the pharmacological relevance of this outcome.
Petroleum ether soluble extract of E. cardamomum found gastroprotective activity, which inhibited lesions by nearly 100% at 12.5 mg/kg in the aspirin-induced gastric ulcer. Methanolic extract also possess gastroprotective effect
Blood Pressure Lowering Activity
Powdered E. Cardamomum possess antihypertensive activity. At a dose of 3 g, it significantly decreases diastolic pressure. In hypertensive patients, without significantly altering blood lipids and fibrinogen level, cardamom enhances fibrinolysis and improves antioxidant status.
Cigarette De addiction
Cardamom is used against cigarette addiction. Smoking of cigarette can be minimized by eating few seeds of cardamom and slowly the smoker may give up the chronic addiction to chain smoking.
Due to its antiseptic and antimicrobial properties, essential oils are very useful in oral health. If used as a mouth wash by adding few drops of this oil in water, it disinfects the oral cavity of all germs