Unveiling the diverse medicinal properties of Murraya koenigii

1. Introduction

India is the habitat to more than 50,000 plant species, the majority of which are employed in folk and traditional herbalism. Many medicinal plants are used directly to treat illnesses or heal wounds, while some natural or pure compounds are consumed every day as a source of vital nutrients (1). For his basic requirements, such as food, clothing, and shelter, man uses plants in a variety of ways. For both urban and rural cultures, wild plants are the primary source of medicines, crafts, and cosmetics (2). Additionally, in rural regions, plants are the primary employers and sources of income (3). Plants have been utilised as remedies for thousands of years all across the world. According to WHO, around 80% of the population still relies on plant-based medications for primary care, especially in underdeveloped Nations. Siddha, Unani, Ayurveda, and indigenous health civilizations are just a few of the medicinal systems used in India; they all make extensive use of herbs to cure human and animal illnesses (4). These therapeutic plants are crucial to us in another manner as well. India has a great variety of natural resources and a successful track record of traditional or old-style medicines; a sizable portion of the population still relies on plant-based medications for primary healthcare (5). The uses of medicinal plants are not only economical, but they also come with few or no adverse effects. Murraya koenigii, commonly known as Curry, Kadi, Kari Patta, or Mitha Neem, is one such plant that is well-known in many nations, including India (6). Murraya koenigii is a native of Sri Lanka and India and is a member of the Rutaceae family. Curry leaves are a common ingredient in south Indian cuisine and have been used to flavor food for a very long time. Utilizing medicinal plants has little to no negative effects and is also cost-effective. One such plant, Murraya koenigii, is well-known in many countries, including India. It is also known by the common names Curry or Mitha Neem. Curry leaves are a common ingredient in south Indian cuisine and have been used to flavour food for a very long time (7). Vitamins A, B, C and E are abundant in this plant. Curry leaves are a good source of folic acid and iron, which fight anaemia (8). Curry leaves include a variety of phytochemicals that prevent cancer, treat liver damage, have neuro-protective capabilities, and fight against issues with the stomach, mouth, heart, and other organs (4, 8).

Various names have been given to Murraya koenigii, including Karepaku in Andhra Pradesh, Kartaphulli in Bengal, Curry/Kari Patta in Hindi, and Curry Leaf in English. Karivempu in Tamilnadu, Kathnim and Karibevu in Karnataka, Narasingha in Assam, Gani, Gandhela and Gandla in Uttarakhand, Mitha Neemin Himachal Pradesh, Kariveppilei in Kerala, and Bhursangain from Orissa; Pindosine from Burmese; Gorenimbin, from Gujarat; Kerriebladeren from Dutch; Karrry bald, from Danish; Curryblatter, from German; Daunkari, from Indonesia; Feuilles de curry from French; Hoja, from Spanish; and Fogli de Car, from Italian (Table 1). Murraya koenigii is one of the therapeutically significant herbs, and its taxonomy, ethnobotany, traditional use, and scientific significance are being evaluated (8). Therefore, the present review will describe and cover prior and current key works on Murraya koenigii linked to the themes chosen rather than covering a small number of carefully chosen studies over a short period of time. The information will be methodically sorted, contrasted, and summarised, including phytochemical screening, identification, and pharmacological activity. We predicted that all of these efforts would result in a useful synthesis of pharmacological activity that would start off future views in the clearest possible way.

Table 1. Vernacular names of Murraya koenigii (8, 9, 10, 11).

2. Taxonomy of plant kingdom

Murraya koenigii, a member of the Rutaceae family and commonly referred to as a "curry-leaf" tree, is a native of Sri Lanka, India, and other south Asian nations (10). It is native to practically all of India and has a distinctive perfume. It is a deciduous tree or shrub that may grow up to 6 meter tall and have trunk diameters of 15 to 40 cm with thin, smooth, brown or grey bark. (12). This plant's majority of parts emit a potent, off-putting odour. A species of tree known as Murraya koenigii is indigenous to the Asian tropical region, which extends from the Indian Himalayan foothills to Sri Lanka, via Indonesia, Myanmar, Southern China, and Hainan. The curry tree has bipinnately complex leaves that are 15–30 cm long, each carrying 11–25 leaflets alternate on rachis, and 2.5–3.5 cm long ovate lanceolate leaves.

The curry tree has grey colour bark with longitudinal striatations, and beneath it, white colour bark is visible (13). Bisexual, funnel-shaped, white, sweetly scented, complete, stalked, irregular flowers with 2-3 mm long petioles and irregular edges have an average diameter when fully opened. 12 cm long terminal cymes with 60–90 blooms each. The ovoid, rough, or wrinkled fruits have glands, (Table 2) (10, 13).

Table 2. Murraya koenigii’s plant taxonomy (8, 10, 11).

3. Ethnobotanical use of Murraya koenigii

In Eastern Asia Murraya koenigii has countless important uses in the traditional system of medicine. Based on ethno-medicine, it is used as an anti-dysentric, anti-diabetic and stimulant (14). In Indian this plant is extremely valued for its leaves as an important ingredient to promote digestion and appetite. The leaves, roots and barks are tonic, carminative and stomachic (15). Leaves are used in dysentery also check vomiting. Steam distillate of leaves can be used as anti-anaemic, febrifuge stomachic and purgative.

Externally leaves are applied to eruption and bruises. The leaves, roots are bitter in test, acrid, cooling, analgesic, anti-helminthic, allays heat of the body, thirst, itching and inflammation, it also cures piles (16, 17). Leuco-derma and blood diseases can both benefit from it. To stop vomiting, use the toasted leaves. Root juice is beneficial for treating kidney-related discomfort. Fruits are regarded as astringent in Indo-China (18). Crushed leaves are applied topically to treat skin eruptions and soothe burns. To cure snake bites from deadly animals, leaf pastes that have been crushed are administered. For flavouring curries, egg, meat, and fish meals, traditional curry powder, etc., people mostly utilise fresh leaves, dried leaf powder, and essential oil (19). To create cosmetics and soaps, the aromatherapy sector uses essential oils (20). The nutritional value of the fruits is very high. The branches of this plant are frequently used as datun to clean teeth. In Table 3, the ethno-botanical profile is presented.

Table 3. Ethnobotanical use of Murraya koenigii.

4. Phytochemical study

Alkaloids, flavonoids, polyphenols, and terpenoids have all been isolated from the Curry leaves, stem, bark, and roots, as well as from plant extractions (31). There is a lot of nearby composition in the plant leaves, including 63.2% moisture, 8.8% protein, 39.4% carbohydrate, 1.15 % total nitrogen, 6.15% fat, 18.92% total sugar, 14.6% starch, and 6.8% crude fibre (32, 33). According to reports, curry leaves are a significant source of a number of vitamins, including calcium, magnesium, sodium, and vitamin A (β-carotene), which has a level of 6.04 0.02 mg/100g, vitamin B3 (niacin), which has a level of 2.73 0.02 mg/100g, vitamin B1 (thiamin), which has a level of 0.89 0.01 mg/100g, and vitamin B3 (niacin Alkaloids, essential oils, carbazole, flavonoids, and terpenoids all play helpful functions all over the world (34). List of Murraya koenigii's main chemical components, including plant parts are described in Table 4 and Figure 1 (35, 36).

The initial phytochemical screening of the extracts in ethanol, petroleum ether, chloroform, aqueous, and ethyl acetate was carried out. Several extracts contained alkaloids, carbohydrates, flavonoids, and sterol, which were all found to be present (37). To confirm the phyto-constituents in the curry tree extract, numerous experiments were carried out. When alkaloids were added to chloroform, petroleum ether, alcohol, ethyl acetate, and water extracts separately, Mayer's reagent confirmed the test for alkaloids, which showed the formation of cream- or white-colored precipitates (38). After adding a few drops of lead acetate (5%) solution to an alcoholic root extraction, the formation of a white precipitate allowed researchers to identify the presence of phenolic components. The presence of flavonoids was detected by dipping yellow filter paper into the aqueous and alcoholic extract with ammonia (39). While the extract exhibited honey comb-like foaming after being shaken with sodium bicarbonate, saponins were thought to be present. The presence of free amino acids and proteins was determined using the Biuret's, Millon's, and Ninhydrin's tests (36, 37). While the hydro-alcoholic extract was being shaken, CHCl3, a few drops of (CH3CO)2O, and a few drops of concentrated H2SO4 were added from the tube's side. This resulted in the formation of a blue to brick-red colour that signifies the presence of triterpenes and sterol (33). The plant's bitterness, which is measured at 2.5 units/gm, can be used. The plant has hemolytic properties. The presence of carbohydrates and amino acids was checked in the extracts, both aqueous and alcoholic (39).

 Alkaloids, flavonoids, polyphenols, and terpenoids have all been isolated from the Curry leaves, stem, bark, and roots, as well as from plant extractions (31). There is a lot of nearby composition in the plant leaves, including 63.2% moisture, 8.8% protein, 39.4% carbohydrate, 1.15 % total nitrogen, 6.15% fat, 18.92% total sugar, 14.6% starch, and 6.8% crude fibre (32, 33). According to reports, curry leaves are a significant source of a number of vitamins, including calcium, magnesium, sodium, and vitamin A (β-carotene), which has a level of 6.04 0.02 mg/100g, vitamin B3 (niacin), which has a level of 2.73 0.02 mg/100g, vitamin B1 (thiamin), which has a level of 0.89 0.01 mg/100g, and vitamin B3 (niacin Alkaloids, essential oils, carbazole, flavonoids, and terpenoids all play helpful functions all over the world (34). List of Murraya koenigii's main chemical components, including plant parts are described in Table 4 and Figure 1 (35, 36).

Figure 1. List of phytochemicals present in Murraya koenigii (16, 33, 40).

The initial phytochemical screening of the extracts in ethanol, petroleum ether, chloroform, aqueous, and ethyl acetate was carried out. Several extracts contained alkaloids, carbohydrates, flavonoids, and sterol, which were all found to be present (37). To confirm the phyto-constituents in the curry tree extract, numerous experiments were carried out. When alkaloids were added to chloroform, petroleum ether, alcohol, ethyl acetate, and water extracts separately, Mayer's reagent confirmed the test for alkaloids, which showed the formation of cream- or white-colored precipitates (38). After adding a few drops of lead acetate (5%) solution to an alcoholic root extraction, the formation of a white precipitate allowed researchers to identify the presence of phenolic components. The presence of flavonoids was detected by dipping yellow filter paper into the aqueous and alcoholic extract with ammonia (39). While the extract exhibited honey comb-like foaming after being shaken with sodium bicarbonate, saponins were thought to be present. The presence of free amino acids and proteins was determined using the Biuret's, Millon's, and Ninhydrin's tests (36, 37). While the hydro-alcoholic extract was being shaken, CHCl3, a few drops of (CH3CO)2O, and a few drops of concentrated H2SO4 were added from the tube's side. This resulted in the formation of a blue to brick-red colour that signifies the presence of triterpenes and sterol (33). The plant's bitterness, which is measured at 2.5 units/gm, can be used. The plant has hemolytic properties. The presence of carbohydrates and amino acids was checked in the extracts, both aqueous and alcoholic (39).

Table 4. The major chemical constituents of Murraya koenigii.

5. Folk/traditional use

Essential oils, fresh leaves, and dried leaf powder are frequently used to season other food preparations, seafood, soups, meat dishes, eggs, and curries. The soap industry and the cosmetic aromatherapy sector both employ essential oils (46). For maintaining healthy hair tenor and promoting hair development, curry leaves are utilised as an excellent hair tonic (47). Coconut oil is used to boil the leaves of this tree until a concentrated residue forms. The whole or parts of the plant are traditionally used as a treatment for nausea, vomiting, blood purification, depressive disorders, fungal infections, bodily aches, and diarrhoea as seen in Figure 2 (48). The indigenous people have employed barks and roots to treat dangerous animal bites. When consumed uncooked, the green leaves of Murraya koenigii assist alleviate morning sickness and diarrhoea. Boils are relieved by root juice and kidney pain is relieved by leaf paste, respectively (49). Along with lime juice, green curry leaves eaten raw aid in the treatment of diarrhoea and morning sickness (50). Boils and kidney pain are respectively relieved by root juice and leaf paste. The flavour of the fragrant leaves is distinctive. The dried curry leaf powder is combined with honey and betel nut juice in the Ayurvedic medical system as an anti-periodic (51, 52). Curry trees also contain iron, Vitamins A, B, B2, and C, and were used as a calcium supply for people who needed it. Traditional uses for this plant include antifungal, antidepressant, anti-diarrheal, anti-inflammatory, and blood purifying properties, either in part or whole (53, 54).