Bioactive Components of Medicinal Plants and Their Health Benefits

Keywords: Medicinal plants, health benefits, bioactive components

Man uses medicinal plants in many ways to meet his basic need that is food, clothing and shelter since ancient times. As per World Health Organization (WHO) 80% of the world population still depend on medicinal plants. Medicinal plants have been utilized for a large number of years to flavour and preserve food, to treat wellbeing issue and to avoid illnesses including epidemics. Arjuna, amla, giloy, curry leaf, mulethi and aloe vera are used in all cultures around the world.These plants are rich source of bioactive components like phenols, flavonoids, triterpenoids, tannins etc. These bioactive components are rich source of functional foods. Recently medicinal plant based functional food becoming more popular among consumers due to constant health awareness, lesser side effects, availabiity and economic value. The medicinal plants based food may have antioxidant, antimicrobial, antiinflammatory, antidiabetic, anticarcinogenic, cadiotonic activities.

Introduction

Plants have also been used as medicines for thousands of years all over the world. Mostly developed countries still rely on plant based medicines for primary care WHO 1978. Globally, medicinal plants are being studied in order to develop new molecules for use in pharmacology, neutraceuticals, food supplements, folk medicines etc. A major traditional medicine which has been used as chemical compounds derived from medicinal plants (Amalraj & Gopi, 2017). Affirmation of the security, quality, and adequacy of therapeutic plants and natural products has now turned into a key issue in industrialized and in developing nations. Across the board utilization of home grown cures and healthcare preparations is depicted in the Vedas and the Bible (Shakya 2016).The information of their healing properties has been transmitted throughout the hundreds of years within and among human groups (Gupta et al., 2018). Therefore this chapter provides a review of major components present in whole grains and their role in maintenance of human health.

It has been reported that mostly plants have pharmacological effects because of metabolites. Plant-metabolites are organic compounds which can be classified into primary metabolites and secondary metabolites. Primary metabolites are organic compounds include glucose, starch, polysaccharide, protein, lipids and nucleic acid which are beneficial for growth and development of the human body. Plants synthesize secondary metabolites which include alkaloids, flavonoids, saponins, terpenoids, steroids, glycosides, tannins, volatile oils etc., The therapeutic efficacy of plants is because of these secondary metabolites for curing many diseases. Phytochemicals are pharmacologically active compounds. These include alkaloids have an antispasmodic, antimalarial, analgesic, diuretic activities; Terpenoids are known for their antiviral, anthelmintic, antibacterial, anticancer, antimalarial, anti-inflammatory properties; Glycosides are reported for antifungal and antibacterial properties; Phenols and flavonoids have an antioxidant, anti-allergic, antibacterial properties etc. and Saponin also known for anti-inflammatory, antiviral, plant defence activities etc.

Arjuna (Terminalia arjuna)

Combretaceae

The most common names of T. arjuna is Arjuna, Arjun (Hindi), Marudhu (Tamil and Malyalam), TellMaddi/Yella maddi (Telugu), Arjhan (Bengali), Sadaru (Marathi), Sadado/ Sadad (Gujrati), (Kannada) Neer Matti (Amalraj & Gopi, 2017).

Distribution

T. arjuna (Roxb.) Wt. and Arn. which is a deciduous and evergreen tree distributed throughout India including sub Indo-Himalayan tracts of Uttar Pradesh, Punjab, Deccan, South Bihar, Orissa,West Bengal and Madhya Pradesh mainly along riverside, rivulets and ponds and growing to a height of 20-30 m above ground level.

Botany

The tree is large about 60-80 feet in height, evergreen with a spreading crown and having drooping branches, new leaves appear in hot season (Feburary to April). Leaves of Arjuna are simple, often crenulations, borne subopposite, shortly acute or obtuse at the apex, coriaceous and oblong or elliptic. Their upper face is pale or dark green and the lower face is pale brown. The tree bears white sessile bisexual flowers in short auxiliary spikes or in a terminal panicle arrangement. Fruits of Arjuna are drupe, ovoid, fibrous-woody and smooth-skinned with five hard wings or angles which are oblique and curved upwards. Stem bark is simple, smooth and pinkish-gray in color in external view. An internal view, the bark is soft and reddish in color.

Bioactive Components

The chemical constituents of Arjuna present in root bark, stem bark, leaves, seeds and fruits. Root contains triterpenoids and glycosides, fruit contains triterpenoids and flavonoids, Leaves and seeds contain flavonoid and glycosides. But bark is considered most important constituent from medicinal point because it contains flavonoids, glycosides, polyphenols, tannins, triterpenoids, saponins, sterols and minerals such as calcium, magnesium, zinc, copper, amino acids also (Kapoor et al., 2014). Triterpenoids isolated from its bark are mainly arjunin, arjunetin, arjunic acid, arjugenin. Flavonoids mainly (arjunolone, flavones, bicalein, quercetin, kempferol and pelorgonidin) are detected from its bark.Various constituent of tannins are found in bark of T. arjuna. The constituent are Pyrocatechols, Punicallin, Castalagin, Casuariin, Punicalagin, Terchebulin, Terflavin C. Bark had 34% ash content consiting entirely of pure calcium carbonate. Aqueous extract of T. arjuna is reported to have 23% calcium salts and 16% tannins (Ramesh & Dhanraj, 2015) (Rasheed et al., 2013).

Health Benefits

Among various medicinal plants Terminalia species are known for their potential uses. Bark of Terminalia arjuna contains triterpenoids, tannins, phenolic acids, glycosides, antioxidants, magnesium, copper and zinc salts. Presence of these compounds plays an important role in curing cardiac diseases, cancer treatment, urinary tract infections, lung diseases and edema. In Ayurveda Arjuna bark powder is used as a cardio tonic, indigestion and bleeding disorders. Arjuna helps in maintaining the cholesterol level at the normal rate. In rural areas bark powder of Arjuna is used for snake bite and scorpion sting. Leaf juice of Arjuna is used to cure dysentery and ear ache. Regular therapy with Terminalia arjuna bark powder leads to significant regression endothelial abnormalities among smokers. T. arjuna based phytochemicals can be used on daily bases as tonic to maintain the healthy cardiovascular system because it is considered as one of the best heart tonic (Dwivedi, 2007) (Seth et al., 2013).

Nutritional Value

The bark of T. arjuna contains large amount of various minerals and trace elements such as magnesium (4000 mg/g), calcium (3133 mg/g), zinc (119 mg/g) and copper (19 mg/g). It contains some amino acids such as tryptophan, tyrosine, histidine and cysteine (Yadav et al., 2013).

Indian Gooseberry (Phyllanthus emblica)

Euphorbiaceae

The most common names of Indian gooseberry is Amalaka (Sanskrit), Adiphala (Hindi), Amla (Marathi), Amlaki (Bengali), Nelli (Tamil), Amalakam (Telugu), Ambala (Gujrati).

Distribution

Indian gooseberry is found through out tropical and subtropical India, Sri Lanka and Malaca. It is abundant in deciduous forests of Madhya Pradesh and Darjeeling, Sikkim and Kashmir. It is also widely cultivated.

Bioactive Components

Amla fruit contains a significant amount of vitamin C. Amla fruit is good source of cytokinin like substances identified as zeatin, zeatin riboside and zeatin nucleotide.

The seeds of Amla fruit yield brownish yellow 16% fixed oil. It also contains tannins like glucogallia, corilagin, chebulagic acid and 3,6-digalloyl glucose. Root of Amla fruit yields ellagic acid, lupeol, quercetin and β- sitosterol (Thakur et al., 1989). The fruit is diuretic, laxative, carminative, stomachic, astringent, antidiarrhoeal, antihaemorrhagic and antianaemic.

Health Benefits

Indian gooseberry or emblic myrobalan is a medium sized tree the fruit of which is used in many Ayurvedic preparations since ancient time. It is useful in treating various diseases like haemorrhage, leucorrhaea, menorrhagia, diarrhoea and dysentery. It is reported that the combination of Amla and iron is useful for treating the various diseases like anaemia, jaundice and dyspepsia. Sanjivani pills are also available which is also made with other ingredients for use in typhoid, snake-bite and cholera. The green fruits are made into pickles and preserves to stimulate appetite. Seed is used for treating various diseases like asthma, bronchitis and biliousness. The combination of tender shoots of butter milk cures indigestion and diarrhoea. Leaves are also useful in conjunctivitis, inflammation, dyspepsia and dysentery. The bark has been used for various ailments including gonorrhoea, jaundice, diarrhoea and myalgia. The root bark is astringent and is useful in ulcerative stomatitis and gastrohelcosis. The anaemia, jaundice, heart complaints, and cold can be prevented by liquor fermented prepared from fruits of Indian gooseberry.

Nutritional Value

The fruit is a very rich source of Vitamin C (600mg/100g) and is used in preserves as a nutritive tonic in general weakness (Dey, 1980).

Moringa oleifera (Sohanjna)

Moringaceae

Distribution

The plant is widely disributed in western and sub- Himalayan tracts, India, Pakistan, Asia Minor, Africa and Arabia (Somali et al., 1984; Mughal et al., 1999) is now distributed in the Philippines, Cambodia, Central America, North and South America and the Caribbean Islands (Morton, 1991).

Botany

The tree ranges in height from 5 to 10 m (Morton, 1991). It is reported that it is found in wild and cultivated throughout the plains, especially in hedges and in house yards, thrives best under the tropical insular climate, and is plentiful near the sandy beds of rivers and streams (The Wealth of India, 1962; Qaiser, 1973). It can grow well in the humid tropics or hot dry lands, can survive destitute soils, and is little affected by drought (Morton, 1991). It tolerates a wide range of rainfall with minimum annual rainfall requirements estimated at 250 mm and maximum at over 3000 mm and a pH of 5.0–9.0 (Palada and Changl, 2003)(Anwar et al., 2007).

Bioactive Components

The whole gum extrudate contain L-rhamnose, galactose, glucuronic acid, and L- rhamnose, mannose and xylose. The stem bark also contain two alkaloids (moringine and moringinine), octacosanoic acid, Vanillin, β- sitosterol, β-sitistenone etc. (kerharo, 1969 & Faizi et al., 1994). Flower contains glucose, sucrose, some amno acids, ash, alkaloids, flavonoids etc. Moringa leaves contain flavonoids, phenolics, ascorbic acid and carotenoids. β- sitosterol, calcium , iron, copper are also present. Leaves are source of protein and contain essential amino acids such as methionine, cystine, tryptophan and lysine and some vitamins also such as (vitamins A, B qand C, α-tocopherol, riboflavin, nicotinic acid, folic acid, pyridoxine, β-carotene etc. Seed oil contains fatty acids (oleic acids), sterols (campesterol, stigmasterol, β- sitosterol, clerosterol) and Tocopherols (α-,γ- & δ-) also.

Health Benefits

Various parts of this plant have been used in treatment of various diseases such as the leaves, roots, seed, bark, fruit, flowers and immature pods act as cardiac and circulatory stimulants, possess antitumor, antioxidant, antipyretic, antiinflammatory, antiulcer, diuretic, antihypertensive, cholesterol lowering, antidiabetic, hepatoprotective, antibacterial and antifungal activities.

Asparagus (Asparagus racemosus)

Liliaceae

The most common names of Asparagus is Satavari (Sanskrit), (Hindi), (Malyalam), Shatamuli (Bengali), Ammaikodi, Kilwari (Tamil), Kan: Aheruballi, Pilligadalu, Philithaga (Telugu), Manajolo (Orrissa).

Distribution

The plant is found wild in tropical and subtropical India including Andaman and Nicobar Islands. It is distributed from mean sea level upto 1500m in the Himalayas from Kashmir eastwards. The crop is cultivated in Kerala, Tamil Nadu, Andhra Predesh and northern states in India. However, most of the requirement of the industry is met through wild collections from forests. It is also grown in gardens. (Alok et al., 2013)

Botany

Satavari, Asparagus racemosus Willd. belongs to the lily family, Liliaceae. Asparagus adscendens Roxb., A. filicinus Lam., A. gonoclados Baker, A. officinalis Linn. and A. sarmentosus Willd. are the other important medicina l plant species of the genus. A. racemosus Willd. is an armed climbing undershrub with woody terete stems and recurved or rarely straight spines. The tuberous succulent roots are 30cm to 100cm or more in length, fascicled at the stem base, smooth tapering at both ends. Young stems are very delicate, brittle and smooth. Leaves are reduced to minute chaffy scales and spines; cladodes triquetrous, curved in tufts of 2-6. Flowers are white fragrant in simple or branched recemes 39on the naked nodes of the main shoots or in the axils of the thorns. Fruits are globular or obscurely 3-lobed, pulpy berries, on ripening purplish black in color; seeds with hard and brittle testa.

Bioactive Components

The major active constituents of Asparagus are steroidal saponins named as shatavarin I and shatavarin IV which are present in the roots. Shatavarins are the glycoside of sarsasapogenin which are generally occurring in two types of skeletons furostanols and spirostanols rhamnose. 8-methoxy-5,6,4’-trihydroxyisoflavone a new isoflavone was isolated by roots of A. racemosus by Saxena et al., 2000 (Aterya 1999).

Health Benefits

The phyto-estrogenic plant is used in Ayurveda because of its immuno-modulatory effects. It exhibit immuno-protective effect in chemotherapy. Ethanolic leaf extract shows anti-inflammatory effect18. It prevents diethylnitrosamine induced hepato-carcinogenesis2. The roots are used to treat inflammations, nephropathy, hepatopathy and tumours9. Asparagamine A, an alkaloid was isolated from root119. The roots extract has anti-oxidant activity60. Polysaccharides were found to be responsible to increase Natural Killer (NK) cell activity and thus also involved in rejuvenating immune system135 (Subramanyam and Immanuel 2016).

Nutritional Value

It is reported that Asparagus roots contain protein 22%, fat 6.2%, Carbohydrate 3.2%, Vitamin B 0.36%, Vitamin C 0.04% and traces of Vitamin A (Joy et al., 1998).