Figure 2. Various sources of plant-based Himalayan anthocyanin.
4.1. Berberis asiatica
With more than 500 species found worldwide, the genus Berberis is widely recognized for its therapeutic potential
[14].
Berberis asiatica is the most widely distributed species in the Western Himalayas and Northeast India. It is found in Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Arunachal Pradesh, and Assam.
Morphological aspects: It is an evergreen shrub with a height of 1.2–1.8 m and the stem is up to 10 cm in diameter. It has a rough, furrowed, and corky bark. Twigs are yellowish with a smooth surface. Leaves are dark green, oblong, elliptic, and usually have large distant spinous teeth. The size of the leaves is 2.5–6.3 by 1.3–3.8 cm. Prominent primary and secondary pale reticulate venation above and glaucous beneath can be observed. Petiole is usually absent but sometimes visible up to 10 mm. Simple racemose type of inflorescence which is 3 cm long. Pedicels are 4–19 mm long, slender, often glaucous. This plant yields fruits that are 7–10 mm long, ovoid, and dark black in color
[15].
Functional and therapeutic roles: The root is widely utilized in many indigenous therapeutic practices to treat a wide range of health problems such as rheumatism, diabetes, jaundice, gastric disorders, skin conditions, malarial fever, and as a tonic, among others. The presence of phenols in this plant is thought to be responsible for its wide range of health-promoting properties. These phenols provide antioxidant action through a variety of mechanisms, including the removal of free radicals, metal chelation, hydrogen donors, and gene expression alterations
[16]. The fruits are eaten raw and taste juicy with an acidic flavor. Traditionally, these fruits are provided to children as mild laxatives and the juice may be helpful in dental ailments. The species is employed in pharmacological, nutraceutical, and cosmetic products
[17].
Phytochemical aspects: The
Berberis asiatica plant is a reservoir of various bioactive chemical compounds such as phenolics, alkaloids, flavonoids, anthocyanins, tannins, vitamins, and minerals
[18]. As per physicochemical investigations, it was revealed that berberine, an alkaloid found in the plant was 2.4%, tannins 1.73%, total ash 2.650%, starch 16.444%, acid insoluble ash 0.266%, and alcohol soluble extractive 11.833%.
[15]. Berberine is the plant’s main alkaloid, it is a quaternary ammonium salt that comes under the protoberberine class of isoquinoline alkaloids. It is known for its biological activity against many chronic diseases
[19].
Anthocyanins: The anthocyanin content expressed as mg of cyanidin-3-glucoside equivalents (CGE) per g of fresh weight (mg CGE/g fw) in these fruits were found to be 24.59 mg/100 g fw
[20]. To date, there are very limited studies available on the anthocyanin composition of the
Berberis asiatica plant.
4.2. Morus alba
The Genus,
Morus (Mulberry) is a genus of flowering plants with approximately 150 species of which
Morus alba L. is the most important
[21]. It is a plant with significant economic value that is extensively cultivated in Centra, East, and South Asia for sericulture.
M. alba species are thought to have evolved on the low Himalayan slopes that border China and India
[22]. With around 626,000 hectares of land under Mulberry cultivation, China comes first in terms of Mulberry production, followed by India at 280,000 hectares of land under cultivation
[23].
Morphological aspects: It is a deciduous tree of medium-sized found in China and hilly areas of the Himalayas at an elevation of up to 3300 m. The tree grows up to a height of 20–30 m and a girth of 1.8 m. It can be reduced to a low-growing bush to make it easier to gather leaves and fruits. Dark grey-brown lenticels run horizontally down the bark. The petioles are long and thin, the leaves are alternating, glossy green collects at the apex, and the margins are notched or toothed at the end (serrated). The leaves’ lengths range from 5.0 to 7.5 cm, and they have a wide range of shapes. It has been observed that the tress are dioecious in temperate and sub-tropical climatic zones but in some cases, they change from one sex to another. Male and female catkins are made up of discrete, pendulous, greenish blooms. The characteristic feature of the mulberry fruit is that it has multiple drupes formed by each flower to make a sorosis. The weight of the fruit is approximately 3.49 g with a moisture content of nearly 71.5%. The color of the fruit varies with its maturity. In the early stages, the color is green which turns orange to red in the intermediate stage. When it is fully matured, the color is purplish black
[24][25][26].
Functional and therapeutic roles: Traditionally, it is used in kidney disorders and purification, curing weakness, anemia, fatigue, and early graying of hair. Due to its calming properties, the plant is beneficial in monitoring illness according to Chinese traditional medicine. It functions by reducing the symptoms of sore throat, cough, and fever, protecting the liver, enhancing vision, helping in urination, and stabilizing blood pressure
[27]. The
Morus alba plant has been also known to show excellent therapeutic activity against diabetes mellitus due to the presence of a special alkaloid 1-deoxynojirimycin (DNJ)
[28].
Phytochemical aspects: It has been revealed that
Morus alba majorly contains alkaloids (Calystegins B2, C1, and 1-Deoxynojirimycin), terpenoids (betulinic acid, ursolic acid, and uvaol), flavonoids (astragalin, atalantoflavone, anthocyanins and chalcones such as Morachalcones B, C), phenolic acids, stilbenoids, and coumarins
[24]. These bioactive components make it highly beneficial for multifunctional applications.
Anthocyanins: The content of anthocyanin in the fruit was found to be 21.97 mg CGE/100 g fw
[20].
4.3. Ficus palmata
The common wild fig (
Ficus palmata) grows on hot, dry slopes of Northwest hills, on clay-loam soils in the states of Uttarakhand, Punjab, and Kashmir in India, Nepal, the Arabian Peninsula, Ethiopia, Somalia, Sudan, Pakistan, Afghanistan, Iran, and Southern parts of Egypt
[29].
Morphological aspects: It is a deciduous tree with an average height of 6 to 10 m. Leaves are broad, ovate, alternate, and membranous with a size of around 12.93 cm long and 14.16 cm broad. It has small flowers which are unisexual, monoecious, and greenish-white in color. It yields deep violet to black colored fruits having a diameter of approximately 2.5 cm and measuring 6 g in weight. Both fruit and seeds are edible. Due to the presence of white latex below the fruit’s outer covering, the fruit may have a little acidic or bitter taste and smell (astringency)
[30].
Functional and therapeutic roles: In the Uttarakhand region of the Indian Himalayas, fruits of
Ficus palmata are well-known for their traditional use in treating ailments such as stomach ulcers, digestive problems, bronchitis, eczemas, hemorrhoids, and as a diuretic. In traditional medicine,
Ficus palmata is commonly used for its digestive, hypoglycemic, insulinase, anti-tumor, anti-ulcer, antidiabetic, lipid-lowering, anti-carcinogenic, antifungal, and inflammation-reducing properties
[31]. It can also be used as a dietary component in the treatment of constipation and ailments related to the gallbladder and respiratory system. The plant’s sap is often administered as the medication for warts
[30].
Phytochemical aspects: Numerous phytoconstituents, including alkaloids, steroids, lipids and fixed oils, flavonoids, tannins, proteins, and sugars, are found in the bark, root, and fruits. It is a promising source of flavonoids, polyphenolic compounds with powerful antioxidant qualities that aid in the prevention and treatment of a variety of oxidative stress-related disorders, including neurological and hepatic conditions
[32].
Anthocyanins: The anthocyanin content in the fruits was estimated to be 19.27 mg CGE/100 g fw
[20].
4.4. Berberis lycium
Berberis lycium is a native plant to the Himalayan mountains and is extensively dispersed in temperate and semi-temperate climatic zones of India, Nepal, Bangladesh, and Pakistan.
Morphological aspects: It has strong woody branches covered by thin, brittle bark. The plant is a small-sized, stiff deciduous shrub that can reach heights of 1.0 to 2.5 m. Leaves are 2.5 to 7.5 by 8.18 mm in size and pale green in color. The plant’s stem has a few noticeable spinous teeth that are alternately placed. The inflorescence is composed of corymbose racemes, which have 11–16 flowers per cluster. Insects pollinate flowers, which are often hermaphrodite, borne in axillary clusters, and pale yellow in color. The plant’s blooming and fruiting season lasts from March through July. The first two weeks of March mark the start of the flowering season, which lasts until April. In the second week of May, the fruit starts to ripen, and it does not fully mature until June. Fruits are incredibly nutrient-rich in the form of 8 mm long globose ovoid berries with bluish-purple color when they are fully mature
[33][34].
Functional and therapeutic role: Since the beginning of time, ancient societies of the Himalayan region of Jammu and Kashmir, and Himachal Pradesh have utilized these berries as a food source
[35]. The herb is employed in traditional medical practices to cure several ailments and disorders. People use the various parts of the plant, such as the leaves, stem, roots, fruits, and flowers, as food and medicines. The plant is well known for preventing diseases of the skin, eyes, and abdomen. Recent research work has revealed that it has good antimicrobial, antidiabetic properties
[36].
Phytochemical aspects: Berberine, palmatine, and jatrorrhizine are the major alkaloid found in this species with berberine being the most prominent one. It was discovered that the root extract of
B. lycium contained 80% dry weight of berberine and very small levels of other alkaloids
[37][38]. There are several important flavonoids and phenolic compounds present in this plant, such as chlorogenic acid, hydroxybenzoic acid, quercetin, rutin, and mandelic acid. Ascorbic acid, β-carotene, and anthocyanins are also found in the fruit in significant amounts
[39].
Anthocyanins: The
B. lycium fruit’s anthocyanin content was reported to be 20.58 mg CGE/100 g fw
[40]. Characterization of
Berberis lycium anthocyanins by LC-MS and UV spectral analysis revealed that there are a total of twelve anthocyanins in the purified extract, but among all the anthocyanins, delphinidin-3-glucoside (35.3%) and cyanidin-3-glucoside (47.2%) were the most prominent. The glycosides of cyanidin, pelargonidin, malvidin, and peonidin were the other ten anthocyanins that were also characterized. Overall, it was discovered that the species has a potential future for use in food systems
[41].
4.5. Myrica esculenta
In India, the genus Myrica is represented by
Myrica esculenta species
[42]. It is an evergreen dioecious small tree of Indian origin and is widely disseminated along the mid-Himachal Pradesh foothills track, which extends from Ravi eastward to Assam and includes the states of Sikkim, Manipur, Arunachal Pradesh, Uttaranchal, and the Khasi, Naga, Jaintia, and Lushai Hills of Meghalaya, all of which are located between 900 and 2100 m above sea level. It is also found in Singapore, China, Pakistan, Japan, Nepal, and the Malayan Islands
[43].
Morphological aspects: It is a medium to large woody tree with a trunk diameter of 92.5 cm and a height between 12 and 15 m. Most leaves are clustered at the ends of branches and are lanceolate with an entire or serrated edge, pale green on the underside, and dark green on the top side. While the inflorescence of staminate flowers is a compound raceme, the inflorescence of pistillate flowers is small, sessile, solitary, and bracteate; the sepals and petals are either absent or not visible; the catkin’s axillary length is 4.2 cm; it bears about 25 flowers in a thread-like fashion. The flowering season begins in February and lasts through the second week of April, however, the first week of March marked the peak flowering period. Fruits are drupe, red to dark brown in color, oval, and about 2–7 mm in diameter. Fruits taste sweet and sour
[44].
Functional and therapeutic roles: Local population use this traditional ayurveda plant in a variety of ways due to the diverse therapeutic benefits of the plant parts. Natural antioxidants included in
M. esculenta fruit are a significant source of protection against oxidative stress and certain degenerative illnesses
[45]. Research has demonstrated that flavonoids and phenolic acids found in the plant are responsible for its antioxidant potential. Analgesic, antiasthmatic, anticancer, antidepressant, antidiabetic, anti-inflammatory, chemopreventive, hepatoprotective, and wound healing effects are some of the pharmacological activities that have been reported recently
[46]. Moreover, they are non-toxic and have no harmful materials which makes them useful for versatile applications.
Phytochemical aspects:
Myrica esculenta plant has been discovered as a rich source of flavonoids, flavonols, and phenolic chemicals. Other bioactive components of the plant include alkaloids, glycosides, diarylheptanoids, ionones, steroids, saponins, triterpenoids, and volatile compounds.
[43][44]. Myricetin and quercetin are the major flavonoids whereas flavonoid glycosides such as Myricitrin (myricetin 3-O-rhamnoside) were also detected. Arjunolic Acid was the major saponin. Corchoionoside C; (6S,9R)-roseoside was the ionone
[47][48].
Anthocyanins: The fruit had an anthocyanin content of 7.17 mg CGE/100 g
[40]. The major anthocyanins detected were malvidin 3-(6″-acetylglucoside), cyanidin 3-O-(6″-acetylglucoside), delphinidin-3-O-arabinoside, and cyanidin-3.5-di-O-beta-D-glucoside
[49].
4.6. Duchesnea indica
Duchesnea indica, generally known as a mock strawberry/Indian strawberry, is a straggling herb belonging to the family Rosaceae
[50]. It is a perennial plant having widespread distribution in Asia, Europe, and America.
Morphological aspects: Stoloniferous species
Duchesnea indica (Andrews) Focke have bostryx-like cymose inflorescences with incredibly long petioles, yellow petals, terminal styles, anthers with two thecae, and achenes. It can be identified by its perennial habit, long, creeping flower stem, roots in nodes, basal leaves with three to seven lobes, and style that is shorter than or equal to the carpel
[51]. Ripened fruits are red, shining, spongy, and 1–2.5 cm in diameter. Achenes are small, ovoid, glabrous, and pitted
[52]. Its fruits are also used as a cooling agent, tonic, and in eye infections. This plant’s ash has long been used to cure burns and skin problems. Additionally, leaf water extract has been utilized as an anthelmintic
[53].
Functional and therapeutic role: For thousands of years, it is employed as a traditional herbal medicine in Asia, mostly to cure leprosy, congenital fever, and tissue inflammation. These days, it is clinically employed for cancer treatment or as a key component of formulae for Chinese herbal medicines used to treat cancers, particularly gynecological cancers. A recent report has shown that extracts of the
Duchesnea indica plant lowered the growth of SKOV-3 ovarian cancer cells by inducing apoptosis via the mitochondrial pathway and stopping cell cycle progression in the S phase
[54].
Phytochemical aspects: This plant has been found to contain a number of phenolic chemicals, such as flavonoids, ellagic acids, and phenolic acids. A total of 27 phenolic compounds have been reported in the species, and they fall into four categories: flavonols, ellagitannins, ellagic acid and its derivatives, hydroxybenzoic acid, and hydroxycinnamic acid. In addition to that, brevifolin carboxylate, caffeic acid, brevifolin, methyl brevifolin carboxylate, and kaempferol O-robinobioside were also reported
[55].
Anthocyanins: The anthocyanin content in its fruit was found to be 7.06 mg CGE/100 g
[40]. Another study found the total amount of anthocyanin on a cyanidin-3-rutinoside basis to be 205 mg/g of fresh stoned fruit, with cyanidin 3-O-rutinoside accounting for major composition
[56].
4.7. Lycium ruthencium
Genus Lycium has long been recognized as a source of nutrients and medications throughout Southeast Asia, specifically in China. This genus contains 97 species and 6 variations of perennial flowering plants belonging to the family Solanaceae, which are primarily found in South America, South Africa, China, and a few species in temperate Asia and Europe.
Lycium ruthencium, locally known as “Khizer”, is a plant that is extensively distributed in the Trans-Himalayan Ladakh region at a height of 3063–3196 m above mean sea level. It grows primarily on the sides of highways in the Nubra valley’s Hunder and Udmaru sections
[57].
Morphological aspects: It is a thorny, perennial shrub with a long lifespan that is a member of the Solanaceae family. It has small sessile leaves, zigzag-shaped stems, internodes with little thorns, and deep roots. It can reach a height of 2 m. It has pale purple funnel-shaped flowers which are hermaphrodite in nature. The shoots are short with a length of approximately 5–10 mm bearing one or two flowers. The fruits are 6–9 mm long, color ranges from black to purple berries commonly called goji berries. Seeds germinate in the late spring or early summer, while the bushes bloom in the months of June and July and bear fruit in the months of August and September
[58].
Functional and therapeutic roles: These berries are utilized in various herbal remedies as a medication or a coloring component in India
[59]. It has been reported that historically, the fruits have been used as treatments for a variety of illnesses, including menstruation-related problems, hypertension, urethral stones, tinea, furuncles, and blindness in camels in mountain communities, particularly in the Chinese and Tibetan medical systems
[60][61][62]. While using leaves as a diuretic to clear urine blockage
[63].
Phytochemical aspects: The primary chemical components that have been identified are alkaloids, phenolic acids, anthocyanins, pro-anthocyanidins, fatty acids, coumarins, polysaccharides, essential oils, carotenoids, and cinnamate derivates. The major bioactive chemical components of
L. ruthenicum Murr are anthocyanins, which belong to the flavonoids class of phytochemicals and are believed to be mostly responsible for the alleged therapeutic benefits
[64].
Anthocyanins: The anthocyanin content in the fruits was estimated to be 9.28 ± 1.19 to 82.58 ± 0.95 mg CGE per g of dry weight (C3GE/g DW)
[58].
4.8. Gaultheria trichophylla
Gaultheria trichophylla (family-Ericaceae), is a highly valuable wild Himalayan plant. It is a decumbent, aromatic shrub that forms a mat at higher elevations, between 3200 and 5300 m above sea level. Its distribution is restricted to the Trans-Himalayan regions of Pakistan, China, India, and Nepal
[65]. The Himalayas are home to this species; hence it is often called ‘Himalayan snowberry’. It produces blueberries that the local community uses as a source of refreshing food. Dried branches are used by people in the Trans Himalaya region of Uttarakhand to make incense fire during religious ceremonies
[66].
Morphological aspects: It is a small herb with a wiry, slender, and dark brown stem of length 4–7 cm. Leaves are oval, with log setae with a dark green upper surface and whitish green lower surface. Leaves are 4–8 mm long with a diameter of 2.3–4 mm. The plant yields oval blue fruits with a length of about 1.4 cm and a diameter of 1 cm
[67].
Functional and therapeutic roles:
Gaultheria trichophylla fruits have a long history of usage in traditional medical practices, particularly for the treatment of pain and inflammation
[67][68].
Phytochemical aspects:
Gaultheria trichophylla’s wild edible fruits have been shown to be extremely nutrient-dense and abundant in polyphenols and antioxidants. The results of the phytochemical analysis show that fruits from the Milam bugyal region have higher levels of total phenolic compounds at 3.71 mg gallic acid equivalents per g of fresh weight (GAE/g FW), flavonoids 1.75 mg quercetin equivalent per g of fresh weight (QE/g FW), tannins 2.62 mg tannic acid equivalent per g fresh weight (TAE/g FW), and flavonols 1.03 mg catechin equivalents per g fresh weight (CE/g FW)
[69]. For this plant, so far, no potential studies of its anthocyanin profiling and composition were reported. So, further research needs to be conducted in this area.
4.9. Species of Genus Begonia
With 1870 species, the pantropical genus Begonia is the sixth-largest genus of flowering plants.
[70]. Begonia is also a significant source of phytochemicals due to its diverse range of taxa and a high degree of morphological variety. Begonia plants have a high content of phenolics such as total phenolic and flavonoids. Begonia is also one of the largest genera of vascular plants, encompassing approximately 1800 species. Additionally, numerous cultivars are grown specifically for their ornamental value as flowers. The northeastern region of India, along with Myanmar, is a significant area for the genus Begonia. Numerous species have been recently described from this region, and many more are currently being studied and evaluated (Taram et al., 2023). Earlier authors have reported the presence of flavonoids in Begonia species. Five flavonols and two flavones were isolated from the leaves of
B. erythrophylla. These phytochemicals were identified as 3-methyl ethers of kaempferol, 3-methyl ethers of quercetin, quercetin, and its 3-O-rutinoside and 3-O-rhamnoside, and 7-O-glycoside of luteolin.
[71]. Additionally, numerous cultivars are grown specifically for their ornamental value as flowers. The red-colored leaves of
B. xanthina,
B. palmata, and
B. megaptera were found to contain a high amount of anthocyanin, which can be used to create biobased color. The amount of anthocyanin in
B. xanthina,
B. palmata, and
B. megaptera was found to be 88.08 mg, 68.26 mg, and 20.08 mg CGE/g fw
[72][73]. It is important to conduct comprehensive phytochemical surveys of more wild Begonia species to further explore their anthocyanin content and composition.
4.10. Fragaria nubicola
Fragaria nubicola, sometimes known as Himalayan strawberry, is a perennial herb that is typically found in shady areas near the edges of forests between the altitudes of 2100 and 4000 m above sea level
[74]. Native to the Himalayas, this species is found in Afghanistan, India, Nepal, Tibet, Myanmar, Pakistan, South-Western China, and Bhutan.
Morphological aspects: This plant is a small herb, stoloniferous, with a height of 2–4 cm. Leaves are trifoliate, lateral leaflets are in the form of distinctly petiolate, elliptic, or obovate. Petioles and stems are resisted from spreading. One to numerous flowers can be seen in the inflorescence. The flowering season is from May to August. Flowers are large, sometimes more than 2.5 cm in diameter
[75]. Its edible fruits have an anthocyanin-tinged monopodial stolon and are broadly ovoid or compressed ovoid in shape, measuring 5.5–16.5 mm long by 7.0–17.5 mm in diameter
[76].
Therapeutic roles: Fresh fruits of the plant in combination with dried leaves of
Potentilla peduncularis and dried roots of
Geumelatum elatum are made into a fine paste and usually taken orally to treat fever and rhinitis
[77]. Tibetan doctors utilize it to treat neuropsychiatric conditions and nerve inflammation
[78]. The unripe fruit is chewed to treat acne, while plant juice is applied to ease heavy menstrual bleeding
[79].
Phytochemical aspects: The plant is abundant in phenolic compounds and ellagic acid, both of which are recognized as powerful antioxidants
[80]. Phenolics (1.18–3.08), proanthocyanidins (0.53–1.01), flavonoids (0.99–2.63), flavonols (0.95–1.80), and tannins (0.73–1.42) mg per g gallic acid equivalent (GAE) are the various phytochemicals identified in this plant
[81].
Anthocyanins: The total monomeric anthocyanins in the berries were found to be 1.46 mg CGE/g fw
[74].
5. Conclusions
Anthocyanins are natural colorants that are gaining popularity due to their diverse color palette as well as safe and favorable health effects. Anthocyanins have a high potential for application in food, pharmaceutical, cosmetic, and related industries. Anthocyanin can be isolated and purified from an endless number of natural resources, but the Himalayan sources of anthocyanin are relatively undiscovered. Most anthocyanin research is currently focused on identifying different sources of anthocyanin, as well as purification and extraction. Natural food colorants are recently being preferred by consumers since they have fewer adverse effects than synthetic/artificial substances. Himalayan plants are rich sources of anthocyanins.