Himalayan Aromatic Medicinal Plants: A Review of their Ethnopharmacology, Volatile Phytochemistry, and Biological Activities

Aromatic plants have played key roles in the lives of tribal peoples living in the Himalaya by providing products for both food and medicine. This review presents a summary of aromatic medicinal plants from the Indian Himalaya, Nepal, and Bhutan, focusing on plant species for which volatile compositions have been described. The review summarizes 116 aromatic plant species distributed over 26 families.


Introduction
The Himalya Center of Plant Diversity [1] is a narrow band of biodiversity lying on the southern margin of the Himalayas, the world's highest mountain range with elevations exceeding 8000 m. The plant diversity of this region is defined by the monsoonal rains, up to 10,000 mm rainfall, concentrated in the summer, altitudinal zonation, consisting of tropical lowland rainforests, 100-1200 m asl, up to alpine meadows, 4800-5500 m asl. Hara and co-workers have estimated there to be around 6000 species of higher plants in Nepal, including 303 species endemic to Nepal and 1957 species restricted to the Himalayan range [2][3][4]. The Indian Himalaya is home to more than 8000 species of vascular plants [5] of which 1748 are known for their medicinal properties [6].  Table 1 summarizes the aromatic medicinal plants of the Himalayan region and includes ethnopharmacological uses of the plants, essential oil compositions, and any biological activities of the essential oils. In addition, we describe in more detail some important genera and species used as aromatic medicinal plants in this region.  Table 1 summarizes the aromatic medicinal plants of the Himalayan region and includes ethnopharmacological uses of the plants, essential oil compositions, and any biological activities of the essential oils. In addition, we describe in more detail some important genera and species used as aromatic medicinal plants in this region. Table 1. Ethnopharmacology, biological activities, and essential oil compositions of Himalayan aromatic medicinal plants.

Plant Species (Family) Ethnopharmacology Bioactivity of Himalayan Essential Oil Major Essential Oil Components
Abies pindrow (Royle ex D. Don) Royle (Pinaceae) The tribal people of the Sewa River area of Jammu and Kashmir, India, use the leaves to treat bronchitis and asthma; the inner bark is taken for constipation; and the cones are used as a diuretic and purgative [7].
None reported for Himalayan essential oils.
The tribal people of the Sewa River area of Jammu and Kashmir, India, use an infusion of plant as a diuretic; vapors from leaves and flowers are used to treat colds and fever; tea from leaves is given to treat cold [7].
None reported for Himalayan essential oils.
The tribal people of the Sewa River area of Jammu and Kashmir, India, apply the leaf paste to wounds [7]. The people of Baitadi and Darchula districts of far-western Nepal use the juice of the rhizome as an anthelmintic; the juice is given for stomachache [10]. In the Rasuwa District of central Nepal [11], and the Seti River area of western Nepal [12], the rhizome is chewed to treat coughs, colds, and sore throat. In the Jutpani Village, Chitwan district of central Nepal, the rhizome paste is applied to wounds and swelling to reduce inflammation [13].
None reported for Himalayan essential oils.

Artemisia roxburghiana Besser (Asteraceae)
In Garhwal Himalaya (Uttarakhand), India, the whole plant extract is used as a tonic and to relieve fever; the plant extract is rubbed on the skin to treat allergic reactions [49]. In the western Himalaya of northern Pakistan, the whole plant extract is used for fever; the powder of whole plant taken for intestinal worms [50].
None reported for Himalayan essential oils.
Artemisia scoparia Waldst. and Kit. (Asteraceae) The tribal people of the Sewa River area of Jammu and Kashmir, India, use the leaves to treat stomach problems, intestinal worms, indigestion; the leaf powder (mixed with oil) is massaged on joints to releave pain [7]. The Bhots people of Spiti Valley, Himachal Pradesh, India, use a paste made from the leaves to treat earache [49]. Inhabitants of Nanda Devi National Park (Uttarakhand), India apply a paste of the leaves to cuts and wounds [67].
In Nepal, crushed leaves are used to stop nosebleeds; leaves are chewed for mouth ulcers [70]. In the western Himalaya of northern Pakistan, the leaf extract is used for fever [50].
Inhabitants of the Sewa River area of Jammu and Kashmir, India, use the shoots to repel insects; the root used to relieve toothache [7]. People in the Mornaula Reserve Forest of Kumaun (Uttarakhand), India, use roots of the plant to kill fleas, lice, and insects [22].
None reported from Himalayan essential oils.
Local people in the Rasuwa district of central Nepal [11] and the Tanahun district of western Nepal [12] take a paste made from the plant for stomach problems. In the Humla district of western Nepal, the juice of the leaves and flowers is applied externally on skin diseases, cuts, and wounds; the juice is taken orally to treat diarrhea [44]. In far western Nepal, the local people apply the leaf juice to control bleeding [30]. In the Parvati valley, Himachal Pradesh, India, a leaf paste is used on tumors; leaf powder used on wounds and sores [56].
None reported for Himalayan essential oils.

Carum carvi L. (Apiaceae)
In far western Nepal, fruits are applied to treat swelling of breast and testicles [30]. In northwestern Nepal, the fruits are chewed to cure stomach problems, fever, swellings, cough, cold, and to kill intestinal worms [44].
None reported for Himalayan essential oils. The people of Baitadi and Darchula districts of far-western Nepal use the leaf juice to treat urinary problems and cuts and wounds [10].
Tribal people in the Seti River area of western Nepal use the juice from the whole plant to treat fever or urinary tract infections [12]. People in the Jutpani Village, Chitwan district of central Nepal, chew the leaves and stems to relieve headache [13]. People in Kumaun, Uttarakhand, use the leaves used to prepare a brain tonic [19]. Tribal people in the Mornaula Reserve Forest of Kumoun, west Himalaya, India, prepare a tonic made from the whole plant to use as an anthelmintic, to treat dysentery, cholera, diarrhea [22].
None reported for Himalayan essential oils, but an essential oil sample from South Africa has shown antibacterial activity (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Shigella sonnei) [86].

Chaerophyllum villosum
Wall. ex DC. (Apiaceae) In the Lahaul-Spiti district of Himachal Pradesh, the people consume the seeds and leaves to cure stomach pain [88], colds and coughs [89].
Chenopodium ambrosioides L. (Amaranthaceae) * People in the Sudhan Gali area of Pakistan, consider an infusion of herb to be carminative, diaphoretic, and emmenagogue; it is given in cough, pulmonary obstruction, and amenorrhea and is recommended for the expulsion of the dead fetus [93].
None reported for Himalayan essential oils, but an ascaridole-rich essential oil sample from Cuba has shown antiparasitic activity (Leishmania amazonensis) [94].
None reported for Himalayan essential oils. In the Dolakha district, Nepal, a paste of the roots is used to treat wounds and toothache [102]. In northern India, the leaves are used as a stimulant, carminative, and to treat coughs and colds [103].
In western Nepal, the rhizome paste is applied externally for bruises, pains, injuries, paralysis [30,44]. In eastern Nepal, the Meche people use the dried rhizome powder as an antiseptic in cuts and wounds, and to check bleeding [109].
None reported for Himalayan essential oils.
In far western Nepal, the plant paste used for headache, body ache, itching [10]. In Nepal, the plant is crushed, decocted, and the liquid taken as a treatment for jaundice [12,42,44].
Elsholtzia flava (Benth.) Benth. (Lamiaceae) In communities of Kathmandu district, Nepal, the leaf juice used to treat insect bites [42]. In the Parvati Valley, the flowers are used to treat skin diseases, diarrhea, and stomachache [126]. The seeds are also used as a curry [127] None reported for Himalayan plants.
None reported for Himalayan essential oils.
In Kashmir, a leaf paste is applied to wounds [133]. None reported for Himalayan essential oils.

Gualtheria fragrantissima
Wall. (Ericaceae) In Newar community of Kathmandu, Nepal, a liquid made from the whole plant is used to treat rheumatism [42].
In Nepal, a decoction of the rhizome is taken for coughs and colds [42]. In Nepal, a decoction of the root is used to treat epilepsy and rheumatism [42].

Jasminum mesnyi
Hance (Oleaceae) In villages of Himachal Pradesh, India, the leaves are used to treat diabetes, central nervous system disorders, gastric disturbance, anorexia, oral sores, nocturnal emission, and for muscular pain [141].
In Nepal, a decoction of the bark is used for scabies, allergies, toothaches [10], and as an anthelmintic [83]; the nut juice is taken as a tonic [11]. In Uttarakhand a decoction of the bark is used as mouthwash [19]; twigs used as toothbrush for treatment of toothache [67].

Juniperus indica Bertol. (Cupressaceae)
In Nepal, the leaves and berries are used to treat fevers, coughs, skin diseases; also used as incense and flavoring [150]. A paste of the leaves and berries applied externally to treat skin diseases [44].
None reported for Himalayan essential oils.

Juniperus recurva
Buch.-Ham. ex D. Don (Cupressaceae) Local people in the Rasuwa district of central Nepal use the plant to treat fever, headache, coughs, and colds [11]. In the Humla district of northwestern Nepal, a paste of the leaves and berries is applied externally to treat skin diseases [44]. In the Nubra valley (Jammu and Kashmir), a leaf decoction is used to reduce fever [7].
None reported for Himalayan essential oils.
None reported for Himalayan essential oils.

Plant Species (Family) Ethnopharmacology Bioactivity of Himalayan Essential Oil Major Essential Oil Components
Lantana camara L.
(Verbenaceae) * Native to the Neotropics; decoction taken for rheumatism, diuretic, snakebite, fever, colds; crushed leaves used externally on wounds, ulcers, skin sores [161]. The tribal people of the Sewa River area of Jammu and Kashmir, India, prepare a decoction of the plant to treat tetanus, theumatism, and malaria [7].
In Nepal, the leaf is used externally for skin wounds and infections [163].
Leaf oil from Nepal not antimicrobial [164].
Leucas aspera (Willd.) Link (Lamiaceae) In India, a decoction of the plant is taken as an antihelmintic, for headache, asthma, bronchitis; extract taken orally for scabies psoriasis, snake bite; plant used externally as insect repellent [166]; the leaf extract applied to releave toothache [167].
In Nepal, the fruits are taken for diarrhea [11]; a paste of the fruit is applied externally to treat boils and scabies [44].
In Newar community of Kathmandu, Nepal, the leaves and branches are used as a spice and flavorant [42].
None reported for Himalayan essential oils, but a leaf oil sample from Banaras Hindu University showed broad spectrum antifungal activity against 14 storage fungi, and insecticidal activitity against Callosobruchus chinensis [179].
Mentha longifolia (L.) Huds. (Lamiaceae) In Jammu and Kashmir, India, the essential oil used for flavorings confectionery [7]; a tea from the leaves is taken as a cooling medicine [182]. In Uttarakhand, India, the herb used for gastrointestinal disorders, cough, colds, and chronic fever [19]. In the Karnali Zone, Nepal, the leaf juice is applied to cuts and wounds as an antiseptic; a leaf decoction is taken to relieve sore throat [83].
None reported for Himalayan essential oils.
In Uttarakhand, India, the crushed leaves are used to treat nausea and vomiting [19,186]. Traditional practitioners in Darjeeling, West Bengal, India, use a paste from the whole plant for bodyache [57].  [180].
The people of Baitadi and Darchula districts of far-western Nepal use the plant to treat asthma and urinary complaints [10]. In the Humla district of western Nepal, the plant is chewed for diarrhea and stomachache [44].
Aerial parts oil from Uttarakhand: carvone (76.7%), limonene (9.6%) [189]. In the Parvati valley, Himachal Pradesh, India, the root powder is applied as a poultice on boils and wounds [56]. In the Chamoli district of Uttarakhand, the people use the fresh leaves to treat boils, cuts and wounds [190]. Indigenous people of Kavrepalanchowk district of central Nepal use the root juice to treat dysentery and diarrhea [191].
In far western Nepal, the leaves used as anthelmintic and in blood disorders [10]. In Uttarakhand, a leaf paste applied to skin diseases [19]. In the Kangra district of Himachal Pradesh, a paste of the branch is applied as a poultice on skin infections [196].
None reported for Himalayan essential oils.

Nardostachys grandiflora DC. (Caprifoliaceae)
In far-western Nepal, the rhizome oil is used for headaches; the rhizome is used in epilepsy and mental weakness [10]. In central Nepal, the juice from the whole plant is taken to treat headache and high altitude sickness [11]; the root paste is applied externally to tumors [13]. In northwestern Nepal, a powder or infusion of rhizomes are taken for cough, cold, fever, food poisoning, stomach disorder, intestinal worms, normal headache, and headache from high altitude sickness; a paste is applied externally on wounds; a paste is also used for joint pains and cuts; a root decoction taken early in the morning is beleived to be tonic; the plant is also used as incense [44].
Neolitsea pallens (D. Don) Momiy. and H. Hara (Lauraceae) In the Parbat district of western Nepal, the juice of the fruit is applied externally to treat scabies and exzema [199].

Nepeta ciliaris Benth. (Lamiaceae)
Local people in the Kedarnath Wildlife Sanctuary of Uttarakhand use a decoction of the leaves to reduce fever [49]. None reported None reported Aerial parts essential oil from Uttarakhand, antimicrobial (Pseudomonas aeruginosa) [200].
In the Bhotiya tribal communities of Niti valley, Uttarakhand, India, a leaf decoction, mixed with honey, is used to treat tuberculosis [190].
In the Nubra valley [38] and the Leh-Ladakh region [202] of Kashmir, a decoction of the leaves is used to treat coughs, colds, and fever.
People of the Deosai Plateau of Pakistani Kashmir use the leaves of N. erecta to cure cough, cold, fever [205].

Nepeta eriostachys Benth. (Lamiaceae)
People in the Devikund, Bageshwar [206], and Sundardhunga valley [207], Uttrakhand, give an extract of the leaves for fever. The whole plant is used in the Kullu district of Himachal Pradesh for eye complaints [208].
None reported. None reported.

Nepeta floccosa Benth. (Lamiaceae)
People in the cold desert of Ladakh, Kashmir prepare a decoction of the leaves as a remedy for colds, coughs, and fever [202]. None reported. None reported.
In the Nubra valley of Kashmir, a decoction of the leaves is taken to treat diarrhea, pneumonia, and fever [38]. None reported. None reported.
In Pakistani Kashmir, a decoction of whole plant taken for sore throat, and as a cardiac tonic [207].
Aerial parts essential oil from Jammu and Kashmir: nepetalactone (71.8%) [210]. In Pakistani Kashmir, an infusion of seeds used to treat dysentery [211]. In the Naran valley, Khyber Pakhtunkhwa, Pakistan, powders of the dried plants used to treat colds, fevers, and headaches [212].
Local healers in the Baglund district, Nepal, recommend using the root juice for fever [215]. In Utturakhand, a leaf paste used to treat malaria [186].
In the Nubra valley of Kashmir, the whole plant is used for stomach disorders [38]. None reported. None reported.
Nyctanthes arbor-tristis L. (Oleaceae) In Nepal, a tea made from the leaves is used to reduce fever [42]. In Ayurvedic medicine, the plant is used as an anthelminthic, anti-pyretic, laxative, sedative, and to treat rheumatism and skin ailments [219].
Villagers in the Kali Gandaki waternshed area of Nepal use a decoction of seeds to treat urinary disorders; a leaf paste is used externally to treat skin diseases and fungal infections [81].
None reported for Himalayan plants.
The aromatic oil of O. vulgare is used as stimulant, rubefacient, and tonic [7]. People in the Parvati valley (Himachal Pradesh), India, apply a paste from the leaves to boils, ulcers, wounds, cuts, burns, and weeping eczema [56]. The plant extract is used by people living in the Nanda Devi National Park (Uttarakhand) to treat bronchitis, coughs, and colds [67]. Local inhabitants of the Kedarnath Wildlife Sanctuary, Uttarakhand, use the leaves to treat toothache and swelling [222]. Local people in the Garhwal Himalaya (Uttarakhand) apply a leaf paste for skin diseases, insect bites, and earache; a leaf decoction is taken for coughs and cold [223]; the powdered leaves are used to treat whooping cough in children [224]. Women in the Gurez Valley of Kashmir take a warm decoction of the plant to alleviate menstrual discomfort [225]. In the Humla district of northwestern Nepal, the dry or fresh plant is boiled with water, liquid is drunk to treat stomachache, diarrhea, dysentry, constipation, toothache, earache and rheumatism. It is also widely used as herbal tea [44].
The plant extract is used by people in the Nubra valley, Jammu and Kashmir, to treat coughs and headache [38].
In India, the tree is not used medicinally; the wood is used for fuel; the leaves are used for fodder; the fruit is edible [234,235].
In India, this tree is not used medicinally; it is used for firewood [235].

Persea odoratissima (Nees) Kosterm. (Lauraceae)
In Nepal, the tree is not used medicinally; the wood is used for fuel; the leaves are used for fodder [236,237].
In Kashmir, the bark resin used as expectorant for bronchitis [7]. In far-western Nepal, a paste made from the bark is used to treat burns and scalds; the bark resin is applied to boils [10]. In Uttarakhand, the bark resin is used to treat snake bite and scorpion sting [19].

Piper betle L. (Piperaceae)
In Nepal, the leaves are fried in ghee and taken to treat cough in children [109]. In Himalayan India, the leaves are used to treat headache, sore throat, constipation [73]. In India, betel leaf is used to various conditions, including bad breath, boils, conjunctivitis, constipation, headache, hysteria, itching, mastitis, ringworm, rheumatism, cuts and wounds [240].
Pleurospermum angelicoides (Wall. ex DC.) Benth. ex C.B. Clarke (Apiaceae) In Uttarakhand, a decoction of the root, mixed with cumin and black pepper, is taken to reduce fever and treat chronic gastric disorders [190,242].
In the Parvati valley (Himachal Pradesh), India, the smoke produced from the roots is used for killing and repelling insects [56]. People in the Pangi Valley, Himachal Pradesh, use a powder of the roots and umbels to treat swelling and knee pain [247].
None reported for Himalayan essential oils.

Senecio rufinervis DC. (Asteraceae)
In the Tons River valley, Uttarakhesh, a decoction of the leaves is used to relieve stomache ache [252].
None reported for Himalayan essential oils.

Skimmia anquetilia Tayl. and Airy Shaw (Rutaceae)
In far western Nepal, the local people take an infusion of the leaf for headache and freshness [30].
The leaf and floral essential oils from Uttarakhand inhibited egg laying by the beetle, Caryedon serratus [254].
None reported for Himalayan essential oils.
Stachys sericea Wall. ex Benth. (Lamiaceae) In Kashmir, the whole plant taken internally to treat epilepsy [203]. None reported for Himalayan essential oils.

Tanacetum longifolium Wall. ex DC. (Asteraceae)
In Kashmir, the root powder is taken with tea to relieve stomach pain [203]. Local inhabitants of the Kedarnath Wildlife Sanctuary, Uttarakhand, use the leaves to treat stomachache and indigestion [222].

Tanacetum nubigenum Wall. ex DC. (Asteraceae)
In Uttarakhand, a decoction of the leaves is used as an antimicrobial [265].

Thymus linearis Benth. (Lamiaceae)
Tribal people of the Sewa River area of Jammu and Kashmir, India, apply an oil from the herb to the gums for toothache [7]. People in the Mornaula Reserve Forest of Kumaun (Uttarakhand), India, use the whole plant as an anthelmintic and vermicide [22]. In the Humla district of western Nepal, a decoction of the ground aerial parts is drunk to treat cough, cold, stomachache, gastritis, diarrhea, indigestion. It is widely used as herbal tea [44]. The powdered leaf (with honey) is used by people living in the Nanda Devi National Park (Uttarakhand, India), to treat eczema and psoriasis [67].

Thymus serpyllum L. (Lamiaceae)
Ethnic people of Almora distric of Uttarakhand use the juice of the whole plant orally to treat cough and asthma; the paste of whole plant is used externally to treat arthritis [275].

Valeriana hardwickii Wall. (Caprifoliaceae)
Local people in the Humla district of northwestern Nepal, use an infusion of the root powder for headache, indigestion, diarrhea, dysentery, and for coughs and cold [44]. Ethnic people of Almora distric of Uttarakhand use the plant extract to treat malaria; the leaf paste is used externally to treat boils and eczema [275].
None reported for Himalayan essential oils.

Vitex negundo L. (Verbenaceae)
The tribal people of the Sewa River area of Jammu and Kashmir, India, use the aromatic leaves as a tonic and vermifuge [7]. In far western Nepal, the local people take the leaf juice for stomachache [30]. In the Parvati valley, Himachal Pradesh, India, the people prepare a paste of the leaves with cow urine and apply it to wounds and swellings [56].
None reported for Himalayan essential oils.
None reported for Himalayan essential oils.
* Introduced species

The Genus Artemisia
There are approximately 400 species of Artemisia distributed throughout temperate regions of the world, and the genus is typically characterized by aromatic shrubs and herbs [299]. Numerous members of the genus are used as traditional medicines by indigenous cultures, and many show biological activities including antimalarial, cytotoxic, antihepatotoxic, antibacterial, antifungal and antioxidant activities [300]. Some particularly notable members of the genus include A. absinthium L., the major component of the notorious spirit drink absinthe [301]; A. annua L., the efficacious antimalarial drug qinghaosu [302]; A. dracunculus L., the flavoring herb tarragon [303]; and A. tridentata Nutt., the "big sagebrush" of western North America [304].
In  [55,59], and some of these have been investigated for volatile compositions and bioactivity (see Table 1). A. dracunculus (tarragon) is used worldwide, including the Himalayan region, as a flavoring agent for food. The plant is also used ethnobotanically. Native peoples in the Nubra valley (Kashmir) [38], Kibber Wildlife Sanctuary (Himachal Pradesh) [39], and the Lahaul Valley (Himachal Pradesh) [40] use a paste from the leaves to treat wounds on the legs of donkeys and yaks; an extract of the whole plant is used to relieve toothache, reduce fever, and as a treatment for dysentery, intestinal worms, and stomachache. A. dracunculus from the Himalayas is a rich source of the diacetylene capillene and the monoterpene (Z)-β-ocimene [36,37,41], and is markedly different from "French tarragon", which is dominated by estragole (up to 74%), or "Russian tarragon", which is dominated by elemicin (up to 57%), or other cultivars of A. dracunculus [303].
The leaf juice of A. dubia is used by villagers in the Dolpa district of Nepal [285] and the Newar community of Kathmandu, Nepal [42], as an antiseptic to cure cuts and wounds and the leaf extracts are used as pesticides. The essential oil of A. dubia was shown to be rich in chrysanthenone (29.0%), coumarins (18.3%), and camphor (16.4%) [43]. Although the leaf oil showed in vitro cytotoxic activity against MCF-7 human breast tumor cells and antifungal activity against Aspergillus niger, it was inactive against the bacteria Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa [43]. Thus, the antiseptic qualities of A. dubia must be due to non-volatile components in the plant.
In the Humla district of northwestern Nepal, the whole fresh plant of A. gmelinii is ground into a paste an applied externally to cure headache, boils, and pimples [44]. The essential oils from the aerial parts of A. gmelinii from Himalayan India are dominated by artemisia ketone and 1,8-cineole [45,46]. Neither of these compounds, however, are notably antibacterial (B. cereus, S. aureus, E. coli, P. aeruginosa) or antifungal (Candida albicans, A. niger) [305].
Artemisia parviflora is widely distributed in the Himalayas between about 900 and 3500 m asl [319]. In the traditional medicine of the Kumaun Himalaya, the leaves of A. parviflora are used to treat skin diseases, burns, cuts, and wounds, while the volatiles from the plant are used to repel insects [19].
The indigenous peoples of Jammu and Kashmir (India) use A. parviflora as a diuretic and to treat gynecological disorders [59]. The plant is also used in ethnoveterinary medicine as an anthelmintic; a decoction of the leaves and buds of the plant are given to stock animals (e.g., horses, mules, sheep, and buffaloes) for round worm [320]. The plant is also used as a fodder plant in mid-altitude rangelands of Uttarakhand [321]. The essential oil from the aerial parts of A. parviflora collected from Pauri, Pauri Garhwal (Uttarakhand, India) was found to contain β-caryophyllene (15.3%), germacrene D (14.7%), camphor (11.4%), artemisia ketone (7.8%), and 1,8-cineole (5.8%) [61]. There are apparently no reports on the bioactivities of Himalayan A. parviflora essential oil, but the oil from southern India has shown antifungal activity against Candida and Cryptococcus species [322].
People living in the Kedarnath Wildlife Sanctuary in the western Himalaya of Chamoli-Rudraprayag (Uttarakhand), India, use an extract of the whole plant to relieve fever [49]. In addition, the plant extract is rubbed on the skin to treat allergic reactions. In Jammu and Kashimir, India, A. roxburghiana is also used to treat skin allergies [62]. In northern Pakistan, an extract of the whole A. roxburghiana plant is used to treat fever and malaria; a powder of the whole plant is taken for intestinal worms [50]. Indigenous people living in the Khyber Pakhtunkhwa Province of Pakistan use the leaves of A. roxburghiana to treat chest cold, sore throat, and toothache [323]. A. roxburghiana is used in ethnoveterinary medicine in Uttarakhand, India, to treat eye diseases, wounds, cuts, and external parasites [306].
Inhabitants of the Nanda Devi National Park, Uttarakhand, India, apply a paste of the leaves of A. scoparia on cuts and wounds [67]. The leaf powder is taken to treat diabetes and as a blood purifier, to treat abdominal complaints, colic, cough, and cold. People in the Agra Valley, Parachinar, Pakistan, use the whole plant of A. scoparia to treat burns, jaundice, and ear ache; the volatiles of the plant are inhaled for chest congestion [325]. The biological activities of A. scoparia and its essential oils are likely due to capillene. This compound has shown antibacterial and antifungal activities [326,327].
Artemisia vulgaris is used in Nepal to treat various ailments [70]. The crushed leaves are inserted into the nose to stop bleeding. A bath prepared with the crushed leaves is used to treat allergic reactions. Raw leaves are chewed as a treatment for oral ulcers. In northern Pakistan, the leaf extract of A. vulgaris is used to treat malaria and fevers [50]. In Sudhan Gali, Kashmir, Pakistan, an extract of the leaves is used for the treatment of ophthalmic diseases [328]. The leaf essential oil of A. vulgaris, collected from Hetauda Makwanpur, Nepal, was found to contain α-thujone (30.5%), 1,8-cineole (12.4%), and camphor (10.3%) [43]. This essential oil was screened for antimicrogial activity against B. cereus, S. aureus, E. coli, P. aeruginosa, and A. niger, but was found to be inactive (MIC = 2500 µg/mL). Another A. vulgaris essential oil sample from Nepal did exhibit antibacterial activity against Streptococcus pyogenes and Propionibacterium acnes [329].
People living in the Dolakha district of Nepal apply a paste from the roots of C. glanduliferum to treat wounds and toothache [102]. In northern India, leaves of C. glanduliferum are used as a stimulant, carminative, and to treat coughs and colds [103]. A leaf oil sample from northern India, rich in 1,8-cineole (41.4%), α-pinene (20.3%), and α-terpineol (9.4%), was found to have antibacterial activity against Gram-positive bacteria (Micrococcus luteus) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Aeromonas salmonicida). The high concentration of 1,8-cineole likely contributes to its efficacy against coughs and colds. 1,8-Cineole has shown clinical efficacy as a mucolytic and spasmolytic as well as beneficial effects in inflammatory airway diseases such as asthma and chronic obstructive pulmonary disease (COPD) [336,337]. The antibacterial activity of C. glanduliferum leaf oil is likely not due to 1,8-cineole alone [338], but may be attributed to synergistic effects between 1,8-cineole and other minor components [339,340]. Another chemotype of C. glanduliferum, rich in (E)-nerolidol (52.2%), has been reported, but no biological activities were investigated for this oil [107]. (E)-Nerolidol has shown antibacterial activity, however [341,342].
Cinnamomum tamala leaf essential oil has shown some variation in composition. Cinnamaldehyde is generally a major component [97,101,108], but a leaf oil sample from Pannagar, Uttarakhand was dominated by eugenol (65%) [97]. By contrast, C. tamala leaf oil from Karachi, Pakistan, was composed largely of β-caryophyllene (25.3%), linalool (13.4%), and caryophyllene oxide (10.3%) [345]. In far-western Nepal, leaves of C. tamala are used to treat gastic problems [10], while in the Kathmandu area of Nepal, the leaves are used as a spice and flavoring agent [42]. The leaf oil from Uttarakhand has shown activity against foodborne bacteria, Salmonella enterica, Escherichia coli, and Pasturella multocida [97]. A leaf oil sample from Jharkhand, India, demonstrated antifungal activity against Aspergillus niger, Aspergillus fumigatus, Candida albicans, Rhizopus stolonifer, and Penicillium spp., but the composition of the oil was not reported [346].

The Genus Juniperus
There are around 75 species of Juniperus (Cupressaceae), and is a very diverse genus ranging in habitat from sea level to above timberline [397]. Important medicinal species include J. communis, the common juniper used to flavor gin [398], J. drupacea from the eastern Mediterranean [399], J. monosperma from southwestern North America [400], J. oxycedrus, the heartwood from which oil of cade is prepared [401], and J. virginiana, used in traditional medicine by Native Americans in eastern North America [402].
In  [397,[403][404][405][406]. J. communis is the most widespread species of Juniperus and is distributed circumpolar, including the Himalayas from Kashmir to Bhutan [407]. J. communis is used in traditional medicine throughout the Himalayas. For example, the local people in Kishtwar, Jammu and Kashmir, India, apply the oil extracted from the plant to treat rheumatism [182]. Similarly, inhabitants of Parvati valley in Himachal Pradesh use an extract from the twigs to treat joint pain [56]. Essential oils of J. communis are rich in α-pinene and limonene [149], and both α-pinene [408,409] and limonene [410] have shown antinociceptive effects in rodents, consistent with the ethnobotanical use of J. communis to treat joint pain. In addition to using the plant for gout, chronic arthritis, and rheumatism, J. communis is taken as a tonic, diuretic, for urinary tract infection [411], and a paste made from the leaves is applied to skin ailments [67]. Essential oils from the berries of J. communis have shown antifungal (Candida albicans, Candida kefyr, Epidermophyton floccosum, Trichophyton rubrum, Trichophyton mentagrophytes, Trichophyton rubrum, Microsporum canis) and antibacterial (Bacillus cereus) activity [146][147][148], which is consistent with its use to treat urinary tract infection and skin infections.
In the Humla district of western Nepal, a decoction of the leaves and berries of Juniperus indica are consumed to treat coughs and colds; a paste of the berries is applied externally to cure skin diseases [44]. Similarly, inhabitants in Upper Mustang, Nepal, use the fruits and leaves of J. indica for skin diseases, fevers, and coughs [150]. The leaf and berry essential oils of Juniperus indica are generally rich in sabinene and terpinene-4-ol [149,151,152]. Terpinen-4-ol has shown antibacterial activity against several bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) [412], respiratory tract pathogens Haemophilus influenza, and penicillin-resistant Streptococcus pneumoniae [413]. In addition, terpinen-4-ol been shown to inhibit the growth of human melanoma (M14 WT) cells [414]. Terpinen-4-ol has shown antifungal activity against several dermatologically important fungi, including Candida albicans (responsible for cutaneous moniliasis), Candida parapsilosis (responsible for onychomycosis), and several dermatophytes responsible for tinea in humans (Trichosporon spp., Rhodotorula rubra, Epidermophyton floccosum, Microsporum canis, and Trichophyton mentagrophytes); the compound was also active against the potential pulmonary fungal pathogens Aspergillus niger, Aspergillus flavus, and Aspergillus fumigatus [415]. Thus, the biological activities of terpinene-4-ol in J. indica oils are consistent with the ethnobotanical uses of the plant for respiratory and dermal infections.
There do not seem to be any published reports on ethnopharmacological uses of Juniperus pseudosabina. J. recurva, on the other hand, is used in Nepal. Thus, the local people in the Rasuwa district of central Nepal use J. recurva to treat fever, headache, coughs, and colds [11]; the local people in the Humla district of northwestern Nepal, apply a paste of the leaves and berries to treat skin conditions [44]. In the Nubra River valley of northern Jammu and Kashmir, the people use a decoction of the leaves of J. recurva to lower fever in children [7]. Leaf essential oils of J. recurva are rich in δ-3-carene [157], but there have apparently been no bioactivity studies on J. recurva essential oils.
Nepeta species are used traditionally as antispasmodic, diuretic, febrifuge, diaphoretic, antimicrobial and antiseptic agents and also in the treatment of dysentery, tooth trouble and kidney and liver diseases [423]. Diverse biological activities, e.g., feline attractant [424], insect repellant [425], and arthropod defense [426,427] are attributed to the presence of biologically active iridoids, monoterpene nepetalactones, in Nepeta species [428]. Aydin et al. investigated the antinociceptive effects of essential oils from Nepeta species, including N. phyllochlamys, N. nuda ssp. nuda, and N. caesarea, using a tail flick and tail immersion tests [429]. These authors detected central and peripheral antinociceptive effects in N. caesarea and concluded that 4aα,7α,7aα-nepetalactone was the active principle and had a specific opioid receptor subtype agonistic activity.
Nepeta species are used in the traditional medicine of many cultural groups in the Himalayas. Many species are used to reduce fever, treat coughs and colds, and relieve digestive disorders ( Table 1). Nepetalactones are generally considered biochemical markers for the genus and some some Himalayan Nepeta essential oils are rich in nepetalactones, e.g., N. elliptica [200] and N. juncea [210]. The antimicrobial activities of these essential oils are likely due to nepetalactone concentrations [430][431][432]. Nevertheless, many Himalayan Nepeta samples contain little or no nepetalactones [216], and therefore, the ethnomedicinal uses and biological activities observed in these Nepeta species are likely due to other constituents.

The Genus Origanum
The members of the genus Origanum L. are usually perennial herbs belonging to the mint family (Lamiaceae). It has been classified into 10 sections including 43 species, 6 subspecies, 3 varieties and 18 naturally occurring hybrids, widely distributed in the Mediterranean, Euro-Siberian and Irano-Siberian regions [444,445]. Members of the genus are mainly distributed along the Mediterranean region, with 75% restricted to the eastern Mediterranean [446]. The genus includes some commercially important culinary herbs, including oregano (Origanum vulgare L.) and marjoram (Origanum majorana L., syn. Majorana hortensis Moench), which are extensively used for flavoring food products and alcoholic beverages. In India and Nepal, only one species is available from sub-tropical to alpine zones of the Himalayan Region [6].

The Genus Valeriana
Valeriana L. (Caprifoliaceae) consists of around 200 species distributed in the temperate and sub-tropical areas globally and is among the important herbal traditional drug in various pharmacopeias [299]. The herbal drug valerian consists of the subterranean organs (rhizome, root, stolons) of Valeriana officinalis L. [172]. The valerian-derived phytomedicines have been used for curing nervous unrest, emotional troubles (as tranquillizer/sedative), epilepsy, insanity, snake envenomation, eye-trouble, skin-diseases, relaxant, carminative, and for improving the complexion [455][456][457]. Valerian is one of the top ten selling herbal supplements in North America [458]. It has also been prescribed as the perfect herbal tranquilizer, and was used for this purpose in the First World War to treat soldiers suffering from shell shock and to calm civilians subjected to air raids during World War II [459].
In India, Valeriana jatamansi Jones (syn. Valeriana wallichii DC.). has long been used in Ayurveda and Unani systems of medicine, which describe its use in skin diseases, insanity, epilepsy, and snake bite, and is considered to have remarkable sedative effects in nervous unrest, stress, and neuralgia [460,461]. A survey of the literature has revealed the presence of flavonoid glycosides [462,463], iridoids, and lignans [464][465][466] in V. jatamansi. Anti-inflammatory [467] antianxiety [468], antidiarrheal, and bronchodilatory activities [469] of V. jatamansi extracts have been scientifically validated. The plant has also shown in vitro cytotoxic [470] and antileishmanial [471] activities. V. jatamansi essential oil has shown antimicrobial activity against pathogenic bacteria and as well as antifungal activity against different human and plant fungal pathogens [472].

Conclusions
The Himalayas, with wide-ranging elevations, deep glacial and river valleys, areas of high rainfall and areas of high desert, is a rich area of biodiversity with much endemism. Traditional herbal medicine continues to play a role in many tribal areas, and numerous medicinal plants and their essential oils have shown remarkable biological activities. Unfortunately, there remains a paucity of information relating biological activities of essential oils with the ethnobotanical uses of the plants. In many cases this may be due to the activity residing in non-volatile components. Additionally, many phytochemical researchers have neglected bioactivity screening related to ethnopharmacological uses. Thus, there is much additional work that can be carried out to identify phytochemicals associated with biological activities that support traditional uses of medicinal plants. In addition, several aromatic plants have shown commercial promise as flavoring agents, fragrances, cosmetics, and pesticides. Due, in part, to the great demand for essential oils, herbal medicines, and pharmaceuticals, the medicinal plants of the Himalayas are threatened by unsustainable harvesting [474], and increasing environmental degradation, invasive plant species, and climate change also threaten Himalayan native flora. We encourage the preservation of traditional knowledge and uses of Himalayan medicinal plants and we hope that additional steps are undertaken to protect and maintain the Himalayan ecology.