1. Journal of Experimental and Integrative Medicine
DOI: 10.5455/jeim.260416.rw.015
www.jeim.org
J Exp Integr Med ● 2016 ● Volume 6 ● Issue 2 93
A review on phyto-pharmacological potentials
of Juniperus recurva
Abila Rashid1
, Raja Amir Hassan Kuchay2
ABSTRACT
Juniperus recurva is a small tree or spreading shrub distributed from Afghanistan eastward through the Himalayas to
southwest China. It is predominant in woodlands of the wetter areas of Himalayas (altitude of 1800 m to 3900 m), with
moist and well-drained soils. It holds great potential as a medicinal plant. It has been traditionally used as anti-rheumatic,
antiseptic, antispasmodic, antitoxic, aphrodisiac, astringent, carminative, rubificant and stomachic. However, very few
authentic pharmacological studies on medicinal benefits of this plant have been conducted thus far. In a first of its kind,
we review this plant for its chemical constituents, pharmacological activity and medicinal benefits. Keeping in view its
success record as a traditional medicine to cure different ailments, it would be of interest to look for various bioactive
natural products that might have therapeutic potential.
KEY WORDS: Juniperus recurva; Distribution; Pharmacological Activity.
Mini Review
INTRODUCTION
Juniperus L. (family Cupressaceae), a genus of evergreen
aromatic shrubs or trees is distributed in temperate and
cold regions of northern Hemisphere [1]. Depending on
taxonomic viewpoint, between 50 and 67 species of Juniper
arewidelydistributedthroughoutthenorthernHemisphere,
from the Arctic, south to tropical Africa in the old world,
and to the mountains of central America, Pakistan, India
and China [2–6]. Leaves remain green for several years and
even after drying may remain on the shoots for indefinite
period [2–6]. Flowers are unisexual [2–6]. In some species
flowers of both the sexes occur on the same plant [2–6]. All
the species can be propagated through seeds; seeds retain
viability for several years when stored in cool dry place
[2–6]. Junipers like open positions and chalky or limestone
soils [2–6]. Common Juniper species of Himalayan range
include: J. communis, J. indica, J. recurva and J. squamata [2,
7]. Juniperus recurva is commonly known as the ‘Drooping
Juniper’[2].
METHODS
Authors carried out electronic searches in PubMed, Embase,
Medline Google Scholar, Scopus and Cochrane Library.
Authors screened the titles and abstracts independently to
identify potential eligible articles. Then full-text articles
were retrieved if necessary. Authors used controlled
vocabulary and text words to construct a highly sensitive
search strategy during the entire process of literature
survey. No limits were imposed in terms of author or type
of publication.
OCCURRENCE AND MORPHOLOGY
J. recurva grows from Pakistan to south west China and is
particularly common in Nepal and Kashmir [2–6]. It can
be found as a large shrub in hilly region of Nepal. It can
also be tree having height of 6-20 m and a trunk up to 2
m diameter and a broadly conical to rounded or irregular
crown. In Nepal it is widely spread in east side of Himalaya
region. In Kashmir it is found in Khilanmarg and on the
route from Sonamarg to Amarnath cave at an altitude of
3000-4000 m. It mainly grows at altitude of 3000-4000
m. Two varieties of J. recurva have been named: J. recurva
var. recurva found throughout the Himalayan range and J.
recurva var. coxii mainly confined to the eastern Himalaya
on high rainfall sites [2, 8]. However, a report has listed
J. recurva var. squamata and J. recurva var. coxii as the two
species of Himalayas [9].
J. recurva is monoecious or rarely dioecious. Trunk bark is
generally light grayish brown or brown, crown conical or
broadly pyramidal. Branches are ascending in apical part of
plant and spreading toward base. Leaves are needle-like, 5-10
mm long, arranged in six ranks in alternating whorls of three.
Seed cones are berry-like, globose to ovoid, 5-10 mm long and
4-7 mm diameter, glossy blue-black, and contain one seed;
they are mature in about 18 months. The male cones are 3-4
mm long, and shed their pollen in early spring [2].
1
Faculty of Pharmaceutical
Sciences, Shri Venkateshwara
University, Gajraula, UP, India.
2
School of Biosciences &
Biotechnology, CBS, BGSB University,
J&K, India.
Address for correspondence:
Raja A.H Kuchay,
School of Biosciences &
Biotechnology, CBS, BGSB University,
J&K, India.
kuchay_bgsbu@yahoo.com
Received: January 12, 2016
Accepted: April 26, 2016
Published: June 30, 2016

2. Abila & Amir: Juniperus recurva Phyto-Pharmacological Activities
94 J Exp Integr Med ● 2016 ● Volume 6 ● Issue 2
SCIENTIFIC CLASSIFICATION
(1) Kingdom: Plantae
(2) Division: Pinophyta
(3) Class: Pinopsida
(4) Order: Pinales
(5) Family: Cupressaceae
(6) Genus: Juniperus
(7) Species: Juniperus recurva
THREATS
In the IUCN (International Union for Conservation
of Nature) Red List of Threatened species Juniperus
recurva var. coxii has been put in the category of Near
Threatened [10]. Having previously been listed as
Vulnerable, it was considered that there is insufficient
evidence to assume an overall reduction greater than 30%.
In certain areas, e.g. Yunnan, deforestation has been cause
of reduction in area of occupancy, but elsewhere the forest
is still intact. It seems more appropriate to list this taxon
as Near Threatened [10]. In its native countries J. recurva
is used for timber as well as ornamental trees in gardens of
monasteries and temples. The wood and foliage are burned
for incense in Buddhist temples [8]. In Myanmar (Burma)
the wood of large trees is used to make coffins. The drooping
form J. recurva var. coxii is a highly ornamental tree much
valued and often planted in regions of Europe with a mild,
moist climate [8].
CHEMICAL CONSTITUENTS
Analysis of the composition of the leaf oils of J. recurva
from India (Sikkim, Nepal) and its comparison to the
composition of J. recurva var. squamata from western
India has been reported [6]. The major components of J.
recurva oil were α-pinene, sabinene, δ-3-carene, limonene,
terpinen-4-ol, γ-cadinene, δ-cadiene, elemol, cubenol,
epi-α-cadinol, epi-α-muurolol, α-cadinol and 4-epi-abietal
[6]. Study on essential oils of leaves and twigs of Juniperus
recurva var. squamata by gas liquid chromatography (GLC),
mass spectrometry (MS), and nuclear magnetic resonance
(NMR) spectroscopy has also been performed [11]. Main
constituents were monoterpene hydrocarbons (68%);
in addition, about 12% of sesquiterpene hydrocarbons,
9% of oxygenated sesquiterpenes, and 5% of oxygenated
monoterpenes were identified. 4β-Hydroxygermacra-1,
5-diene, β-oplopenone, oplopanone, 8-acetoxy elemol, and
manool were found as trace components (Figure 1) [11].
Recently a study was conducted on the phytochemical
screening for the presence of different phytochemicals
like alkaloids, tannins, reducing sugar, coumarin,
glycosides, quinones, steroids, terpenoids and saponin in
the different plant parts of J. recurva [12]. Leaf and seed
fractions demonstrated differences in the presence of
various phytochemicals. Leaf fractions showed only the
presence of coumarins and quinones with the absence of
other mentioned phytochemicals. Seed fractions showed
the presence of tannins, coumarin, glycosides, saponin,
alkaloids, steroids and terpenoids [12]. In a preliminary
phytochemicalscreeningofmethanolicextractofsixspecies
of Juniperus including J. recurva, the presence of alkaloids,
tannins, flavonoids, terpenoids and steroids was reported
[13]. The contents of phenolic compounds were highest in
J. communis and the total flavonoid contents were highest
in J. indica. For J. recurva total phenolic content in (equiv
L-1
) was 2.10 ± 0.13 and total flavonoid content (equiv L-1
)
was 0.890 ± 0.17 [13]. Amentoflavone was also isolated
from aerial parts of different Juniperus species including
J. recurva and authenticated by high performance liquid
chromatography (HPLC) and physicochemical parameters
[13].
Production of podophyllotoxin by an endophytic fungus
Fusarium oxysporum isolated from the medicinal plant J.
recurva has been reported [14]. Further confirmation and
quantification of podophyllotoxin was performed by HPLC,
liquid chromatography-mass spectrometry (LC-MS), and
LC-MS/MS [14]. Podophyllotoxin is a well-known naturally
occurring aryltetralin lignan that occurs in few plant species
that is used as a precursor for the chemical synthesis of the
anticancer drugs like etoposide, teniposide and etopophose
phosphate. The availiability of this lignan is becoming
increasingly limited because of the scarce occurance of
its natural sources and also because synthetic approaches
for its production are still commercially unacceptable [14].
PHARMACOLOGICAL ACTIVITIES AND MEDICINAL
USES
Essential oils and their components are widely used in
medicine as constituents of different medical products,
in the food industry as flavouring additives and also in
cosmetics as fragrances and pharmaceutical industries [15,
16]. Essential oils are valuable natural products used as raw
materials in many fields, including perfumes, cosmetics,
Fig. 1. Leaf Essential Oil Composition of J. recurva var. squamata [6,11]

3. Abila & Amir: Juniperus recurva Phyto-Pharmacological Activities
J Exp Integr Med ● 2016 ● Volume 6 ● Issue 2 95
aromatherapy, phototherapy, spices and nutrition [17].
Also the essential oils are used in traditional medicine for
their antiseptic action. Juniper berry essential oil is found in
soaps and in pomades with the aim of curing alopecia [18].
The oil is also irritating to microbes, so much so that it kills
many of them [19]. Juniper berries (mature female cones)
have long been used as flavouring agents in foods and
alcoholic beverages such as gin [20]. In herbal medicine,
Juniper oil has been used as a carminative, diuretic and as a
steam inhalant in the management of bronchitis. It has also
been used in arthritis as well as antioxidant [21]. Berries
are also recommended in cough, infantile tuberculosis
and diabetes, whereas, ash of the bark is used for certain
skin diseases [22, 23]. Mentioned below are few reported
pharmacological activities associated with J. recurva and its
different constituents.
Insecticidal Activity
Many insecticidal principles have been reported in the
heartwood of J. recurva including thujopsene and 8-cedren-
13-ol. Additional 12 sesquiterpenes were also detected
in the neutral fraction of ether extracts [24]. The active
componentsfromtheheartwoodofJ.recurvaweremonitored
for the insecticidal activity against mosquito female adults
(Culex pipiens pallens) with topical application test [24].
Essential oils of two Tibetan Junipers, J. saltuaria and
J. squamata var. fargesii have also been reported to have
insecticidal activity against adult lace bugs [25].
Xanthine Oxidase Inhibitory Activity
Xanthine oxidase inhibitory activity of J. recurva has been
recently assessed [26]. The inhibitory effect of polyphenolic
rich fractions of J. recurva was determined to find out the
natural inhibitors of xanthine oxidase. Xanthine oxidase
is a cytoplasmic enzyme, converting hypoxanthine to
xanthine and generates superoxides and uric acid. Gout
attacks can be treated with the use of xanthine oxidase
inhibitors. Allopurinol is generally used in the management
of gout and conditions associated with hyper-uricemia but
its adverse effect leads to GIT distress, hypersensitivity
reactions and hepatitis. It was reported that the methanol
fraction of J. recurva has more inhibition against xanthine
oxidase activity in the samples treated with different
concentrations of hypoxanthine on second, third, fourth
and fifth weeks as compared to other plant extracts [26].
Antimicrobial Activity
Antimicrobial assay with the leaf and seed plant extracts
of J. recurva by agar plate diffusion method has been
reported [12]. Five antibiotics were used as standard
drugs. Six different bacteria Bacillus cereus, Bacillus
thuringiensis, Escherichia coli, Pseudomonas aeruginosa,
Bacillus subtilis and Proteus mirabilis were used for the
assay. The antimicrobial activity was assayed by measuring
the diameter Zone of Inhibition in millimetres (ZOI) of
different extracts on the agar disc plate. Both the J. recurva
leaf and seed extract fractions showed the concentration
dependence antimicrobialactivitytowardsthebacteriaused
with the highest ZOI being 17 mm for the J. recurva leaves
at 200 mg/ml [12]. Various other species of Juniperus have
also been reported to have antimicrobial activity [27, 28].
Sensitivity of five pathogenic multi drug resistant bacteria
(Bacillus subtilis, Erwinia chrysanthemi, Escherichia coli,
Agrobacterium tumefaciens and Xanthomonas phaseoli) was
tested against the crude leaf organic extracts (methanol,
ethanol, chloroform and hexane) and aqueous extracts of
a Kumaun Himalayan gymnospermous plant J. communis,
employing disc diffusion method. All the extracts of J.
communis were found effective by showing a mark zone
of inhibition except aqueous extract [27]. Antimicrobial
activity of Juniper essential oil has also been reported in
many other studies [29, 30].
Antioxidant Activity
Furthermore, antioxidant (2,2-diphenyl-1-picrylhydrazyl;
DPPH) assay of different plant-parts of J. recurva has
also been investigated [12]. The results demonstrate that
the selected plant extract fractions of J. recurva possess
significant antioxidant activities. Antioxidants compounds
scavenge free radicals such as peroxide, hydroperoxide or
lipid peroxyl and thus inhibit the oxidative mechanisms
that lead to degenerative diseases [12]. Antioxidant effects
of J. communis essential oils has also been reported in vivo
[31].
The protective effect of methanolic extracts from different
species of Juniperus in different concentration has been
reported against H2
O2
induced oxidative damage in human
erythrocytes and leucocytes [13]. Human blood cells are
the key fighters against various oxidative stress diseases
and remain the primary target for natural products and
plants. These cells are continuously exposed to radicals
and are unable to replace damaged components, especially
polyunsaturated fatty acids chains from peroxidation [32].
The measurements of different antioxidant parameters
like superoxide dismutase, glutathion peroxidase, lipid
peroxidase, catalase and glutathione levels were performed
under each set of extracts including J. recurva. Isolated
fractions from all the six Juniperus species were reported
as potential source of natural antioxidants for treatment
and prevention of diseases in which oxidative stress takes
place [13]. Antioxidant potential has also been reported
for essential oils of Juniper berries of different species of
Junipers [33, 34].
Cytotoxic Activity
In-vitro cytotoxicity assay with the leaf and seed plant
extracts of J. recurva demonstrated its anticancer properties
against MCF7 (Breast Cancer) cell lines [12]. The
cytotoxic effect or the inhibitory effect of these extracts was
compared with standard (Dexorubicin). The percentage
inhibition was reported to be concentration dependent. It
was suggested that isolated pure compounds with bioassay
guided extraction, could possibly get the higher inhibitory

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96 J Exp Integr Med ● 2016 ● Volume 6 ● Issue 2
effect against MCF7 cells from the plant J. recurva.
Essential oils of few other species of Juniperus have also
been reported to have cytotoxic activity [35–37].
Other Uses
Various parts of J. recurva are tradition used as anti-
rheumatic, anti-septic, anti-spasmodic, astringent,
carminative, depurative, stimulant, stomachic, tonic, and
in aroma industry. One of the most ancient rituals of the
Himalayan region is the burning of J. recurva on mountain
tops to purify and sanctify the area. J. recurva has also
been reported to be useful in the treatment of various
ailments including fever, headache, cough, cold and kidney
problems. High FIC
(informant consensus factor) value
was obtained for these ailments, indicating that the J.
recurva traditionally used to treat these ailments is worth
searching for bioactive compounds [38]. Summary of its
pharmacological activities and traditional uses is given in
Figure 2.
CONCLUSION
In this review paper various traditional and medicinal
aspects of J. recurva have been discussed. There is a shortage
of research reports on J. recurva. It remains one of least
studied species of Juniperus. Further evaluation needs to be
carried out on J. recurva in order to establish and confirm
its medicinal uses and development of formulations
containing this plant for their practical clinical applications,
which can be used for the welfare of mankind.
ACKNOWLEDGEMENTS
The authours are thankful to Dr. P. H. Qazi, Senior
Scientist, Indian Institute of Integrative Medicine, Sanat
Nagar, Srinagar for providing laboratory support and
valuable suggestions. We are thankful to reviewers for their
inputs.
CONFLICT OF INTERESTS
The authors declare that there is no conflict of interests
regarding the publication of this paper.
REFERENCES
1. Hooker JD. The flora of British India. Publ, Bishen Singh Mahendra
Pal Singh, Dehradun, 1999.
2. Adams RP. Junipers of the world: The genus Juniperus. Trafford
Publ, Canada, Victoria BC, 2004.
3. Farjon A. World checklist and bibliography of conifers. Kew, 2001.
4. Farjon A. Monograph of Cupressaceae and Sciadopitys. Royal
Botanic Gardens, Kew, 2005.
5. Mao K, Hao G, Liu J, Adams RP, Milne RI. Diversification and
biogeography of Juniperus (Cupressaceae): variable diversification
rates and multiple intercontinental dispersals. New Phytologist
2010; 188(1):254–72.
6. Adams P, Thappa RK, Agrawal SG, Kapahi BK, Srivastava TN,
Chaudhary RP. The leaf essential oil of Juniperus recurva Buch.-
Ham. Ex D. Don from India and Nepal compared with Juniperus
recurva var. squamata (D. Don) Parl. J Essent Oil Res 1998;
10(1):21–4.
7. Lohani H, Haider SZ, Chauhan NK, Mohan M. Essential oil
composition of leaves and berries of Juniperus communis and
Juniperus indica from Uttarakhand Himalaya. J Med Aromat Plant
Sci 2010; 32(3):199–201.
8. Farjon A. A handbook of the World’s conifers. Koninklijke Brill,
Leiden, 2010.
9. Gulati BC, Shawi AS, Garn SN, Channa GN. Essential
oil of Juniperus recurva var squamata and other oils of
Juniperus spp. Indian Perfumer 1980; 24:57–65.
10. Li N, Christian T, Farjon A, Rushforth K. Juniperus recurva var. coxii.
The IUCN Red List of Threatened Species 2013: e.T34142A2847725,
2013.
11. 11.Weyaerstahl P, Marschal-Weyerstahl H, Manteuffel E, Kaul VK.
Constituents of Juniperus recurva var. squamata oil. Planta Med
1988; 54(3):259–61.
12. Bhandari J, Naqvi A, Niraula P, Thapa P, Thapa N, Shrestha N,
Shrestha BG. Phytochemical screening, antioxidant assay of
Juniperus recurva and study of it’s in vitro cytotoxicity against
breast cancer cell lines. Int J Pharm Bio Sci 2015; 6:1134–45.
13. Bais S, Prashar Y. Identification and characterization of
amentoflavone from six species of Juniperus against H2
O2
induced
oxidative damage in human erythrocytes and leucocytes. Res J
Phytochem 2015; 2:1–15.
14. Kour A, Shawl AS, Rehman S, Sultan P, Qazi PH, Suden P, Khajuria
RK, Verma V. Isolation and identification of an endophytic strain
of Fusarium oxysporum producing podophyllotoxin from Juniperus
recurva. World J Microbiol Biotechnol 2008; 24:1115–21.
15. Cowan M. Plant products as antimicrobial agents. Clin Microbiol
Reviews 1990; 12:564–82.
16. Reische D, Lillard D, Eitenmiller R. Antioxidants in food lipids. In:
Ahoh CC, Min DB (eds) Chemistry, Nutrition and Biotechnology,
Marcel Dekker, New York, pp 423–48, 1998.
17. Buchbauer G. The detailed analysis of essential oils leads to the
understanding of their properties. Perfumer & Flavorist 2000;
25:64–7.
18. Bown D. The Royal Horticultural Society Encyclopedia of Herbs and
Their Uses. Dorling Kindersley Ltd, London, pp 424, 1999.
19. Watt O, Breyer-Brandwijk M. The medicinal and poisonus plants
of Southern and Eastern Africa. E & S Livingstone Ltd, Edinburgh &
London, pp 841, 1962.
20. Clutton DM. History of Gin. Flavour. Ind, pp 454, 1972.
21. Takacsova M, Pribela A, Faktorova M, Nahrung. Study of the
antioxidative effects of thyme, sage, juniper and oregano. Nah rung
Food 1995; 39:241–3.
22. Zaman MB, Khan MS. Hundred drug plants of West Pakistan.
Pakistan Forest Institute Peshawar, Pakistan, 1970.
23. Baquar SR. Medicinal and poisonous plants of Pakistan. Printas
Karachi, Pakistan, pp 506, 1989.
24. Oda J, Ando N, Nakajima Y, Inouye Y. Studies on insecticidal
constituents of Juniperus recurva Buch Agr. Biol Chem 1977;
41:201–4.
25. Wedge DE, Tabanca N, Sampson BJ, Werle C, Demirci B, Baser
KH, Nan P, Duan J, Liu Z. Antifungal and insecticidal activity of two
Juniperus essential oils. Nat Prod Commun 2009; 4(1):123–7.
26. MahajanJ, KumarR, KaurR, AroraS.Explorationofxanthineoxidase
producing microorganisms from hypoxanthine supplemented soil
and their inhibitors from plants employing nitroblue tetrazolium
based colorimetric assay method. Glo Adv Res J of Environ Sci
Toxicol 2012; 1:10–3
27. Sati SC, Joshi S. Antibacterial potential of leaf extracts of Juniperus
communis L. from Kumaun Himalaya. Afr J Microbiol Res 2010;
4:1291–4.
Fig. 2. Summary of Pharmacological Activities and Traditional Uses
of J. recurva

5. Abila & Amir: Juniperus recurva Phyto-Pharmacological Activities
J Exp Integr Med ● 2016 ● Volume 6 ● Issue 2 97
28. Angioni A, Barra A, Russo AT, Coroneo A, Dessia S, Cabras P.
Chemical composition of the essential oils of Juniperus from ripe
and unripe berries and leaves and their antimicrobial activity. J Agric
Food Chem 2003; 5:3073–78.
29. Pepeljnjak S, Kosalec I, Kalodera Z, Blazevic N. Antimicrobial
activity of juniper berry essential oil (Juniperus communis L.,
Cupressaceae). Acta Pharm 2005; 55(4):417–22.
30. Filipowicz N, Kamiński M, Kurlenda J, Asztemborska M, Ochocka
JR. Antibacterial and antifungal activity of juniper berry oil and its
selected components. Phytother Res 2003; 17(3):227–31.
31. Hoferl M, Stoilova I, Schmidt E, Wanner J, Jirovetz L, Trifonova
D, Krastev L, Krastonov A. Chemical composition and antioxidant
properties of Juniper Berry (J. communis L.) essential oil. Action
of the essential oil on the antioxidant protection of Saccharomyces
cerevisiae model organism. Antioxidants 2014; 3(1);81–98.
32. Bukowska B. Effects of 2,4-D and its metabolite 2,4-dichlorophenol
on antioxidant enzymes and level of glutathione in human
erythrocytes. Comp Biochem Physiol C Toxicol Pharmacol 2003;
135:435–41.
33. Cioanca O, Hancianu M, Mihasan M, Hritcu L. Anti-
acetylcholinesterase and antioxidant activities of inhaled Juniper
oil on amyloid beta (1-42)-induced oxidative stress in the rat
hippocampus. Neurochem Res 2015; 40(5):952–60.
34. Stoilova IS, Wanner J, Jirovetz L, Trifonova D, Krastev L, Stoyanova
AS, Krastanov AI. Chemical composition and antioxidant properties
of juniper berry (Juniperus communis L.) essential oil. Bulg J Agric
Sci 2014; 20:227–37
35. Saab AM, Guerrini A, Sacchetti G, Maietti S, Zeino M, Arend J,
Gambari R, Bernardi F, Efferth T. Phytochemical analysis and
cytotoxicity towards multidrug-resistant leukemia cells of essential
oils derived from Lebanese medicinal plants. Planta Med 2012;
78:1927–31.
36. El-Sawi S, Motawae H, Ali M. Chemical composition, cytotoxic
activity and antimicrobial activity of essential oils of leaves and
berries of Juniperus phoenicea growing in Egypt. Afr J Trad Compl
Alt Med 2007; 4:417–26.
37. Cabral C , Francisco V, Cavaleiro C, Gonçalves MJ, Cruz MT, Sales
F, Batista MT, Salgueiro L. Essential oil of Juniperus communis sub
sp. alpina (Suter) Celak needles: chemical composition, antifungal
activity and cytotoxicity. Phytother Res 2012; 26(9):1352–7.
38. Uprety Y, Asselin H, Boon EK, Yadav S, Shrestha KK. Indigenous
use and bio-efficacy of medicinal plants in the Rasuwa District,
Central Nepal. J. Ethnobiol Ethnomed 2010; 6:3–9.
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