An Insight into Endangered Himalayan Paeony (Paeonia emodi Royle): Ethnobotany, Phytochemistry and Pharmacology

Article History Received: February 03, 2020 Revised: April 08, 2020 Accepted: May 11, 2020 Paeonia emodi Royle is an endangered herb native to Himalayan region with diverse traditional therapeutic uses. It is categorized as critically endangered plant species. Traditionally plant parts are used for nervous diseases, uterine diseases, dysentery, colic, backache, hypertension, and piles. The medicinal activity is the result of presence of various important phytochemicals triterpenes, monoterpenes, phenolics, lipooxygenases, Nortriprenoids, steroids and aldehydes. P. emodi has many biological activities including antimicrobial, antifungal, anti-toxicity, and spasmolytic activity. Due to remarkable medicinal potential, this species is facing extremely high risk of extinction. This article briefly reviews botanical, medicinal, phytochemical, pharmacological and molecular attributes of this plant species along with its conservation strategies.


INTRODUCTION
The biological diversity is concerned with the species diversity, ecosystem diversity and genetic diversity. (Ahmad and Ismail, 2003). It is essential for human survival and economic wellbeing and for the ecosystem function and stability. Plants play an important part of ecosystem and should be prior to be conserved. (Ellstrand and Elam, 1993). These plant species, having slow growth rate, low population density and narrow geographic ranges are more prone to extinction due to overutilization (Jablonski, 2004;Dhyani and Kala 2005). Biodiversity is the life that flourishes on the earth surface. (Rahman et al., 2018) Floristic inventory and biodiversity is important for the present diversity status and conservation of the plant species diversity. It is important for the ecosystem function and stability (Jayakumar et al., 2011). These provide useful information on the distribution and abundance of species and insights into processes that control diversity (Davidar et al., 2007). Paeonia emodi Royle (Paeoniaceae) is endemic to Himalayan region and distributed in the northern areas of Pakistan, Northern west India and northern Nepal and Afghanistan (Khan et al., 2005;Khan and Ahmad, 2007;Riaz et al., 2004;Tantry et al., 2012). It is commonly called as Mamekh and Himalayan Paeony rose (Haq et al., 2012;Khan et al., 2008) and also called as king of flower (Tantry et al., 2012). It is perennial herb, 50-70cm long with glabrous ex-stipulated leaves and axillary solitary flower. Carpels are densely pubescent and 3 flowers in a stem. Plant paeonia is known as 'Queen of herbs' due to its medicinal importance and beauty of flower (Ahmad et al., 2018;Haq et al., 2012;Khan et al., 2005). Phylogeny of Paeonia species based on previous phylogenetic reconstruction using multiple gene showed that Paeonia emodi is presumably a hybrid between P. veitchii and P. lactiflora (Zand and Sang, 1999). The plant is critically endangered under category A with population reduction of 81% (Haq, 2011). People use local plants for their multidimensional purposes (Hamayun et al., 2003). According to World Health Organization report, 80% of the world population depends on medicinal plants and thus it increased the threat to the natural population of medicinal plants (Kandari et al., 2012). Many plant species are threatened with extinction because of the gradual disappearance of the terrestrial natural ecosystems for various human activities and small patches are extremely valuable for maintain regional plant diversity (ARROYO-RODRÍGUEZ et al., 2008). Often, this is due to the clearing of indigenous vegetation for agriculture and the resulting erosion, salinization, and invasion of alien species, but more recently climate change is looming as a significant new threat (Reed et al., 2011;Wang et al., 2017). The causes of loss of species are numerous but fragmentation and loss of natural habitats are major. (Jayakumar et al., 2011). Paeonia emodi is highly medicinal plant and found several applications in indigenous medicinal system as well. The rhizomes of plant are used to make tonic for backbone (Hamayun et al., 2004). Roots are used for headache, to cure vomiting and as aid for pregnancy (Khan et al., 2005). The seeds are purgative and emetic (Riaz et al., 2004). Paeonia emodi shows antifungal, antibacterial, phytotoxic, cytotoxic, and insecticidal activity (Mufti et al., 2012;Ismail et al., 2003;Khan et al., 2005). It is highly useful medicinally and it is dire need to conserve this plant species. It is reported critically endangered in Pakistan. Its conservation should be the prior concern. In view of biodiversity, Pakistan is under the great threat of extinction. Managing of the disturbance regime of the landscapes is one of the foundations for the biodiversity conservation. (Jayakumar et al., 2011).

Ethnopharmacology
The folk recipes are prepared either from the whole plant or from their different organs, like leaves, stem, bark, root, flower, seed, prop roots etc and from their secondary product such as gum, resins, and latex (Haq et al., 2012). The root of Paeonia emodi is crushed and mixed with milk, sugar and is used in backache and internal body pains. et al., 2006) Rhizome is used to increase milk production in livestock, also used as tonic (Haq et al., 2012). The dried leaves are used as a vegetable, which helps to purify the blood. The dried leaves are fried with ghee and use to cure dysentery and colic (Negi and Maikhuri et al., 2017). The infusion of dried flower is used in diarrhea (Haq et al., 2012). The underground tubers are used in nervous diseases, uterine diseases, colic, bilious obstructions, dropsy, epilepsy, convulsions, and hysteria (Riaz et al., 2003;Zargar et al., 2013). Plant is medicinally important, and its conservation is the major issue. Due to lack of knowledge, people indigenously use this to cure diseases and it leads to threatening of species. 3 Leaves Dried leaves are used to purify blood and often mixed with ghee to cure dysentery and colic (Negi and Maikhuri, 2017;Haq et al., 2012) 4 Tubers It is used for nervous disorder and uterine diseases (Riaz et al., 2003;Zargar et al., 2013) Pharmacological properties Antifungal activity Air dried and aerial and ground plant material are used against fungal growth (Mufti et al., 2012;Ismail et al., 2003;Khan et al., 2005). Fungi can cause infection of blood, liver, lungs, and mouth etc. The crude extract of P. emodi is used against Trichophyton longifusus, Candida albicans, Aspergilus flavus, Microsporum canis and Fusarium solani. This in-vitro study shows no growth of fungi (Khan et al., 2005). Because of this activity people locally use this plant and lead to the threatning of species and there is need to conserve the plant.

Antimicrobial activity
The crude extract of plant is also potent against many pathogenic bacteria and show antimicrobial activity (Ismail et al., 2003;Mufti et al., 2012;Khan et al., 2005). E. coli, P. aeruginosa, S. Aureus, Pseudomonas aeruginosa and Salmonella typhi were potently killed by this extract (Mufti et al., 2012). This plant could be used as pharmaceutical industry and need to preserve this.

Free radical scavenging activity
The potential antioxidant activity of the plant extracts was assessed on the basis of the scavenging activity of free radical (Zargar et al., 2014) and enzyme inhibition activities against jack bean and Bacillus pasteurii urease. (Khan et al., 2005b) Plant show potent activities against them. (Riaz et al., 2004).

Insecticidal activity
Insecticidal activity of extract of paeonia was also observed against Tribolium castaneum, Bruchus pisorum and Rhyzopartha dominica. Permethrin. It is medicinally important plant and show the activity by killing them (Khan et al., 2005;Ismail et al., 2003).

Brine shrimp toxicity
Artemia salina (brine-shrimp eggs) was used to determine the cytotoxicity of the extract. This exract is shows the activity against cytotoxicity of brine shrimp (Khan et al., 2005;Ismail et al., 2003).

Spasmolytic activity
The crude extract and subsequent fractions from the aerial parts of P. emodi were studied for their effects on the isolated rabbit jejunum. The crude extract displayed significant spasmolytic activity in a dose-dependent manner and inhibited the spontaneous motility of the rabbit jejunum by 76% (Khan and Ahmad, 2007).

Threats towards its extinction
Over exploitation, loss of habitat, attack of pathogens, effect of introduced taxa and change in environments were responsible for making these species either endangered or critically endangered species. Extensive grazing and deforestation which have led to forest fragmentation and degradation of the habitat are the primary causes of species extinction in the area (Haq, 2011) Indiginously, it is being over exploited which has contributed in being critically endangered. Excessive harvesting and large-scale developmental activities have resulted in fragmentation and reduced population size (Ravikanth et al., 2018).

Conservation strategies
The destruction of biological diversity has reached to the proportions of a global crisis in its magnitude, severity, and urgency. Effective conservation of biological diversity requires a sound basis in scientific understanding of the entities being protected and this is a fundamental need of conservation biology (Schemske et al., 1994).

Ex-situ conservation
Ex situ conservation methods sample genetic diversity of species using certain criteria and store/propagate the collected material outside its native habitat (Volis and Blecher, 2010). RAPD PCR amplification is one of method to conserve plant species. The ex-situ conserved population ML holds an intermediate level of genetic diversity compared with three natural populations and conserved 88.31% of the total genetic variation of the species (Li et al., 2002) The restored environments will undoubtedly differ from the original habitats and communities (Schemske er al. 1994) It is therefore critical that the released populations have sufficient genetic variability to provide adaptive flexibility in an uncertain future (Li et al., 2002). Botanical Gardens have played important role in ex situ conservation of rare and endangered plants (Li et al., 2002;Volis and Blecher, 2010) They also focus on wild plants and non-economic plants. But plants could only be genetically conserved due to lack of available space to grow them (Li et al., 2002). In conservation, the inter-situ approach proposed an offsite collection maintained within the natural habitat. This approach was treated as potentially very promising. It can be applied to the lands of low economic value such as abandoned agricultural lands and allows simultaneous reintroduction of large number of species (Volis and Blecher, 2010). Therefore, another method to conserve is planting of sampled germplasm as live gene banks and creation of living collection.

In-situ conservation
For speies threatened with extinction, in situ conservation may be the best option. The use of in vitro-propagated plants for reintroduction or restoration of rare species is also finding application, and this relies on the development of successful methods for acclimatizing plants from culture to in situ conditions (Reed et al., 2011) when several species within an ecosystem are endangered, sampling and planting can be done in parallel for several coexisting species. In this case the only factor limiting number of species to be preserved in living collections is available space. In general, multi-species living collections should be viewed as a preferred option. (Volis, 2010). Another promising approach is to identify `hotspots', or areas featuring exceptional concentrations of endemic species and experiencing exceptional loss of habitat (Myers et al., 2000).

CONCLUSIONS
The medicinal properties of Paeonia emodi discussed in this review have highlighted significant traditional and pharmacological activities of this plant. It is reported as critically endangered species. It is highly medicinal, and it is used by indigenous people for treatment. This excessive use and exploitation lead to the threatening of this species from its habitat. Different efficient, wise, and sustainable conservation strategies could be applied to protect this plant. The integrated approach is to match the biological subject of concern with the most suitable conservation method.