Pedalium murex L.: Potential genetic resource for herbal medicine and mucilage

Pedalium murex (Pedaliaceae), commonly known as large caltrops in English and bada gokharu in Hindi is an underutilized mucilaginous medicinal herb having multiple uses in traditional system of medicine. It is mainly used to cure reproductive disorders, like impotency in men, nocturnal emissions, gonorrhoea as well as leucorrhoea in women. It is also useful in the treatment of urinary and gastrointestinal tract disorders. The present paper deals with botanical identity, vernacular names, ecology, environmental requirement and growth conditions, origin and geographical distribution, morphological/botanical description, propagation and cultivation, usages as a source of food, mucilage, medicine and biodiesel, important Ayurvedic formulations, phytochemical and pharmacological prole, future prospect.

Ecology, environmental requirement and growth condition P. murex generally grows as a weed at the edges/ open grassland near seashore, up to 500 m altitude. It is a saline soil indicator, and also occurs on sandy and limestone soils. It grows luxuriously in fertile soils and crop land as a weed at 25-30°C temperature. In Western Uttar Pradesh germination starts during the month of June-July and owering fruiting occurs during September to December. Geographical distribution P. murex is native to Africa and Asia. It is distributed in most of the dry and coastal areas of Africa and Asia. In Africa, it is distributed in nearly all directions of Tropical Africa i.e., Northeast Tropical Africa (Djibouti, Somalia), East Tropical Africa (Kenya, Tanzania), West Tropical Africa (Ghana, Nigeria, Togo), South Tropical Africa (Mozambique) and in western Indian Ocean (Madagascar and Comoros). In Asia the species is distributed in Arabian Peninsula (Yemen) and Indian Subcontinent (India and Sri Lanka) ( Fig. 1). In India, it mainly occurs as a weed of waste places in the southern India especially in Deccan Peninsula and Corommandal coasts, and in saline sandy areas along river belts in the Tamil Nadu, Andra Pradesh, Haryana, Delhi, Rajasthan, Punjab, Gujarat and Madhy Pradesh, Uttar Pradesh etc.

Morphological description
Morphological study of P. murex collected from Bahadurpur site (established in 2017 for rehabilitation of degraded sandy soil and conservation of local phytodiversity) of Botany department, Dayalbagh Educational Institute (Deemeed to be University), Dayalbagh, Agra shows that it is an annual, diffuse, succulent, mucilaginous herb of about 60-70 cm height (Fig. 2).

Root
Tap root system, 4 to 5 inch long, reddish brown in colour and bear a sweet aroma.

Stem
Stem is of about one cm diameter, much branched, succulent, glandular green in colour having branches spread up to 30 X 30 to 60 X 60 cm east-west and north-south diameter. The main shoot may be prostrate or erect. Phyllotaxy is opposite decussate.
Leaf length and width varies from 4.0-6.5 cm, and 4.0-5.0 cm respectively. Petiole length varies from 2.7-3.0 cm. Leaf contain prominent midrib, slightly thicker lateral veins, uniformly thick lamina with smooth surface, at petiole and glandular trichomes are also found on both abaxial and adaxial sides of leaf.
Venation is reticulate type with thick and straight veins.

Flowers
Flowers arise on leaf axis, pentamerous, gamopetalus, 2.5-3.0 cm long and 1.0-1.5 cm width and are yellow in colour with short pedicel. Calyx ve, parietal with gamopetalous corolla, ve lobes, round, tetradynamous stamens, bicarpellary stigma, ovules four celled Fruits Fruits are 1.5-2.0 cm long, 0.8-1.5 cm diameter in size with pale yellowish to brown colour, indehiscent hard drupe, pyramidal glabrous surface and ovoid, globular in shape with four-ridges, having four spreading spines of 2.0-4.0 mm long at the base; attached with a short curved pedicle and having a terminal apex. Fruit possess 5-12 compartments having single seed in each compartment.

Seeds
Seeds are oblong, black in colour and covered with pappus. Seeds are mucilaginous, odourless and sweet in taste. Average weight of 1000 seeds was estimated to 151.69 grams.

Propagation And Cultivation
Plant is propagated by seeds in nature, but the germination requirement of seed and information regarding dormancy and viability period of the seeds are not known. There is no information regarding cultivation practices, requirement of nutrients and irrigation. Germination of seed without any seed treatment from the seeds collected from Bahadurpur site before one year was unsuccessful in soil as well as by lter paper method; however plant was propagated successfully by stem cuttings.
An experiment was carried out in the month of October, 2019 in the Department of Botany, Dayalbagh Educational Institute, Agra (27°13'45.57"N and 78°0'9.45"E). About 4-5 inches long and one cm thick stem cuttings were collected from natural vegetation with the help of a sharp sterilized knife. Leaves from the cutting were trimmed, and 6 cuttings were planted in four replicate in pots containing a potting mixture farm yard manure and sandy soil in a ratio of 1:3. The average environmental condition at that time in the month of October (post monsoon month) with temperature ranges of average high was 29.4°C (85°F) in day time and an average low of 20°C (68°F) during night and average relative humidity was near to about 40%. Sprouting started in 4 th day after transplantation (DAT) and all the cuttings were sprouted in seven days. The number of sprouts' increases with time ( Fig. 3 and 4) Usages As A Source Of Food, Mucilage, Medicine And Biodiesel P. murex is a very important source of food, mucilage and medicine. Leaves are used as vegetable (Kirtikar and Basu, 1935). Various parts of the plant are used for the maintenance of general health and vitality, prevention and treatment of various disease and ailments of human being and domestic animals. The leaves and stems when agitated in cold water turn into tasteless, colourless thick mucilage, which is of high medicinal importance. It is a cheap and effective natural excipient that can be used as an effective alternative for the formulation of pharmaceutical suspensions. It have low rate of sedimentation, high viscosity, slightly basic pH and is easily redispersible (Yeole et al. 2010). An infusion of the stem and leaves is also used in gonorrhoea and dysuria (Kirtikar and Basu, 1935). It is a medicinal plant used in Ayurveda for the treatment of calculi, spermatorrhoea, amenorrhea, dysmenorrhea, in ammation, ulcers, fevers and other disorders. In Ayurveda, it is used as a tonic, aphrodisiac, appetizer, strangury, bladder stone, cough, asthma, pain, heart trouble, piles, leprosy, blood puri er and to cure skin diseases (Chopra et al. 1956). It is a major constituent of Ayurvedic formulations such as Gokhuradiguggul, Gokhurkwath, Gokhuradiawalaha, and Deshnularishta (Sivarajan and Balchandra 1994). According to Unani system of medicine, it helps to cure gleet, lumbago, stomachache, emmenagogue etc. (Shukla and Khanuja 2004). Beside Ayurveda and Unani system of medicine various parts of the plant are used as ethno medicine by the indigenous communities for treatment and prevention from various diseases and ailments in various parts of the world (Table 1). P. murex is also used for the biological synthesis nanoparticles. Biosynthesis of gold nanoparticle using cold and hot extract of P. murex showed that both the extracts produced nanoparticles in the range of 180-200nm. The biosynthesized AgNPs were found to have a potent antibacterial activity against E. coli, K. pneumonia, B. subtilis, S. aureus, etc. Ceramic SrO/CeO2 mixed oxide NPs biosynthesised from leaves of P. murex shows high antibacterial activity against S. aureus (G+) and E. coli (G−) bacteria and high antioxidant activity (Peter et al. 2014;Anandalakshmi et al. 2015;Pandiyan et al. 2019). Due to presence of high lipid content in areal parts P murex can be used for biodiesel production (Shivprakash et al. 2019) Phytochemical And Pharmacological Pro le Phytochemical and pharmacological pro le of the plant is studied well and documented in scienti c literatures. P. murex is a rich source of various triterpenoids, fatty acids, steroids, avonoids, tannins, saponins, vitamins, proteins, sugars, vanillin, ursolic acid. It contains higher concentrations of steroids and sterols, and moderate concentrations of avanoids, phenols, glycosides, alkaloids, proteins, terpenes, carbohydrates, gums and mucilage. It has been reported that steroidal components found in the plants possess fertility potentiating properties, and they have been found to be useful in the treatment of impotence (Das et al. 1966;Subramanian and Nair 1972;Rastogi et al.1982;Zafar et al.1989;Bhakuni et al. 1992;Vedavathy et al. 1997;Srinivasrao et al. 1999

Conclusion And Future Perspectives
On the basis of multidimensional potential of P. murex it is concluded that the species is underutilized and used for the healthcare management only by the practiceners of Ayurveda, Unani, and folklore system of medicines. The plant has industrial value and hard and prickly fruits are traded as raw medicine in Indian herbal mandies and used by Aurvedic medicines manufacturers for the medicinal preparations. Due to edible nature of leaves as green vegetable and high mucilage and lipid content (to be used for industrial production) the plant may have high demand in near future. As the plant is collected from natural resources and seeds are collected for selling in local market/venders the species should be properly conserved and domesticated. Studies for the development of suitable agro-technology for commercial cultivation of P. murex should be conducted to utilize full potential of this species for human welfare.

Declarations Funding
No speci c fund was available from any funding agency. The research was conducted by using facilities available in the Department of Botany, Dayalbagh Educational Institute, Agra.   Water boiled with whole plant is fed to animals to help in expel out the placenta after delivery.

Con icts of interest/Competing interests
Gujarat (Sach gokhru) Mistry et al. (2003) Whole plant extract is used as a tonic for health and vigour.
Plant mucilage is administered to livestock for every delivery of young ones.
Tamil Nadu (Anai nerunji) Ganesan et al. (2006) The entire plant is macerated and is given for ephemeral fever in cattle for 4 days.
Andhra Pradesh (Yenugu Palleru) Reddy et al. (1989) Whole plant is fed to the animal for its cooling effect during summer.
Rajasthan (Dakhinigokhru) Galav et al. (2013) Fresh whole herb is soaked overnight in water. The sticky infusion mixed with cane sugar is taken daily once to cure painful urination, excess urination, haematuria, etc. An infusion is a remedy for dysuria.
Plant infusion is given for common fever Uttar Pradesh (Bara gokhru) Ali Z. A (1998) Fine powder or paste is mixed with butter milk and given to drunk to reduce body heat in animals and plants are given as a fodder or soaked in water and this medicated water is given to drink to reduce the exposure to diseases in animals.

Rajasthan (Gokhru Bada)
Upadhyay et al. (2011) Aerial Part The plant twig is dipped in water seven to ten times and this water is taken orally to cure dysentery.
Crushed plant is soaked in water, ltered in next morning, mixed with sugar candy and seed powder of black pepper and taken as refrigerant as well as skin diseases.
Aerial part of the plant is stirred in cup of water, to make oil appearance preparation; taken orally once a day up to one week for the treatment of hyperacidity.
Tamil Nadu (Anaineringi) Nazar et al. (2008) Stem and leaves are soaked and stirred in milk for few minutes until the milk becomes thick and is taken internally to treat diabetes, urinary irritations, uterine and puerperal diseases and local ulcers.
Fruit powder is mixed with powdered sugar and ghee is Haryana Yadav et al. Sprouting in P. murex L cuttings