**2. Boerhavia diffusa**

*Boerhavia diffusa* is a herbaceous plant commonly known as punarnava in Sanskrit. The whole plant is known to have medicinal properties and being used in most parts of the subcontinent. Alkaloids are best known principle product present in the roots which is known as punarnavine. In traditional medicine, *Boerhavia diffusa* is more commonly used in the treatment of jaundice, dyspepsia, abdominal pain, spleen enlargement and as an antistress agent. In the year 1980–1991, researchers proved that *B. diffusa* root extract had strong antihepatotoxic properties which can be used to cure viral hepatitis [3].

### **2.1 Origin and distribution**

*B. diffusa* is found mostly in Asia, that too in warmer parts with an altitude of 2000. It grows well in crop fields and wastelands after the rainy season [4]. The genus *Boerhavia* has many species, and is also found spread in few regions of the world. *B. diffusa* is found in few places of Australia, South Africa and USA apart from Asian countries like China, Egypt, Pakistan, Sudan, Sri Lanka and in several countries of the Middle East [5]. Out of the 40 species of this genus, 6 species are found in India namely *B. diffusa*, *B. chinensis*, *B. erecta*, *B. repens*, *B. rependa* and *B. rubicunda* [6].


### **2.2 Chemical constituents**

The main component 2-glucopyranose-4-hydroxy-5-[P-hydroxyphenyl] propionyldiphenyl methane was found in the roots of the plant. Many steroids, triterpenoids, alkaloids, flavonoids, lipids, lignins, proteins, carbohydrates and glycoproteins are mostly found [7]. Punarnavine, hypoxanthine 9-L-arabinofuranoside, ursolic acid, boeravinone, punarnavoside and liirodendrin have been purified and elucidated in detail for their biological activity with antiviral properties. Large amount of potassium nitrate is mostly found in this plant. The entire plant has huge percentage of proteins and fats. It also contains 14 amino acids in root, out of which 7 are essential amino acids. Punarnavoside is an antifibrinolytic compound isolated from the roots of *B. diffusa* long back [8]. When roots were analyzed for phytochemical screening, maximum alkaloid content [2%] was found.

**57**

*Antiviral Plant Extracts*

**2.3 Pharmacology**

protection [9].

**3.** *Eclipta alba*

strong analgesic properties [14].

**3.1 Origin and distribution**

in low altitudes [17].

of *B. diffusa* are used [12].

**2.4 Antiviral activity of** *Boerhavia diffusa*

*tabacum*, Sunhemp and *Crotalaria juncea* [13].

*DOI: http://dx.doi.org/10.5772/intechopen.85126*

Pharmacological studies have demonstrated strong antiviral properties. Wide diuretic properties have been found in punarnavoside obtained from Punarnava, apart from that anthelmintic, antifibrinolytic, anticonvulsant, antibacterial, antihepatotoxic, antiasthmatic and antinematodal activity have also been observed. Against various abnormal production of liver enzymes AST, ALT and pigment bilirubin, the aqueous root extracts of *B. diffusa* at a dose of 2 ml/kg exhibited strong

Drugs obtained from this herb, given either alone or in combination with other drugs were found to be effective in killing many virus for disorders pertaining to liver, infections of the respiratory tract and heart disease [10]. Against various bacteria, the purified form of glycoprotein obtained from *B. diffusa* exhibited strong antimicrobial activity. Many clinical researches have proved that against bacteriophages punarnava is found to be very effective [11]. For inducing systemic resistance in various crops against different viruses, the roots

Against potato virus X, *Boerhavia diffusa* have shown a very good effect in inhibiting in hypersensitive and systemic hosts. The inhibition of these extracts was found to be very sensitive to actinomycin D. By the application of the aqueous root extract of *B. diffusa*, the destructive yellow mosaic disease of mung bean [*Vigna radiata*], caused by mung bean yellow mosaic virus was controlled. The treatment also resulted in increased plant height, root nodulation, primary and secondary branches, grain yield and pod formation. Against bacteriophage, the purified form of glycoprotein obtained from *Boerhavia diffusa* showed strong antimicrobial activity. To resist viral infection in many susceptible crops, the extracts obtained from the roots of *B. diffusa* was used. This antiviral agent was active against *Nicotiana* 

*Eclipta alba* grows as a weed commonly in wet places around the world. It is widely distributed in India, China, Thailand and Brazil. *Eclipta alba* [L.] Hassk. [syn. *Eclipta prostrata* L.], commonly known as False Daisy is a plant from the family Asteraceae. Different varieties of indigenous drugs possessing analgesic properties have been obtained from this plant in Ayurveda. Extract of *E. alba* showed

In the tropical and subtropical regions of the earth. *Eclipta alba* is usually found on poorly drained wet areas, on the dikes of rice paddies, along streams and ditches in marshes. It is most commonly found in elevated lands with 1200 mm of rainfall or more. It grows very well in salty and humid conditions but is mostly a plantation crop [15]. In few countries, it is found near sea level and is said to be a naturalized weed in waste places, open fields often near ditches and in cultivated areas [16]. In some parts of the world, it is a common plant of foreshores, streamsides, wet situations, weed of wet pasture and in roadside ditches. In is also found
