Aerva lanata L. (Amaranthaceae) is a woody, prostrate or succulent, perennial herb or under shrub. It is traditionally known as, Pashana beda. Leaves are woolly, tomentose throughout, and smaller in flowering branches. Flowers are very small, sessile, bisexual, greenish or dull white, often clustered with spikes. Seeds are kidney-shaped and shining black in color. The root has camphor like aroma and medicinally important [1]. The extract of A. lanata is endowed with flavonoids, alkaloids, triterpenes, steroids, polysaccharides, tannins and saponins. A. lanata is used as an important medicinal plant for illness. It is also called in English as a stone breaking plant. A. lanata comprises medicinal and pharmaceutical importance [2]. It is used by ayurvedic practitioners for many pathological conditions. A variety of pharmacological activities of the Aerva plant such as anthelmintic, demulcent, anti-inflammatory, diuretic, expectorant, hepato-protective and nephron- protective [3].

Scientific classification

Kingdom: Plantae

Order: Caryophyllus

Family: Amaranthaceae

Subfamily: Amaranthoideae

Genus: Aerva

Species: persica, lanata, artemisioides, coriacea, humbertii, javanica, madagassica, microphylla, transvaalensis, revolute, sanguinolenta.

Common name

Tamil: Sirupulai, Cerupulai

Sanskrit: Bhadra

Hindi: Aa, Gorakhganja

Kannada: Bilihindisoppu

Telugu: Pindiconda, Pindicettu

Malayalam: Cherula, Cheruvula, Cerupula

Bengali: Chaya

Marathi: Kapur-madura

Gujarati: Gorakhaganjo

Punjabi: Buikallan

Oriya: Paunsia (Figure 1)

Figure 1: Aerva plant.

Traditional uses

The plant is used for arresting hemorrhage during pregnancy burn healing, as an anti-inflammatory, headache, skin disease, to dissolve kidney, and gall bladder stones, for uterus clearance after delivery and to prevent lactation. The plant extract is used to treat, nasal bleeding, cough, scorpion sting, fractures and spermatorrhoea. Aerva lanata serves as a purpose of anthelmintic and medication that soothes inflamed and injured skin. The people of biharuse use the plant as a treatment of diarrhea, cholera and dysentery. The roots also used for diuretic and demulcent, and are credit with tonic properties [4].

Macroscopy

This plant is commonly known as polpala, of Amaranthaceae family an important gregarious shrub growing throughout Bangladesh, particularly along waste places in India. It is a branched plant which has white to pale pink spikes of clusters of flowers 1 to 1.5 inches long. The herb is cultivated throughout India, Ceylon, Arabia, Tropical Africa, Java, Philippines [5]. Aerva lanata Linn.is a ramous many branched hardy erect prostrate woody herb from 30 to 80 cm height, the main stem short but stout and woody at base from which arise 4 to 10 or more elongate hairy branches. The branches bears short petioles nearly orbicular leaves 8 to 20 mm long, numerous minute hairy white flowers [6].

Microscopic properties

Powder microscopy of Aerva lanata roots: Powder microscopy was done according to the standard procedure mentioned. The powder microscopy revealed the following

a) Fibers: lignified and non-lignified, long, slender and cylindrical shaped (Figure 2.1).

Figure 2: Microscopy of Aerva lanata roots.

b) Xylem vessels: it is lignified with bordered pits (Figure 2.2).

c) Calcium oxalate crystals: present in parenchymatous cells and scattered. The druces are 40 μm in diameters (Figure 2.3).

d) Starch grains: most are simple, oval or rounded without any striation (Figure 2.4).

e) Parenchyma cells are intermingled between the xylem elements (Figure 2.5).

f) Secondary phloem was dominant with phloem parenchyma with embedded fibers (Figure 2.6).

g) Cork cells were commonly reported (Figure 2.7).

h) Tricho scelride are present [7].

Powder Microscopy of flowers: The powder microscopy of flower shows trichomes, pollen grains, starch grains, calcium oxalate crystals epidermal cells and stomata. Trichomes are multicellular, uniseriate with spinulated surface, tapered at the end and multiarticulate. Pollen grains are spherical in shape and are about 17-20 μm in diameter. Starch grains are oval toellipsoidal, mostly simple, without any striations (Figures 2 and 3) [8].

Figure 3: Powder microscopy of roots of Aerva lanata.

Chemical constituents

Aerva lanata leaves contained low levels of anti-nutrients, such as tannic acid (0.35%), saponin(7.67%) flavonoids (3.75%), oxalate (3.69%) and phytin-phosphorus (6.50%) but a little bit high in alkaloids(11.4%) and phyticacid (23.1%). The aerial parts of A.lanata have been reported to contain Oacylglycosides, narcissin(isorhamnetin- 7-O-rutinoside), feruloyltyramine, aervitrine, syringic acid, vanillic acid, ferulic acid (chawla et al.). The whole plant of A. lanata contains β-Sitosterol, α-amyrin,betulin, hentriacontane, sitosteryl palmitate, D-glucoside, glycosides, Kaempferol-3-galactoside and Kaempferol-3- rhamnogalactoside, starch, free: sugars (fructose, galactose, rhamnose and sucrose). Alkaloids, phenolic compounds, phytosterols, carbohydrates, proteins, amino acids, flavonoids and quinones were identified in different solvents extracts (Figure 4) [9].

Figure 4: Chemical constituents identified in different solvents extracts.

Biological activities

Diuretic activity of Aerva lanata flowers: The hydro-alcoholic extract of flowers of Aerva lanata was screened for its diuretic activity in rats. The diuretic activity studied in 5 and 24 hours and the extract showed increase of urine volume, Na⁺, K⁺, Cl⁺ ions as compared to normal saline. The hydro alcoholic extract of flowers of Aerva lanata upon phytochemical investigation revealed the presence of flavonoids, glycosides, carbohydrates, alkaloids and phytosterols [10].

Anthelmintic activity: The phyto constituents may be responsible to show a potent anthelmintic activity .Methanolic extract of aerial parts of Aerva lanata at concentration of 100 mg/ ml caused paralysisin 7.5 min and death in 11.16 min, while aqueous extractshowed paralysis in 13.83 min and death in 18 min against Pheritimapostuma [4].

Antibacterial activity: Ethyl extract of A. lanata shows antibacterial activity against Bacilllus cereus, Staphylococcus aureus, Shigellashiga, Klebsiella sp. and antifungal activities against Aspergillus niger, Candidaalbicans. The ethyl acetate extract shows more interesting antibacterial and antifungal properties than petroleum ether and methanolic extract [11].

Anti- HIV activity: Chloroform and methanol extraction of A. lanata shows highest inhibition of recombinant HIV-RT (91.0% and 89.0% respectively) at 2 mg/ml concentrate. At the concentration of 0.5 mg/ml to 2 mg/ml all extractions of Aervalanata shows significant inhibition of recombinant HIV-RT [12].

Antioxidant activity: B. diffusa and A. lanata extracts, in the dose of 100 mg/kg, improved the SOD, Catalase, and Peroxidase levels significantly, which were comparable with Silymarin. Methonolic extract of aerial parts of B. diffusa and methanolic extract of A. lanata whole plant showed significant dose dependent inhibition of lipid peroxidation with increasing concentration from 50-100 mg/kg. Both the extracts were found to inhibit lipid per oxidation [13].

Antinociceptive: Anti-nociceptive effect of A. lanata ethanolic extract has shown a significant dose dependent reduction in the number of abdominal writhes compared to the control values. Strong inhibition of this effect was observed at a dose of 100 mg·kg^-1 and the activity is comparable with that of acetyl salicylic acid. In addition, pretreatment with non-selective opioid receptor antagonist naloxone has not antagonized the A. lanata (100 mg·kg^-1) and acetyl salicylic acid induced analgesic activity [14].

Hepatoprotective activity: Hydroalcoholic extract of Aerva lanata is used against paracetamol induced liver damage in rats. The hydroalcoholic extract of Aerva lanata (600 mg/kg) was administered orally to the animals with hepatotoxicity induced by paracetamol (3 gm/kg). Silymarin (25 mg/kg) was used as the standard. All the test drugs were administered orally by suspending in 0.5% carboxy methyl cellulose solution. The plant extract was effective in protecting the liver against the injury induced by paracetamol in rats. This is due to significant reduction in serum enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphates (ALP) and bilirubin [15].

Antifertility activity: Due the presence of α-amyrin in A. lanata, it is used as antifertility activity. The study was carried out at two different doses of 200 and 400 mg/kg b/w. Corresponds to anti-implantation activity at a dose of 200 mg/kg b/w that shows only 20%, and 40%, respectively400 mg/kg b/w shows 30% pre-implantation loss. Similarly, in the abortifacient model, 200 and 400 mg/kg b/w show pregnancy failure of 30%.

Authors are thankful to President and Hon. Secretary of Khalsa College Charitable Society, Amritsar and Director-Principal, Khalsa college of Pharmacy, Amritsar for their inspiration, encouragement and support.