Phenolic Substances and Biological Activities of Verbana officinalis L.: A Mini-Review

The published data related to the identification of the major phenolic compounds as well as its biological activities present in Verbana officinalis L. This plant has received a great interest in the worldwide for its diuretic, expectorant and anti-rheumatic, anti-inflammatory, antifungal, antibacterial, analgesic and antioxidant activities.


Introduction
Verbena officinalis or commonly referred as vervain belongs to the verbenaceae family (Table 1) which can be found in West Asia, North Africa and throughout Europe [1]. It is listed in the Chinese Pharmacopoeia and the British Herbal Pharmacopoeia [2]. Verbana is a medicinally used herb, where most people still depend on the folk medicine, despite the great progress in all opathic medicines, particularly to all eviateanxiety, insomnia, depression [3]. Verbena officinalis has been widely used for amenorrhea, insufficient lactation (lactogogue plant), assisting contractions duringlabor, promoting wound healing and for disorders of menstruation [4].  Verbena officinalis is a perennial herb. It is erect, 25-100 cm tall and branched above. Its leaves are 3.5-8 cm long and 1.5-3.5 cm broad. It has pale pink or purplish color flowers about 4 mm across [5] (Figures 1 & 2).  The compounds were detected either at 205 or 235 nm. Calibration data confirmed linearity of the detector response within the concentration range injected (R2 from 0.997 to 0.999), and revealed detection limits ranging from 5.0 lg mL )1 (verbascoside) to 13.6 lg mL )1 (hastatoside). The five markers were readily

Verbenalin [10] Hastatoside
Verbascoside UPLC separation was achieved using a Waters Acquity BHE C18 Column (150 3.9 mm i.d. 1.7 mm particle size maintained at 25°C), with a mobile phase flow rate of 0.4 mL/min. The mobile phase contained acetonitrile-ammonium acetate 5 mmol/L (A) and water-ammonium acetate (B) in different proportions.
The main class of compounds of these plants were phenylpropanoids, being verbascoside the most abundant in all the preparations up to 97 % of the total phenylpropanoids. In addition, iri-doids, has hastato side and verbenalin together with flavonoids, mono-and di-glucuronidic derivatives of luteolin and apigenin were found [6] (Table 2).

The Biological Activities of Verbana officinalis
The famous properties of vervain herb are sedative, antispasmodic and diaphoretic [11]. Verbena officinalis L. has been traditionally used as nervine tonic, antidepressant, and anticonvulsant; prescribed in liver and gall bladder complaints (spasm of the bladder and strangury), nervous and menstrual disorders; also, for bronchitis, asthma and febrile affections [12].
In addition to that, Verbana officinalis can be utilized to treat enteritis, acute dysentery, depression and amenorrhea [13]. The scavenging activity against DPPH (1,1diphenil-2-picrylhydrazyl) radical and the antifungal effect against chloroform, ethylacetate and 50% methanolic extracts of Verbena officinalis leaves were investigated. The activity of different fractions of 50% methanolic extract and some isolated compounds were also investigated. The

Organic and Medicinal Chemistry International Journal
results suggest that 50% methanolic extract and caffeoyl derivatives could potentially be considered as excellent and readily available sources of natural antifungal and antioxidant compounds [2].
The antimicrobial potential of verbana herb leaves, and roots was evaluated against 24 strains of Gram-positive and Gram-negative bacteria by Dildar [5]. Ethanolic extracts of stems, leaves, and roots of Verbena officinalis and their fractions in various solvents were assessed. The stems proved to be most potent against all the strains. Its activity against Staphylococcus aureus and Pseudomonas aeruginos a was higher than the antibiotic Amoxicillin.
The leaves also showed considerable activity against Pseudomonas aeruginosa, Citrobacter freundii, and Staphylococcus aureus. The roots turned out to be highly effective against Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa. The study confirmed the efficacy of Verbena officinalis against infectious diseases. While all the three parts of the plant were active against the test micro-organisms, stems were most powerful. The plant has great potential to provide exploitable leads for new antimicrobial drugs [5].