Vasaka is a single-herb formulation prepared from the aerial part extract of Vasaka (Adhatoda vasica). Vasaka contains vasicine (parent compound of bromhexine) that liberates lysosomal enzymes involved in mucolytic action. Vasaka exhibits antitussive action by bronchial muscle relaxation or decreased airway resistance. Vasaka produces a significant anti-inflammatory effect on acute inflammatory processes by inhibiting cyclooxygenase (COX) and 5-lipoxygenase (5-LOX). Vasaka shows an immunomodulatory effect by inhibiting delayed-type hypersensitivity (DTH) reaction due to its influence on biological mediators such as histamine, products of arachidonic acid metabolism, and interferon (IFN)-y. The enzymatic antioxidant activity of Vasaka prevents chain initiation, binding of transition metal ion catalysts, reductive capacity, and radical scavenging.
Pharmacological Actions
1. Mucolytic and expectorant activities
Bromhexine (N-methyl-N-cyclohexane-3,5-dibromo 2-aminobenzylamine hydrochloride) is derived from vasicine, an alkaloid from Vasaka. Bromhexine increases mucus secretion, reduces sputum viscosity, and facilitates expectoration.
Bromhexine liberates lysosomal enzymes into the cytoplasm. Lysosomal enzymes are involved in the mucolytic action on acid glycoprotein contained in the mucus granules of the submucosal gland. Bromhexine disintegrates the fibril in the sputum and lowers the viscosity of the mucus.
2. Antitussive and bronchodilatory activities
The antitussive activity of the pectic arabinogalactan obtained from Vasaka works by an antispasmodic or bronchodilatory action. Pectic arabinogalactan causes bronchial muscle relaxation in vitro or decreases airway resistance in vivo. Arabinogalactan possesses high cough-suppressive effect and decreases the values of specific airway resistance under in vivo conditions.
Vasicine shows inhibitory effect against carbachol, 5-hydroxytryptamine, and histamine-induced bronchoconstriction. The occupation of the receptor sites by vasicine molecules enhances the bronchodilatory effect of vasicine in vivo.
3. Anti-inflammatory activity
Vasaka produces significant anti-inflammatory activity in acute inflammatory processes.Vasaka has highest inhibitory effects on COX and 5-LOX, found among the class of phenolic compounds and arachidonic acid analogs. Both COX and 5-LOX are enzymes responsible for the formation of inflammatory mediators such as prostanoids and leukotrienes.
4. Immunomodulatory activity
Vasaka potentiates both humoral as well as cell mediated immunities. Vasaka inhibits DTH reactiveness. The interaction of sensitized T cells with the presented antigen is known to be associated with the release of mediators such as histamines. Products of arachidonic acid metabolism and IFN-y eventually lead to DTH. Therefore, the inhibitory action could be due to an influence of fraction on the biological mediators.
5. Antioxidant activity
The enzymatic and nonenzymatic antioxidants in Vasaka exhibit antioxidant and radical scavenging activities. The activity of enzymatic antioxidants such as superoxide dismutase, catalase, and ascorbic acid oxidase has been attributed to various mechanisms such as prevention of chain initiation, binding of transition metal ion catalysts, decomposition of peroxides, prevention of continued hydrogen abstraction, reductive capacity, and radical scavenging.
Indications
- Productive cough
- Cough associated with chronic obstructive pulmonary disease (COPD)
- Smoker's cough
- Bronchitis
- Asthma