Anti-asthmatic property and possible mode of activity of an ethanol leaf extract of Polyscias fruticosa

CONTEXT

Polyscias fruticosa (L.) Harms (Araliaceae) is used as a traditional remedy for asthma in Ghana.

OBJECTIVE

The objective of this study is to establish the anti-asthmatic property and a possible mode of activity of an ethanol leaf extract of P. fruticosa (PFE).

MATERIALS AND METHODS

The time (min) for pre-convulsive dyspnea, and time for recovery, after sensitization with 150 μg OVA and induction of bronchospasm with 1% acetylcholine or histamine in normal, and 100, 250, and 500 mg/kg PFE-treated Dunkin Hartley guinea pigs, were recorded. Atropine (0.1 mg), mepyramine (0.1 mg), and PFE (1 mg) effect on a contractile response of 2.0 × 10(-2) μg/ml acetylcholine and 5.8 × 10(-2) μg/ml histamine on the isolated guinea pig ileum was investigated. Cytological and histological studies were conducted using guinea pig peritoneal mast cells and mesenteric cells, respectively, to establish PFE effect on compound 48/80-induced mast cell degranulation.

RESULTS

PFE (100-500 mg/kg) prolonged the onset of pre-convulsive dyspnea by 76.1-180.2% (p ≤ 0.01-0.001), and decreased recovery time by 71.9-78.5% (p ≤ 0.01-0.001). It also enhanced percentage protection against histamine-induced bronchospasm by 15.8-80.1-fold (p ≤ 0.05-0.01), and decreased percentage recovery time 2.5-3.3-fold (p ≤ 0.05-0.01). PFE significantly inhibited (60.4 ± 8.3%) contractile responses of histamine and produced significant inhibition (56-79%: p ≤ 0.001) of mast cell degranulation.

CONCLUSION

PFE has anti-asthmatic, antihistaminic, and mast cell stabilization effect making it useful in traditional asthma management.

Anti-histaminic, mast cell stabilizing and bronchodilator effect of hydroalcoholic extract of polyherbal compound- Bharangyadi

Bronchial asthma is a chronic inflammatory disorder of the airways associated with reversible airway obstruction and increased airway responsiveness to a variety of stimuli. An intuitive inference from this definition is that a causal relationship may exist between airway inflammation and airway hyperresponsiveness. It can be say that “airway inflammation equal to airway hyperresponsiveness”. Attachment of antigen antibody complex to the mast cell causes its disruption and release of inflammatory mediators such as histamine.To evaluate the efficacy of anti-asthmatic property of a drug, evaluation of anti-histaminic, mast cell stabilizing and bronchodilator property can be use as pharmacodynamic parameter. Bharangyadi is a polyherbal compound having Bharangi (Clerodendrum serratum), Sati (Hedychium spicatum) and Pushkarmoola (Inula racemosa) as ingredient herbs The present study aimed to evaluate the anti-asthmatic activity of an indigenous polyherbal compound Bharangyadi through various in-vitro & in-vivo experimental models.

The results demonstrate that drug has potent histamine antagonism property with significant mast cell stabilizing and spasmolytic activity in the experimental animals. Compound 48/80, a potent mast cell degranulator, provoked 76% degranulation of mast cells in the control group. Ethanolic extract of Bharangyadi at the doses 500 and 1000 μg/ml protected from compound 48/80-evoked degranulation (P < 0.01) in dose dependent manner.

Pre-treatment with Bharangyadi extract showed 80% & 86% protection from histamine induced bronchoconstriction in guinea pigs with 27.8% and 36.1% increase in preconvoulsion time (equal to standard drug). Screening of Histamine antagonism activity on guinea pig ileum showed that drug reduces the smooth muscle contraction in dose dependent manner. Increasing concentration of Bharangyadi extract with maximum dose of histamine (1.6μg) showed maximum inhibition at the dose of 50mg (99.78%). Inhibition of smooth muscle contraction by addition of drug in organ bath before adding histamine showed that drug has preventive type antagonism.

Herbex-kid Inhibits Immediate Hypersensitivity Reactions in Mice and Rats

Herbex-kid (HK), a polyherbal formulation was evaluated in various experimental allergic models of Type I hypersensitivity reactions. Compound 48/80 (C 48/80) has been shown to induce rat mesentery mast cell degranulation and HK (1.07, 10.75 and 107.5 mg ml⁻¹) inhibited the mast cell degranulation in a dose dependent manner. HK (1.07, 10.75 and 107.5 mg kg⁻¹; p.o.) showed dose-dependent protection against C 48/80 induced systemic anaphylaxis in male Balb/C mice. In active anaphylaxis model, male Wistar rats orally administered with 10.75 and 107.5 mg kg⁻¹ of HK showed significant (P < 0.01) protection against mast cell degranulation, while in passive anaphylaxis model, only at 107.5 mg kg⁻¹ showed significant (P < 0.01) reduction in mast cell degranulation. HK at all dose levels was able to significantly decrease the time spent in nasal rubbing in Wistar rats sensitized to ovalbumin, while only at 107.5 mg kg⁻¹ it showed significant (P < 0.01) reduction in number of sneezes. In C 48/80-induced skin itch model, all dose levels of HK significantly (P < 0.001) decreased the time spent in itching and the number of itches. HK did not produce any significant inhibition in histamine induced contraction in guinea pig ileum. From the above findings we conclude that the HK possesses antiallergic activity mediated by reducing of the release mediators from mast cells and also by 5-HT antagonism without the involvement of histamine (H1) receptors.

Azelastine hydrochloride, a dual-acting anti-inflammatory ophthalmic solution, for treatment of allergic conjunctivitis

Over 50% of patients who seek treatment for allergies present with ocular symptoms. Our current ability to control ocular allergic symptoms is greater than ever before. Newer dual-acting topical eyedrops attack multiple facets of the allergic cascade. Azelastine has antihistaminic effects providing immediate relief, mast cell stabilization providing early-phase intervention, and inhibition of expression and activation of anti-inflammatory mediators which characterize the late phase of the immune reaction. The ophthalmic eyedrop formulation is approved for treatment of allergic conjunctivitis in adults and children aged over 3 years. In clinical trials comparing azelastine with other dual-acting eyedrops, such as levocabastine and olopatadine, azelastine was reported to be slightly less efficacious and to sting briefly upon administration. Even so, many patients experienced the full benefit of symptom relief, and preferred azelastine. As a broad-spectrum drug, azelastine offers many desirable properties for management of ocular allergies. Because it can often produce maximal effect with just twice-daily dosing, azelastine is a particularly good choice for the allergic population in whom minimizing exposure to topical products and preservatives is a key concern.