Cromoglicic acid (INN) — also referred to as cromolyn (USAN), cromoglycate (former BAN), or cromoglicate — is traditionally described as a mast cell stabilizer, and is commonly marketed as the sodium salt sodium cromoglicate or cromolyn sodium. This drug prevents the release of inflammatory chemicals such as histamine from mast cells.

Source : Wikipedia

Cromoglicic acid was originally derived from longstanding herbal remedies in the mid 1960s, and is now in widespread use as an active ingredient for asthma inhalers ( sold under the brand name Intal and others).

As the quote explains, it's known to be a mast cell stabilizer (mast cells are responsible for the release of histamine and related mediators which lead to immune responses).

However, the exact mechanism by which Cromoglicic acid helps to reduce the severity of asthmaplugin-autotooltip__plain plugin-autotooltip_bigAsthma

Asthma is a common, (and currently incurable) long term inflammatory disease of the airways of the lungs, characterized by variable and recurring symptoms such as reversible airflow obstruction, and bronchospasm. Episodes of asthma frequently feature wheezing, coughing, chest tightness, and shortness of breath. attacks is unknown. Several other compounds which are also known to be powerful mast cell stabilizers appear to have no effect on asthma.

The underlying mechanism of action is not fully understood; for while cromoglicate stabilizes mast cells, this mechanism is probably not why it works in asthma

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