Nigeria Health & Lifstyle

Researchers Affirm Efficacy of Bitter Kola in Respiratory Diseases - Continued

Intake of Gk will therefore reduce the inhibition of antihistamine activity of flavonoids by copper which is as a result of its high content of vitamin C and zinc. Some studies noted that naturally occurring plant flavonoids affect a variety of cell activation phenomena including the secretion of histamine from human basophils. They also showed that flavonoids inhibit the degranulation of mast cells. Degranulation of mast cells would release not only histamine, but all the mediators of the allergy response.

The review reported that flavonoids exhibited anti-spasmodic and anti-inflammatory properties induced by acetylcholine, histamine, noradrenaline and barium chloride in four different smooth muscles. In addition, flavonoids are said to inhibit antigen-induced release of histamine from mast cells, basophils and also inhibit contractions induced by histamine, acetylcholine and PGEÂÂÂ2. It was noted that this effect was concentration dependent.

Flavonoids are said to inhibit phospholipids metabolism and 5- lipoxygenase (5-LO). Leukotrienes are derived from arachidonic acid through 5-LO and the nucleophilic attack to produce peptidoleukotrienes. These 5-LO products mediate constriction of airway smooth muscles, leukocyte chemotaxis and vascular permeability . Therefore inhibiting 5-LO can attenuate leukotriene production.

The presence of phenol in GK further indicated that it could act as anti-inflammatory, antioxidant and immune enhancers. Phenols have been responsible in having the ability to block specific enzymes that cause inflammation. They also modify the prostaglandin pathways and thereby protect platelet from clumping.



From this review, the following could be the underlying physiological mechanisms by which Garcinia kola may be beneficial in the treatment of asthma:

Inhibition of Ca2+ influx by acting as a blocker of both receptor-operated and voltage-dependent Ca2+ channels. Increasing the intracellular levels of cAMP by inhibiting the effects of phosphodiesterase.

Inhibition of histamine release stimulated by IgE dependent ligands. Inhibition of platelet-activating factor and platelet aggregation. Its high vitamin C and zinc content. Inhibition of 5-lipoxygenase (5-LO) pathway, thereby attenuating leukotriene production.

"Garcinia kola appears to be very promising in the treatment and management of asthma. There is therefore the need to further examine its various phytochemical contents on respiratory smooth muscle, with a view to possibly formulating its extracts or active constituents as medicines.".

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