Antihistaminic Activity of the Paediatric Siddha Formulation Kana Ennai: An Ex Vivo Study Using a Guinea Pig Model

Abstract

Childhood bronchial asthma and other allergy-related disorders remain significant health concerns due to the limited availability of effective and conclusive treatments in paediatric care. This situation has increased interest in traditional Siddha formulations for managing such conditions. The present study aimed to evaluate the antihistaminic activity of the Siddha paediatric herbal formulation Kana Ennai (KE) using an ex-vivo guinea pig model of bronchial hyperresponsiveness. In this experimental study, guinea pigs were euthanized with ketamine, and 1-cm ileal segments were mounted in a 30-mL organ bath containing aerated Tyrode solution maintained at 37 °C. Contractile responses were induced by cumulative addition of histamine at concentrations of 5, 10, 20, 40, and 80 µg until submaximal contractions were achieved. After treatment with Kana Ennai (KE), the ileal responses to the same histamine concentrations were recorded and compared. The results demonstrated that Kana Ennai (0.2%) significantly reduced histamine-induced contractions and effectively blocked hyper-responsive histamine receptors in ileal smooth muscle, as evidenced by changes in the histamine concentration–response curve. These findings suggest that Kana Ennai possesses notable antihistaminic activity and therapeutic potential in the management of bronchial asthma. Further experimental investigations and clinical trials are required to confirm its efficacy and elucidate its mechanism in histamine receptor blockade.

Abbreviations:

KE: Kana Ennai; CRC for concentration response curve; NaCl stands for sodium chloride; KCl for potassium chloride; CaCl2 for calcium chloride; MgCl2 for magnesium chloride; H2O for dihydrogen monoxide; NaHCO3 for sodium bicarbonate; NaH2PO4 for monosodium phosphate or sodium dihydrogen phosphate;