Zanthoxylum zanthoxyloides Lam. Chewing Stick Elicits Salivation in Male Wistar Rats Via a Muscarinic-Dependent Pathway
Keywords:
Zanthoxylum zanthoxyloides, Adrenergic receptor, Muscarinic receptor, Calcium channel, salivaAbstract
A recent study has documented empirical evidence that Zanthoxylum zanthoxyloides (Lam.) Watermann root stimulates salivation in healthy adult humans. The mechanism underlining the Z. zanthoxyloides-stimulated salivation was however not known. This study was therefore designed to determine the role of adrenergic, muscarinic and calcium channels on Z. zanthoxyloides-induced salivation in male Wistar rats. Twenty male Wistar rats (120-130 g) were randomly grouped into four (n=5) as: Z. zanthoxyloides (Z), Z. zanthoxyloides+Atropine (ZA), Z. zanthoxyloides+Prazosin (ZP) and Z. zanthoxyloides+Nifedipine (ZN). Cotton swab soaked in juiced Zanthoxylum zanthoxyloides root was rubbed into the oral cavity of anaesthetized rats in Z to stimulate saliva. Rats in ZA, ZP and ZN were pretreated with atropine (2 mg/kg), prazosin (2 mg/kg) and nifedipine (20 mg/kg), respectively, before introduction of Z. zanthoxyloides. Saliva volume, flow rate, amylase activity and total protein were determined using standard methods. All experiments were conducted in triplicates. Z. zanthoxyloides significantly increased production of saliva (0.49±0.036ml) when compared with the unstimulated animals that produced no visible saliva throughout the observation period. Treatment with atropine in ZA (0.095±0.002ml) significantly decreased saliva production when compared with Z. There was however no significant difference in the saliva volume of ZP (0.35±0.032 ml) and ZN (0.445±0.75ml) when compared with Z. Salivary flow rate increased in similar pattern with saliva volume in all the groups. Salivary amylase activity and total protein were significantly reduced in ZA compared with Z while they were not different in the ZN and ZP groups. Z. zanthoxyloides increases salivation through a mechanism that may involve the muscarinic pathway.