Mediation of cholino-piperine like receptors by extracts of Piper nigrum induces melanin dispersion in Rana tigerina tadpole melanophores

Abstract

Aim: The present study was carried out to determine the effects of lyophilized dried fruit extracts of Piper nigrum and pure piperine on the tadpole melanophores of frog Rana tigerina which offer excellent in vitro opportunities for studying the effects of pharmacological and pharmaceutical agents. The nature of specific cellular receptors present on the neuro-melanophore junction and their involvement in pigmentary responses has been explored.

Material: Effects of lyophilized extracts of P. nigrum and pure piperine were studied on the isolated tail melanophores of tadpoles of the frog R. tigerina as per the modified method.

Results: The extract of P. nigrum and its active ingredient piperine caused significant melanin dispersal responses leading to darkening of the tail melanophores, which were completely antagonized by atropine and hyoscine. These per se melanin dispersal effects were also found to be markedly potentiated by neostigmine an anticholinesterase agent.

Conclusion: It appears that the melanin dispersal effects of the extracts of P. nigrum and pure piperine leading to skin darkening are mediated by cholinergic muscarinic or piperine-like receptors having similar properties.

Keywords::

• Anticholinesterase
• atropine
• cholinergic-piperine like receptors
• melanin
• melanophores
• muscarinic
• Piper nigrum
• piperine

Acknowledgments

Authors are thankful to Mr. Zainuddin Shah, Secretary, Saifia Education Society, and Dr. H. Abbas, Principal, Saifia Science College, Bhopal, affiliated to Barkatullah University Bhopal, for providing necessary facilities.

Declaration of interest

The authors report no conflict of interest. The authors alone are responsible for the content and writing of the article.