Long pepper (Piper longum L.) commonly known as Pippali, Indian or Javanese long pepper is a slender, aromatic plant grown for its small red spikes which are tremendously used in traditional medicine systems. This plant grows wild in the evergreen forests in India and is cultivated in areas of Assam, Tamil Nadu, and Andhra Pradesh with heavy rainfall and high relative humidity. Its fruits grow in fleshy spikes which are dried and sold as the commercial form of pippali.
Different parts of the plant are used in the Ayurvedic medicine systems, for its major pharmacologically active compound piperine and piperlongumine. It is one of the main ingredients in the renowned formulation called ‘Trikatu’ well-known for its prominent bio-enhancing properties. It holds a significant place in Ayurveda, particularly in the therapy known as ‘Rasayana’. Rasayana focuses on promoting strength, vitality, and overall well-being. The traditional use of pippali for enhancing cognitive function and addressing cognitive impairment is also mentioned in the ancient Ayurvedic text Charaka Samhita. It is one of the earliest spices traded between eastern and western civilisations, and was a valuable commodity even in ancient Greece and Rome.
Geographical distribution
Piper longum is indigenous to the Indo-Malaya region, thriving primarily in the warmer areas of India, spanning from the central Himalayas to Assam, Mikir, and Khasi hills, as well as the lower plains of West Bengal and the evergreen forests of Kerala. It can also be found in the Western Ghats, extending from the Konkan to the Travancore regions, and has been documented in the Car Nicobar Islands as well. This plant is known to grow in the wild within the tropical evergreen rainforests of India, Nepal, Indonesia, Malaysia, Singapore, Sri Lanka, Timor, and the Philippines.
Pharmacological importance
Piper longum has been mentioned in several ancient Ayurvedic texts, including the Susruta Samhita, which was documented in the first century A.D. by the renowned Hindu physician Susruta. Additionally, it is also mentioned in other important texts such as Charaka's Shri Bhav Prakasha, dated around A.D. 1310, and Shankar Nighantu, written during the 14th century. These references highlight the longstanding recognition and utilization of Piper longum in traditional Ayurvedic medicine.
Traditionally, various parts of the plant, including the fruit, have been utilized. Piperine, an important alkaloid is the most abundant along with numerous alkaloids and related compounds found in its fruit. Several compounds, including piperine, piperlongumine, tetrahydropiperlongumine, trimethoxy cinnamoyl-piperidine, and piperlonguminine have been isolated from its roots. Apart from alkaloids, its fruit contain a complex mixture of essential oils such as caryophyllene, pentadecane and bisabolene.
Pippali has been used for treatment of cold and mucus conditions of the lungs as it increases vasodialation, it has the properties of a bronchodilator and an expectorant and is used as a strong lung rejuvenator. Pipali has also been used for treatment of indigestion and diarrhea. It is used for treating stomach pain, gastritis, chronic dysentery, and spleen enlargement. It is used as a herbal medicine for piles, irregular fever and anemia. It has hepatoprotective, antihyperlipidemic and immunodialatory activities along with being antidepressent and antiamoebic. The petroleum ether extract derived from its roots has been found to effectively combat oxidative damage caused by free radicals. It has been documented to a part of more than 135 Ayurvedic formulations, several of which are mentioned in the Ayurvedic Pharmacopoeia of India (The Ayurvedic Pharmacopoeia of India Parts II and IV, Ministry of Health and Family Welfare, Dept of AYUSH).
In the Unani system of medicine, both the roots and fruits of Piper longum have been employed for various therapeutic purposes. They have been used in the treatment of conditions such as palsy, gout, and lumbago. Furthermore, these plant parts have been reported to possess carminative, liver tonic, stomachic, abortifacient, aphrodisiac, haematinic, diuretic, digestive, emmenagogue properties, among others. In the Traditional Chinese Medicinal (TCM) system, there are reports of the uses of P. longum for treating stomach diseases, providing analgesic effects, and acting as a vasorelaxant. This indicates the recognition of P. longum's therapeutic properties in the TCM system for addressing various conditions related to the stomach, pain relief, and relaxing blood vessels.
Some of its identified pharmacological activities are enlisted below:
- Antiproliferative, and antitumour activities
- Neuro-pharmacological activity
- Antidepressant activity
- Antistress activity
- Antihyperglycaemic activity
- Antioxidant activity
- Hepatoprotective activity
- Antiulcer activity
- Biocidal activities
- Antiplatelet activity
However, its uses in traditional medicines have been validated with little scientific evidence.
Despite the high demand for long pepper due to its numerous medicinal properties, there has been limited focus on its commercial production, cultivation, and exportation and the establishment of a robust industry around long pepper remains lacking to this day. Moreover, well-designed randomized, double-blind, and placebo-controlled clinical studies are required to validate the broad pharmacological properties of long pepper for human use. These rigorous studies would provide reliable scientific evidence regarding the efficacy and safety of long pepper in various medicinal applications.
References
Ali MA, Alam NM, Yeasmin MS, Khan AM, et al. (2007) Antimicrobial screening of different extracts of Piper longum Linn. Research Journal of Agriculture and Biological Sciences 3(60): 852–857
Biswas P, Ghorai M, Mishra T, Gopalakrishnan AV, et al. (2022) Piper longum L.: A comprehensive review on traditional uses, phytochemistry, pharmacology, and health-promoting activities. Phytotherapy Research: 36(12): 4425–4476
Chaudhary S, Mukherjee P, Maiti N, Kumar A, et al. (2013) Evaluation of angiotensin converting enzyme inhibition and anti-oxidant activity of Piper longum L. Indian Journal of Traditional Knowledge 12: 478–482
Kumar S, Kamboj J, Sharma S (2011) Overview for various aspects of the health benefits of Piper longum Linn. fruit. Journal of Acupuncture and Meridian Studies 4(2): 134-140
Saraf A, Saraf A (2014) Phytochemical and antimicrobial studies of medicinal plant Piper longum Linn. International Journal of Pharmacognosy and Phytochemistry Research 6(2): 213–222
Zaveri M, Khandhar A, Patel S, Patel A (2010). Chemistry and pharmacology of Piper longum L. International Journal of Pharmaceutical Sciences Review and Research 5(1): 67–76