KĀHU (LACTUCA SATIVA LINN.) IN UNANI MEDICINE: A COMPREHENSIVE REVIEW OF TRADITIONAL USES AND SCIENTIFIC EVIDENCE

Abstract

Kāhu (Lactuca sativa Linn.), commonly known as lettuce, is an important medicinal plant extensively described in the Unani system of medicine. Traditionally, its seeds (Tukhm-i-Kāhu), leaves, latex (Afyūn-i-Kāhu or lactucarium), and seed oil (Roghan-i-Kāhu) have been used for the management of insomnia, headache, nervous disorders, inflammatory conditions, dry cough, fever, jaundice, excessive thirst, and various disorders associated with hot temperament. Classical Unani texts describe Kāhu as possessing Munawwim (hypnotic), Musakkin (sedative), Mubarrid (refrigerant), Muḥallil-i-Awrām (anti-inflammatory), and Mudirr-i-Bawl (diuretic) properties. A comprehensive search was conducted using classical Unani references, pharmacopoeias, national formularies, and scientific databases including PubMed, Scopus, Google Scholar, and ScienceDirect. Phytochemical investigations reveal the presence of diverse bioactive constituents, including lactucin, lactucopicrin, sesquiterpene lactones, flavonoids, phenolic compounds, terpenoids, glycosides, vitamins, and minerals. Experimental studies have demonstrated significant sedative, hypnotic, anxiolytic, antioxidant, anti-inflammatory, antidiabetic, neuroprotective, cardioprotective, and anticancer activities, thereby supporting many traditional therapeutic claims. Clinical studies have reported beneficial effects of lettuce seed preparations in improving sleep quality in patients with insomnia, including pregnancy-related insomnia, and have also shown favorable effects on lipid profiles in dyslipidemic individuals. Furthermore, Tukhm-i-Kāhu is incorporated into numerous compound formulations described in the National Formulary of Unani Medicine, highlighting its therapeutic significance in Unani practice. The available evidence suggests that Lactuca sativa is a valuable medicinal plant with substantial traditional and scientific support. However, well-designed clinical trials with larger sample sizes are required to validate its broader therapeutic applications and elucidate the underlying mechanisms of action.