A REVIEW ON CITRON-PHARMACOGNOSY, PHYTOCHEMISTRY AND MEDICINAL USES

Abstract

The citron is a fragrant   fruit   with   the   botanical   name Citrus   medica,   which   applies   to   both the Swingle and Tanaka systems. It is   a   prominent   member   in   the   genus Citrus,   belonging   to the Rutaceae or Rue family, sub-family Aurantioideae. The citron is unlike the more common citrus species like the lemon or orange. While the most popular fruits are peeled to consume their pulpy and juicy segments, the citron's pulp is very dry, containing only little insipid juice. Moreover, the main content of a citron is the thick white rind, which is very adherent to the segments, and cannot be separated from them easily. Thus, from ancient through medieval times, the citron was used mainly for medical purposes:   to   combat   sea   sickness, pulmonary troubles, intestinal ailments,   and   other   disorders. The essential oil of the flavedo (the outermost,   pigmented   layer   of rind)   was   also   regarded   as an antibiotic. Citron juice with honey was considered an effective antidote to poison. In India, the peel is a remedy for dysentery and is eaten to overcome halitosis. The distilled juice is given as a sedative. The candied peel is sold in China as a stomachic, stimulant, expectorant and tonic. In West Tropical Africa, the citron is used only as a medicine, particularly against rheumatism. The flowers are used medicinally by the Chinese. In Malaya, a decoction of the fruit is taken to drive off evil spirits. A decoction of the shoots of wild plants is administered to improve appetite, relieve stomachache and expel intestinal worms. The leaf juice, combined with that of Polygonum and Indigofera is taken after childbirth. A leaf infusion is given as an antispasmodic. In Southeast Asia, citron seeds are given as a vennifuge. In Panama, they are ground up and combined with other ingredients and given as an antidote for poison. The essential oil of the peel is regarded as an antibiotic.

The citron fruit is usually ovate or oblong, narrowing towards the stylar end. However, the citron's fruit shape is highly variable, due to the large quantity of albedo, which forms independently according to the fruits' position on the tree, twig orientation, and many other factors. This could also be the reason for its being protuberant, forming a "v" shape after the end of the segments towards the stylar end. The rind is leathery, furrowed, and adherent. The inner portion thick, white and fleshy – the outer uniformly thin, and very fragrant. The pulp is usually acidic, but also sweet and even pulps less variety are found.Most citron varieties contain a large number of seeds. The monoembryonic seeds are white colored; with dark inner coat and red-purplish chalazal spot for the acidic varieties, and colorless for the sweet ones. Some citron varieties are also distinct with their persistent style.