Chemical Constituents and Biological Activities of Cassia Genus: Review

A review of chemical constituents and pharmacological activities of genus Cassia, Family Leguminosae has been presented. There are about 600 species of this genus distributed all around the world. Many of these species are still not investigated. Hence, an attempt is made to present a review on the phytochemical and biological studies of Cassia species that remain a potential source for new natural pharmacologically active components. (cid:10)


INTRODUCTION
Since ancient times, several societies have resorted to nature, mainly to plants as medical and healthy sources.Today, a great percentage of the world population, particularly in developing countries, use plants for facing the primary needs of medical assistance [1].

Taxonomy
Family Leguminosae is one of the largest families of the flowering plants.It comprises about 650 genera and 18000 species [2].The Fabaceae or Leguminosae, commonly known as the legume, pea or bean family, is a large and economically important family of flowering plants.Plants of this family are found throughout the world, growing in many different environments and climates.The plants range in habit from giant trees to small annual herbs, with the majority being herbaceous perennials.The plants have indeterminate inflorescences, which are sometimes reduced to a single flower.The flowers have a short hypanthium and a single carpel with a short gynophore, and after fertilization produces fruits that are legumes.The leaves are usually alternate compounds and are even -or odd-pinnately compound.The name "Cassia" means "Cinnamon-like bark".Besides, the genus Cassia was for long ill-delimited with regards to the related Cassiinae -especially Senna (which has many medicinal important species) [3].
Leguminosae is divided into three subfamilies: Caesalpinioideae, Papilionoideae, and Mimosoideae.These sub-families are now treated as independent families due to their numerous species and named, Caesalpiniaceae, Papilionaceae, and Mimosaceae [4].The name Caesalpinioideae is derived from the generic name Caesalpinia.The Caesalpinioideae are mainly trees distributed in the moist tropical area.Caesalpinacae represents approximately 11% of the known legume flora, with 152 genera and 2800 species [5].Cassia is a major genus of the Caesalpiniaceae, comprising about 600 species [6].

Traditional uses of Genus Cassia
Some of them are used in traditional folk medicines as a laxative, purgative, antimalarial, ulcer healing, antidiabetic, hepatoprotective, nephroprotective, antitumor and also used in the treatment of skin infection and periodic fever throughout the tropical and subtropical region.

Chemical constituents of genus Cassia
Deep reviewing of literature concerning genus Cassia revealed the isolation and separation of different following classes of compounds: A number of authors isolated and identified several compounds from different Cassia species such as anthraquinones, anthracenes, polyphenols, fatty acids, sterols, polysaccharides and some other miscellaneous compounds from different Cassia species

Reported biological activities of species belonging to genus Cassia
Previous evaluation of the pharmacological benefits of many Cassia species showed that most of them possess many biological activities of great importance made some of them be included in the pharmacopeia like C. glauca C. angustifolia and C. acutifolia.Some of these important activities such as antioxidant activity, antidiabetic, hepatoprotective activity and cytotoxic activity; all are summarized in table 4. The phytochemical constituents and biological activities of compounds isolated and identified from Cassia were searched through SciFinder that retrieves information in databases produced by Chemical Abstracts Service (CAS) as well as the MEDLINE database of the National Library of Medicine.The data was updated in March 2019, regarding chemical constituents or biological activities and Cassia keywords.

CONCLUSION
The Cassia species have been carefully studied for their phytoconstituents as well as for their biological activities.From collected data it was observed that many phytochemical constituents were isolated from different Cassia species; anthraquinones, anthracene and phenolic acids.Many biological activities were reported about Cassia species such as; antidiabetic, antioxidant hepatoprotective, cytotoxic and hypolipidemic effects.Emodin, chrysophanol, and rhein are widely distributed throughout this genus which recommends that these compounds may be chemotaxonomic markers of the genus Cassia  C. marginata

Table 1 .
Reported anthraquinones, anthracenes and their derivatives in different

Table 2 .
Phenolic compounds reported in different Cassia species

Table 3 .
Some miscellaneous compounds have been isolated from different Cassia species