Pharmacological activities of plant

PHYTOCHEMICAL STUDIES AND PHARMACOLOGICAL ACTIVITIES OF PLANTS IN GENUS HEDYOTIS7 OLDENLANDIA... 

ABSTRACT This paper attempts to present a review on the study of phytochemical and pharmacological activities of plants from the genus Hedyotis (Rubiaceae) in the last seven decades, which include our work on Malaysian Hedyotis species. The structure-activity relationships of compounds isolated from this genus are compiled and discussed. Finally, there is also a brief discussion on the biosynthesis of anthraquinones, iridoid glycosides and alkaloids, which are the common constituents of Hedyotis species. 

Large quantities of polysaccharides are available in nature and many of them display a variety of biological functions [1 ]. There is an abundance of literature on the isolation of bioactive polysaccharides from botanical sources [1-5]. This area of research has attracted a lot of interest due to the fact that most of the bioactive polysaccharides are nontoxic with minimal side effects [4,5]. Hence, this class of biopolymers forms ideal candidates for therapeutic applications. Some of the notable bioactivities of botanical polysaccharides include antioxidant, immunomodulatory, and antitumor properties [4-10]. However, the mechanism of action of these biopolymers is not well understood. In general, one of the primary mechanisms of action of polysaccharides is nonspecific immunomodulation [8]. The key mechanism behind the immunomodulatory, anticancer, antibacterial, and other pharmacological activities of plant polysaccharides is to activate macrophages, which then leads to modulation of the complement system that activates the cells involved in innate immunity and improves host defense [1—4,11,12]. 

One of the primary mechanisms of action of polysaccharides is nonspecific immunomodulation that leads to the production of cytokines [4,8]. The key mechanism behind the immunomodulatory, anticancer, antibacterial, and other pharmacological activities of plant polysaccharides is to activate macrophages, which then leads to the modulation of the complement system that activates the cells involved in innate immunity and improves host defense [1, 11,12]. 

Pharmacological activity of pectins isolated from plants containing... 

Vieira, J. E. V., G. S. G. Barros, M. C. Medeiros, F. J. A. Matos, M. P. Souza and M. J. Medeiros. Pharmacologic screening of plants from Northeast Brazil. II. Rev Brasil Farm 1968 49 67-75. Dixit, V. P., V. N. Sharma and N. K. Lohiya. The effect of chronically administered cannabis extract on the testicular function of mice. Eur J Pharmacol 1974 26 111-114. Pinheiro de Sousa, M. and M. Z. Rouquayrol. Molluscicidal activity of plants from Northeast Brazil. Rev Bras... 

Tian, Y, Wu, J, Zhang, S. Advances in research of chemical constituents and pharmacological activities of semi-mangrove medicinal plant Thespesia populnea [J]. Chinese Traditional and Herbal Drugs, (2003). 

The observed pharmacological activities of medicinal plants relate to the chlorogenic acids constituents of the plant. However, medicinal plants are a complex mixture of chemically different compounds. 

Quantitation of Napelline.—The pharmacological activity of napelline (35)38 has prompted the development of a method for the quantitation of this alkaloid in raw plant materials.39 This method consists of the extraction of the total alkaloids, chromatographic separation, and a micro-scale acid-base titration of the napelline eluate in a non-aqueous medium. The total alkaloids were exhaustively extracted from a sodium carbonate suspension with chloroform. This extract was concentrated, dissolved in acetone, and chromatographed on silica-gel plates, with a standard reference of napelline as a marker. The appropriate bands were quantitatively removed and extracted, and the extracts were concentrated to dryness. These residues were dissolved in glacial acetic acid and titrated with 0.01N perchloric acid. The standard deviation of this method was 3.39 x 10 3. No limits of detection are reported. 

The present review will focus on the pharmacological activities of BEO. Particular attention has been devoted to antinociceptive characteristics of BEO to discuss the possible role of linalool or linalyl acetate (Fig. 1), which is present in the essential oil of bergamot as well as other aromatic plants. 

Proteases are regulated in vivo by autoinhibition (as zymogens), proteolytic activation, turnover and by endogenous protease inhibitor proteins. The following brief sketch of protease complexity is accompanied by succinct reference to the physiological context and hence the potential pharmacological relevance of plant-derived protease inhibitors to be described later in this review. 

Of the drugs that are contained in cannabis products, it is A -tetrahydrocannab-inol (A -THC) (1) which is responsible for the pharmacological activity of cannabis. This compound is formed in the glandular trichomes (see below) which are found on the surface of the plant. Cannabis sativa is dioecious, that is, it has both male plants and female plants. These are most easily recognized at the flowering stage because the flower structures are different. The female plants are preferred because they produce more of the glandular trichomes and, as a consequence, are richer in cannabinoids. 

Pharmacological Activity of Pectins Isolated from Plants... 

Sesquiterpene laetones constitute significant group of phytochemicals. The sesquiterpenes are widely distributed in plant flora particularly in Compositae. The pharmacological activity of the sesquiterpenes ranges from neurotoxic to antimicrobial. The chemistry of sesquiterpenes is very complex. They are formed by condensation of three isoprene molecules followed by oxidation. 

Considering the morphological and systematic affinities of S. desoleana with S. sclarea, used more in folk medicine, these authors (Peana and Moretti) examined comparatively some pharmacological activities of the essential oils of these aromatic plants after their bioassay-guided fractionation and chemical and physical characterization. Some pharmaceutical preparations, suitable for topical applications, were also prepared and tested to evaluate the ability of the main oil components to permeate oral mucous membrane in an in vitro system. 

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