Anthraquinones and its derivatives include many important drugs(collectively called anthracenediones).They acts as Laxatives (dantron, emodin, and aloe emodin), and some of the senna glycosides, Antimalarials ( rufigallol), Antineoplastics used in the treatmentof cancer (mitoxantrone, pixantrone, and the anthracyclines) (Panigrahi et al., 2015).Rhein(4,5-dihydroxyanthraquinone-2-carboxylic acid) is a anthraquinone which islipophillic in nature. It is extensively found in medicinal herbs and have beenused medicinally in China formore than 1,000 years.
Rhein exhibits a linearpharmacokinetics between 50 and 200mg (Layek et al., 2008) and has manypharmacological effects, including hepatoprotective, nephroprotective,antiinflammatory, antioxidant, anticancer, and antimicrobial activities. Thesepharmacological effects lay the foundation for the treatment of hepatic disease(Guo et al., 2003), osteoarthritis (Moldovan et al., 2000), various cancers,such as nasopharyngeal carcinoma (Lin et al., 2009), hepatocellular carcinoma(Shi et al.
, 2008), lung cancer (Hsia et al., 2009), tongue cancer (Chen et al.,2010), atherosclerosis (Heo et al., 2009) and diabetes (Du et al., 2011), Catechin isa type of natural phenol and antioxidant. It belongs to the group flavanols, part of thechemical family of flavonoids. Catechin containing extracts were thought to beuseful for treating heart diseases (Schroederand Johann, 1655; Berends, 1829) and an effect on thepermeability of capillaries was shown by Armentano et al., in 1936.
Someground evidences from dietary studies indicated that catechins have an effecton endotheliumdependent vasodilation which aids in to normal blood flowregulation in human beings (Hooper et al., 2012; Ellinger et al., 2012).
Catechins also improve blood pressure (Khalesi et al., 2014). Kaempferol isa natural flavonol,a type of flavonoid,found Cassia fistula. It acts as an antioxidantby reducing oxidative stress. Anti-bacterial activity of kaempferol and itsglycosides have demonstrated to decrease the number of Helicobacter pylori colonies in gerbils.
Kaempferol has been reported to inhibit theactivity of enzymes that are responsible for viral infection such as reversetranscriptase, viral proteases and neuraminidase.Kaempferol has been shown tohave an array of antioxidant effects invitro and in vivo. At lowconcentrations, it acts as a superoxide scavenger, specifically against thehighly reactive OH.
radical and peroxynitrite species. At high concentrations it increases theactivity of superoxide dismutase, catalase, and heme oxygenase-1. Kaempferol can preventthe oxidation of low-density lipid proteins indicating its protective role inatherosclerosis (Calderon-Montaño etal., 2011).
Many studies suggest thatconsuming kaempferol can reduce the risk of various cancers, and it iscurrently under consideration as a possible cancer treatment drug. In vitro studies along has demonstrated the wide rangeof potential anticancer properties of kaempferol. It has been shown effectiveagainst malignant cancer cells. They interrupt cell growth, limit angiogenesis,induce apoptosis, and reduce their available energy and ability to metastasizeby reducing the MMP-3 protein activity (Calderon-Montañoet al., 2011).
Kaempferol has been shown to interact with the estrogenreceptor pathway and alter signaling leding to slow growth. It has the abilityto lower levels of Aromatase (Wang et al., 1994). Kaempferol has alsofound to induce apoptosis in breast cancer cells via extracellularsignal regulated kinase activation and up-regulation of p53 (Aiyeret al., 2012). Evidenceshas shown that kaempferol can inhibit VEGF production thereby suppressing theovarian cancer cell metastasis under invitro conditions (Chen et al.,2012). Kaempferol has also been shown to reduce growth in promyelocyticleukemic cells by altering the cell cycle (Jaganathan and Mandal, 2009).
There is a correlation found between increased levels of kaempferolin the diet and a relatively reduced risk of type 2 diabetes in a cohort study in 2005 (Calderon-Montaño et al., 2011).Kaempferol has also been reported to impart a protective effect on the apoptosisinduced by the ischemia reperfusion of cardiac cells.
Therefore, it has a potentialpharmacological role in prevention of cardiovascular disease (Khalil and Sulaiman, 2010)Coumarinwhich is a potent phytocompound of C. fistula,has also been demonstrated to be protective in terms of deleterious sideeffects of many cancer treatments. Effectivity of coumarin and troxerutincombination therapy for the protection of salivary glands and mucosa inpatients undergoing head and neck radiotherapy. It has been suggested thatcoumarin/troxerutin has a favorable impact in the treatment of radiogenicsialadentis and mucositis (Mahler et al, 1992).
Coumarin and7-hydroxycoumarin are now being used as anti-cancer agents in view of theireffectiveness in acheving objective responses in some patients with advancedmalignancies (Myers et al, 1994). The coumarin is also used as anticoagulants,that blocks multiple steps in the coagulation cascade by competitivelyinhibiting vitamin K in the biosynthesis of prothrombin. The coagulationcascade relies on the conversion of prothrombin to thrombin in a very importantstep under the condition (Goodman & Gilman’s, 2006).Heterocyclic compounds like chromones (4H-chromen-4-ones) arewith the benzo-c-pyrone framework. Molecules containing the chromone orbenzopyranone ring have a very wide range of biological activities. They areshown to be tyrosine and protein kinase inhibitors (Kim et al.
, 2004), as wellas anti-inflammatory (Ma et al., 2003), antiviral (Bennettet al., 2004), antioxidant (Krishnamachariet al., 2004), antihypertensive agents (Bennettet al., 2004) and Chromone derivatives are alsoactive at benzodiazepine receptors (Kametani et al., 2007). In addition to this, they have been shown to beanticancer agents (Machado and Marques, 2010),and possessing antimutagenic properties (Galietta et al.
, 2001). Chromones may also have application in cystic fibrosistreatment, as they activate the cystic fibrosis transmembrane conductanceregulator (Horton et al., 2003). Therefore,the vast range of biological effects associated with this scaffold has resultedin the chromone ring system being considered as a privileged structure (Prottiet al., 2008). The main objectives of chromonessyntheses are not only for the development of more diverse and complexbioactive compounds for biological activity and structure-activity relationship(SAR) studies but also for other applications in Medicinal Chemistry, such aspreparation of fluorescence probes, due to photochemical properties ofchromones (Kim et al., 2012).Lupeol has a complex pharmacology, displaying antiprotozoal,antimicrobial, antiinflammatory, antitumor and chemopreventiveproperties (Gallo and.
Sarachine, 2009).Lupeol can act as an anti-inflammatory agent. A study found lupeol to decreasepaw swelling in rats by 39%, compared to 35% for the standardized controlcompound indomethacin (Geethaand Varalakshmi, 2001). Itis an effective inhibitor in laboratory models of prostateand skin cancers(Prasad et al., 2008; Nigum et al.
, 2007; Saleem et al., 2004). It also act asan anti-inflammatory agent, acts primarily upon the interleukinsystem. Lupeol decreases IL-4 production by T-helper type 2cells ( Bani et al.
, 2006). Lupeolhas also been found to have a contraceptive effect due to its inhibiting effecton the calcium channel of sperm (CatSper) (Nadja Mannowetza et al., 2017).