Biological Activity of Phytochemicals - Assignment Example

Pharmacognosy Q1 The mechanism of action of saponins in animals has not been understood clearly, but in plants, several explanations have been put forward. Saponins are bioactive compounds mainly produced by plant also by some organisms and insects in the marine. According to research, they occur generally as glycosides of steroids, this is because of their bipolar properties, thus they are able to interact with the cell membranes also decrease the surface tension of an aqueous solution. Saponin is mainly stored as inactive bidesmosidic saponin in plants vacuoles; upon wounding and decompartmentation, later they are converted into the membrane-active monodesmosidic saponin that is amphiphilic with detergent activities (GANG, p. 14-16). Saponin has diverse range of properties that include medicinal properties, sweetness and bitterness, pharmacological and hemolytic properties, therefore, finding a variety of application in beverages and confectionery, also in pharmaceutical products as hormone synthesis. Examples of the plants containing saponin include Quillaja saponaria, Glycine max, Dioscorea villosa, Sapindus, and Gynostemma pentaphyllum. They provide good examples of sources of nutrition and traditional medicine, nd has gained interest mainly from the medical community due to their high concentration of saponins (GANG, p. 14-16). Q2 Alkaloids are alkaline nitrogen containing heterocyclic compounds derived from higher plants and exhibiting marked pharmacological activity. They are important chemical compounds that serve as a rich reservoir for drug discovery. Many alkaloids isolated from natural herbs exhibit anti-proliferation and anti-metastasis effects on the various effects on several types’ illness such as cancers. Alkaloids contain a ring structure and a nitrogen atom mainly located inside the heterocyclic ring structure. Several categories of alkaloids exhibit biological activities, for instance relieving action of ephedrine for asthma. Additionally, alkaloids are mainly active in plants belonging to Papaveraceae, Ranunculaceae, and Loganiaceae, therefore, containing important active components in natural herbs, with some of its compounds being developed successfully into chemotherapeutic drugs. It also has a wide range of bioactivities such as antibacterial, antiulcer, anti-inflammatory, and sedation among others. Depending on the plant species, alkaloids can occur in all parts of the plant, mostly in roots, thus serves as a storage form of nitrogen and act as a protective agent against damage from Ultra violet light, that is why alkaloids serves as an important aspect in herbal medicine (HOFFMANN, p. 120-122). Q3 Over the years, there have been several human diseases that have been recorded due to consumption of products made from plants containing pyrrolizidine alkaloid. Plants produce them as defense mechanism against herbivores. The primary toxic metabolites of pyrrolizidine alkaloids are highly electrophilic therefore; they react with nucleophilic constituents in the cell to exert their effect. Moreover, the structure of the individual unsaturated pyrrolizidine alkaloid determines the metabolic route, which determines the toxicity of the metabolite once they are formed (HOFFMANN, p. 130-131). On the mechanism of action, pyrrolizidine alkaloids are absorbed in humans from the small intestine and transported to the liver. Thereafter, the pyrrolizidine alkaloids are in high concentration, they will cause damage of the liver, where the reversibility is uncertain and unpredictable. According to statistics, an acute toxicity in human will lead to 50% of patients will recover while 20% will die. However, among the 50%, 20% will seem to recover clinically but later develops liver failure after some years. Some of the plants species that contains pyrrolizidine alkaloid include Cacalia hastate, Cordia Myxa, and Echium Vulgare (HOFFMANN, p. 130-131). Q4 Over the years, scientist have discovered an increasing incidence of drug resistant pathogens, drawing attention to pharmaceuticals and the scientific world towards studies on the potential antimicrobial activities of plant derived substances, also some untapped sources of antimicrobial chemo types mainly used as traditional medicines in several countries. The antimicrobial effect of oils and extracts has formed the basis of several applications, and this includes raw and processed food preservation, natural therapies, alternative medicines, and pharmaceuticals (RAI, & KON, p. 166). Plants have an almost limitless ability to synthesize aromatic substances with most of them having secondary metabolism. On the other hand, these substances serve as plant defense mechanisms against predators such as insects and herbivores. Chili Pepper has terpenoid capsaicin, where its compounds are used as herbs and others as species by human to season food yield useful medicinal compounds. Additionally, Aloe Vera is said to contain latex compound, and has Salmonella antimicrobial activity, which is used as medicine o treat various illnesses and allergies. Laurus Nobilis also contains essential oils compounds and contains bacteria or fungi antimicrobial activity that mostly helps in decomposition (RAI, & KON, p. 166). Q5 Symbiosis is a biological relationship in which two species live in close proximity to each other and interact regularly in a manner that they benefit one or both of the organisms. Parasitism is one example of symbiosis in which one individual is damaged while the other is severely damaged therefore considered as the battle for the fittest. Animals, insects, and plants all have some point of relationship where they all benefit from each other. In this case, plants use insects; small animals use insects; and animals use plants. This symbiotic relationship between these three is referred to as mutualism, where all benefit from each other. In this case, plants will use insects for pollination and in some cases, some plants uses their leaves to enclose insects and feed on them, on the other hand, small animals will feed on the insects and others will benefit from feeding the plants. This mutualism relationship shows that all these three species benefits from each other in one way or another (BERG, p. 523). Q6 An alkaloid is nay class of organic compounds that are made up of nitrogen, hydrogen, oxygen, and carbon derived from plants. Some of these compounds exist in their alkali state but some of them do not exhibit alkaline properties. Several Alkaloids, though they are poisonous, they have a psychological effect that make themselves useful medicines. For example, Curarine alkaloid, found in the deadly extract curare, is significant and powerful muscle relaxant; physostigmine is also used for various muscular diseases, while atropine is used to dilate the pupils of the eyes. Additionally, Narcotic alkaloids used in medicines, for example morphine and codeine are important since they are used in relieving pain, while cocaine is used a local anesthetic (BERG, p. 504). In countries like New Zealand and Australia, Betel, which contain arecoline, muscarine, and pilocarpine alkaloids, used to be chewed by immigrants from India and still it is being chewed until to date, is useful as a stress reduction, heightened awareness, and feelings of well-being. Vinca alkaloids derived from common periwinkle plant and are used as anti cancer drugs that inhibit cancer cell growth stopping cell division. Lastly, Belladonna alkaloid and Barbiturates are said to be a combination of medicines taken by humans to relieve cramping and spasms of the intestine and stomach (BERG, p. 504). Q7 Willow bark, according to research is an effective analgesic if the content of salicylate content is adequate. According to clinical trials, they show that willow has demonstrated efficacy in treating lower back pain, however, they have little efficacy n treating arthritic conditions. In general, any drug interactions associated with salicylates may apply to willow bark-containing products. Therefore, pharmacological actions normally associated with salicylates are applicable to willow that support most of the herbal uses, in this case, Salicin is probably the most active anti-inflammatory compound found in willow bark, which is metabolized to salicylic acid (CRAIG, & STITZEL, p. 42). Q8 Members of the Zingiberaceae such as Curcuma Longa accumulate elevated levels in their rhizomes, significant pharmacologically vigorous metabolites that emerge to result from the phenylpropanoid pathway. Curcuma Longa is a perennial herb that is distributed throughout tropical and some sub –tropical regions of the world such as China and India. Despite the importance of curcuminoids in Curcuma Longa, small is known about the biosynthesis of this compound (Wichtl, p. 162). Examination for enzymes in the phenylpropanoid has identified the pathway corresponding enzymes activities in the recent found in protein crude extracts from rhizome, leaf, and shoot tissues in Curcuma Longa. This results from experiments done on Curcuma Longa, is explained by the identification of thioesterase activities that cleaved phenylpropanoid pathways that were found to be evident in high levels in all tissues. These enzyme activities may shunt phenylpropanoid pathway intermediates away from the production of curcuminoids, thereby potentially playing a regulatory role in the biosynthesis of these compounds (Wichtl, p.171-172). References BERG, L. R. (2008). Introductory botany: plants, people, and the environment. Belmont, CA, Thomson Brooks/Cole CRAIG, C. R., & STITZEL, R. E. (2004). Modern pharmacology with clinical applications. Philadelphia, Lippincott Williams & Wilkins. GANG, D. R. (2011). The biological activity of phytochemicals. New York, Springer. HOFFMANN, D. (2003). Medical herbalism the science and practice of herbal medicine. Rochester, Vt, Healing Arts Press: RAI, M., & KON, K. V. (2013). Fighting multidrug resistance with herbal extracts, essential oils, and their components. London, Elsevier. Wichtl, M. (2004). Herbal drugs and phytopharmaceuticals: a handbook for practice on a scientific basis. CRC press. Read More