Aspects of Chemistry Related to Plants and Medicine: Exploring the Presence and Role of Antioxidants and Antimicrobial activities in plants.

Mariam Agaybi

Chemistry Writing

5/4/22

Introduction

Plants play an important role in the field of medicine. Discovering the chemical composition of certain plants may lead to the discovery of other potentially lifesaving ingredients that have the potential to cure diseases such as cancer and other infectious diseases. Chemistry can contribute to this area because it can look into the specific requirements of certain plants that produce these life-saving ingredients to determine what is required for their survival and how to increase the number of plants that produce them. The availability of various types of plants and the ease with which we can access them have searched for natural alternatives to infectious diseases a very common practice. This discovery has the potential to serve as a building block for the development of a new pharmaceutical. Taking a closer look at the extracts found in specific plant species can lead to the discovery of several life-saving medicinal ingredients.

The use of plants to discover and manufacture medicine came with the introduction of technology, however, the practice existed where plants were used as medicine itself. Due to this reason, compounds and plant ingredients are resourceful acting as the basic components of manufactured drugs. Notably, to date, there are regions in the world still using natural herbs to cure various illnesses and the plants are proving resourceful in the process. The most dominant natural herbs include the Mexican and the Chinese herbs that have gained popularity worldwide. Traditional Chinese medicinal plants have been associated with mitigating and curing cancer in some cases. The Chinese traditional medicinal plants contain antioxidants characterized by phenolic compounds and structures that aid their usefulness in curing several illnesses. Notably, despite the introduction of technology to ease inventions and the development of new medicine, the solution to chronic diseases such as cancer has not been found yet. The existence of the different varieties of plants however offers a chance for more discoveries hence presenting itself as an area with unlimited potential that has not been fully tapped into.

This paper will be an exploration of the aspects of chemistry related to plants that have revolutionized the medical industry in the 21st century.

Genus Thymus

The Lamiaceae family, which includes Thymus, has about 215 different species of herbaceous perennials and small shrubs. They originate from the Middle East where they had lived for some time. Thyme has long been used in a variety of ways, including as a food preservative and a folk remedy. It has a pungent aroma, but it’s also good for individual health. This genus is of scientific importance because it contains so many volatile components.[1] These components include Thymol and carvacrol which are the primary constituents of many Thymus essential oils. You can get thyme’s health benefits from things like carvacrol, flavonoids, eugenol, saponins, luteolin, and tetra methoxylated flavones. All of these properties can be found in thyme essential oil, which is also an antioxidant. It belongs to the family Lamiaceae and the subfamily Nepetoideae. Which is a fragrant herb.

Polyphenolic and flavonoid compounds are examples of natural antioxidants. Because of the health benefits of these ingredients, they are increasingly being used in food and some industrial products. Polyphenolic components derived from plants are also important, and as a result, there is increasing interest in using natural antioxidants rather than synthetic antioxidants. Thyme (Thymus spp.) has a long history of use as a culinary herb and as a medicinal plant in pharmaceutical formulations.[1] There are significant differences in flavonoids and their derivatives such as phenolic acids and flavonoids between Thymus species such as T. algeriensis, T. pulegioides, and T. capitatus, as well as between different Thymus species. A variety of polyphenols are also found in Thymus. These include rosmarinic acid, salvianolic acid, cinnamic acid, ferulic acid, caffeic acid, and apigenin, among others. Rosmanic acid is one of the most abundant phenolic acids found in the plants of this genus.

Polyphenols present in the genus thymus are accrued with numerous health benefits. Notably, regular intake of polyphenols into the body increases brain health, boosts digestion, prevents type 2 diabetes, and prevents heart disease among other numerous functions[1]. The antioxidants present in polyphenols are beneficial in reducing chronic inflammations subsequently reducing the risks of heart diseases. In addition, the compounds present in polyphenols are responsible for the stimulation of insulin secretion that helps the body in keeping the sugar levels stable[1]. Lastly, polyphenols have also been linked with the prevention and protection of cancer. The strong antioxidants and anti-inflammatory compounds present in polyphenols block the growth and development of cancerous cells in the body.

Genus Thymus has been branded with pharmaceutical benefits. Thyme has evolved from a traditional herb to a serious drug rational phytotherapy in recent years. Iron, calcium, manganese, and vitamin K are abundant in this food, which also improves blood flow and has a stimulating effect on the entire body[1]. For the treatment of physical and mental weakness and for reducing insomnia, this herb’s energizing effect on anxious frameworks made it useful for both of those ailments. Thymol, carvacrol, eugenol, phenols, luteolin, and tetramethoxylated flavonoids all contribute to Thymus’ healing properties. As an antispasmodic, antimycotic, age-delaying agent, bactericide, anthelmintic, and cancer prevention agent, it has a wide range of beneficial properties. It has been recently recommended as a cancer prevention agent. Additionally, according to studies conducted by Nickkavar, et al, the decoction and infusion of some parts of the Thymus are instrumental in the production of tonic, antispasmodic, and carminative which are known to be effective in the treatment of colds. Lastly, the thymus has been established to pose antimicrobial activity. The species possess antibacterial, antifungal, and antioxidant activities mostly due to the presence of thymol in the genus. It has been instrumental in the production of disinfectants.

Genus thymus is known to be resourceful in the production of essential oils used for the treatment of infectious diseases and pathogens associated with oxidation. Notably, the Lamiaceae family is widely used as a source of oil extracts characterized by high antioxidants with antimicrobial properties[1]. The species widely known for the extraction of Essential Oils include T. capitatus, T. kotschyanus, T. carmanicus, and T. fallax among others. however, scientists have only managed to extract oil from T. capitatus.

The chemical composition of oil extracted from T. capitatus include carvacrol (68.8%), α-pinène (12.5%), p-cymène (11.1%) and thymol (89.06%), p-cymène (5.04%), γ-terpinène (3.19%)[1].

Fig1; CarvacrolImage retrieved from:National Center for Biotechnology Information. PubChem Compound Summary for CID 10364, Carvacrol. https://pubchem.ncbi.nlm.nih.gov/compound/Carvacrol. Accessed May 5, 2022.

Fig 2; Thymol Image retrieved from National Center for Biotechnology Information. PubChem Compound Summary for CID 6989, Thymol. https://pubchem.ncbi.nlm.nih.gov/compound/Thymol. Accessed May 5, 2022.

Allium Cepa

Allium Cepa is commonly known worldwide as onions that belong to the family Liliaceae. It is a well-known fact that onions (Allium cepa L.) are one of the world’s most widely consumed and grown vegetables. With its distinct flavor, the onion bulb is the world’s third most important horticultural spice, with significant commercial importance[2]. Apart from its culinary qualities, Allium cepa has long been regarded as a medicinal plant in a variety of indigenous cultures. In addition to the commonly known Allium cepa, Allium fistulosum, Allium proliferum, and Allium canadense are the other species under this genus. Although the term “wild onion” is applied to a variety of Allium species, A. cepa is only known from cultivation. Its origins can be traced back to Egypt.

Onions or rather Allium Cepa is mainly consumed in Africa as a vegetable and an essential ingredient in many African sauces. Notably, Onions are an essential dietary requirement due to the many benefits they possess. Further, Allium cepa has been known to contain a variety of components sufficient in the medical field due to its health benefits. According to research by Upadhyay 2017, onions contain organic sulfur compounds which can be broken down into diallyl disulphate, ajoene, and sallymercaptocysteiene[2]. In addition, they possess polyphenol and flavonol acids which show an 80% concentration using a High-Performance Liquid Chromatography (HPLC).

Effective molecules found in Allium cepa include saponins, flavonoids, glycosides, terpenoids, and amino groups. Due to the existence of the aforementioned molecules, they have other properties such as antioxidant, anti-melanogenesis, antispasmodic and antiproliferative activities[2]. Notably, the polysaccharides present in onions act as free radical formation, therefore, presenting it as a suitable antioxidant. The bulb of the onion is the most edible part and also contains medicinal properties. Additionally, onion contains a variety of bioactive compounds, including flavonol and quercetin derivatives[2]. Scientists claim that onions contain the highest concentration of quercetin of all plants, which makes it a unique vegetable to consume regularly.

The medicinal properties of onion are not limited to a single effect. On the contrary, onion has several medicinal properties. The most important are anticancer, anticoagulant, antiviral, immune-modulating, anti-inflammatory, anti-complementary, and anti-diabetic effects[2]. Onions aren’t eaten by everyone, especially dyspeptics, who complain that they cause flatulence, a common symptom of onion overconsumption. Boiling onions eliminates this problem to a large extent. One of the most common home remedies for treating children’s coughs and other respiratory ailments is a syrup made from a combination of sugar and onion juice. This is considered one of the basic use of onions domestically to benefit medicinally.

The anti-inflammatory properties of onions help to alleviate the pain and swelling associated with osteoarthritis and rheumatoid arthritis, asthmatic allergic inflammatory response, and cold-related respiratory congestion, among other conditions. Because of their anti-inflammatory properties, isothiocyanates, along with vitamin C and quercetin, have made onions a popular traditional ingredient in soups and stews during the cold and flu season that helps in reducing the impact of cold[2]. Allium Cepa is important because recent research has found a link between increased body weight and fat deposition, as well as elevated oxidative stress levels in the body. Obesity-related comorbidities such as diabetes may be exacerbated by a lack of antioxidants. Numerous studies have suggested that obesity and antioxidant intake are inversely related. Furthermore, antioxidants may help with the management and prevention of several obesity-related diseases, such as cardiovascular disease and diabetes.

Onions are also recommended by the World Health Organization for the treatment and prevention of anorexia and atherosclerosis. Onions, like garlic, have been shown to lower blood pressure, triglyceride, and cholesterol levels while increasing HDL levels when consumed regularly[2]. Diabetes-related heart disease, as well as the risk of heart attack and stroke, can all be avoided by following a healthy diet and exercising regularly. Onions are one of only a handful of vegetables that have been shown to lower the risk of heart disease. Specifically, vitamin B6 is responsible for this beneficial effect because it lowers homocysteine levels, which are risk factors for heart attacks and strokes. Onions contain sulfur, which makes them effective anti-clotting agents in their natural state.

Viola species(C29H36O15) and Tinospora cordifolia

In Indian folklore medicine, Viola species and Tinosporacordiofolia were traditionally used to treat bacterial infections. Various solvents, including pure methanol, 50 percent methanol, water, acetone, and hexane, were used to extract the plants. There are about 500 species of the genus in the world, including small, solid-colored violets and larger, multicolored violas and pansies. They are all members of the Violaceae family, which includes the viola and the pansy. For those who live in temperate climates, the Andes Mountains of South America, which are home to many different species, have the most diverse collection of Viola species[3]. On the other hand, the genus Tinospora contains about 34 species mainly found in the subtropical parts of Asia.

The extraction of both plants uses different solvents. The extraction of Viola was done by the use of methanol, water, hexane, or 50% methanol. On the other hand, the extraction of Tinospora Cordifolia is done by the use of methanol and acetone[3]. Notably, both plants show the existence of antimicrobial activity due to the presence of antioxidants. However, Tinosporacordiofolia possesses high levels of antioxidants as compared to any Viola species. Phytochemicals found in these two plants are involved in both disease prevention and overall health promotion[3]. Phytochemicals may decrease the risk of coronary heart disease by preventing the oxidation of low-density lipoprotein (LDL) cholesterol, inhibiting cholesterol synthesis or absorption, and maintaining normal blood pressure and clotting times[3]. Additionally, the antioxidants found in both plants are extremely effective at preventing heart disease and play a significant role in weight management and obesity regulation.

Tinospora cordifolia, a plant with numerous functions, is a valuable resource for all forms of life due to its adaptability. As previously stated, plant extracts have been reported to contain active compounds such as alkaloids, glycosides, lactones, and steroids[3]. Each of these active compounds possesses a diverse array of immunomodulatory and physiological properties, demonstrating the plant’s adaptability. In future research, it is necessary to investigate in greater detail how active compounds interact with living systems and how they affect structure-function relationships. By examining membrane-bound receptor crystal structures, downstream signaling cascade activation, and changes in the immediate environment of the site of action, novel perspectives on nature can be discovered. Investigating nature’s vivacious sources can also reveal differences in how evolutionarily related groups of organisms interact.

Verbascoside and catechin.

Verbascoside and catechin are widespread polyphenolic plant compounds that could play a role in the anti-inflammatory and health-promoting effects of plants and plant extracts. All of the phenolic compounds found in plants, including flavonoids, phenylethanoid glycosides, tannins, and phenolic acids, belong to the larger class of secondary metabolites known as phenolic compounds[4]. Phenolic compounds, which are found in nearly all plant species, play a significant role in medicinal plant activity. An aromatic acyl unit is typically esterified with the hydroxyphenylethyl moiety of phenylethanoid glycosides. All four families are found in the Lamiaceane, Plantaginaceae, Scrophulariaceous, and Olaceaegenera[4].

Notably, Catechins have been known to be resourceful in stress reduction. Catechins, flavanols from the flavonoid family, are found in a wide variety of plants. Flavanols are primarily found in green tea, red wine, and chocolate-based products, among other things. Although catechins are powerful antioxidants, they may also have a pro-oxidant effect in the body [4]. It is thought that catechins have indirect antioxidant activity because they stimulate the production of antioxidants and antioxidative enzymes while inhibiting the production of prooxidants and enzymes involved in the production of phase II detoxification enzymes and antioxidative enzymes. Catechins are antioxidants that neutralize reactive oxygen species (ROS) and act as metal ion chelators[4]. Inflammatory diseases such as neurodegenerative disease, cancer, cardiovascular disease, and diabetes are associated with chronic oxidative stress and reactive oxygen species (ROS) (ROS). In addition to being antioxidants, catechins are effective in the prevention and treatment of diseases caused by oxidative stress.

Verbascoside is a molecule with potential therapeutic value in the prevention and treatment of neurodegenerative diseases, particularly due to its ability to inhibit the enzyme MAO-A and thus reduce the degradation of monoaminergic neurotransmitters[4]. This property, combined with its ability to trap free radicals and alleviate oxidative stress-induced in neuronal cells, demonstrates the compound’s therapeutic potential and justifies future research aimed at gaining a better understanding of how it works. 

Fig 3. Verbascoside Image retrieved from National Center for Biotechnology Information. PubChem Compound Summary for CID 5459010, Verbascoside. https://pubchem.ncbi.nlm.nih.gov/compound/Verbascoside. Accessed May 5, 2022.

Conclusion

Plants are resourceful substitutes for synthetic pharmacology. Genus Thymus, Allium Cepa, verbascoside, and Voila are among the major plants that were traditionally used for medicinal purposes and possess the potential to revolutionize the medical world. Notably, they have a common characteristic in that they possess antioxidants which play important roles in curing and preventing various diseases ranging from minor infections to chronic diseases. Notably, the use of plant components in the pharmacology industry carries more potential for the solving and curing of untreatable diseases worldwide.

References

1. Nabavi, S. M., Marchese, A., Izadi, M., Curti, V., Daglia, M., &Nabavi, S. F. (2015). Plants belonging to the genus Thymus as antibacterial agents: From farm to pharmacy. Food Chemistry, 173, 339–347. https://doiorg.proxy.libraries.rutgers.edu/10.1016/j.foodchem.2014.10.042
2. Sulaiman, A. F., Alwan, W. M., Salman, S. A., & Al-Abodi, E. E. (2021). A Comparative Study of Chemical Compounds and Anti-Bacterial Efficacy of Different Allium Cepa Plant Extracts. Systematic Reviews in Pharmacy, 12(1), 45–48.
3. Alok, J., Prabhjot, K., & Raj, S. N. (2012). Viola species and Tinospora cordifolia — Potential as Herbal Antibiotics. Journal of Tropical Medicinal Plants, 13(1), 23–27.
4. Sipahi, H., Gostner, J. M., Becker, K., Charehsaz, M., Kirmizibekmez, H., Schennach, H., Aydin, A., & Fuchs, D. (2016). Bioactivites of two common polyphenolic compounds: Verbascoside and catechin. Pharmaceutical Biology, 54(4), 712–719. https://doiorg.proxy.libraries.rutgers.edu/10.3109/13880209.2015.1072830