Essay on Phytochemistry and Ethnopharmacological Aspects of Calendula

Taxonomic Hierarchy This plant belongs to the kingdom Plantae, Viridiplantae subkingdom, Tracheophyta (vascular plants) division, Spermatophytina (seed plants) subdivision, Magnoliopsida class, Asterales Order, Asteraceae family (sunflowers), and Calendula family (L. Marigold) (Itis.gov., 2017).

Common names The accepted scientific name is Calendula officinalis. Other common names include: L.-pot marigold, Scotch Marigold, calendula, and ruddles (Itis.gov., 2017).

Synonyms Calendula aurantiaca, Calendula eriocarpa, Calendula hydruntina, Calendula prolifera, calendula sinuate, and Calendula officinalis (L.) or (var) (Theplantlist.org., 2017).

Botany and Parts Used

Habitat Calendula plant was natively found in Mediterranean countries, but it is currently found in North America and also grown in gardens all over the world (The Herbal Resource, 2017). The growth characteristics include light or sandy, average rich, and well-drained soils (loam). It also grows well in complete sunlight exposure, and it is a self-sowing plant. Additionally, the plant grows to a height of 30-60 cm and has a branching stem pattern (The Herbal Resource, 2017).

Parts used The plant has bright yellow or orange flowers.

The leaves have two appearances whereby the lower leaves are paddle-shaped, and the upper leaves are smaller and pointed (Pfaf.org., 2017).

The calendula flower is the most used part of this plant that is dried or used fresh. They are picked soon after fully opening. The leaves are also eaten for their vivid sweetness in juices. Fresh petals are also used in salads while dried ones are crushed and added to soups. A yellow dye obtained from the petals is also used in food coloring and as a rice flavor (Pfaf.org., 2017).

Plant Chemistry

Main constituents The main constituents include triterpenoids that are used as anti-inflammatory and anti-edematous agents. Other components include flavonoids, saponins, polysaccharides, and tannins that are used as anti-inflammatory, antioxidant, anti-edematous and wound healing (Miguel , et al., 2016).

Medicinal actions and research reports

Traditional uses

Clinical research on usage and mechanism of actions. Traditionally, the medicinal applications of calendula extracts varied widely, and it was both used as a traditional herb and repellant plant in gardens. In the gardens, they used the plant to keep away garden pests such as aphids, and asparagus beetles (Chestnut School of Herbal Medicine, 2017).There are current studies for garden use, but there are studies that have indicated its usefulness in animal medication. Some of the traditional uses included treatment of peptic ulcers, GERD, and inflammatory bowel disease. According to Chestnut School of Herbal Medicine, (2017), human applications of calendula are the most common because of the anti-inflammatory effect.

According to WebMD, the calendula flower is used for medicinal purpose in preventing muscle spasms and reduction of fever. It is also topically applied on the skin to reduce inflammation and pain, and for wound healing. Its application is based on the belief that the chemical components help in tissue growing (wound healing) and reducing swelling. Other uses include treatment of a sore throat and mouth, proctitis, and stomach and duodenal ulcers (Webmd.com., 2017).

A study by Arora, Rani, and Sharma (2013) evaluated the phytochemistry and ethnopharmacological aspects of Calendula and found that it has been traditionally used in the treatment of various skin diseases, ulcers, and used in cosmetic formulations such as shampoos. Further studies should be carried out to establish the multifarious biological uses and their mode of action. Medical reports revealed that tincture of C. arvensis worked against staph. Aureaus with a concentration of 10 mg/ml. In clinical studies, a randomized, open controlled study was also used to investigate the usefulness of calendula ointments. From the clinical study, Arora, Rani, and Sharma (2013) found that there was statistically significant wound healing that suggested the positive effects of calendula extract. The study has provided both in vitro and vivo applications of this plant.

Another toxicological experiment by Arora, Rani, and Sharma (2013), indicated that calendula preparations caused allergic reaction thus establishing the sensitization effects of the extracts. Additionally, the plant caused anaphylactic shock following its infusion.

According to herbal resources, there are various therapeutic benefits of calendula that have been clinically approved. It has been in use since the 12th century as a topical agent in wound healing and prevention of infections. The plant has high levels of flavonoids that increase the rate of neovascularization and deposition of hyaluronan which facilitates wound healing through extracellular matrix cells (The Herbal Resource, 2017). Calendula has also been found to have antifungal properties, and it is used primarily for the treatment of thrush, dermatophytosis, and athlete's foot. The essential oil can again be applied as a suppository to treat yeast infections in the birth canal (The Herbal Resource, 2017).

In the medicinal usage, Calendula is believed to inhibit bacteria proliferation especially Helicobacter pylori that are the common cause of ulcers of the stomach and duodenum, gastritis, and PUD (The Herbal Resource, 2017). It is also believed to poses a positive impact on the immune system. The flavonoids which are major constituents are plant-based antioxidants that are used in neutralizing the free radicals responsible for immune suppression. Similarly, there are other plants with flavonoids that have been found to be an immune booster (The Herbal Resource, 2017).

Other medicinal applications of Calendula include treatment of complications associated with menopause and menstruation especially painful cramps and relieving breast tenderness. During delivery, it has also been used to enhance uterine contractions and promoting delivery of placenta after birth. During breastfeeding, it is also one of the components added into creams used to soothe nipple sores (The Herbal Resource, 2017).

Concerning skin disorders, Calendula is the most commonly used herb. It is used to facilitate burns, and a traditional herbal remedy for treating rashes and systemic skin diseases including acne, psoriasis, and dermatitis (Kodiyan & Amber, 2015). According to Kodiyan and Amber, (2015), the allergic effects of calendula it is a useful agent for treating radiotherapy-induced skin reactions. Calendula has detoxifying properties, and it is used in liver and gallbladder detoxification as well promoting their functions. Concerning detoxification, it is also used to promote sweating which a way of getting rid of toxins. Other topical applications include ear drop administration in the treatment of ear infections and Calendula eyewash for the treatment of chronic conjunctivitis. The herb has been widely used for topical administration and additional composition in ointments. The topical usage has been facilitated by its anti-inflammatory mechanisms and other skin diseases.

Preparation and dosage: Safety Considerations

Preparation and dosage Calendula products are stored in dark places, moisture-free, and should not be used after three years of storage.

An infusion is prepared using dried florets and boiling water by mixing one teaspoon in 250 ml of water. The dosage is then two or three cups of the infusion daily.

A tincture can be prepared with alcohol (90%) in the ratio of 1:5 and a dosage of 1-2 ml three times per day.

Calendula is also used in ointments that may contain around 5% of its extracts and applied four times a day (The Herbal Resource, 2017).

Safety Considerations It should be used with a lot of caution to avoid interaction with other medications such as sedatives. It belongs to Class 2 of herbal drugs.

It may cause skin rashes to people sensitive to plants products in the ester family.

It should not be used during pregnancy and breastfeeding.

Lastly, for children, only topical appliances are recommended (The Herbal Resource, 2017).

References

Arora D, Rani A, & Sharma A. (2013). A review on phytochemistry and ethnopharmacological

aspects of genus Calendula. Pharmacognosy Reviews. 7, 179-87.Chestnut School of Herbal Medicine. (2017). Calendula - Edible, Medicinal Flower | Chestnut

School of Herbal Medicine. [online] Available at: https://chestnutherbs.com/calendula-sunshine-incarnate-an-edible-and-medicinal-flower/ [Accessed 5 Oct. 2017].

Itis.gov. (2017). ITIS Standard Report Page: Calendula officinalis. [online] Available at:

https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=36910#null [Accessed 5 Oct. 2017].Kodiyan J, & Amber Kt. (2015). A Review of the Use of Topical Calendula in the Prevention and

Treatment of Radiotherapy-Induced Skin Reactions. Antioxidants (Basel, Switzerland). 4, 293-303.

Miguel M, Barros L, Pereira C, Calhelha Rc, Garcia Pa, Castro M, Santos-Buelga C, & Ferreira Ic.

(2016). Chemical characterization and bioactive properties of two aromatic plants: Calendula officinalis L. (flowers) and Mentha cervina L. (leaves). Food & Function. 7, 2223-32.

Pfaf.org. (2017). calendula officinalis Pot Marigold, Common Marigold, Scotch Marigold,

Ruddles, Pot Marigold PFAF Plant Database. [online] Available at: http://www.pfaf.org/user/Plant.aspx?LatinName=calendula+officinalis [Accessed 5 Oct. 2017].

The Herbal Resource, (2017). Calendula - Side Effects, Uses and Benefits. [online] The Herbal

Resource. Available at: https://www.herbal-supplement-resource.com/calendula-herbs.html [Accessed 5 Oct. 2017].

Theplantlist.org. (2017). Calendula officinalis L. The Plant List. [online] Available at:

http://www.theplantlist.org/tpl/record/gcc-107206 [Accessed 5 Oct. 2017].Webmd.com. (2017). CALENDULA: Uses, Side Effects, Interactions and Warnings - WebMD.

[online] Available at: https://www.webmd.com/vitamins-supplements/ingredientmono-235-calendula.aspx?activeingredientid=235&activeingredientname=calendula [Accessed 5 Oct. 2017].