Geranium Finding Its Way Into the Lab

By Leslie Hammond

A Brief Overview

Commonly known as geranium, species of Pelargonium are widely cultivated around the world. Of the hundreds of varieties of this perennial shrub, only about a handful are actively cultivated for commercial use. There is an actual botanical genius called Geranium that shares the same family as Pelargonium, known as Geraniaceae. Although they are similar, their uses are quite different. Pelargonium is cultivated and used in perfume and aromatherapy, while Geranium species grow almost anywhere except in water logged soil and sometimes used in the horticulture trade. Physical differences are also apparent with Geranium (commonly known as cranesbill) having symmetrical flowers and Pelargonium having irregular or maculate petals. Gardeners have taken up the practice of distinguishing the two by using their genus names versus their common names.

Indigenous to South Africa, geranium was first introduced into Europe in the 17th century and later hybridized. These hybrid cultivars have a wide variety of scents, including rose, citrus, mint, coconut and nutmeg. The main species cultivated for the aromatherapy and perfume industry is Pelargonium graveolens, or rose geranium. This specific species is indispensable in the aromatherapy industry and highly prized in the perfume industry. Extracted by steam distillation of the leaves and branches, the rose geranium essential oil is used by aromatherapists to assist with a wide array of maladies such as mood swings, skin disorders and feminine menstrual irregularities as well as to balance feminine hormone levels during menopause. Rose geranium has similar chemical constituents as those present in rose oil, namely geraniol, linalool and citronellol, thus making it a favorable alternative for the perfume industry to the more expensive essential oil of rose petals. Such a fragrance is also widely used by the cosmetic industry as a component in soaps, detergents, creams and lotions. The essential oil itself is extracted from the leaves and branches of the plant. After cutting, a common practice is to partially dry the plants in order to increase the yield of oil.

The first geranium plants grown for the French perfume industry were planted in Algeria in 1847 and then in the 1880s extensive plantations were established in Reunion - an island in the Indian Ocean governed by France. Geranium oil is also cultivated in other parts of the world for its commercial value such as China, Egypt, Russia and Central America. The oil from China is thought to be similar to that of Reunion (known as Bourbon), while the Egyptian geranium is quite different. This is due to various soil and climatic conditions. The Bourbon variety, with its rich aroma, is considered to be the most important of the geranium oils.

Geranium as a Strong Antimicrobial

In the last decade there has been a rise in attention given to antibiotic-resistant microbes, especially ones that cause severe infectious diseases and lead to fatality. On the first day of this new year of 2010, researchers from the National University of Ireland in Galway announced to the world that disinfectants can cause bacteria to resist antibiotics. Their study, published in the January 2010 issue of Microbiology, looked at the response of Pseudomonas aeruginosa to increasing levels of disinfectant. (P. aeruginosa is a bacterium that is a known occupant in hospitals, causing a wide range of infections in hospital patients. Standard hospital procedure is to use a surface disinfectant to prevent the spread of bacteria. If bacteria manage to survive and in turn infect patients, then antibiotics are administered.) The researchers found that P. aeruginosa adapted to increasing levels of disinfectant and even developed a resistance to an antibiotic (ciprofloxacin) without being exposed to the drug directly. More specifically, the researchers revealed that the bacteria had created a more efficient means of pumping out the antimicrobial agents (such as disinfectants and antibiotics) through their cell wall and developed a mutation in their DNA to resist ciprofloxacin-type antibiotics specifically. With such findings, the researchers concluded that such bacterial adaptations could be of great harm to hospital patients and advised to reconsider how disinfectants are used in hospital settings.

Pseudomonas aeruginosa bacteria are widespread in nature, inhabiting soil, water, plants, and animals. Yet these pathogens usually do not infect healthy human individuals, only those with compromised immune systems. According to the Center for Disease Control (CDC), P. aeruginosa accounts for 10.1 percent of all hospital-acquired infections and can be a cause of such diseases as pneumonia, urinary tract infections (UTIs), bone and joint infections, gastrointestinal infections and bacteremia. These infections are considered complicated and possibly life threatening.

There are an increasing number of studies being published in peer-reviewed journals on the potent antimicrobial properties of essential oils, including geranium. A 2004 study (Burns 2004 Dec; 30(8): 772-7) found that geranium in combination with Citracidal (grapefruit seed extract) had great effectiveness against methicillin-resistant Staphylococcus aureus (MRSA) and in combination with tea tree was highly effective against methicillin-sensitive Staphylococcus aureus. These researchers concluded that essential oils serve as highly useful antimicrobial agents and in treatment of MSRA infection. A more recent study (BMC Complementary and Alternative Medicine 2006 Nov 30; 6:39) found that essential oils, including geranium were effective against Staphylococcus aureus, including the ubiquitous bacterium Pseudomonas aeruginosa.

Conclusion

Geranium essential oil has been praised for centuries for its medicinal qualities and beginning in the late 1800s for its aromatic fragrance in perfumes and cosmetics. Species of Pelargonium are found in flower gardens throughout the world. In recent times, with the rise of drug resistant pathogens, essential oils such as geranium have evoked interest as an alternative remedy in treating and preventing many infectious diseases. It is clear that the spread of drug resistant pathogens, such as P. aeruginosa, is one of the most serious threats to hospital patients. According to the World Health Organization (WHO), a majority of the world's population depends on traditional medicine for primary healthcare. There may come at time in the near future where the entire world will once again turn to the medicinal qualities of plants and their constituents as a main source of illness recovery and wellness. - 31372

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