Antimicrobial spectrum of different solvent based extraction from rhizomes of species of the two genera Curcuma and Zingiber
4.2 Literature Review
Plants have been used medicinally in different countries and are a rich source of many potent and powerful drugs (Gislene et al. 2000; Srinivasan 2001). Medicinal herbs have always been used as traditional primary health care agents, especially in Asian countries, and over the last 20 years, there have been rapid changes in the popularity of the use of natural systems to maintain health and for alternative therapy in Western countries (Kirana et al. 2007). However, scientific studies on the use of most traditional medicinal plants have not been carried out to assure their efficacy and non-toxicity. Researchers from divergent fields are developing a keen interest in investigating plants with a new eye for their
antimicrobial usefulness and as an alternative source to existing drugs. Plants with their wide variety of chemical constituents offer a promising source of new antimicrobial agents with general as well as specific activity (Evans 1996). There are several reports on the presence of antimicrobial compounds in various plants (Ravindra et al. 2005; Prusti et al.
2008; Nair et al. 2005; Tushar et al. 2010). Although large number of plant species has been tested for antimicrobial properties, the vast majority of them have not been adequately evaluated (Srinivasan 2001; Jantan et al. 2003). Recently, there has been a renewed interest in plant essential oils and their antimicrobial activity due to the spread of antibiotic resistance (Gislene et al. 2000; Cavanagh 2007).
In a biodiversity rich country like India, over 4686 ecosystem specific species of plants are used by ethnic communalities for human and veterinary healthcare, across the various ecosystems from Ladakh from trans-Himalayas to the southern coastal tip of Kanyakumari and from the deserts of Rajasthan and Kachch to the hills of Northeast (Muthusamy et al. 2009). Across the codified medicinal systems of Ayurveda, Siddha, Unani and Sowa-rigpa, a recent study enumerates around 2400 unique species of plants that are fully documented in terms of their biological properties, actions and drug formulations for a range of health conditions (Muthusamy et al. 2009). Among those, plants belonging to the family Zingiberaceae occupy a prime position in virtue of their rich medicinal properties.
All of the members of Zingiberaceae possess a rich amount of essential oils in their rhizomes, leaves and flowers or seeds as well. The family is distributed widely throughout the tropics, particularly in Southeast Asia. It is an important natural resource that provides many useful products for food, spices, medicines, dyes, perfume and aesthetics (Bhavnani and Ballow 2000; Jantan et al. 2003). The aromatic plants are known to be used traditionally by most of the Asian countries including India for various health aliments. Around 200 species of Zingiberaceae belonging to 20 different genera have been reported alone in India of which NE India houses a vast reservoir of these plants. Most of the members of Zingiberaceae are found here at wild states which are yet to be explored. In recent years, several reports have been published concerning the biological properties (antimicrobial, antioxidant, anticancer and a stimulated effect on the immune system) of Zingiberaceae plant extracts (Ekwenye and Elegalam 2005; Cavanagh 2007) containing many essential oils like terpenes, alcohols, ketones, flavanoids, carotenoids, gingeroles and phytoestrogens
gingeroles etc. have been reported to have great antifungal, antioxidant, insecticidal and anti-inflammatory activities (Bhavnani and Ballow 2000).
The genus Curcuma is a perennial herb with simple and large leaves with oblong, ovate or cylindrical rhizomes and has about 70 species, of which C. xanthorrhiza, C.
zedoaria, C. aromatica, C. caesia and C. amada are important members. The most common species of the genus is C. longa popularly known as haldi, turmeric or Indian saffron. The rhizome of the species is yellowish red in color with characteristic odor and slightly pungent bitter taste and is used as a household remedy as anti inflammatory (antiseptic and irritant).
The genus Curcuma has been extensively worked on regarding antimicrobial and other biological properties (Negi et al. 1999; Yano et al. 2000; Kim et al. 2003; Matsuda et al.
2004; Sacchetti et al. 2005; Cousins et al. 2007; Policegoudra 2007). Curcumin (diferuloyl methane), the yellow pigment from the rhizomes of turmeric is getting much attention of cancer investigations because of its chemopreventive properties against human malignancies. Besides its daily dietary use, turmeric is used in Asian herbal medicines (Ayurveda) for skin and gut-diseases (Ramachandran and You 1999). Medical use of turmeric as a wound healing agent with anti-inflammatory, antitumor and anti-proliferative effects has been well recognized (Rao et al. 1995; Ramachandran and You 1999). C.
aromatica and C. zedoaria rhizome essential oils were found to possess fair antifungal and insecticidal properties (Singh et al. 2002). C. amada also has a record of traditional use in medicine in diverse ethnic groups and is an ingredient in culinary preparations in the Indian subcontinent (Jatoi et al. 2007). The C. amada rhizome is large and branched, with a buff colored external surface, fresh color of rhizome is pale yellow with a brilliant fragrance of green mango. The rhizome is considered good as a stomachic because of its bitter, aromatic, cooling, astringent and carminative qualities (Anonymous 1997). Combined with other medicines, rhizomes are also used to improve blood qualities (Kapoor 1990). Mango ginger is used therapeutically as a carminative, stomachic, in treatment of piles, and topically for contusions and sprains (Rao et al. 1989;). Traditionally the mango ginger rhizome has been extensively used as appetizer, alexteric, antipyretic, aphrodisiac, laxative and in the ancient Indian system of medicine Ayurveda, to cure biliousness, itching, skin diseases, bronchitis, asthma hiccough and inflammation (Kiritikar and Basu 1984; Warrier et al. 1994). The antimicrobial activity of C. amada alone or in combination with ginger and turmeric was
2007, a new antimicrobial compound was isolated and identified by Policegoudra et al. from C. amada.
Zingiber is another common genus which comprises the common ginger, Z.
officinale. The rhizomes of the genus are larger, oblong, fibrous and whitish in color with strong pungent smell. Other members of this genus are Z. zerumbet, Z. casuamonar, Z.
wrayi etc. with immense medicinal values. Almost all the plants in this genus contain active phenolic compounds in their rhizomes which possess numerous biological properties. Most studied species across the globe is the common ginger (Z. officinale). The underground rhizome of the plant has been used as a medicine in Asian, Indian and Arabic herbal traditions since ancient times (Altman and Marcussen 2001). Next to Curcuma, the genus Zingiber has been studied for its various medicinal values. It has been used extensively for thousands of years in Asian countries for headaches, nausea and common cold (Grant and Lutz 2000) and in Mediterranean and Western parts in herbal medicine practice for the treatment of arthritis, rheumatological conditions and muscular discomfort (Bordia et al.
1997; Langner et al. 1998). Reports on biological properties are available in Z. officinale, Z.
zerumbet, Z. casuamonar, Z. wrayi, Z. nimmonii etc. (Jantan et al. 2003; Chairgulprasert et al. 2004; Sabulal et al. 2006; Ali et al. 2008; Akihiro et al. 2008). Z. zerumbet commonly known as shampoo ginger has also been known for it various therapeutic uses. It is a perennial herb with large rhizomes and characteristic odor. The rhizomes are widely used as a folk medicine for sprains, indigestion, cure of swelling, sores and loss of appetite, toothache and other aliments. The juice of the boiled rhizome is has also been used as a medicine for worm infestation in children (Bhuiyan et al. 2009). Recently, Z. zerumbet has received considerable attention because of the pharmacological significance of
‘Zerumbone’, the most abundant component of the rhizome oil. Zerumbone possesses striking anti-inflammatory and anti-HIV activities (Das et al.1997; Chien et al. 2008). Z.
zerumbet is used to treat stomach-aches in Indonesian traditional medicine under the name of ‘Jamu’ (Burkill 1966).
Like ginger and turmeric, other members of Zingiberaceae also have tremendous medicinal values which are not evaluated properly till date. In fact, many members are still not recognized taxonomically and scientifically but have been used traditionally for their medicinal virtue. Literature is available on many members of the family Zingiberaceae all
(Sekiwa et al. 2000; Srinivasan 2001; Kumar et al. 2001; Hseih et al. 2001; Jirovetz et al.
2003; Burt 2004; Konning et al. 2004). In 2005, Khattak and coworkers have reported on antifungal effects of Alpinia galanga and Curcuma longa from Thailand. Tewtrakul and Subhandhirasakul (2007) studied antiallergic property of different Zingiberaceae members and found excellent results. Alpinia is another significant genus comprising many members with economic and medicinal value. Plants are mostly wild and some of them produce seeds.
A. nigra, A. galanga, A. bracteata are some of the key species and biochemical studies are reportd on their medicinal use of rhizome essential oils (Qiao et al. 2007; Yang and Eilerman 1999). Ibrahim et al. (2009) investigated antimicrobial properties of A. conchigera rhizome oil against bacterial and fungal pathogens. Kaempferia stands a unique status in Indian system of traditional medicine since long back. Common species like K. galanga, K.
rotunda, K. pulchera, K. indica etc. are with immense use in healthcare and treatments of various aliments (Sarma 2005; Tushar et al. 2010). In India investigations are reported on the antimicrobial and other biological activities of different Zingiberaceae members; viz.
Ammomum (Sabulal et al. 2006), Curcuma (Srinivasan 2001; Kim et al. 2003), Hedychium (Gopanraj 2005; Parekh et al. 2010), Kaempferia (Jantan et al. 2003; Sukari 2008), Zingiber (Indu et al. 2006; Pushpangadan and Kumar 2005; Daswani et al. 2010; Indu and Menon 2010) etc. However no attempt has been made till date to study the wild and endemic members from NE India which holds immense hidden medicinal properties. This might be due to the inaccessible nature of habitats of these plants and also very short reproductive and vegetative phase during the monsoons which pose great difficulties in collection and identification as well.
Therefore, in this chapter the objectives were aimed to investigate the antimicrobial activity of the rhizome essential oil of selected Zingiberaceae members including the endemic species Zingiber moran, from NE India against common pathogenic bacteria and fungi. Also to evaluate the minimal inhibitory concentrations (MIC) of the rhizome essential oils in an attempt to contribute to the use of these plants as an alternative for microbial control and food preservation. The second objective was to compare the amount of oil yield and antimicrobial activity of the rhizome extracts derived using various polar and non polar solvents. This study is the first report on these important species of Zingiberaceae from NE India using different organic solvents, wide range of microbial agents and different
Bacterial pathogens transmitted commonly through foods are responsible for a significant portion of food-related illnesses (Mead et al. 1999) and pose a high risk to public health. Pathogenic strains from Campylobacter, Salmonella, Listeria and Escherichia coli are well recognized as important food borne pathogens. Bacterial food borne illnesses are still a global health concern and present a continuous challenge for food safety. Assurance of food safety, and prevention and control of bacterial food borne diseases necessarily rely on the ability to detect the pathogens especially in a low number in foods. Increasing investigations on rapid, sensitive and specific detection of bacterial food borne pathogens have advanced the development of detection methods from conventional culture plating techniques to newer techniques. Raman spectroscopy is such a technique based on molecular vibrations and is emerging as an important nondestructive, noninvasive, analytical tool for biologic materials including whole bacteria (Naumann 2000) because of the high specificity and high resolution of vibrational spectra and weak background signal from the aqueous environment (Maquelin et al. 2002). A number of studies employing the Raman spectroscopic technique for the microbiologic analysis (detection, identification and characterization) of bacteria in forms of single cells, colonies or aqueous culture (after drying) have been reported (Kirschner et al. 2001; Grow et al. 2003; Zeiri et al. 2004).
Researchers have examined the bactericidal activity of some metal nanoparticle using Raman spectroscopy and surface enhanced Raman spectroscopy (SERS) (Lindsay et al.
2007; Peter et al. 2002; Raffi et al. 2010). However, reports are scanty in evaluating antibacterial potential of biological samples like essential oils till date. Hence, another aim of the study was to characterize the rhizome essential oils of the selected gingers against Gram-positive and Gram-negative bacteria with the help of micro-Raman spectroscopy.