Date Published: July 18, 2016
Publisher: Springer Berlin Heidelberg
Author(s): Sandeep Rawat, Arun K. Jugran, Amit Bahukhandi, Asutosh Bahuguna, Indra D. Bhatt, Ranbeer S. Rawal, Uppeandra Dhar.
Therapeutic potential of medicinal plants as a source of noble natural anti-oxidants and anti-microbial agents has been well recognised all across the globe. In this study, phenolic compounds, in vitro anti-oxidant activity and anti-microbial properties have been investigated in five Himalayan medicinal plants, (e.g., Acorus calamus, Habenaria intermedia, Hedychium spicatum, Roscoea procera and Valeriana jatamansi) in different solvent systems. R. procera exhibited significantly (p < 0.05) higher phenolics; while H. spicatum was rich in flavonoids and V. jatamansi in anti-oxidant activity. Also, R. procera and H. spicatum were found rich in gallic acid; V. jatamansi in catechin, hydroxylbenzoic acid and caffeic acid and H. intermedia in hydroxyl benzoic acid. Solvent systems showed species specific response for extraction of total flavonoids and anti-oxidant activity. All the extracts were found effective against different bacterial and fungal strains in a dose dependent manner and maximum antimicrobial activity was found in R. procera as compared to other species. All the plant extracts showed greater activity against bacterial strains as compared to fungal strains. The results of this study suggest that extract of these species can be used as natural anti-oxidant to reduce free radical mediated disorders and as natural alternative for food preservation.
The therapeutic potential of medicinal plants as a source of noble natural anti-oxidants and anti-microbial agents has been well recognized world-wide (Cowan 1999; Aqil and Ahmad 2003; Vasinauskiene et al. 2006; Tenore et al. 2011). This potential might be due to the presence of several biomolecules i.e., phenolics, flavonoids, alkaloids, terpenoids, etc., which have distinct mechanism of action (Ajaib et al. 2011). Among these, phenolics and flavonoids are recognised for their multiple biological effects including anti-oxidants, anti-inflammatory, anti-microbial, anti-carcinogenic properties, etc. (Rice-Evans et al. 1997; Cowan 1999). As such, anti-oxidants are known to prevent various diseases e.g., diabetes, coronary artery diseases, cancer, inflammatory diseases etc., by decreasing localized oxygen concentration; preventing chain initiation by scavenging radicals; decomposing lipid peroxides to peroxyl and alkoxyl radicals; decomposing peroxides by converting them to non radical products, and chain breaking to prevent continued hydrogen abstraction (Deshpande et al. 1996; Bhatt et al. 2013). Similarly, anti-microbial property of medicinal plants is preventive against various infectious diseases and degradation of food products during production, storage and processing. A number of reports are available on the anti-oxidants (Wojdylo et al. 2007; Ajaib et al. 2011; Rawat et al. 2011) and anti-microbial properties of medicinal plants (Vlietinck et al. 1995; Essawi and Srour 2000; Vasinauskiene et al. 2006; Joshi et al. 2008). However, in case of many Himalayan medicinal plants, no such detail studies are available. Therefore, there is the need of systematic evaluation of these medicinal plants. Keeping all these facts in view, this study is performed to evaluate anti-oxidant and anti-microbial properties of five ethno-therapeutically important medicinal plants namely Acorus calmus,Habenaria intermedia,Hedychium spicatum, Roscoea procera, and Valeriana jatamansi using different solvent systems. All these species are used traditionally for treating various ailments (Table 1). Besides, R. procera and H. intermedia are known for their vitality strengthening properties and used as ingredients of Chyavanprash (a herbal combination used in traditional Indian Medicinal System), which is known to protect degenerative diseases and maintain youthfulness, vigor, vitality, etc. (Bhatt et al. 2013). The rhizomes of H. spicatum are stomachic carminative, stimulant and tonic, and used for curing dyspepsia, asthma and bronchitis, and used as a poultice for various acnes and pains due to its anti-microbial properties (Joshi et al. 2008; Rawat et al. 2011). The essential oil of A. calamus and V. jatamansi is used in mental/nervous disorders and several other purposes (Raina et al. 2003; Kalim et al. 2010). Thus, most of the species are used in food/herbal formulations, it become crucial to analyze the anti-oxidant activity and anti-microbial properties of these species (Table 1).Table 1Details of traditional medicinal uses and active content of selected medicinal plantsPlant speciesFamilyTraditional usesActive constituentsReferencesAcorus calamusAracaceraeAsthma, epilepsy, chronic diarrhea, dysentery, bronchial catarrh and abdominal tumors, hysteria, syncope and mental weaknessβ-asarone α-asarone, caryophylene, isoasarone, methyle isoeugenol and safrolRaina et al. (2003), Phongpaichit et al. (2005)Habenaria intermediaOrchidaceaeBurning sensation, fever, cough, asthma, leprosy and skin diseases. Tuber is edible and used as depurative, anthelmentic, rejuvenating and tonicUnknownWarrier et al. (1994), Prajapati et al. (2003)Hedychium spicatumZingiberaceaeDyspepsia, nausea, asthma, vomiting, pain and inflammation. Boiled rhizome is edible and seeds are eaten with lentilsHedychenone, spicatanol and 6-hydroxy-cineolJoshi et al. (2008), Rawat et al. (2011)Roscoea proceraZingiberaceaeImpotency, diabetes, leucorrhoea, diarrhea, dysentery, and malaria. Tubers are edible and used in preparation of rejuvenating and tonicUnknownRawat et al. (2014)Valeriana jatamansiValerianaceaeObesity, skin disorder, insanity, epilepsy and snake poisoningValepotriates, valeric acids and flavonoidsJugran et al. (2013), Kalim et al. (2010)
This is a systematic investigation on anti-oxidant and anti-microbial potential of selected edible and ethno-therapeutically important medicinal plants of west Himalaya (i.e., H. spicatum, R. procera, H. intermedia, V. jatamansi and A. calamus), which justify their role in food preservative and reported their ethno-therapeutic uses. Although reports on anti-oxidant activity in some of these species are available but the anti-microbial activity of R. procera and H. intermedia against bacterial and fungal strain is reported for the first time. Similarly, extract of H. spicatum was tested first time against some pathogenic bacterial strains, such as, B. subtitis and M. luteus. While, the study on anti-oxidant activity of H. intermedia is first of its kind.
Anti-microbial activity along with the anti-oxidant effectiveness of plant extracts is one of the most examined features, important for both food preservation and control of human and animal diseases of microbial origin. Numerous reports suggest strong anti-microbial and anti-oxidant activities of various plant extracts. Our results indicate that the most of the target species possess a good anti-oxidant activity and exhibit a broad spectrum of anti-microbial activity against referenced strains, especially bacterial strains. The results of this study suggest that extract of these species could be used as natural anti-oxidant to reduce free radical mediated disorders and may helpful as self preserving agent for its processed products and also may be a source of active molecule against disease causing pathogens.