Review Article Ravi Kant Upadhyay et al. / Journal of Pharmacy Research 2011,4(4),1179-1185 ISSN: 0974-6943 Available online through http://jprsolutions.info Plant natural products: Their pharmaceutical potential against disease and drug resistant microbial pathogens Ravi Kant Upadhyay Department of Zoology,D D U Gorakhpur University, Gorakhpur 273009, U.P. India Received on: 01-01-2011; Revised on: 04-02-2011; Accepted on:21-03-2011 ABSTRACT Plants contain diverse groups of phytochemicals such as tannins, terpenoids, alkaloids, and flavonoids that possess enormous antimicrobial potential against bacteria, fungi and other microorganisms. These are much safer than synthetic drugsand show lesser side effects. Approximately 25 to 50 % of current pharmaceuticals are derived from plants. Plant products are also used for the treatment of skin urinary, cardiovascular and respiratory diseases, which also show antidiarrheal, hepato-protective, hypoglycemic, lipid lowering, antiseptic, and antioxidant activities. Few important plant products such as ellagic acid coumarin, gallic acid, benzenoide, chebulic acid, corilagin, punicalagin, terchebulin, terflabin A-tannin, ellagic acid, ethyl acetate, galloyl glucose and chebulagic acid, triterpenes, flavonoids, quercetin, pentacyclic triterpenoids, guajanoic acid, saponins, carotenoids, lectins, leucocyanidin, ellagic acid, amritoside, beta- sitosterol, uvaol, oleanolic acid and ursolic acid are considered as prominent antimicrobial agents. Natural products also exhibit high susceptibility to drug resistant microbial pathogens such as methicillin- resistant and methicillin- sensitive strains of Staphylococcus aureus. These effectively check proliferation of MRSA. Some of these natural products are used as alternative medicine which are much safer and show lesser side effects than the synthetic drugs. Plant products have ethnopharmacological importance and are used as traditional medicine and food by local tribes. Key words: Phytochemicals, antimicrobial activity, drug resistanace INTRODUCTION The problem of microbial resistance is world wide, which arises due to indiscriminate use of was found effective against multiple drug resistant pathogens. Besides this, few nutraceuticals antimicrobial drugs. Till the date so many antimicrobial drugs failed to control infectious (Serrentino et al., 1991) were also found effective against drug resistant Pseudomonas aeruginosa diseases due to acquiring antibiotic resistance and become a serious public health problem (Adwan et al., 2006). (Peng, 2006). Besides this, synthetic drugs, after entering inside the body, generate so many biochemical aleterations and side effects in patients show cross reactivity inside the body fluid Natural plant products possess enormous antimicrobial potential (Akendengue et al., 2002; and widely inhibit bio-membrane functioning. In addition to it, microbes have generated new Cosentino et al., 1999; Delorenzi et al., 2001) and are used as tradiional medicines to kill enzyme system, which can cleave drug structure and nullify the effect of synthetic drugs. human pathogenic micro-organisms (Scazzocchio et al., 2001; Elizabeth et al., 2002 and Therefore, effective drug dose level of wide spectrum antibiotics has been increased manifold. Buwa et al., 2006). Few plant species such as B. orellana L.(Bixaceae), C. peltata L(Moraceae), There are so many cases of drug resistance, reported from all corners of the world. First C. officinalis Sepium H.B and K(Fabaceae), J. mimisifolia D. don (Bignoniaceae), J. secunda vancomycin resistance was reported in Enterococci and Staphylococcus aureus in 1990. It is P. pulchrum C.DC(Piperaceae), P. paniculta L.(Polygalaceae), and S. amerio (Asteraceae)( a single drug which efficiently controls Staphylococcus aureus infection (Smith et al., 1999). Rojas et al., 2006) are used as folk medicine for the treatment of gingivitis, bronchitis, infected Later on quinopristin /dalfopristin and methicilin resistance was came in to light. However, wounds and topical ulcers. Sesame is a used as a folk medicine in Africa and Asia for the there is no synthetic drug working against methicillin- resistant Staphylococcus aureus. treatment of bruised or erupted skins, cataract and eye pains (Ram et al., 1990) while palm oil Similarly, in many parts of the world, particularly in developed countries, fluoroquinolones is used against intestinal disorders such as diarrhea and dysentery (Gills, 1992). Morespecifically, (Pefloxacin, Ciprofloxacin and Ofloxacin) are recommended for treatment of Staphylococci few plants extracts such as B. pilosa is used as anti-helmintic and anti-protozoan (Bondarenko infection. But these drugs are not providing good clinical results. Hence, efforts have been et al., 1985) while C. peltata as anti diuretic (Caceres et al., 1991) and Orellana is used as made to explore new sources of active antimicrobials of plant origin to combat the infectious anti- malarial and anti-leishmaniasis agent (Irobi et al., 1996). The decoction of the leaves of diseases. These plant products are considered as good pharmaceuticals and some of them are C. officinalis is used to treat amoebiasis. Few ethanomedicinal plants such as Litsea glutinosa, under use as established medicine. Such alternate medicines exibit strong disease curing Vitex peduncularis, Elephantopus scaber contain carbohydrates, tannins, alkaloids and glyco- potential and can combat with drug resistant microbes and kill them. sides (Daisy et al., 2008). These are used by tribals of Orrisa for cure of major urinary tract infection (UTI) caused by pathogens viz. Staphylococcus aureus, Pseudomonas aeruginosa, Plant extract Proteus mirabilis, Enterococcus jaecalis and Escherichia coli (Prusti et al., 2008). Simi- Plants are valuable sources of medicinal compounds that contain broad spectrum biological larly, Stachytarpheta jamaicensis leaves are used as antidiarrheal and antimicrobial medicine activity. Approximately 25 to 50 % of current pharmaceuticals are derived from plants and (Sasidharan et al., 2007). Its methanolic extracts more effeciently kill Escherichia coli, S. show lesser side effects than the synthetic drugs. Normally during their life cycle, plants epidermis and Pseudomonas aeruginosa. Similarly, aqueous extracts of Mallotus oppositifolium encounter various infectious agents’ viz. viruses, bacteria, fungi and other parasites and were found effective against Shigella dysenteriae (Kamgang et al., 2006) while Streblus asper synthesize a variety of secondary metabolites capable of destroying the infectious agents. Both was found effective against microfilaiae at a very low dose 90 -33.5mg/ml (Singh and Singh, plants extracts and phytochemicals were found highly susceptible to antibiotic resistant 1976). It also shows cytotoxicity in cancer cells (Phuthawong et al., 2004). Besides his, few microorganisms. For example, single and combined plant extracts of Rhus coriaria and plans such as Althea officinalis, Origanum vulgare, Plantago lanceolata, Polygonum bistorta, Thymus vulgaris were found highly effective against multiple drug resistant Pseudomonas Satureja hortensis, Solanum dulcamara and Caesalpinia coriaria (Mohana et al., 2006) have aeruginosa (Adwan et al., 2006). Similarly, plant products isolated from Achillea shown very strong antibacterial and antifungal activity. millifolium(yarrow), Caryophyllus aromaticus (clove), Mellisa officinalis (rosemary), Salvia officinalis (sage), Syzygium joabolanum (Jambolan) and Thymus vulgaris (thyme) were found More specifically Terminalia avicenoides (Combretaceae) roots are used to cure dental caries effective against against antibiotic-resistant microbes (Nascimento et al., 2000). Ethyl gallate and skin infections (Gills et al., 1986) while bark extract of T. avicennioides is used as purified from a dried pod of Tara lactam shows susceptibility to methicillin- resistant and vibrocidal and typhocidal (Akinside et al., 1995; Akinyemi et al., 2000). Similarly, methanolic methicillin-sensistive strains of Staphylococcus aureus at 15.6 ìg/ml concentration. It effec- leaf extract of A. conzyoides is effectively used for cure of fibrinogaemia in poultry chicks tively checks proliferation of methicillin- resistant Staphylococcus aureus (Chang et al., (Ogbeche et al., 1997). Leaf extract of Ocimum gratissimum (Lamiaceae), is used for the 2003). Similarly, xanthones isolated from Calophyllum showed very high antimicrobial treatment of diarrhea, Acalpha wilkinsiana (Euphorbiaceae) for treatment of malaria and gas- activity against methicillin- resistant Staphylococcus aureus (MRSA) (Dharmaratne et al., trointestinal disorders (Akinde et al, 1987), Chelidonium majus (Papaveraceae) (Colombo et 1999). More specifically, Kigelia pinnata was found effective against vancomycin resistant al., 1996). Indigofera dendroids (Esimone et al., 1999), Indigofera oblongifera (Dahot et al., Staphylococcus aureus (Peterson, 1998). Triphala mashi is an ayurvedic formulation, which 1999) Cassia alata (Khan et al., 2001) and Indigofera suffruticosa (Leite et al., 2003) are used to cure microbial diseases. However, water extract of dry fruits of Terminalia chebula is used for the treatment of diabetes mellitus (Murali et al., 2004) while ethanolic and aqueous *Corresponding author. extracts of Sesame radiatum leaf showed very good antimicrobial activity against both Gram- Ravi Kant Upadhyay positive and Gram negative bacteria (Shittu et al., 2006;Yogesh et al., 2007). It is also used Department of Zoology, as a blood