Medicinal Value of Artemisia, Essay Example

Antibacterial activity of Artemisia nilagirica leaf extracts

The genera Artemisia belongs to Asteraceae family which has various vital medicinally valuable secondary metabolites and essential oils. The essential oils of Artemisia spp. Have found broad use for a variety of medicinal purposes in many years. Artemisia nilagirica (Clarke) pamp often known as Indian wormwood is widely spread in the hilly areas of India (Ambasta SP1986).

Various species of Artemisia have been considered to produce most medicinally important secondary metabolites (Juteau F & Masotti V. 2002) and have been characterized for their biological activities. Various studies conducted using Artemisia spp. have showed a series of antioxidant and antimicrobial activities (

Cha JD& Jung EK2007).HPLC, NMR and GC-MS were used for qualitative determination of various secondary metabolites such as terpenoids, flavonoids, polysaccharides and saponins of Artemisia spp. Studies have shown that artemesia extracts may be used as natural pesticide, and in treating malaria human beings with the secondary metabolites finding use in food industry as well as antimicrobials (Priscila IU & Mariama TNS2007):. This study aims at determining the potential antimicrobial activity of extracts of Artemisia nilagirica which could provide more information for the future use in clinical treatment against microbial and in controlling phytopathogens.

The antimicrobials could be used against the pathogenic organisms like klebsiella, Escherichia, proteus. Enterobacter, Klebsiella, Proteus, Staphylococcus and shigella species which have been implicated to cause severe infections in human.  Phytopathogens like Clavibacter michiganense, Erwinia spp., Xanthomonas campestris as well as Pseudomonas syringae which cause  severe damage in carrots,  tomato, potato, onions, leafy greens, squash, green pepper, squash as well as  other cucurbits( Setubal JC &  Moreira LM, 2005).

The study also explored the antimicrobial potency of extracts upon use of different solvents like diethyl ether, chloroform, ethanol, methanol, petroleum. Using disk diffusion method and minimum inhibitory concentration (MIC) test the antibacterial activity was determined. The study used 11 clinically important reference bacterial strains from test cultures obtained from Microbial Type Culture Collection (MTCC, American Type Culture Collection (ATCC),) as well as local isolate from SPIC Science Foundation Patholab (SSFP) and four plant pathogens.

Analysis of variance (ANOVA) was the statistical procedure applied in analyzing the results. ANOVA was performed using GeneSpring GX – 7.3 microarray software in determining   whether the MIC values between the extracts against bacterial culture were significant with the probability value (p) ? 0.05 being considered as significant.

The study concluded that extracts of A. nilagirica have broad spectrum of antibacterial activity on the tested microorganisms with methanol extract showing maximum inhibition against clinical pathogens with the exception of E. facials, K. pneumoniae and S. aureus. Hexane extract on the other hand hexane exhibited highest inhibitory potency against phytopathogens. The phytochemical analysis showed the presence of effective biological compounds such as amino acids, alkaloids, phenols,flavonoids, terpenoids and tannins  derivatives which  could be potentially  be used as alternatives to the traditional chemical control of phytopathogenic bacteria and  clinical pathogens. The natural antimicrobials have an advantage over synthetic drugs in that they do not have the side effects experienced with the conventional medicine and therefore should be developed. The conclusions of this study are appropriate  because first we see that out of 15 bacterial strains tested, 12 showed inhibition activity to one or more extracts meaning the extracts have a broad spectrum effect and that the three test species which did not show inhibition they are resistant to the extracts. Methanol and hexane extracts are considerably good inhibitors for clinical pathogenic bacteria and phytopathogens respectively because from the results obtained from the MIC and zone of inhibition studies they are seen to produce the biggest zone of inhibition compare to others. For example results from the  MIC studies  of clinical pathogens  indicated  that the methanol extract was highly active compared  to other extracts as it  inhibited the series of 12 study organisms even at  low concentration of 32 ?g/ml.

The analysis of chloroform and methanol extracts against phytopathogens gave a significant level of inhibition against X. campestris and Erwinia sp. with diethyl ether and ethanol extracts showing high activity against P. syringae and C. michiganense (p ? 0.05). With hexane extract of exhibiting maximum inhibitory activity against all the phytopathogens as compared to other extracts as seen in table 1. A similar analysis of A. nilagirica leaf extracts was done on clinical bacterial pathogens.  Methanol, petroleum ether and hexane extracts exhibited significant high inhibitory zones against P. vulgaris, S. typhi. and P. aeruginosa, while diethyl ether, chloroform extracts exhibited maximum inhibition (10 mm) for B. subtilis, compared to other extracts (8 mm) and  ethanol extract showed 14 mm zone for E. coli, which is the maximum with respect to streptomycin  standard used.

Generally the results obtained were statistically significant a conclusion reached by using ANOVA for analysis with the value of p? 0.05 for a statistically significant results. One-way ANOVA was used to test for differences because the means of the groups in question were more than two and the level o significance was found to be p<0.05.

References 

Ambasta SP(1986): The useful plants of India. Publications & Information Directorate. CSIR.

Cha JD& Jung EK(2007). Chemical composition and antibacterial activity of essential oil from Artemisia feddei. J Microbiol Biotechnol. PubMed

Juteau F & Masotti V. (2002).Antibacterial and antioxidant activities of Artemisia annua essential oi l. Fitoterapia  73:532-535. PubMed

Priscila IU & Mariama TNS(2007): Antibacterial activity of medicinal plant extracts. Braz J Microbiol. PubMed

Setubal JC &  Moreira LM, (2005): Bacterial phytopathogens and genome science. Curr Opin Microbiol , 8:595-600. PubMed .