Introduction of guyabano research paper
Annona muricata also called as Guyabano is a, flowering evergreen tree native to Mexico, Cuba, Central America and parts of India. The miracle tree as it is widely known as a natural cancer killer that is 10,000 times stronger than chemotherapy. Based on these miraculous claims, the leaves of these plants were used as an extract at varying concentrations as an antibacterial agent against oral pathogens.
The aim of the study was to assess antimicrobial efficacy of Guyabano leaf extarct and benefits of guyabano leaves(Annona muricata) on Streptococcus mutans, Streptococcus mitis, Porphyromonas gingivalis, Prevotella intermedia and Candida albicans using disc diffusion method.
Materials and Methods
Extracts of Annona muricata leaves of concentrations of 1%, 5%, 10%, 15% and 20% were prepared. The anti-microbial efficacy was evaluated using disc diffusion method against Streptococcus mutans, Streptococcus mitis, Porphyromonas gingivalis, Prevotella intermedia and Candida albicans on agar plates.
The use of Guyabanoextract on microorganisms has a strong traditional foundation; many countries in the world use this extract for treatment of various diseases. In countries like Peru, Brazil and Togo the extracts have been used for various treatments such as liver disorders, diarrhoea, dysentery, fevers, hypertension, sores, internal ulcers and diabetes. These various curative properties and its effect against cancer prompted the authors of the present study to investigate into the effect of Soursop extract, on oral microbiota .
The anti-microbial efficacy of the extracts of Guyabano have been investigated in the past but to a very less extent, very few studies have been found on the effect of these extracts. The microorganisms on which these extracts were evaluated by Vieira et al., Staphylococcus aureus, Vibrio cholerae, Escherichia coli and Salmonella spp., were susceptible to the extracts and gram positive bacteria showed higher zones of inhibition than that of gram negative bacteria, this may form the basis of the present study too where the extracts were less effective on P. gingivalis and P. Intermedia was completely resistant to these extracts which may be due to cell wall in gram negative bacteria that act as barrier for diffusion of the extracts into them thus, rendering them ineffective .
The anti-fungal efficacy of Guyabano extracts have been evaluated on a much larger degree than its antibacterial properties. The anti-fungal property of Guyabano extract is comparatively higher than its antibacterial efficacy, as at all concentrations the extract showed potent anti-fungal property against Candida albicans, which substantiates the previous findings of Jonny et al., and Donati M et al., [19,20].
The anti-microbial activity of Guyabano extracts have never been evaluated on oral microorganisms; hence, it is difficult to compare its efficacy to that of any other extract; therefore, a positive control Chlorhexidine Gluconate was used, as an effective scale to compare the same. The most effective concentration of Guyabanoextract was 20%, the effects of this extract was much less than that of the gold standard control in both the cases (i.e., Ciprofloxacin for bacteria and fluconozole for Candida), but were nearly similar to that of Chlorhexidine Gluconate, which paves way for further analysis of the same at higher concentration.
The mode of action of Guyabano extract against microorganisms is presently unknown but the common mechanism as to how they act against microbes, insects, and herbivores in their natural environment might prevail.
Biologically as to what makes Guyabano potent against micro-organisms is the presence of acetogenins. These are bioactive compounds found in the annonacea family, these acetogenins, are known to have tumoricidal, anti-malarial, anti-helmintic, anti-viral, and anti-microbial effects, suggesting many potentially useful application. Of the annonaceous-acetogenins, bullatacin, an acetogenin is a powerful tumoricidal and antibacterial agent .
The current concentrations of extracts used were just anecdotal. For, it remains a matter of consensus whether an increase in concentration would prove to be better than chlorhexidine 0.2% and/or gold standard or the ‘ceiling effect’ as seen in most of the therapeutic drugs, might come into focus. Hence, it is difficult to conclude without investigating the efficacy of higher concentrations of these extracts, that Annona muricata would make any significant difference in oral microbial activity. Assuming that an increase in concentration improves efficacy, most of the problems encountered with the use of synthetic drugs and chemicals might tend to taper . Hence, it might open new avenues for research in treating patients who might be undergoing chemotherapy and radiotherapy for oral cancer as it shows both anti-cancer and antimicrobial activity.