Evaluation of the Efficacy of Guava Extract as an Antimicrobial Agent on Periodontal Pathogens.

AIM: The present study was undertaken to assess the inhibitory effect of guava extracts on Porphyromonas gingivalis and Aggregatibacteractinomycetemcomitans, to assess the time-kill curve of P. gingivalis and A. actinomycetemcomitans, and to determine the antiproteolytic activity of guava on P. gingivalis. MATERIALS AND METHODS: Kanamycin blood agar was used to isolate P. gingivalis and A. actinomycetemcomitans. Ethanolic guava extract (EGE) and aqueous guava extract (AGE) were prepared and the inhibitory effects of these extracts for two periodontal pathogens were tested by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) procedures. Antibacterial activity of guava extracts was determined by well diffusion method. Antiproteolytic activity of guava on protease of P. gingivalis was determined by gelatin liquefaction test. RESULTS: The MIC determined for AGE and EGE was at 75 µL/mL concentration for P. gingivalis, whereas EGE exhibited the activity at 75 µL/mL on P. gingivalis. The MIC determined for AGE was at 50 µL/mL for A. actinomycetemcomitans, whereas MIC determined for EGE was at 3.12 µL/mL for A. actinomycetemcomitans. Porphyromonas gingivalis was susceptible to EGE compared with AGE. Aggregatibacter actinomycetemcomitans was more susceptible to guava extracts compared with P. gingivalis. CONCLUSION: Guava extract may be a potential therapeutic agent for periodontitis as it shows significant activity against both P. gingivalis and A. actinomycetemcomitans. CLINICAL SIGNIFICANCE: Guava leaves extract can be used as economical and suitable adjuvant to synthetic drugs and can be a potential therapeutic agent for periodontitis.

Cardioprotective actions of two bioflavonoids, quercetin and rutin, in experimental myocardial infarction in both normal and streptozotocin-induced type I diabetic rats.

OBJECTIVES: Revascularization therapy is the mainstay of treatment in the management of myocardial infarction in normal and diabetic patients. We attempted to evaluate the cardioprotective actions of quercetin and rutin in ischaemia-reperfusion-induced myocardial infarction in both normal and diabetic rats. METHODS: Myocardial infarct size was measured using the staining agent 2,3,5-triphenyltetrazoliumchloride. Serum and tissue malondialdehyde levels and superoxide dismutase and catalase in heart tissue were estimated spectrophotometrically. A lead II electrocardiogram was monitored at various intervals throughout the experiment. KEY FINDINGS: Results demonstrated the larger infarct size, enhanced lipid peroxidation, partial depletion of antioxidant enzymes and drastic drop in heart rate in diabetic hearts subjected to in-vivo ischaemia-reperfusion in comparison to normal rats subjected to ischaemia-reperfusion. Furthermore, quercetin and rutin significantly limit the infarct size in both normal and diabetic animals in a similar fashion. However, rutin offered complete cardioprotection at a dose of 10 mg/kg in terms of limiting infarct size. Both flavonoids could partially but significantly attenuate the lipid peroxidation. In addition, treatment has shown moderate improvement in heart rate in both normal and diabetic rats. CONCLUSIONS: Our data suggest the possible cardioprotective effects of quercetin and rutin in ischaemia-reperfusion injury in both normal and diabetic rats, and that protection might be in part due to the attenuation of oxidative stress and moderate increment in antioxidant reserves.