Evaluation of Conocarpus erectus against multidrug resistant Staphylococcus aureus: Cell to animal study.

Antibiotic resistant infections by Staphylococcus aureus (S. aureus) in high risk patients is critical challenge for all clinicians across globe. In an effort to achieve robust bactericidal effect, therapeutic approach based on antimicrobial plant extract of Conocarpus erectus (C. erectus) been assessed in-vitro and in-vivo against S. aureus resistant clinical strains isolated from burn patients and antibiotic susceptibility was conducted using Kirby-baur disc diffusion technique. C. erectus plant extract obtained and characterized for phytochemical constituents, its hemocompatibility and for antioxidant potential. Minimum inhibitory concentration studied for C. erectus extract against multidrug resistance (MDR) S. aureus clinical isolates in-vitro and in rat's sepsis model. Therapeutic activity along acute toxicity was evaluated in rat's model. C. erectus extract showed marked antioxidant activity attributed to its phenolic components predominately along others. Hemocompatibility results were significantly different (p<0.05) compared to vancomycin (positive control). Statistically significant reduction in bacterial colony count (p<0.05) observed in rat's sepsis model with C. erectus treated group vs. controls. C. erectus extract offered higher bactericidal effect both in-vitro and in-vivo along no acute toxicity at therapeutic dose. We infer that it can serve as alternative promising treatment option against antibiotic resistant against MDR S. aureus strains.

In vivo screening and evaluation of four herbs against MRSA infections.

BACKGROUND: Recently, we reported high in vitro antibacterial efficacy of Althaea officinalis, Ziziphus jujuba, Cordia latifolia and Thymus vulgaris out of a total 21 plants against wide range of bacteria including MRSA. This study was therefore, designed to confirm efficacy of these four herbs against MRSA in an animal model. METHODS: A pilot study was conducted to establish the dose of S. aureus (KY698020) required to induce clinical infection. Afterword, in main trial, efficacy of aforementioned plant extracts on the course of sore throat was checked by evaluating general health, gross lesion score, bacterial load and hematology in mice. RESULTS: Pilot study revealed that 40 µl dose of 107 CFU/ml could induce infection which persist upto 08 days post infection. Mice treated with T. vulgaris and Z. jujuba showed reduction in gross lesion score of both heart and lungs. Treatment with only some plants could significantly decrease bacterial load of throat (T. vulgaris) heart, blood and joint (C. latifolia, and T. vulagris). Hematological indicators confirmed in vivo control of MRSA infection in all treatment groups except A. officinalis. CONCLUSION: This is first report confirming in vivo anti-MRSA potential of C. latifolia and T. vulgaris and highlight the need to explore bioactive constituents of these plants. Moreover, previously reported in vitro antibacterial efficiency of A. officinalis could not be validated in current study.

Phytochemical, Antimicrobial, and Toxicological Evaluation of Traditional Herbs Used to Treat Sore Throat.

The in vitro antibacterial activities of 29 traditional medicinal plants used in respiratory ailments were assessed on multidrug resistant Gram-positive and Gram-negative bacteria isolated from the sore throat patients and two reference strains. The methanolic, n-hexane, and aqueous extracts were screened by the agar well diffusion assay. Bioactive fractions of effective extracts were identified on TLC coupled with bioautography, while their toxicity was determined using haemolytic assay against human erythrocytes. Qualitative and quantitative phytochemical analysis of effective extracts was also performed. Methanolic extract of 18 plants showed antimicrobial activity against test strains. Adhatoda vasica (ZI = 17-21 mm, MIC: 7.12-62.5 µg/mL), Althaea officinalis (ZI = 16-20 mm, MIC: 15.62-31.25 µg/mL), Cordia latifolia (ZI = 16-20 mm, MIC: 12.62-62.5 µg/mL), Origanum vulgare (ZI = 20-22 mm, MIC: 3-15.62 µg/mL), Thymus vulgaris (ZI = 21-25 mm, MIC: 7.81-31.25 µg/mL), and Ziziphus jujuba (ZI = 14-20 mm, MIC: 7.81-31.25 µg/mL) showed significant antibacterial activity. Alkaloid fractions of Adhatoda vasica, Cordia latifolia, and Origanum vulgare and flavonoid fraction of the Althaea officinalis, Origanum vulgare, Thymus Vulgaris, and Ziziphus jujuba exhibited antimicrobial activity. Effective plant extracts show 0.93-0.7% erythrocyte haemolysis. The results obtained from this study provide a scientific rationale for the traditional use of these herbs and laid the basis for future studies to explore novel antimicrobial compounds.