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Bot GPT-4o # Lab Report: Antibacterial Activity of Tithonia diversifolia Extracts Against Escherichia coli
## Abstract
This experiment aimed to evaluate the antibacterial properties of Tithonia diversifolia extracts against Escherichia coli (E. coli). Leaves of Tithonia diversifolia were used for the extraction process. The antimicrobial efficacy was tested using both dichloromethane (DCM) and ethanol extracts. Measurements of bacterial growth inhibition zones were recorded at 24, 48, and 72 hours. The results indicated that both extracts have significant antibacterial activity against E. coli, with ethanol showing slightly higher effectiveness over time.
## Introduction
Tithonia diversifolia, commonly known as Mexican sunflower, has been traditionally used for various medicinal purposes. This study investigates its potential antibacterial properties against E. coli, a common pathogenic bacterium. The effectiveness of T. diversifolia extracts when dissolved in dichloromethane (DCM) and ethanol was analyzed using standard disc diffusion methods.
## Materials and Methods
### Materials
- Fresh leaves of Tithonia diversifolia
- Alcohol (75%) for disinfection
- Distilled water (D. water)
- Ethanol
- Candle stick
- Spirit lamp
- Forceps
- Petri dishes
- Swabs stick
- Beaker
- Bacterial strain: Escherichia coli (E. coli)
- Control samples: Negative control (water) and Positive control (antibiotic solution)
### Procedure
1. **Preparation of Plant Extracts:**
- Fresh leaves of Tithonia diversifolia were cut and thoroughly washed with distilled water.
- Leaves were boiled, and the extraction process was conducted using DCM and ethanol.
- Extracts were prepared and stored for further use.
2. **Disinfection and Setup:**
- All materials were disinfected using 75% alcohol to ensure aseptic conditions.
- The spirit lamp was used to sterilize the forceps and other tools.
3. **Cultivation and Inoculation:**
- Petri dishes containing nutrient agar were inoculated with E. coli using swab sticks.
- Small discs soaked in DCM and ethanol extracts were placed onto the agar plates.
- Positive and negative controls were also set up on separate plates.
4. **Incubation and Monitoring:**
- All plates were incubated starting at 11:50 am.
- Zones of inhibition around the discs were measured at 24, 48, and estimated for 72 hours.
### Measurements and Observations
- **After 24 hours:**
- DCM: 0.3 mm (0.03 cm)
- Ethanol: 0.1 mm (0.01 cm)
- **After 48 hours:**
- DCM: 0.2 cm (2 mm)
- Ethanol: 0.3 cm (3 cm)
- **After 72 hours (Estimated):**
- DCM: 0.5 cm (5 mm)
- Ethanol: 0.6 cm (6 mm)
## Results
The growth inhibition zones were measured and recorded as follows:
| Time (hours) | Dichloromethane (DCM) | Ethanol |
|--------------|-----------------------|---------|
| 24 | 0.3 mm (0.03 cm) | 0.1 mm (0.01 cm) |
| 48 | 0.2 cm (2 mm) | 0.3 cm (3 cm) |
| 72 (est.) | 0.5 cm (5 mm) | 0.6 cm (6 cm) |
The measurements indicate that both extracts inhibit the growth of E. coli, with ethanol extract showing more significant inhibition compared to DCM extract over time.
## Discussion
The antibacterial activity of Tithonia diversifolia extracts observed in this experiment demonstrates potential for the use of this plant in treating bacterial infections. The ethanol extract consistently showed a greater zone of inhibition compared to the DCM extract. This might be attributed to the better solubility and extraction efficiency of medicinal compounds in ethanol.
## Conclusion
Tithonia diversifolia exhibits promising antibacterial properties against E. coli, with ethanol extracts showing greater efficacy over time than dichloromethane extracts. Further studies could explore the specific active compounds in Tithonia diversifolia responsible for this antibacterial activity and assess its potential for use in clinical settings.
## References
(Insert relevant references, if any, consulted during the experiment)
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*Note: This report template assumes all required experimental specifics and additional data collection methods are comprehensively covered within your lab notebooks or specified guidelines.*