Research Summary
While the final proof of efficacy in common dermatitis, such as atopic dermatitis, is still lacking, the authors found ample evidence for the activity of witch hazel against cutaneous inflammation in humans. This conclusion is drawn from experiments with normal volunteers, where unwanted effects related to the drug were virtually absent. Witch hazel extracts, when applied topically to dermatological areas, provide a calming effect due to the tannin content, making it useful in both cosmetics and therapeutic applications.
The active components of *Hamamelis virginiana* (witch hazel) extracts can be traced to flavonoids, leucoanthocyanidins, tannins, and essential oils, all of which contribute to benefits in blood circulation, antimicrobial activity, and antioxidant effects. This research aims to evaluate the biological activity of the herbal substances found in the bark, leaves, and twigs of *Hamamelis virginiana*, with a focus on their classification as products under well-established or traditional use. The study also seeks to establish corresponding Community herbal monographs.
The extraction process involves determining the best method to prepare the extracts, which includes milling, extracting active compounds using soxhlets, evaporating the extract to form semi-solid substances, and analyzing the functional groups using an FTIR instrument. The biological activity is assessed by measuring the minimum inhibition concentration (MIC).
The results illustrate that witch hazel extracts, in concentrations of 10 mg/ml, 50 mg/ml, and 100 mg/ml, have an inhibitory effect on 10 plates of *Candida albicans*, with the optimum concentration being 50 mg/ml. *Staphylococcus aureus* showed that a higher concentration of 100 mg/ml had an optimum effect with a wider MIC radius (0.54 cm ± 0.5). *E. coli* exhibited similar effects to *S. aureus* in biological tests. The 100 mg/ml concentration demonstrated a significant inhibition of bacterial growth within 24 hours.
Witch hazel exhibits deteriorating effects on both Gram-positive and Gram-negative bacteria, as well as fungi. These preferable actions are attributed to functional groups, particularly the carbonyl group, which has strong effects as it is a form of aldehyde. The alkyl and ketone groups also contribute to the degradation of microbial cell walls. As chelating agents, they make witch hazel an effective disinfectant, in addition to its antioxidant effects and its ability to constrict blood vessels.
Keywords: Witch hazel, Pharmaceutical effects, FTIR.
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