[Antiinflammatory potential of seven plant extracts in the ultraviolet erythema test. A randomized, placebo-controlled study]

Efficacy and safety of Melaleuca alternifolia (tea tree) oil for human health-A systematic review of randomized controlled trials

Introduction: Leaves of the Australian tea tree plant Melaleuca alternifolia were used traditionally by First Nations Australians for treating wounds, burns, and insect bites. Tea tree oil, the essential oil steam-distilled from M. alternifolia, is well-known for its medicinal properties, the evidence for most applications however is limited. This review aimed to critically appraise evidence from clinical trials examining the therapeutic efficacy and safety of tea tree oil on outcomes. Methods: Randomized controlled trials with participants of any age, gender, or health status, comparing tea tree oil to any control were included, without limit on publication date. Electronic databases were searched on 12 August 2022 with additional records sourced from article reference sections, reviews, and industry white papers. Risk of bias was assessed by two authors independently using the Cochrane risk-of-bias 1.0 tool. Results were summarized and synthesized thematically. Results: Forty-six articles were eligible from the following medical fields (Dentistry n = 18, Dermatology n = 9, Infectious disease n = 9, Ophthalmology n = 6, Podiatry n = 3; and Other n = 1). Results indicate that oral mouthwashes with 0.2%-0.5% tea tree oil may limit accumulation of dental plaque. Gels containing 5% tea tree oil applied directly to the periodontium may aid treatment of periodontitis as an adjunctive therapy to scaling and root planing. More evidence is needed to confirm the benefits of tea tree oil for reducing acne lesions and severity. Local anti-inflammatory effects on skin, if any, also require further elucidation. Topical tea tree oil regimens show similar efficacy to standard treatments for decolonizing the body from methicillin-resistant Staphylococcus aureus, although intra-nasal use of tea tree oil may cause irritation to mucous membranes. Tea tree oil with added iodine may provide an effective treatment for molluscum contagiosum lesions in young children. More evidence on efficacy of tea tree oil-based eyelid wipes for Demodex mite control are needed. Side effects were reported in 60% of included studies and were minor, except where tea tree oil was applied topically in concentrations ≥ 25%. Discussion: Overall, the quality of research was poor to modest and higher quality trials with larger samples and better reporting are required to substantiate potential therapeutic applications of tea tree oil. Systematic Review Registration: PROSPERO, identifier [CRD42021285168].

Non-pharmacological remedies for post-viral acute cough

The post-viral acute cough (PAC) is a widespread symptom, mainly in childhood and adolescence, and is usually associated with an acute upper respiratory infection, namely the common cold. The use of cough relievers is, therefore, impressive, as documented by the market data. There are many medical devices and dietary supplements for treating PAC, which contain non-pharmacological components. Ancient people used traditional herbs to treat PAC. Thus, a well-established tradition considers natural remedies as an effective and safe way to relieve PAC. The herbal agents include polyphenols, flavonoids, saponins, glucosides, and alkaloids. Also, the European Medicine Agency has recognized the value of plant extracts and other natural substances to treat PAC. Nevertheless, a few studies investigated the role of non-pharmacologic remedies for PAC. There is some evidence for honey, glycerol, Althea officinalis, Drosera rotundifolia, Grindelia, Hedera helix, Pelargonium sidoides, Sambucus nigra, Thymus vulgaris, hyaluronic acid, and saline solutions. However, further rigorous studies should confirm natural products' efficacy and safety to relieve PAC.

Polyherbal combination for wound healing: Matricaria chamomilla L. and Punica granatum L

BACKGROUND

Punica granatum L. (pomegranate) with astringent activities and Matricaria chamomilla L. (chamomile) with anti-inflammatory and antioxidant properties are natural remedies used for various skin disorders, including wound healing.

OBJECTIVES

This study was conducted to evaluate the individual and combined wound healing activity of the methanol extracts of pomegranate and chamomile flowers.

METHODS

After preparing the menthol fraction of pomegranate and chamomile flowers, the content of total phenols, total tannins, and total flavonoids of fractions was measured. For standardization of pomegranate and chamomile fractions, Gallic acid and apigenin-7-O-glucoside contents of them were determined using high-performance liquid chromatography (HPLC). Moreover, their antioxidant activities were examined using DPPH and FRAP tests. The antimicrobial assay was performed against Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa. Three different concentrations of methanol fraction of each plant and one combination dose of fractions were investigated for their wound healing activities in an excision wound model on the rats' dorsum. Finally, histopathological studies were done at the end of the experiment.

RESULTS

Phytochemical examinations showed high amounts of phenolic compounds in pomegranate flowers, while chamomile flower fractions contained a high amount of total flavonoids. Both fractions, especially pomegranate, had potent antioxidant activity. The best results for wound closure were observed 7 days after wound induction. All treated groups exhibited superior wound contraction compared to their placebo at all measurement times. The combined form of pomegranate and chamomile had better wound healing properties compared to a single therapy, especially on time earlier to wound induction.

CONCLUSION

This study represented high antioxidant and wound healing activities for methanol fraction of pomegranate and chamomile flowers, which could be related to their high content of phytochemicals. In comparison with single herb treatment, the combined form of these two fractions in lower concentrations accelerated wound closure.

Botanicals With Dermatologic Properties Derived From First Nations Healing: Part 2-Plants and Algae

INTRODUCTION

Plants and algae have played a central role in the treatment of skin conditions in both traditional First Nations healing and in modern dermatology. The objective of this study was to examine the evidence supporting the dermatological use of seaweed, witch hazel, bearberry, and mayapple.

METHODS

Four plants and algae used in traditional First Nations treatments of skin disease were selected based on expert recommendations. Several databases were searched to identify relevant citations without language restrictions.

RESULTS

Seaweed has potential clinical use in the treatment of acne and wrinkles and may be incorporated into biofunctional textiles. Witch hazel is an effective and well-tolerated treatment of inflammation and diaper dermatitis. Bearberry leaves contain arbutin, a skin-lightening agent that is an alternative for the treatment of hyperpigmentation. Mayapple contains podophyllotoxin, a treatment for condyloma accuminata, molluscum contagiosum, and recalcitrant palmoplantar warts.

DISCUSSION

Common plants and algae are replete with bioactive agents that may have beneficial effects on the skin. Further research will open the door to new and innovative products in the future. Limitations of this study include that the scope of our study is limited to 4 plants and algae, a small sample of the breadth of plants used by First Nations for dermatological treatments.