Banana leaves: an alternative wound dressing material?

Keywords::

• alternative
• banana leaves
• decontamination techniques
• wound dressing
• wound-dressing properties
• wound healing

Banana leaves have been used through the ages as wound dressings in certain countries as part of an ancient practice. Recent studies scientifically assessed for the first time the wound-dressing properties of banana leaves in research and clinical settings. These studies determined the best sterilization methods for banana leaves and compared banana leaves with standard wound dressings in clinical trials. As a result of these investigations, banana leaves may be considered an alternative dressing material easily available in tropical countries at a low cost.

Wound dressings are local therapeutic agents intended to create an optimal environment for wound healing, with specific properties according to the type and physiologic healing stage of the wounds. Modern wound dressing include alginates, hydrocolloids, hydrogels, enzymatic dressings and many others [1]. The ideal wound dressing should combine the following features: a moist environment at the wound interface, a barrier function to microorganisms and non-adherent, non-toxic, non-allergenic, non-sensitizing properties [2,3]. Modern dressings possess most of these requirements. However, these dressings are expensive, especially when required over a long period of time. As a consequence, their use is limited in developing countries.

Banana leaves as a wound-dressing material

Banana trees grow throughout the tropics in approximately 107 countries. Their leaves are an unlimited source of biomaterial in these countries and have been used as decorations, wrappings, plate mats, writing surfaces and in cooking. Banana leaves are about 18 × 36 inches in size and have a smooth and waxy surface that does not stick. Banana leaf dressings are usually prepared by cutting out the midrib of the leaf. These leaves are then pre-treated differently before applied on the patient’s wounds. In some reports, banana leaves are first coated with a paste made of cooking fine flour. These dressings are then dried for 24 h and sterilized before use. Others directly apply banana leaves on patient’s wounds without any pre-treatment [4]. As a natural product, banana leaves must be sterilized before use to remove the pathogenic flora. Untreated leaves are heavily contaminated with 7000 to 5 × 10⁵ colony-forming units (CFU), mainly consisting of aerobic spore-forming bacilli (Bacillus spp.), Gram-positive cluster-forming cocci (mainly Micrococcus spp.) and molds [5]. Of importance, contaminants likely include potentially pathogenic organisms, such as anaerobic spore-forming bacilli (e.g., Clostridium spp.). According to generally accepted standards, wound dressings as a class of medical device are classified as ‘critical’, meaning they must be sterile. In a recent study, we compared different thermal decontamination (cooking in boiling, chemical disinfection, sterilization) to identify the optimal procedure for reducing the natural microbial load of the leaves without significantly affecting their beneficial wound-dressing properties [5]. Steam sterilization (autoclaving) resulted in the complete inactivation of mesophilic bacteria and sterile banana leaves. Interestingly, other easily applicable methods, such as boiling in water, also reduce the bacterial load on the leaves to an extent that renders them suitable for use on surgical wounds. This might be of importance, if proper sterilization equipment is not available, for example, in certain African countries.

As described in ancient reports, smallpox patients were treated lying on a base of banana leaves in India because they cool the skin and do not stick to the patient’s wounds [4]. Banana leaves were first reported in the literature as a wound-dressing material used on burn patients in 1980 [6]. Gore and Akolekar extended these preliminary reports and published several clinical trials in which they compared the use of banana leaves on burn patients with petroleum jelly gauze (Vaseline gauze) [4,7]. Banana leaf dressing resulted in rapid epithelization and was associated with less pain during dressing changes than Vaseline gauze. These results are in line with data from a mouse model of skin transplantation [5]. In this wound model punch biopsies were performed on the shaved back skin of mice. The removed skin was then replaced and the resulting wound was either dressed with sterilized banana leaves or Vaseline gauze. In line with results from clinical trials, wounds treated with banana leaves healed in the same period of time as wounds treated with Vaseline gauze dressings. Importantly, bacterial swab tests revealed normal mouse skin flora in wounds dressed with banana leaves with no signs of infection. These studies add important knowledge because banana leaves as wound dressings have never been studied from a scientific point of view.

The use of various biological dressings has been tested for some chronic conditions, such as venous leg ulcers and burns [4,6–8]. However, experience with the use of biological dressings for acute surgical wounds, especially in dermatological surgery, is limited. In a recent study, we assessed the ‘on-site use’ of sterilized banana leaves on patients with dermatological surgery in Uganda, Africa [5]. Approximately 100 patients were treated with banana leaf dressings after surgery and followed-up for 2 weeks. Due to logistic reasons, data from only 43 patients were recorded during the follow-up phase. However, these results demonstrate banana leaves as a safe and effective dressing material in patients with surgical skin wounds. Importantly, banana leaf dressings are 1500- to 5000-times less expensive than collagen or biosynthetic dressings, respectively [9].

Today, we possess a plethora of modern wound-dressing materials. However, their use is often restricted in developing countries because modern wound dressings are expensive, especially when used over a long time. Thus, there is a need for cheap and affordable wound-dressing materials in those countries. Beside banana leaves, boiled potato peels have been described to be efficacious in an experimental wound model in rats and in patients with burn wounds [8]. Similar to banana leaves, potatoes are easily available in most developing countries and might be suitable as an alternative wound-dressing material. However, further studies are urgently needed to assess the safety profile and the physical and biological properties of alternative wound-dressing materials. Finally, alternative wound dressings need to be tested in clinical trials and compared with modern wound dressings in controlled studies in order to get them licensed as medical devices.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

No writing assistance was utilized in the production of this manuscript.