Australian Eucalytpus kinos – Past, Present, Future

Kinos are tannin-rich, mostly red-coloured wood exudates. Their characteristic astringency has made them a popular remedy in a number of traditional systems of medicine around the world. The most abundant kinos of Australian origin are that of Eucalyptus species which have played an important role in the traditional medicines of Australian Aboriginal people and were also a valued source of antibacterial and astringent agents for early European settlers.

Fig. 1

For this study a detailed literature review on a large number of Western Australian Eucalyptus kinos was carried out to collate information on their traditional medicinal use as well as any published chemical data. Whilst it was possible to find mainly historical and ethnopharmacological documentation it appears that not much is known about their chemical composition and potential pharmacological effects. To establish some baseline data these kinos were therefore analysed for their total phenolics and total tannin content as well as their relative amounts of hydrolysable and condensed tannins. They were also classified in accordance with Maiden's traditional kino categories and assessed for their antimicrobial properties against some Gram positive and Gram negative bacteria as well as a yeast species using well plate diffusion assays. Based on the obtained data possible correlations between chemical composition and antimicrobial activity are drawn and individual kinos are identified which warrant more research in the future.