Most people who walk past a kangaroo apple in a garden or bushland think nothing of it. The sprawling shrub with its distinctive deeply-lobed leaves and purple flowers, followed by bright orange berries, is a moderately common sight in south-eastern Australia and New Zealand. It looks unremarkable. Its medical history is anything but.
Kangaroo apple — primarily Solanum laciniatum and the closely related Solanum aviculare — has one of the most interesting compound profiles of any Australian native plant. Traditional Aboriginal communities used it medicinally for a range of conditions. And in the mid-twentieth century, the plant's chemistry made it quietly significant in the pharmaceutical history of the Western world — as a natural source of compounds used in the production of steroid hormones, including the early oral contraceptive pill.
The plant: what it is and where it grows
Solanum laciniatum and Solanum aviculare are members of the nightshade family (Solanaceae) — the same family as tomatoes, potatoes, capsicums and eggplants. Native to south-eastern Australia and New Zealand, these species grow naturally along forest edges, disturbed ground and coastal scrub from Queensland south through NSW, Victoria, South Australia and Tasmania. They are widespread and reasonably easy to identify when in flower or fruit, though they can be confused with other Solanum species.
The orange berries, when fully ripe, are edible — sweet and gelatinous. Unripe green berries are toxic and should never be consumed. This distinction between ripe (safe) and unripe (toxic) is consistent with many Solanum species and was well understood in traditional use. The leaves and other parts of the plant contain toxic alkaloids at concentrations that require careful preparation before any medicinal use.
Traditional Aboriginal uses
Kangaroo apple has documented traditional uses across south-eastern Aboriginal communities, though it was not as widely used as some other bush medicine plants and its traditional use is less extensively documented in the published ethnobotanical literature than, say, tea tree or eucalyptus. This may partly reflect research gaps rather than limited traditional use.
Documented applications include topical use of leaf preparations for pain and skin conditions. The alkaloids in kangaroo apple have analgesic properties that are pharmacologically plausible for these applications. Some sources document use of the ripe fruit as a food source. The unripe fruit was understood to be toxic, and traditional knowledge carefully distinguished between stages of fruit ripeness — knowledge that is essential for safe use of a plant in the nightshade family.
As with all bush medicine knowledge, the specific preparation methods and applications varied between communities and regions, and much traditional knowledge about this plant was not publicly documented. The conventional pharmacological investigation of the plant proceeded largely independently of, rather than in partnership with, Aboriginal knowledge holders.
The pharmaceutical story: solasodine and the steroid connection
This is where kangaroo apple's history becomes genuinely surprising. The plant contains high concentrations of a compound called solasodine — a steroidal alkaloid. In the 1950s and 1960s, as the pharmaceutical industry was racing to develop commercially viable steroid hormone drugs (including cortisone and sex hormones), researchers were looking for plant sources of compounds that could serve as steroidal precursors — raw material for chemical conversion into pharmaceutical hormones.
Solasodine turned out to be an excellent candidate. Its molecular structure was suitable for conversion into progesterone and other steroid hormones through established chemical processes. New Zealand, where Solanum laciniatum also grows naturally, developed a significant commercial cultivation and processing industry around the plant for pharmaceutical precursor production during this period. Australian researchers and farmers were also involved in investigating cultivation potential.
While Mexican yam (Dioscorea species) ultimately became the primary source for pharmaceutical steroid production at scale, the kangaroo apple's role in early steroid hormone research — including research connected to early oral contraceptive development — is historically documented. It is a remarkable footnote: a native Australian plant contributing to one of the most significant pharmaceutical developments of the twentieth century.
Contemporary research: anti-cancer potential
The current scientific interest in kangaroo apple goes beyond its historical pharmaceutical use. Solasodine and related glycoalkaloids from Solanum species have attracted significant research interest for potential anti-cancer applications. Laboratory studies have demonstrated cytotoxic activity — the ability to kill cancer cells — in multiple cancer cell lines. A proprietary cream formulation containing solasodine glycosides, known as BEC (Bioequivalence Compound), was developed in Australia and has been the subject of clinical research for the treatment of certain skin cancers and keratoses.
The clinical evidence for BEC preparations is disputed in the medical community — some studies have shown promising results for solar keratoses and superficial skin cancers; others have raised methodological concerns. The compounds are not approved as pharmaceutical cancer treatments and should not be used to treat cancer in place of medical care. But the scientific interest is genuine, and kangaroo apple remains an active area of pharmaceutical research.
Anti-inflammatory and analgesic activity
Beyond the cancer research, the steroidal alkaloid compounds in kangaroo apple have demonstrated anti-inflammatory activity in laboratory studies, consistent with the traditional use of the plant for pain and inflammation. Steroidal compounds of this class have well-established anti-inflammatory mechanisms, and the traditional analgesic applications documented in ethnobotanical literature have pharmacological plausibility.
Safety — a critical note
Kangaroo apple is a plant that requires careful handling and correct preparation. The unripe berries are toxic — containing solanine and related glycoalkaloids at concentrations that cause gastrointestinal distress and potentially more serious toxicity. The leaves also contain these compounds. Only fully ripe berries (which are bright orange) are safe for consumption.
This is a plant with genuine pharmacological activity, and that activity cuts both ways. The same compounds that demonstrate antimicrobial, anti-inflammatory and cytotoxic effects in research are also toxic at incorrect doses or in incorrect preparations. Self-medication with kangaroo apple preparations — particularly anything involving the unripe fruit or concentrated leaf extracts — is not recommended without specialist guidance.
The appropriate way to engage with kangaroo apple's medicinal potential for most people is through commercially prepared, quality-controlled products from reputable suppliers, not through foraging and home preparation.
Kangaroo apple today
The plant is widely grown as an ornamental — its purple flowers and bright orange berries make it attractive in gardens across south-eastern Australia, and it is available from native plant nurseries. As a garden plant it is low-maintenance, frost-sensitive in colder areas, and supports native birds that eat the ripe berries. Growing it connects you to one of Australia's more botanically interesting native species.
Commercial products containing kangaroo apple or related Solanum glycoalkaloids are available in the natural medicine space, though quality and evidence behind specific products varies considerably. If you are interested in exploring this plant medicinally, source products from reputable Australian suppliers and be clear-eyed about what the current evidence does and does not support.
Kangaroo apple is a plant that rewards careful attention — ordinary-looking in the garden, remarkable in its chemistry, and connected to a history that runs from Aboriginal healing country through to twentieth-century pharmaceutical laboratories. That is an unusual combination, and one that makes it one of the more fascinating native plants on the continent.