Solanine – a detrimental substance in potatoes. Poisoning due to excessive consumption

Solanine constitutes an organic yet highly toxic chemical compound categorized within the steroid glycoalkaloid group (TGA), predominantly localized in the tissues of plants belonging to the *Solanaceae* family, with the potato (*Solanum tuberosum*) serving as the most prominent example. Its principal physiological function in potato tissue appears to be defensive in nature—a hypothesis substantiated by the marked upregulation of solanine biosynthesis in response to mechanical injury, microbial pathogen invasion, or abiotic stress conditions. While excessive ingestion may provoke dyspeptic symptoms or even neurotoxic effects, controlled doses extracted from potato fruits demonstrate potential therapeutic benefits. Both *in vitro* and *in vivo* investigations indicate that solanine exhibits antiviral activity against herpes simplex virus type 1 (HSV-1) by inhibiting viral replication, and it may further modulate signaling pathways associated with tumor cell proliferation, particularly in the context of hepatocellular carcinomas and colorectal adenocarcinomas.

The biosynthesis of steroidal glycoalkaloids (TGA), including solanine, in potato plants commences during the seed germination stage, peaks at the flowering phase, and gradually diminishes with the onset of tuber senescence. The highest concentrations of these compounds are predominantly observed in immature tubers and the berry-like fruits of the potato plant. They exhibit exceptional thermal stability: exposure to 210°C for 10 minutes results in only approximately 40% degradation, while frying at temperatures exceeding 170°C induces a gradual yet incomplete breakdown. Extensive scientific research confirms that the glycoalkaloid content in tubers is influenced by multiple factors, including genotypic variation, agronomic practices (such as mineral fertilization), physiological maturity, mechanical tissue damage, and storage conditions (temperature, humidity, light exposure). According to guidelines established by the U.S. Food and Drug Administration (FDA), the maximum permissible TGA concentration in tubers intended for consumption is 200 mg·kg⁻¹. However, in practice, the average content of these compounds in table potatoes ranges from 20 to 130 mg·kg⁻¹, with levels exceeding 140 mg·kg⁻¹ associated with a detectable bitterness. Analyses of Polish potato cultivars revealed that the mean TGA concentration fluctuates between 33 and 89 mg·kg⁻¹, highlighting the variability of this parameter depending on environmental and genetic determinants.

The toxicological profile of glycoalkaloids naturally occurring in potato tubers—primarily solanine and chaconine—continues to be the subject of extensive experimental and clinical investigations. In individuals who have ingested products containing elevated concentrations of these compounds, the initial manifestations of systemic dysfunction typically emerge within a window of seven to nineteen hours post-ingestion, though certain pathological responses may present significantly earlier. Characteristic symptoms encompass recurrent episodes of vomiting, persistent headaches of varying severity, pyrexia or febrile states, impaired temporospatial orientation, and auditory or visual hallucinatory experiences. Should the total glycoalkaloid concentration (TGA) in serum remain elevated over prolonged periods, secondary complications may arise, including accelerated cardiac rhythm (tachycardia), cervical muscle rigidity, partial motor paralysis, and—in extreme clinical scenarios—profound loss of consciousness progressing to coma. Notably, excess quantities of these toxins, which the body fails to metabolize or excrete efficiently, preferentially accumulate within hepatic, renal, and cardiac muscle tissues. Current toxicological evidence suggests that the threshold dose inducing symptomatic poisoning in humans approximates 3–6 milligrams per kilogram of the patient’s body weight.