Solanum nigrum (Black Nightshade Berries)

Solanum nigrum, or black nightshade, contains steroidal alkaloids (solanine, solasonine) and glycoproteins that inhibit cancer cell proliferation by inducing mitochondria-mediated apoptosis and suppressing angiogenesis. Preclinical research highlights its polysaccharides and alkaloids as primary bioactive drivers of anti-tumor and hepatoprotective activity.

Origin & History

Solanum nigrum, commonly known as black nightshade, is an annual plant in the Solanaceae family, native to Eurasia and now naturalized globally.[2][5] Its berries, the primary edible part, are harvested fresh or dried, from which extracts are prepared using solvents to isolate a rich concentration of bioactive compounds like steroidal saponins and alkaloids.[1][2][3] The plant is categorized as a nutrient-dense, wild-harvested food and medicinal herb.[2][6]

Historical & Cultural Context

Solanum nigrum has a long history in Traditional Chinese Medicine (TCM) and other Oriental medicine systems for treating conditions like cancers, nephritis, sore throat, and skin ailments such as dermatitis and eczema.[2][6] It is traditionally used as an edible medicinal herb and is often combined with other botanicals like Hedyotis diffusa for therapeutic purposes.[1][2]

Health Benefits

[{"benefit": "May reduce tumor growth and metastasis.", "evidence_quality": "Evidence is preclinical. In a study on melanoma-bearing mice, a 1% oral aqueous extract reduced tumor mass by over 50% and suppressed lung metastasis.[1][3]"}, {"benefit": "May induce cancer cell death (apoptosis).", "evidence_quality": "Evidence is from in-vitro studies. Bioactive compounds like solamargine have been shown to induce apoptosis in cancer cell lines by modulating Bcl-2/Bax pathways.[1][3]"}, {"benefit": "May inhibit cancer cell invasion.", "evidence_quality": "Evidence is preclinical. The compound solasodine was found to inhibit the invasion and migration of colorectal cancer stem cells in both in-vitro and in-vivo models.[1]"}, {"benefit": "May enhance the effects of chemotherapy.", "evidence_quality": "Evidence is preclinical. S. nigrum demonstrated a synergistic effect, enhancing the tumor-inhibiting activity of the chemotherapy drug cisplatin in animal models.[1]"}, {"benefit": "May regulate gene expression related to cancer.", "evidence_quality": "Evidence is from in-vitro studies. Extracts have been shown to suppress oncogenic pathways like HOTAIR in non-small cell lung cancer and LIF/miR-192-5p/CYR61/Akt in hepatoma cells.[1]"}]

How It Works

Steroidal alkaloids such as solanine and solasonine disrupt cancer cell membranes and activate the intrinsic apoptosis pathway by downregulating Bcl-2 and upregulating Bax, triggering cytochrome c release and caspase-3 activation. Solanum nigrum polysaccharides modulate immune response by enhancing macrophage phagocytosis and NK cell activity, while also inhibiting VEGF-mediated tumor angiogenesis. Hepatoprotective effects are attributed to flavonoids and phenolic acids that scavenge reactive oxygen species and suppress NF-κB-driven inflammatory signaling in liver tissue.

Scientific Research

The clinical evidence for Solanum nigrum is extremely limited, with no randomized controlled trials (RCTs) or meta-analyses cited in available research.[2] One study involving a Solanum nigrum mixture in patients with advanced liver cancer was noted, but specific details regarding its design, sample size, or PubMed PMID were not provided.[2] The vast majority of evidence is preclinical, derived from in-vitro and animal models.[1][3]

Clinical Summary

The majority of evidence for Solanum nigrum is preclinical, derived from in vitro cell line studies and rodent models. In one murine melanoma study, oral administration of a 1% aqueous extract reduced tumor mass by over 50% and significantly suppressed lung metastasis. Animal models using carbon tetrachloride-induced hepatotoxicity have demonstrated measurable reductions in serum ALT and AST, suggesting liver-protective effects. No large-scale randomized controlled trials in humans have been published, making it premature to draw definitive clinical conclusions.

Nutritional Profile

Black nightshade berries (Solanum nigrum) are consumed in some traditional food cultures but are primarily valued for their bioactive phytochemical content rather than macronutrient density. Per 100g of ripe berries (approximate values from available analyses): Water: ~80–85g; Energy: ~35–50 kcal; Protein: ~2–3g; Fat: ~0.5–1g; Carbohydrates: ~8–12g (including sugars and small amounts of dietary fiber ~1.5–2.5g). **Key Micronutrients:** Calcium: ~30–50mg/100g; Iron: ~1.0–1.5mg/100g; Phosphorus: ~35–50mg/100g; Vitamin C (ascorbic acid): ~15–30mg/100g (varies significantly with ripeness and growing conditions); modest amounts of B-vitamins (riboflavin, niacin). **Bioactive Compounds (primary pharmacological interest):** Steroidal glycoalkaloids — solasonine (~0.02–0.1% dry weight), solamargine (~0.01–0.08% dry weight), and solanine (present in unripe berries at higher concentrations, decreasing substantially upon ripening); Steroidal saponins — diosgenin and related aglycones (trace to ~0.05%); Polyphenols — gallic acid, catechin, caffeic acid, rutin, quercetin, and naringenin (total phenolic content reported at ~15–45 mg GAE/g dry extract depending on extraction method); Anthocyanins — primarily in ripe dark berries, contributing antioxidant capacity (~5–20 mg/100g fresh weight); Riboflavin-binding proteins (unique lectins); Polysaccharides — water-soluble polysaccharides with reported immunomodulatory activity (yield ~2–5% of dry fruit weight). **Bioavailability Notes:** Glycoalkaloid bioavailability is moderate orally; they are partially hydrolyzed in the GI tract to their aglycone forms (solasodine, solanidine) which may be more readily absorbed. Toxicity risk from glycoalkaloids is significantly higher in unripe (green) berries — solanine/solasonine concentrations can be 3–5× higher than in fully ripe (black) berries. Polyphenol bioavailability is generally low (5–10% absorption) but may be enhanced by gut microbiota metabolism. Vitamin C content supports iron absorption from the same source. Traditional preparation methods (cooking, boiling) substantially reduce glycoalkaloid content and associated toxicity risk.

Preparation & Dosage

No clinically studied dosage ranges for Solanum nigrum have been established for humans, as clinical trials are scarce.[2] Preclinical studies used concentrations like a 1% aqueous extract in mice, but these do not have standardized human equivalents.[1][3] Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Duchesnea indica, Hedyotis diffusa (traditional pairings)

Safety & Interactions

Unripe or raw black nightshade berries contain elevated levels of solanine, a toxic glycoalkaloid that can cause gastrointestinal distress, nausea, vomiting, and in high doses, neurological symptoms including dizziness and confusion. The plant is contraindicated during pregnancy and breastfeeding due to potential teratogenic and abortifacient effects documented in animal studies. Solanum nigrum may potentiate the effects of hepatotoxic drugs or interact with immunosuppressants given its immune-modulating properties, and concurrent use warrants medical supervision. Individuals with nightshade (Solanaceae) sensitivities or autoimmune conditions should avoid use without physician guidance.