Sutherlandia frutescens (Cancer Bush)

Sutherlandia frutescens (Cancer Bush) is not consumed as a macronutrient-dense food but rather as a medicinal herb, typically prepared as a tea or taken in capsule/tincture form. Its value lies primarily in its bioactive compound profile rather than caloric or macronutrient content. Key bioactive compounds include: Amino acids: L-canavanine (a non-protein amino acid, approximately 30–40 mg/g dry leaf weight), which exhibits antiviral and antitumor properties but also acts as an arginine analog that may interfere with protein synthesis at high doses; GABA (gamma-aminobutyric acid, approximately 10–14 mg/g dry weight), contributing to anxiolytic and calming effects; L-arginine (approximately 1–3 mg/g dry weight), supporting nitric oxide synthesis and cardiovascular function. Triterpenoid saponins: Sutherlandiosides A–D (cycloartane-type glycosides, collectively approximately 2–8 mg/g dry weight), which are considered marker compounds unique to this species and are associated with anti-inflammatory and anticancer activity. Flavonoids: Sutherlandins A–D (flavonol glycosides, approximately 1.5–6 mg/g dry weight), providing antioxidant capacity with moderate bioavailability enhanced by co-occurring organic acids. Pinitol (D-pinitol): Approximately 10–15 mg/g dry weight, a cyclitol with documented hypoglycemic and anti-inflammatory properties; bioavailability is relatively high when taken orally. Polyphenols and tannins: Total phenolic content approximately 25–50 mg gallic acid equivalents per gram dry weight, contributing significant free radical scavenging activity (ORAC values comparable to green tea). Minerals: Contains trace amounts of iron (approximately 0.3–0.8 mg/g), zinc (approximately 0.02–0.05 mg/g), magnesium (approximately 1.5–3.0 mg/g), potassium (approximately 8–15 mg/g), and calcium (approximately 5–10 mg/g) in dried leaf material; mineral bioavailability may be partially reduced by tannin content. Vitamins: Minor amounts of vitamin C (approximately 0.5–1.5 mg/g dry weight) and traces of B-vitamins. Fiber: Dried leaf material contains roughly 15–20% crude fiber, though this is largely irrelevant in tea preparations. Protein: Approximately 8–12% crude protein in dry leaf, mostly relevant only in powdered whole-leaf preparations. Bioavailability notes: L-canavanine and pinitol demonstrate good oral bioavailability; flavonol glycosides (sutherlandins) require partial hydrolysis in the gut for absorption; cycloartane saponins (sutherlandiosides) have moderate bioavailability but may be enhanced by the saponin-mediated increase in membrane permeability; GABA bioavailability across the blood-brain barrier is limited, though peripheral effects on the enteric nervous system are notable. Traditional preparation as a hot water infusion extracts approximately 40–60% of water-soluble bioactives.