Scientific Name: Salix alba
- Salicylates: Salicin & salicin esters (salicortin, fragilin & tremulacin)
- Phenolic acids & glycosides (vanillin, syringin, vanillic & syringic, coumaric)
- Flavonoids (isoquercitrin & naringin)
- Tannins (Condensed)
Mechanism of Action & Pharmacology:
- Salicylates (e.g. Salicin) have been shown to reduce prostaglandin levels in body tissues through an inhibition of cyclooxygenase in inflamed tissues (i.e. COX–2), and Salix extract has demonstrated antioxidant activity in several in vitro systems, including the scavenging of free radicals.
- Salicin is a phenolic glucoside consisting of the aglycone saligenin (aka. salicyl alcohol) and glucose. Salicin is metabolized & absorbed in the bowels to salicylic acid, which has aspirin-like effects without irritating the gastric lining. Note: Salicin is less of an irritant to mucus membranes than salicylic acid derivatives.
- Salicin is split by intestinal flora into saligenin (salicyl alcohol) and glucose. Saligenin is then absorbed and oxidized in the blood and liver to salicylic acid and has antipyretic, analgesic, anti-rheumatic, and antiseptic actions. Their activity may also be due to their ability to inhibit cyclooxygenase, complement activation, and T-cell proliferation and thus interfere with the production of reactive oxygen species (ROS).
Safety & Toxicity Concerns:
- Avoid in those with allergy or hypersensitivity to salicylates (may experience rare reaction causing urticaria, rhinitis, asthma & bronchial spasm) and in glucose-6-phosphate dehydrogenase-deficient (causes haemolytic anaemia).
- Use with caution during lactation (salicylates may cause rashes in babies).
- Expected to have only mild effects on platelet function (irreversible inhibition of platelet aggregation seen with Aspirin cannot be induced by Salix).
- Theoretical possibility of Reye’s syndrome, an acute sepsis-like illness encountered exclusively in children below 15 years of age. The cause is unknown, although viral agents and drugs, especially salicylates, have been implicated.
- In high doses salicylic acid has an ototoxic effect by inhibiting prestin, which is the motor protein of the outer hair cells of the inner ear of the mammalian cochlea. It has been known to induce transient hearing loss in zinc-deficient individuals.
- Theoretically Salicylism, which is an acute overdose of salicylates, can produce toxicity symptoms, ranging from mild nausea, vomiting, abdominal pain, lethargy, tinnitus, and dizziness, depending on the dose consumed.
- Theoretical additive effect with antiplatelets, aspirin or other salicylate containing substances, NSAIDs, methotrexate, spironolactone, phenytoin, and valproate medications.
- May reduce mineral absorption from food (e.g. zinc & non-heme iron).