A Randomized, Double-blind Placebo-controlled Phase 1 Trial of Lessertia Frutescens in Adults.
Objectives: Lessertia frutescens (L.) Goldblatt & J.C. Manning (syn. Sutherlandia frutescens
(L.) R. Br.), infusions and decoctions are widely used in South Africa as indigenous
medicines, to combat cancer, infections and symptoms associated with AIDS. The aim of this
study was to evaluate the safety of this phytotherapy in healthy adults.
Design: A randomised, double blind, placebo-controlled trial to evaluate the safety of
Lessertia frutescens in healthy adults.
Setting: Karl Bremer Hospital, Bellville, South Africa.
Participants: 25 adults, aged 18 to 45 years, who provided informed consent. They had no
significant diseases or clinically abnormal laboratory blood profiles during screening. They
had no history of allergic conditions and were not on regular medical treatment.
Intervention: 12 healthy participants were randomized to a treatment arm where they received
400mg L. frutescens leaf powder capsules twice daily (800mg/day), available as a product
called Sutherlandia. 13 healthy participants were randomized to the control arm, where they
received an identical placebo capsule. The trial lasted 3 months.
Outcome Measures: The primary endpoint was frequency of adverse events and the secondary
endpoint, changes in physical, vital, blood and biomarker indices.
Results: There were no significant differences in general adverse events, cardiovascular,
CNS, GIT, infection, allergy, malaise, most physical, haematological, biochemical or
physiological parameters, between the treatment and the placebo groups (P>0.05). However,
subjects consuming L. frutescens mostly reported improved appetite compared to those in the
placebo group (P<0.01). Although the treatment group exhibited a lower respiration rate
(P<0.04), higher platelet count (P<0.03), MCH (P<0.01), MCHC (P<0.02), total protein
(P<0.03) and albumin levels (P<0.03), than the placebo group, these differences remained
within the normal physiological range, and were not clinically relevant. The L. frutescens
biomarker, Canavanine, was undetectable in subject plasma.
Conclusion: Overall, consumption of 800mg/day L. frutescens leaf powder capsules, was well
tolerated by healthy adults.
Allocation: Randomized, Endpoint Classification: Safety Study, Intervention Model: Parallel Assignment, Masking: Double-Blind, Primary Purpose: Screening
The primary endpoint of this study was adverse events, incidence (number) and type recorded during a three-month treatment period.
Haylene Nell, MBChB
Tiger Trial Centre, Karl Bremmer Hospital, Tygerberg, South Africa
South Africa: Medicines Control Council