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.

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.

Inclusion Criteria:

Healthy males and females between 18 and 45 years of age will:

• be informed of the nature of the study and will give written informed consent;
• have body weights within 25% of the appropriate range;
• have no significant decreases or clinically abnormal laboratory values during screening;
• have 12 lead ECG without significant abnormalities;
• be on no regular medical treatment;
• be able to communicate effectively with study personnel.

Exclusion Criteria:

• Any disease or condition which might compromise the haematopoietic, renal, endocrine, pulmonary, central nervous system, cardiovascular, immunological, dermatological, gastrointestinal or any other body system.
• History of allergic conditions - asthma, urticaria and eczema.
• History of autoimmune disorders - Lupus erythematosis.
• History or presence of dyspepsia, gastric ulcer or duodenal ulcer.
• History of psychiatric disorders.
• Intake of any medication within 14 days before the start of the study.
• Recent history of alcoholism (<2 years) or consumption of alcohol within 48 hours of receiving study medication.
• Smokers who smoke more than 10 cigarettes per day and cannot refrain from smoking during the study period.
• Presence of clinically significant abnormal laboratory results during screening.
• Pregnancy or not using appropriate means of contraception.
• Use of any recreational drugs or a history of drug addiction.