β-Carotene from cassava (Manihot esculenta Crantz) leaves improves vitamin A status in rats

The bioavailability of β-carotene from cassava (Manihot esculenta Crantz) leaves was assayed in vitamin A deficient Wistar rats (Rattus norvegicus). Rats were separated into three groups and fed with a modified AIN-93G – vitamin A deficient – diet. Deficient rat received this diet without any additional vitamin A source. Controls received the diet with 7200 μg of synthetic β-carotene (control), while experimentals (test) received 19.5 g of cassava leaves powder per kg of diet. The cassava leaves with β-carotene promotes similar growth and tissue weight in rats to the synthetic β-carotene. The relative bioavailability, estimated as the Retinol Accumulation Factor (RAF), was 16.5 and 27.5 for control and test groups, respectively, indicating that control and test rats should have an intake of 16.5 μg or 27.5 μg of β-carotene from synthetic form or cassava leaves powder for each 1 μg of hepatic retinol stored, respectively. The cassava leaves β-carotene bioavailability was lower than the synthetic β-carotene probably because the β-carotene from the leaf matrix may be bounded to protein complex or inside organelles, which impair carotenoid absorption. Our findings showed that beside the hepatic retinol recovery, cassava leaf β-carotene could maintain rat growth and avoid vitamin A deficient symptoms.