Sclerocaryabirrea fruit pulp and fruit peel protect against acute cadmium-induced testicular damage.

Sclerocaryabirrea (marula) forms an important component of medicinal practices and diet in Southern Africa. The fermented fruit pulp beverage locally called “mukumbi” isused to treat male impotence and infertility. However, the peel tends to bediscarded in most traditional uses favouring the fruit pulp and tree bark. The aim of this study was to compare the effects of S. birrea fruit pulp and peel extracts on cadmium (Cd) induced testicular damage. Twenty four adult male Wistar rats were divided into four treatment groups (n = 6/group): Control, Cd only, Cd simultaneously treated with S. birreafruit pulp or peel (200 mg/kg). Cd (1 mg/kg body weight as CdCl2) was given intraperitoneally dissolved in normal saline for 3 consecutive days (day 1 – 3) and treatment continued for a total of 10 days. Sperm count, testicular total antioxidant capacity, lipid peroxidation, superoxide dismutase activity (SOD), pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α), serum reproductive hormones (T, FSH and LH) and testis histology were assessed. Results showed significant adverse effects on male reproductive system after acute Cd exposure with reduced sperm count, deranged serum reproductive hormones and in testicular homogenates: increased malondialdehyde (MDA) content, decreased superoxide dismutase (SOD) activity, and upregulated levels of the proinflammatory cytokineTNF-α. Histology showed an amorphous acellular material filling the seminiferous tubules in place of the regularly arranged cellular dynamics observed in control animals. Significant alleviation of these toxic effects was observed with both S. birrea fruit pulp and fruit peel treatment. The fruit peel was more effective in alleviating testicular damage than fruit pulp especially for testicular structural protection as observed histologically. Mechanism of action of these extracts may involve inhibiting lipid peroxidation, restoration of SOD activity, reduction of inflammation by reducing TNF-α and protection of testis-blood barrier. Our data suggests that S. birrea extracts exerted protective effects against Cd-induced damage through antioxidant and anti-inflammatory effects.