Plasma vitamin C concentration in control and diabetic rats. Vitamin C concentration was determined in the plasma of the control and diabetic animals at delivery (day21). Values are mean ± SEM. (§) p < 0.01 = significant difference between diabetic rats compared with treated/untreated control animals. (*) p < 0.01 = significant difference between plant/insulin-treated diabetic rats compared with untreated diabetic animals. NS = non-significant difference. A: Picra-EtOH: ethanolic fraction of Picralima nitida; B: Picra-But: butaniolic fraction of Picralima nitida; C: Nauclea-EtOH: ethanolic fraction of Nauclea latifolia; D: Nauclea-But: butanolic fraction of Nauclea latifolia; E: Oxy-EtOH: butanolic fraction of Oxytenanthera abyssinica.