Sabien Vermaut

Evidences for a satiating effect of defatted jojoba meal

Abstract Supplementation of food with increasing doses (3, 5, and 10%) of defatted jojoba meal induced a pronounced dose-dependent food intake reduction in fasted and non-fasted rats. This effect was more pronounced in non-fasted than in fasted rats, which is typical for satiety agents. Water intake was reduced to the pair-fed level in non-fasted rats with free access to water and receiving food supplemented with 10% defatted jojoba meal. This was also observed in fasted rats deprived of water during the fasting period and receiving food supplemented with 10% defatted jojoba meal. The reduced water intake in defatted jojoba meal treated rats was entirely due to the food intake reduction. These observations are in favour of the hypothesis that defatted jojoba meal induces its food intake reduction by stimulating satiety. Possible mechanisms are discussed.

The vagus nerve is involved in the anorexigenic effect of simmondsin in the rat

Simmondsin, 2-(cyanomethylene)-3 hydroxy 4,5 dimethoxy cyclohexyl beta-D-glucoside, from jojoba meal reduces food intake in rats. We investigated the mechanism of action simmondsin, by studying the effects of fasting or of vagotomy on the food intake reduction. The food intake reduction was significantly less in fasted rats than in non-fasted rats. The reduction of food intake was also significantly diminished after vagotomy. The results of the present experiments suggest that simmondsin reduces intake of food in rats through the augmentation of satiety, in part vagally mediated.

Reproductive performance of rats treated with defatted jojoba meal or simmondsin before or during gestation

The effects on food intake, growth and reproductive performance parameters of defatted jojoba meal and pure simmondsin, an extract from jojoba meal, were compared in female Wistar rats. Rats fed 0.15% simmondsin or 3% defatted jojoba meal (equivalent to 0.15% simmondsin) for 8 weeks before conception showed a similar reduction in food intake (about 20%) and a similar growth retardation compared with controls. Both treatments induced a reduction in the number of corpora lutea on gestation day 16: this effect could be ascribed to the lower food intake before conception because it was also observed in rats pair-fed to the treated ones. Rats given feed containing 0.15% simmondsin or 3% defatted jojoba meal during days 1-16 of gestation showed a similar reduction in food intake relative to controls. Foetal and placental weights were reduced, relative to controls, to a similar extent in both groups, and the reductions were slightly greater than in the corresponding pair-fed groups. We conclude that the effects on food intake, growth and reproductive performance that were seen after feeding rats defatted jojoba meal were due to the simmondsin content of the meal. The simmondsin induced reduction in food intake and probably also a relative protein shortage.

Effects of simmondsin on food intake, growth, and metabolic variables in lean (+/?) and obese (fa/fa) Zucker rats

Incorporation of 2.5 g/kg of the anorexigen, simmondsin, in the diet resulted in food intake reduction in both lean and obese Zucker rats; however, the obese rats were much more sensitive to the food intake-reducing activity of simmondsin. In both obese and lean simmondsin-treated Zucker rats, growth was slower than in control rats, but was the same as that in pair-fed animals. The 24 h heat production pattern showed a smaller diurnal variation and a lower mean in obese rats than in lean rats. Food intake reduction, as a result of either simmondsin treatment or pair feeding, caused a decrease in mean heat production. Simmondsin treatment, but not pair feeding, caused a decrease in the diurnal variation of heat production. Plasma total cholesterol levels were increased in both simmondsin-treated and pair-fed obese and lean Zucker rats compared with control animals; this increase was mainly due to an increase in HDL-cholesterol levels. Blood leptin levels in both obese and lean rats decreased with decreased food intake and decreased fat deposition, but in obese rats, simmondsin treatment resulted in an additional decrease in leptin levels. It is concluded that the food intake-reducing effect of simmondsin is more pronounced in obese Zucker rats than in their lean littermates, and except for the simmondsin-specific effects on leptin and total cholesterol values in obese littermates, the effects of simmondsin are related to food intake restriction in obese and lean Zucker rats.

Teratological studies in defatted jojoba meal-supplemented rats

To look for possible developmental effects in the offspring of jojoba meal-treated Wistar rats, and to distinguish between the effects of reduced food intake and the specific developmental effects of jojoba meal itself, mated female rats were divided into three groups of 20 rats. They received during gestation: (a) normal rodent food (control group); (b) normal rodent food supplemented with 3% defatted jojoba meal (jojoba group); or (c) normal rodent food pair-fed with the jojoba group (pair-fed group). The jojoba meal group showed approximately 30% inhibition of food intake. Ten rats from each group were killed on gestation day 21. Compared to the control group, foetal body weight was reduced in both the jojoba and pair-fed groups, with a greater reduction in the jojoba group. Skeletal ossification was retarded to the same extent in both the jojoba and pair-fed groups. The other 10 rats from each group were left to produce litters. Compared with controls, the body weight of the pups was lower in both the jojoba and pair-fed groups; the reduction was slightly greater in the jojoba group, but this difference disappeared after 1 week. The offspring showed no other abnormalities and reproduced normally. We conclude that, at the dose used, the retardation in foetal skeletal ossification, induced by jojoba meal supplementation during gestation, is due to food intake inhibition. Moreover, the lower birth weight of the young of jojoba-treated dams compared with the pair-fed group is merely due to a lower body weight gain during gestation.

Digestive performance of dogs fed a jojoba meal supplemented diet

Abstract Jojoba meal, the simmondsin containing by-product of oil expelling from jojoba seeds (Simmondsia chinensis) reduces food intake in rats. In the search for diet meals for dogs, we tested the digestive effects of supplementation of jojoba meal to the diet of Beagle dogs at two different concentrations. Supplementation at a low dose (2.7%) did not reduce the body weight to lower values than control animals, and did not influence the digestibility of the food. At higher concentrations (8.1%) jojoba meal reduced body weight, which was not only due to a lower food intake, but also to a less than optimal digestibility of the jojoba supplemented food.

Evaluation of jojoba meal as a potential supplement in the diet of broiler breeder females during laying

1. This study was undertaken to investigate whether jojoba meal can be used as a food supplement during the laying period of chickens. 2. The size of eggs laid were smaller and the overall production rate was lower compared to control birds on food without jojoba meal supplementation. Furthermore, both ovary and oviduct weights were lower in jojoba fed birds. 3. This lowering of egg size and production rate was caused by factors present in jojoba which interfere with follicle growth, yolk deposition, progesterone production and the follicular maturation processes, resulting in the ovulation of smaller follicles and a lower ovulation rate.