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Biological and Nutritional Effects of Sandalwood Seed Oil

Yandi Liu, School of Pharmacy

Dietary fats have important and essential roles in human and animal nutrition. The edible seed

kernel of West Australian sandalwood (Santalum spicatum) has formed a valuable part of the

traditional aborigines diet. The macerated kernels were also used as a topical application for

skin lesions and to treat arthritis by oral ingestion. Although kernels of the seed (containing

50% fixed oil) have been eaten in the past without apparent harm, concern has been

expressed about the possible long term toxicity of the acetylenic fatty acid (containing 34%

of xirnenynic, trans-11-octadecen-9-ynoic acid). Such fatty acids are potentially bioactive as

enzyme inhibitors particularly in prostaglandin synthesis and fatty acid metabolism.

Six week old ARC strain female mice were randomly divided into three groups each of 15

animals, fed semi-synthetic diets containing 5% fat (standard lab chow, SLC), 15% canola oil

(CO), or 15% sandalwood seed oil (SWO) for 8 weeks. The progress of the feeding

experiment was monitored by determining initial body weight of the mice. Blood (max. 0.3

mL) was collected from the retro orbital venous plexus for serum glutamate oxaloacetate

transaminase (SGOT) activity test. SGOT may be used as an index of potential liver damage

caused by the diets. All the mice were killed by cervical dislocation at the end of feeding

experiment, and selected tissue removed by dissection for total lipid fatty acid analysis.

The most significant effect of SWO-fed group was an apparent reduction in body weight gain.

One way ANOVA analysis indicated that there is no significantly on growth rates (g/week)

between SWO- and SLC-fed mice. However, when compared between SWO- and CO-fed

groups, significant differences are found (p<0.05). This result may suggest an effect by the

presence of ximenynic acid as a growth retardant. No specific essential fatty acid deficiency

symptoms were observed beside mice losing their whiskers after three weeks on the SWO

diet. SGOT activities in the test mice were higher than that in the control, which could be

considered to reflect liver damage, and suggest that xirnenynic acid may affect the

liver-specific enzyme activity.

Analysis of the total lipid fatty acids of various tissues and organs showed that feeding SWO

to mice resulted in only low incorporation of ximenynic acid into the general tissues (0.3-3%),

and absence in brain. There is a possibility that ximenynic acid was further oxidised to C02

and H20, however the marked increase in the proportion of oleic acid in mouse liver of with a

concomitant increase in vaccenic acid, indicated that xirmenynic acid may also have mainly

been biohydrogenated. It was also found that the markedly low levels of arachidonic acid

being compensated by a higher levels of docosahexaenoic acid, and the regulation of these

two fatty acids together with higher incorporation of oleic acid in various tissue by digestion of

SWO may provide a biochemical data for further clinical investigation of inflammatory disease

in human.

The sandalwood seed oil feeding caused no specific pathological or morphological

changes or changes in mortality. In conclusion, sandalwood seed may be both a

food and medicine.