I have to admit, moving can be stressful. I mentioned in my last blog how essential oils are a wellness tool that is topping my gratitude list for modulating “freak-out” episodes.

One of my favorite oils for solace is cedarwood because it is the overlooked sidekick of sandalwood essential oil. If you’ve been reading my blogs for a while, you know of my love of sesquiterpenes. These compounds are a class of terpenes that consist of three isoprene units that have immune and neural supportive properties. Cedarwood happens to be loaded with them!

Recently, I was reading one of my favorite doc’s newsletters highlighting cedarwood’s partner-in-crime, sandalwood essential oil. I got caught in cross-reference cross-fire again and decided that, just because it stole the spotlight from one of my favorite side-kick oils, cedarwood, didn’t mean I shouldn’t allow it to shine.

Below are some highlights of research abstracts I compiled. I wanted to at least provide you with some information this week amongst my moving boxes, so here are some of my favorite study abstracts and my comments below.

The Superpowers of Sandalwood (Santalum album)

1. Its Effect on Modulating Inflammation

This abstract demonstrates the immune modulating effect of sandalwood and its sesquiterpene constituents, a-santalol and B-sanatol on human cells. Various mechanisms that affected inflammatory signals were also demonstrated and compared with a common non-steroidal anti-inflammatory drug:

Medicinally, sandalwood oil (SO) has been attributed with antiinflammatory properties; however, mechanism(s) for this activity have not been elucidated. To examine how SOs affect inflammation, cytokine antibody arrays and enzyme-linked immunosorbent assays were used to assess changes in production of cytokines and chemokines by co-cultured human dermal fibroblasts and neo-epidermal keratinocytes exposed to lipopolysaccharides and SOs from Western Australian and East Indian sandalwood trees or to the primary SO components, a-santalol and B-santalol. Lipopolysaccharides stimulated the release of 26 cytokines and chemokines, 20 of which were substantially suppressed by simultaneous exposure to either of the two sandalwood essential oils and to ibuprofen. The increased activity of East Indian SO correlated with increased santalol concentrations. Purified a-santalol and B-santalol equivalently suppressed production of five indicator cytokines/chemokines at concentrations proportional to the santalol concentrations of the oils. Purified a-santalol and B-santalol also suppressed lipopolysaccharide-induced production of the arachidonic acid metabolites, prostaglandin E2, and thromboxane B2, by the skin cell co-cultures. The ability of SOs to mimic ibuprofen non-steroidal antiinflammatory drugs that act by inhibiting cyclooxygenases suggests a possible mechanism for the observed antiinflammatory properties of topically applied SOs and provides a rationale for use in products requiring antiinflammatory effects. (1)

2. Its Action on Viruses:

An in vitro study showed viral killing activity with sandalwood among a combination of oils:

Acyclovir-resistant clinical isolates of herpes simplex virus type 1 (HSV-1) were analyzed in vitro for their susceptibilities to essential oils of ginger, thyme, hyssop, and sandalwood. All essential oils exhibited high levels of virucidal activity against acyclovir-sensitive strain KOS and acyclovir-resistant HSV-1 clinical isolates and reduced plaque formation significantly. (2)

A second in vitro study showed inhibition of herpes virus verses killing action of this oil:

Sandalwood oil, the essential oil of Santalum album L., was tested for in vitro antiviral activity against Herpes simplex viruses-1 and -2. It was found that the replication of these viruses was inhibited in the presence of the oil. This effect was dose-dependent and more pronounced against HSV-1. A slight diminution of the effect was observed at higher multiplicity of infections. The oil was not virucidal and showed no cytotoxicity at the concentrations tested. (3)

3. Its Potential Calming Action

Here’s a key reason for my highlighting sandalwood right now! Sandalwood has been evaluated for its calming effect with some promising results:

A number of essential oils are currently in use as aromatherapy agents to relieve anxiety, stress, and depression. Popular anxiolytic oils include lavender (Lavandula angustifolia), rose (Rosa damascena), orange (Citrus sinensis), bergamot (Citrus aurantium), lemon (Citrus limon), sandalwood (Santalum album), clary sage (Salvia sclarea), Roman chamomile (Anthemis nobilis), and rose-scented geranium (Pelargonium spp.). This review discusses the chemical constituents and CNS effects of these aromatherapeutic essential oils, as well as recent studies on additional essential oils with anxiolytic activities. (4)

Note this trial did not use inhalation and only 1% of an oil:

Results of the pilot study of the four counties randomised controlled trial to evaluate the effectiveness of aromatherapy massage with 1% Santalum album (Sandalwood) (group A) when compared with massage with Sweet Almond Carrier oil, (group B) or Sandalwood oil via an aromastone (group C), in reducing levels of anxiety in palliative care.

The aims of the pilot study were to evaluate the effectiveness of aromatherapy in reducing anxiety in patients receiving palliative care in four counties. The primary end points of the research were to report a statistically significant difference in anxiety scores between experimental group (B) and comparison groups (A and C) and to influence the integration of aromatherapy into all aspects of palliative care. The limited data of the pilot study (N=34)(N=34) tested the logistics of the research, particularly the 25% attrition rate and the robustness of the data collection tools. The results were not substantial enough to generate coherent statistics. Therefore no assumptions could be drawn from these results due to the inconsistencies that were bound to occur in such a small sample. However, the results do seem to support the notion that Sandalwood oil is effective in reducing anxiety. (5)

4. Its Metabolic Actions

A study with diabetic rats demonstrated blood sugar and lipid modulating effects of sandalwood when compared with metformin, a drug used for lowering blood sugar

CONTEXT: Santalum album Linn (Santalaceae), commonly known as Sandalwood is used traditionally for its antihyperlipidemic and diuretic activity.

OBJECTIVE: This study investigated the antihyperglycemic and antihyperlipidemic effect of long-term oral administration of the Santalum album pet ether fraction in streptozotocin-induced diabetic rats.

MATERIALS AND METHODS: Diabetes was induced by a single intraperitoneal injection of streptozotocin at 70?mg/kg body weight. Rats were treated with Santalum album pet ether fraction orally at a dose of 10 µg/kg body weight twice daily for 60 days. Metformin (30?mg/kg body weight) was used as positive control. Lipid profile and glycated hemoglobin were estimated. HPLC profiling of Santalum album pet ether fraction was carried out.

RESULTS AND DISCUSSION: Treatment of diabetic rats for 60 days demonstrated reduction in blood glucose level by 140 mg/dl. Metformin treated group showed a decrease in blood glucose by 70 mg/dl, as against an increase in diabetic control group by 125 mg/dl. Total cholesterol (TC), low density lipoprotein (LDL) and triglyceride (TG) levels were decreased by 22, 31 and 44%, respectively, in treated diabetic rats whereas, cardioprotective, high density lipoprotein (HDL) increased by 46%. In case of metformin, the values were 11, 29 and 15% respectively, while HDL increased by 7%. Significant improvement in atherogenic index from 267 to 139% was observed in treated rats.

CONCLUSION: Santalum album pet ether fraction has potential antihyperlipidemic activity that can help in overcoming insulin resistance. (6)

Another study with mice demonstrated sandalwood and its major constituent’s ability to modulate oxidative stress and further supported changes in metabolic markers:

Sandalwood finds numerous mentions across diverse traditional medicinal systems in use worldwide. The objective of this study was to evaluate the in vivo anti-hyperglycemic and antioxidant potential of sandalwood oil and its major constituent a-santalol. The in vivo anti-hyperglycemic experiment was conducted in alloxan-induced diabetic male Swiss albino mice models. The in vivo antioxidant experiment was performed in d-galactose mediated oxidative stress induced male Swiss albino mice models. Intraperitoneal administration of a-santalol (100mg/kg BW) and sandalwood oil (1g/kg BW) for an week modulated parameters such as body weight, blood glucose, serum bilirubin, liver glycogen, and lipid peroxides contents to normoglycemic levels in the alloxan-induced diabetic mice. Similarly, intraperitoneal administration of a-santalol (100mg/kg BW) and sandalwood oil (1g/kg BW) for two weeks modulated parameters such as serum aminotransferases, alkaline phosphatase, bilirubin, superoxide dismutase, catalase, free sulfhydryl, protein carbonyl, nitric oxide, liver lipid peroxide contents, and antioxidant capacity in d-galactose mediated oxidative stress induced mice. Besides, it was observed that the beneficial effects of a-santalol were well complimented, differentially by other constituents present in sandalwood oil, thus indicating synergism in biological activity of this traditionally used bioresource. (7)

5. Its Potential For Supporting Skin Health

An in vitro study with human skin cell tumors showed that an active constituent in sandalwood modulated various pathways to kill unhealthy cells:

a-Santalol, an active component of sandalwood oil, has been studied in detail in recent years for its skin cancer preventive efficacy in murine models of skin carcinogenesis; however, the mechanism of its efficacy is not defined. Two major biological events responsible for the clonal expansion of transformed/initiated cells into tumors are uncontrolled growth and loss of apoptotic death. Accordingly, in the present study, employing human epidermoid carcinoma A431 cells, we assessed whether a-santalol causes cell growth inhibition and/or cell death by apoptosis. Treatment of cells with a-santalol at concentrations of 25–75 µM resulted in a concentration- and a time-dependent decrease in cell number, which was largely due to cell death. Fluorescence-activated cell sorting analysis of Annexin V/propidium iodide (PI) stained cells revealed that a-santalol induces a strong apoptosis as early as 3 h post-treatment, which increases further in a concentration- and a time-dependent manner up to 12 h. Mechanistic studies showed an involvement of caspase-3 activation and poly(ADP-ribose) polymerase cleavage through activation of upstream caspase-8 and -9. Further, the treatment of cells with a-santalol also led to disruption of the mitochondrial membrane potential and cytochrome c release into the cytosol, thereby implicating the involvement of the mitochondrial pathway. Pre-treatment of cells with caspase-8 or -9 inhibitor, pan caspase inhibitor or cycloheximide totally blocked a-santalol-caused caspase-3 activity and cleavage, but only partially reversed apoptotic cell death. This suggests involvement of both caspase-dependent and -independent pathways, at least under caspase inhibiting conditions, in a-santalol-caused apoptosis. Together, this study for the first time identifies the apoptotic effect of a-santalol, and defines the mechanism of apoptotic cascade activated by this agent in A431 cells, which might be contributing to its overall cancer preventive efficacy in mouse skin cancer models. (8)

A Note On Chemotypes and Constituents

Remember, the species of sandalwood, the quality of the oil, and the distillation technique will all affect the properties and predominant action of the sandalwood used. Santalum album, with sesquiterpenes as the highest percentage of constituents, seems to be the most studied. However, other species of sandalwood also exist with similar but not identical properties, as the following abstract demonstrates:

Three qualities of New Caledonian sandalwood oil were analyzed using GC and GC/MS. Eighty-four constituents were identified: 10 monoterpenes, 72 sesquiterpenes and two others. In addition B-bisabolol/epi-B-bisabolol isomers were isolated and characterized via chiral GC chromatography. Our results indicate that New Caledonian sandalwood oil is much closer related to East Indian sandalwood oil than its Western Australian counterpart. (9)

Furthermore, remember that sandalwood is more than just isolated components. Other constituents with additional properties such as lignans and esters, could be contributing to synergistic wellness benefits:

A phytochemical investigation of the polar constituents in the heartwood of Indian Santalum album L. resulted in the isolation of three new neolignans (1—3) and a new aromatic ester (4), along with 14 known components. The structures of the new compounds (1—4) were established using spectroscopic methods. (10)

Furthermore, this abstract demonstrates we are still learning about the various properties and components of essential oils, including additional sesquiterpene compounds found in sandalwood essential oils:

Six new sesquiterpenes, (Z)-2beta-hydroxy-14-hydro-beta-santalol (1), (Z)-2alpha-hydroxy-albumol (2), 2R-(Z)-campherene-2,13-diol (3), (Z)-campherene-2beta,13-diol (4), (Z)-7-hydroxynuciferol (5), and (Z)-1beta-hydroxy-2-hydrolanceol (6), together with five known compounds, (Z)-alpha-santalol (7), (Z)-beta-santalol (8), (Z)-lanceol (9), alpha-santaldiol (10), and beta-santaldiol (11), were isolated from Santalum album, by using bioassay-guided fractionation for Helicobacter pylori. The structures were determined by extensive NMR studies. The absolute configuration of compound 3 was determined by a modified Mosher method. The crude extracts as well as the isolated compounds showed antibacterial activity against H. pylori. Especially, compounds 7 and 8 have strong anti-H. pylori activities against a clarithromycin-resistant strain (TS281) as well as other strains. (11)

Summary

Sandalwood has many potent superhero actions. I like to diffuse 4-5 drops during yoga or mediation, alternating with cedarwood and lavender. I also apply 1-2 drops on the bottom of my feet, back of my neck, or sometimes on a skin irritation to support my immune system and skin health.

If you listen to my podcast with Lucas Rockwood, he highlights his love of this oil.

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Disclaimer: This information is applicable ONLY for therapeutic, Grade A essential oils. This information DOES NOT apply to essential oils that have not been AFNOR and ISO standardized. There is no quality control in the United States and oils labeled as “100% pure” need only contain 5% of the actual oil. The rest of the bottle can be filled with fillers and sometimes toxic ingredients that can irritate the skin.

This information is for information purposes only and is not intended to diagnose, treat, or prescribe for any illness

References:

Chapter 6: Sandalwood Essential Oil. FAO. http://www.fao.org/docrep/v5350e/v5350e08.htm

(1) Suppression of lipopolysaccharide-stimulated cytokine/chemokine production in skin cells by sandalwood oils and purified ?-santalol and ?-santalol. Phytother Res. 2014 Jun;28(6):925-32. doi: 10.1002/ptr.5080. Epub 2013 Dec 6.

(2) Susceptibility of Drug-Resistant Clinical Herpes Simplex Virus Type 1 Strains to Essential Oils of Ginger, Thyme, Hyssop, and Sandalwood. Antimicrob. Agents Chemother. May 2007. http://aac.asm.org/content/51/5/1859.full

(3) Antiviral activity of sandalwood oil against Herpes simplex viruses-1 and -2. Phytomedicine. 1999. doi:10.1016/S0944-7113(99)80046-4

(4) Essential oils and anxiolytic aromatherapy. Nat Prod Commun. 2009 Sep;4(9):1305-16.PMID:19831048

(5) Evaluating the effectiveness of aromatherapy in reducing levels of anxiety in palliative care patients: Results of a pilot study. Complemenatary Therapy in Clinical Practice. 2006; 12(2): doi:10.1016/j.ctcp.2005.11.003

(6) Antihyperglycemic and antihyperlipidemic effect of Santalum album in streptozotocin induced diabetic rats. Pharm Biol. 2012 Mar;50(3):360-5. doi: 10.3109/13880209.2011.604677. Epub 2011 Dec 1.

(7) Evaluation of in vivo anti-hyperglycemic and antioxidant potentials of ?-santalol and sandalwood oil. Phytomedicine. 2013 Mar 15;20(5):409-16. doi: 10.1016/j.phymed.2012.12.017. Epub 2013 Jan 29.

(8) Skin cancer chemopreventive agent, ?-santalol, induces apoptotic death of human epidermoid carcinoma A431 cells via caspase activation together with dissipation of mitochondrial membrane potential and cytochrome c release. Carcinogenesis. 2005; 26 (2): 369-380. doi: 10.1093/carcin/bgh325 First published online: November 4, 2004

(9) New Caledonian Sandalwood Oil—a Substitute for East Indian Sandalwood Oil? Journal of Essential Oils Research. 2005: 17(5). DOI: 10.1080/10412905.2005.9698969

(10) Aromatic Constituents from the Heartwood of Santalum album L. Chemical and Pharmaceutical Bulletin. 2005. Doi: http://dx.doi.org/10.1248/cpb.53.641

(11) Anti-Helicobacter pylori compounds from Santalum album. J Nat Prod. 2005 Jun;68(6):819-24. http://www.ncbi.nlm.nih.gov/pubmed/15974602