The International Journal of Aromatherapy (2004) 14, 15–21

The InternationalJournal of

Aromatherapy

intl.elsevierhealth.com/journals/ijar

The effect of aloe vera gel on theanti-acne properties of the essential oilof Ocimum gratissimum Linn leaf – a preliminaryclinical investigation

L.O. Orafidiyaa,*, E.O. Agbania, A.O. Oyedelea, O.O. Babalolab,O. Onayemic, F.F. Aiyeduna

a Department of Pharmaceutics, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeriab Department of Clinical Pharmacy and Pharmacy Administration, Faculty of Pharmacy, Obafemi AwolowoUniversity, Ile-Ife, Nigeriac Department of Dermatology and Venereology, College of Health Sciences, Obafemi Awolowo University,Ile-Ife, Nigeria

Summary Aim: This study was designed to investigate possible synergistic effectof aloe vera gel on the anti-acne properties of Ocimum gratissimum oil and tocompare the activities of both agents singly and in combinations with the anti-acneagent Dalacin� – a 1% Clindamycin phosphate solution.Methods: 84 subjects presenting with clinically significant Acne vulgaris (mainlyundergraduates of a University) were randomly assigned into seven groups andtreated with different test preparations (2% v/v Ocimum oil lotion containing gradedconcentrations (0– � 100%) of aloe gel, placebo or control preparations). Samplestested were applied to the face after washing morning and evening. The numbers ofinflammatory lesions (papules and pustules) were counted prior to application anddaily for 4 weeks. The efficacy of the preparations was rated in terms of productactivity (1=D), which is the reciprocal value of the number of days taken to achieve50% reduction in lesion count.Results: The efficacy of the Ocimum oil lotion products increased with increasingaloe gel contents. Products formulated with the undiluted or 50% aloe gels weremost active and resolved inflammatory lesions faster than the standard product. Thealoe gel alone showed minimal activity. Adverse effect was mild and tolerable.Conclusion: Aloe vera gel enhanced the anti-acne properties of Ocimum oil; the oilor its combination with aloe vera gel is more effective than 1% Clindamycin in thetreatment of Acne vulgaris.

�c 2003 Elsevier Ltd. All rights reserved.

KEYWORDSAloe vera gel;Ocimum gratissimum

essential oil;Acne vulgaris treatment;Clindamycin

* Corresponding author. Tel.: +08034551845.E-mail address: laraoraf@yahoo.com (L.O. Orafidiya).

0962-4562/$ - see front matter �c 2003 Elsevier Ltd. All rights reserved.doi:10.1016/j.ijat.2003.12.005

16 L.O. Orafidiya et al.

Introduction

The gel and extracts of aloe vera (Aloe barbad-ensis Miller) are widely used unofficially in topi-cal and internal folk medicines, in beverages andin cosmetic products (Grindlay and Reynolds,1986). The gel is said to possess immunomodu-latory properties, antidiabetic, anticancer andantibiotic activities (Reynolds and Dweck, 1999),and has been further suggested to enhance in-tended therapeutic and/or protective effectswhen included in topical preparations or devicesfor the management of certain pathologic skinconditions in man (Olsen et al., 2001; Visuthiko-sol et al., 1995). Chemical analysis has shown thegel to contain various carbohydrate polymers,particularly glucomannans and/or pectic acid,along with a range of other organic and inorganiccomponents (Grindlay and Reynolds, 1986). Aloegel and extracts have been clinically investigated(Olsen et al., 2001; Syed et al., 1996; Visut-hikosol et al., 1995); they promote generalhealth and provide skin protection and healing,showing only mild side effects. A 0.5% aloe veraextract in a hydrophilic cream, for instance, wasfound more effective than placebo, elicitingneither toxicity nor side effects in a 60-patientrandomized controlled clinical study that inves-tigated the management of Psoriasis vulgariswith aloe extract (Syed et al., 1996). However,contradictory results have been occasionally en-countered, such as a case of adverse (hypersen-sitivity) side effect (Morrow et al., 1980) anddelay in wound healing in both animal and humanexperiments (Kaufman et al., 1988; Schmidt andGreenspoon, 1991).

We have recently reported the anti-acne effectof the leaf essential oil of Ocimum gratissimum(Ocimum oil). A 2% hydrophilic cream preparationof the oil, applied 12-hourly (morning and even-ing), proved more effective within 1–2 weeks than10% benzoyl peroxide lotion (a commercial prod-uct) indicated in the topical treatment of Acnevulgaris (Orafidiya et al., 2002). The chemicalconstituents and percentage composition of Oci-mum oil have been reported (Martins et al., 1999).Its antimicrobial activity is said to be due mainly toits 48% thymol content (Hammer et al., 1999). Thepresent investigation was designed to determineand evaluate the effects of aloe vera leaf gel onthe anti-acne properties of Ocimum oil and tocompare the activities of both agents singly and incombinations with another standard commercialanti-acne agent, Dalacin� – a 1% Clindamycinphosphate solution.

Materials, patients and methods

Test preparations

Ocimum oil dispersed in Polysorbate 80 (Tween80�, Honeywill-Atlas, Halewood Chemicals Ltd.,Middlesex, UK) as described by Orafidiya et al.(2002) was incorporated into homogenized and fil-tered aloe leaf gel or its 50% or 25% aqueous dilu-tions, giving three test formulations eachcontaining 2% v/v Ocimum oil and 1% v/v Polysor-bate 80. The surfactant Polysorbate 80 was in-cluded in the preparations to ensure uniformdispersion of the slightly water miscible Ocimumoil.

Other similar preparations for control testingwere also made namely, Ocimum oil 2% v/v emul-sified in 1% v/v Polysorbate 80 solution excludingaloe gel, a dispersion of the undiluted gel in 1% v/vPolysorbate 80 solution but excluding the oil, andthe placebo (a 40% v/v arachis oil emulsion in 1% v/v Polysorbate 80). Clindamycin solution (Dalacin�,Pharmacia & Upjohn N.V./S.A. Puurs, Belgium), acommercial topical product indicated for thetreatment of Acne vulgaris, containing 1% Clinda-mycin phosphate as active principle, was alsostudied as a reference/standard drug product.Each test sample was packaged in coded 5 ml sy-ringes and distributed randomly to subjects withinstruction that it could not be shared or trans-ferred. Furthermore the participants were visitedat random during the study to ensure compliance.

Patients and methods

The research followed the tenets of the Declara-tion of Helsinki promulgated in 1964 and approvedby the Institutional Human Experimentation Com-mittee. A careful explanation of the aims of thetests was given to the subjects. Each subject freelysigned an informed consent form and filled thequestionnaire provided. The study is a pilot for asubsequent larger trial. Approval was obtainedfrom the Research and Ethical Committee of theObafemi Awolowo University Teaching HospitalsComplex, Ile-Ife, Nigeria.

Eighty-four subjects consisting mainly of under-graduate students of the Obafemi Awolowo Uni-versity, Ile-Ife, Nigeria, presenting with clinicallysignificant Acne vulgaris participated in the study.Power calculation following the methods of Kirk-wood (1988) indicated aminimum of 11 subjects pergroup for statistical significance (power¼ 90% at 5%significance level). The subjects were randomly

The effect of aloe vera gel on the anti-acne properties of Ocimum gratissimum oil 1717

assigned to seven groups each of 12 candidates. Oneof the seven test preparations was administered toone group of the subjects, respectively.

Subjects who presented with alcohol or drugabuse were not included in the study. Those on long-term antibiotic medication were excluded. Preg-nant and nursing mothers as well as subjects whoclaimed to have sensitive skin were also excluded.Concomitant medications considered to be vital tothe general health of the subjects were permittedand noted in the subjects’ report sheets. Suchmedications included analgesics, non-steroidalanti-inflammatory drugs and antispasmodics.

The syringes used for dispensing the test prod-ucts were all identical in appearance. The subjectswere instructed to apply the preparations morningand evening after washing the face with non-medicated soap and water. The prescribed dose ofapproximately 0.25 cm3 was applied gently overthe affected areas (approximately 5 cm� 5 cmsquare site) twice daily. The site of applicationremained the same for the duration of the studyregardless of improving conditions. Treatmentcontinued uninterrupted for 4 weeks. At the end ofeach week, used syringes were collected and thesubjects provided with fresh syringes containingappropriate preparations. This was done to preventpossible microbial spoilage of the test preparationssince they contained no antimicrobial preservativeand also to monitor compliance.

Questionnaires and report sheets

A questionnaire was prepared to evaluate the ef-ficacy and subject acceptability of the varioussamples. It was also designed to reveal personalinformation about the subjects. There was a reportsheet for each subject on which the effectivenessof therapy, compliance, product stability, adverseeffect and other information about the productsand subjects relevant to the clinical trial weremonitored by the investigators.

Evaluation of clinical tests

Single blind and group parallel design was adopted(Spilker, 1985) with the blind imposed on the sub-jects and raters who evaluated the resolutions.Upon admission to the clinical trials, subjects un-derwent physical examination of the affected area.History was taken. Subject evaluation was done ona daily basis throughout the test period. The eval-uation was based on criteria such as site of acne(forehead, nose, cheeks, chin and chest), numberof papules and pustules (lesion count), and the

presence or absence of precipitating factors.Comedones were also counted. The efficacy of thepreparations used by the subjects was evaluated byacne lesion count, mainly papules and pustulescounted separately (Lucky et al., 1991). The num-ber of days taken to achieve a 50% reduction inlesion count (relative to pre-treatment count), D,was noted for each subject and taken as an index ofproduct activity. The reciprocal value, 1=D, wascalculated and taken as a direct proportion mea-sure of product efficacy. Skin tolerance of thetest preparations was noted in the course ofexperiments.

Statistical analysis

The differences in results obtained between thegroups of subjects for the test, placebo and controlpreparations were evaluated by a modified t test(n < 20) (Gardiner and Gettinby, 1998). A one-wayanalysis of variance at p ¼ 5% (ANOVA) and F testcomputations were further employed to determinethe significance of the variations resulting fromsubjects’ use of the different test preparations.Between-treatment differences were tested fol-lowing twice-daily treatments for 3, 7 and 11 days,respectively.

Results

Subjects’ history

Of the 84 subjects that participated in the trial, 49(58.33%) were female and 35 (41.66%) were male.All the subjects were within the ages of 20–25years and presented with acne that had persistedfor periods ranging from 1–5 years. All of them hadused one or more topical medications for the acneprior to the test. All such medications were, how-ever, discontinued two months before the studycommenced.

Skin tolerance to the test products

Only mild skin irritation due to the topically ap-plied Ocimum oil preparations was generally ob-servable. Most (96%) subjects commonly reported amild stinging sensation on the skin which, however,was tolerable and did not preclude any subjectfrom participating in the trial. All the subjectscomplied satisfactorily with the treatment regi-men, and none dropped out.

18 L.O. Orafidiya et al.

Efficacy

Papulopustular lesions were the most frequentlyseen (82%), followed by comedones (15.5%) andnodules (2.5%). The cheek, the forehead and thelower peri-orbital region were the most commonsites of significant occurrence. The effect of theOcimum oil preparations was similar at all the sites.

Table 1 shows the efficacy of the test samples asdetermined from the subject report sheets. Withinthe placebo group, there were few cases of re-duction in lesion count attributable to natural

Table 1 Efficacya of Ocimum oil – Aloe gel preparations,

Test preparations

40% Arachis oil in 1% Polysorbate 80 (placebo)Neat aloe gel dispersed in 1% Polysorbate 80 (negative con1% Clindamycin (Reference drug product, positive control)2% Ocimum oil lotion2% Ocimum oil lotion in 25% aqueous aloe gel2% Ocimum oil lotion in 50% aqueous aloe gel2% Ocimum oil lotion in 100% aloe gel

Note. –, no consistent decrease observed in the papulopustulapapulopustular lesion counts (�SD); 1=D, mean efficacy index (�SD)aqueous Polysorbate 80 solution.

a Values indicate the mean of results for 12 subjects.

Table 2 Mean number of papulopustular lesions countedplacebo and controlsa

Test preparations Baseline

Pustular

40% Arachis oil in 1% Polysorbate 80 (placebo) 25.4� 1Neat aloe gel dispersed in 1% Polysorbate 80(negative control)

23.8� 1

1% Clindamycin (Reference drug product,positive control)

26.5� 9

2% Ocimum oil lotion 27.1� 12% Ocimum oil lotion in 25% aqueous aloe gel 26.4� 12% Ocimum oil lotion in 50% aqueous aloe gel 25.2� 12% Ocimum oil lotion in 100% aloe gel 28.0� 1

Papular

40% Arachis oil in 1% Polysorbate 80 (placebo) 42.8� 2Neat aloe gel dispersed in 1% Polysorbate 80(negative control)

41.2� 2

1% Clindamycin (Reference drug product,positive control)

40.8� 2

2% Ocimum oil lotion 42.3� 12% Ocimum oil lotion in 25% aqueous aloe gel 41.4� 22% Ocimum oil lotion in 50% aqueous aloe gel 39.0� 22% Ocimum oil lotion in 100% aloe gel 44.3� 3

Note. –, complete resolution of baseline lesions in most subjreduction (�SD); 1=D, mean efficacy index (�SD); 2% Ocimum oPolysorbate 80 solution.

a Values indicate mean of results for 12 subjects.

resolution; however, this effect was masked in thegroup mean papulopustular count by the increasesin lesion counts observed in other patients duringthe test period. The negative control preparation(neat aloe gel in surfactant dispersion without Oc-imum oil) showed some minimal activity (1=D ¼0:10� 0:09). It produced 50% lesion counts reduc-tion in 19.5� 19.0 days of treatment (Table 1).However, all the Ocimum oil lotion preparationstested effected more substantial lesion countsreduction than the negative control (1=D ¼ 0:23–0:49), which was comparable to or greater than

placebo and controls in treatment of Acne vulgaris

D 1=D

– –trol) 19.5� 19.0 0.100� 0.09

5.3� 1.2 0.200� 0.044.5� 1.3 0.233� 0.054.1� 0.8 0.255� 0.083.0� 0.8 0.369� 0.062.1� 0.6 0.491� 0.10

r counts; D, number of days taken to achieve 50% reduction in; 2% Ocimum oil lotion¼ 2% v/v Ocimum oil emulsified in 1% v/v

before and after treatment with the test preparations,

Day 3 Day 7 Day 11

count

2.5 25.1� 12.6 22.6� 15.3 26.7� 11.40.5 23.0� 10.1 21.9� 10.3 20.9� 10.4

.5 18.0� 8.2 10.0� 3.4 6.3� 1.7

1.4 20.1� 9.2 11.1� 2.9 –3.6 19.3� 10.3 10.4� 5.1 –1.5 16.0� 8.6 08.8� 2.4 –6.3 05.0� 4.4 01.6� 0.8 –

count

2.7 41.1� 20.6 40.5� 24.7 43.8� 19.41.8 37.9� 20.4 34.1� 20.6 28. 7� 17.7

0.0 33.0� 11.2 14.3� 9.1 05.2 � 4.4

9.0 25.0� 12.1 09.1� 7.3 –2.1 28.0� 10.8 11.0� 8.2 –0.3 18.0� 12.8 02.4� 0.9 –0.7 18.0� 13.4 01.7� 0.8 –

ects; D, number of days taken to achieve 50% lesion countsil lotion¼ 2% v/v Ocimum oil emulsified in 1% v/v aqueous

The effect of aloe vera gel on the anti-acne properties of Ocimum gratissimum oil 1919

that of the positive control product (1% Clindamy-cin solution, 1=D ¼ 0:20).

All the different Ocimum oil lotion preparationseffected 50% or higher lesion resolution in 2–5 days(Table 1). These preparations, containing increasingquantities of aloe gel, generally produced succes-sively decreasing papulopustular counts and corre-sponding higher product activities with the higheraloe gel contents (Tables 1 and 2). Thus, while theactivity of 0% and approx. 25% aloe gel-contentOcimum oil preparations (1=D ¼ 0:23–0:25) wassimilar to that of 1% Clindamycin (the positivecontrol product, Table 1), the preparations con-taining approx. 50% or the neat (approx. 100%) aloegel exhibited significantly better effects (1=D ¼0:37–0:49, p < 0:05) than the control (Table 1).Hence the Ocimum oil lotion products formulatedwith neat or 50% aqueous dilution of aloe gel provedto be the most active of all.

Table 2 affords a comparison of the meannumber of papules and pustules counted on thefaces of subjects receiving the various treatmentsat baseline and after continual application for 3, 7,and 11 days, respectively, while Fig. 1 illustratesthe enhancing effect of the aloe gel contents onactivity of the Ocimum oil lotion preparations.Acne lesions treated by all the Ocimum oil lotionpreparations were cleared from most subjects’faces by the 11th day of regular treatment (Table2). The Ocimum oil lotion treatment was generallyobserved to resolve the subjects’ papulopustular

Figure 1 Mean number of papulopustules counted on subjeof treatment with test preparations, placebo and controls.

lesions more readily than the nodulocystic lesions,which were apparently more obdurate to thetreatments. We noted that the papulopustular le-sions in male subjects generally resolved slower(D ¼ 3:43� 1:3) when compared to female partic-ipants (D ¼ 2:52� 0:6).

Discussion

The mucilagenous gel (aloe vera gel) derived fromthe parenchymatous cells of the leaf pulp of Aloebarbadensis is to be clearly distinguished from thebitter, yellow exudate obtainable from the bundlesheath cells (Grindlay and Reynolds, 1986). Con-flicting reports on the wound healing effects ofaloe vera gel and/or its extracts appearing in theliterature (Reynolds and Dweck, 1999; Vogler andErnst, 1999) can be partly resolved by paying at-tention to this distinction. Many anecdotal andscientific articles (Lee et al., 2001; Pribitkin andBoger, 2001; Mantle et al., 2001; Visuthikosolet al., 1995) support the uses and application ofaloe vera gel or its component(s) in folk and mod-ern medicines as an agent for healing wounds andburn injuries. But others give indications for cau-tion (Atherton, 1998), indications of an inconclu-sive data (Vogler and Ernst, 1999; Ernst et al.,2002), contradictory results (Kaufman et al., 1988;Schmidt and Greenspoon, 1991) or toxic conse-quences resulting from the use of aloe gel (Morrow

cts’ faces relative to baseline counts (%) on Days 3 and 7

20 L.O. Orafidiya et al.

et al., 1980; Avila et al., 1997; Hunter and Frum-kin, 1991). The present study has followed up onthe promising clinical literature reports of efficacyof aloe gel in pathologic skin conditions. Acnevulgaris (acne) is a common skin disease of youngadults that often involves the inflammation (withor without bacterial colonization) of the piloseba-ceous follicles of the face and upper trunk. Aloe gelis said to possess antibacterial and antifungalproperties (Bruce, 1967; Soeda et al., 1966) thatcan be useful in treatment of infected cases ofacne, in addition to the more pertinent anti-in-flammatory potential of the gel (Vazquez et al.,1966) to which its tissue repair activity is largelyattributed (Reynolds and Dweck, 1999; Davis et al.,1989). The anti-inflammatory components thathave been identified in aloe gel include mannose-6-phosphate (Davis et al., 1994.) and C-glucosylchromone (Hutter et al., 1996).

In this study, Ocimum lotion preparations con-taining 2% oil and graded quantities of aloe vera gelhave generally shown increasing effectiveness inacne lesion treatment with increase in the aloe gelcontents. Favorable effect of aloe vera plantproduct(s) in treatment of acne had been earliersuggested (Mantle et al., 2001). The results of thepresent study have confirmed this, in that the neataloe dispersion test product (negative controlpreparation) exhibited some anti-acne activity(Tables 1 and 2) but this was not significantly dif-ferent from the placebo preparation; on the otherhand compliments of results reveal that greaterpotency of Ocimum oil preparations against acnecondition is obtained when aloe gel is incorporatedinto the Ocimum oil products. This combinationhastened and more thoroughly accomplished reso-lution of the clinical lesions (Table 1, Fig. 1). Otherinstances of rapid and improved dermal restorationwhen aloe gel or extract is included or combinedwith auxiliary therapeutic agents are also known(Heggers et al., 1997; Heggers et al., 1996).

The 2% Ocimum oil in 50% aloe gel proved to bethe optimal formulation; it was as effective as the2% oil in neat (approx. 100%) aloe after 7 days’treatment. Continuous treatment for not less than7 days is recommended for the effective treatmentof Acne vulgaris.

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