Traditional Herbal Medicine Use Associated with Liver
Fibrosis in Rural Rakai, Uganda
Brandon J. Auerbach1,2*, Steven J. Reynolds3,4, Mohammed Lamorde1,5, Concepta Merry1,5,6,
Collins Kukunda-Byobona8, Ponsiano Ocama2,7, Aggrey S. Semeere1,7, Anthony Ndyanabo9, Iga Boaz9,
Valerian Kiggundu9, Fred Nalugoda9, Ron H. Gray9,10, Maria J. Wawer9,10, David L. Thomas4,
Gregory D. Kirk11, Thomas C. Quinn3,4, Lara Stabinski3,11, on behalf of the Rakai Health Sciences
1Infectious Diseases Institute, College of Health Sciences, Makerere University, Kampala, Uganda, 2Harvard Medical School, Boston, Massachusetts, United States of
America, 3Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of
America, 4Division of Infectious Diseases, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America,
5Department of Pharmacology and Therapeutics, School of Medicine, University of Dublin, Trinity College, Dublin, Ireland, 6St James’s Hospital, Dublin, Ireland,
7Department of Medicine, College of Health Sciences, Makerere University, Kampala, Uganda, 8Department of Botany, Makerere University, Kampala, Uganda, 9Rakai
Health Sciences Program, Entebbe, Uganda, 10Department of Population, Family, and Reproductive Health, Bloomberg School of Public Health, Johns Hopkins University,
Baltimore, Maryland, United States of America, 11Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland,
United States of America
Background: Traditional herbal medicines are commonly used in sub-Saharan Africa and some herbs are known to be
hepatotoxic. However little is known about the effect of herbal medicines on liver disease in sub-Saharan Africa.
Methods: 500 HIV-infected participants in a rural HIV care program in Rakai, Uganda, were frequency matched to 500 HIV-
uninfected participants. Participants were asked about traditional herbal medicine use and assessed for other potential risk
factors for liver disease. All participants underwent transient elastography (FibroScanH) to quantify liver fibrosis. The
association between herb use and significant liver fibrosis was measured with adjusted prevalence risk ratios (adjPRR) and
95% confidence intervals (CI) using modified Poisson multivariable logistic regression.
Results: 19 unique herbs from 13 plant families were used by 42/1000 of all participants, including 9/500 HIV-infected
participants. The three most-used plant families were Asteraceae, Fabaceae, and Lamiaceae. Among all participants, use of
any herb (adjPRR=2.2, 95% CI 1.3–3.5, p=0.002), herbs from the Asteraceae family (adjPRR=5.0, 95% CI 2.9–8.7, p,0.001),
and herbs from the Lamiaceae family (adjPRR=3.4, 95% CI 1.2–9.2, p=0.017) were associated with significant liver fibrosis.
Among HIV infected participants, use of any herb (adjPRR=2.3, 95% CI 1.0–5.0, p=0.044) and use of herbs from the
Asteraceae family (adjPRR=5.0, 95% CI 1.7–14.7, p=0.004) were associated with increased liver fibrosis.
Conclusions: Traditional herbal medicine use was independently associated with a substantial increase in significant liver
fibrosis in both HIV-infected and HIV-uninfected study participants. Pharmacokinetic and prospective clinical studies are
needed to inform herb safety recommendations in sub-Saharan Africa. Counseling about herb use should be part of routine
health counseling and counseling of HIV-infected persons in Uganda.
Citation: Auerbach BJ, Reynolds SJ, Lamorde M, Merry C, Kukunda-Byobona C, et al. (2012) Traditional Herbal Medicine Use Associated with Liver Fibrosis in Rural
Rakai, Uganda. PLoS ONE 7(11): e41737. doi:10.1371/journal.pone.0041737
Editor: John E. Tavis, Saint Louis University, United States of America
Received June 6, 2011; Accepted June 28, 2012; Published November 27, 2012
This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for
any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
Funding: The study was primarily funded by the United States National Institutes of Health (NIH) Bench to Bedside Program. Additional support was provided by
the Division of Intramural Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health. Support was also provided by the National
Institute on Drug Abuse (PI: DLT, R01-AI-16078) and the American Cancer Society (PI: GDK, MRSG-07-284-01-CCE). The study was jointly conducted and benefited
from close collaboration of researchers from the intramural NIH Laboratory of Immunoregulation, Johns Hopkins University, the Infectious Diseases Institute of
Makerere University, and the Rakai Health Sciences Program. Support for the RHSP HIV Care Program was provided by the President’s Emergency Fund for AIDS
Relief (PEPFAR) and support for the Rakai Community Cohort Study was provided by the Department of the Army, United States Army Medical Research and
Material Command Cooperative Agreement DAMD17-98-2-8007; grants R01 A134826 and R01 A134265 from the National Institute of Allergy and Infectious
Diseases; grant R01 016078 (DLT) from the National Institute on Drug Abuse; and grant 5P30HD06826 from the National Institute of Child and Health
Development. BJA and ASS were funded by the Fogarty International Clinical Research Scholars (FICRS) program of the NIH, administered by the Vanderbilt
University Institute for Global Health (R24 TW007988). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of
Competing Interests: The authors have declared that no competing interests exist.
* E-mail: email@example.com
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Traditional herbal medicines are commonly used for HIV/
AIDS and other health conditions in Uganda and sub-Saharan
Africa, often in parallel with programs that provide antiretroviral
therapy (ART). In the 1990’s an estimated 80% of Ugandans
living in rural villages used traditional healers for primary health
care . A study of 137 HIV-infected Ugandans receiving ART
found that 60% used herbs concurrently with ART .
In Uganda traditional herbal medicines are usually boiled
extracts of herbs taken orally . Some potentially hepatotoxic
traditional herbal medicines used in Uganda and sub-Saharan
Africa include Hoodia gordoni , kava , Phytolacca dioica , and
herbs from the Asteraceae family . Little is known about the
hepatotoxicity of other commonly used herbs or the contribution
of herbs to the burden of liver fibrosis and hepatocellular
carcinoma in sub- Saharan Africa, including when used concom-
itantly with ART. Data on the specific types of herbs taken by
HIV-infected persons in Uganda is limited, as is information about
their components, side effects, toxicities, and ART interactions .
In Rakai, Uganda, liver toxicity associated with herbal medicine
may be of particular concern given the high prevalence of
significant liver disease (17%) among HIV-infected persons in
Rakai recently identified by transient elastography (FibroScanH,
Echosense, Paris, France) . In the aforementioned study,
reported herbal medicine use was associated with a two-fold
increased risk of significant liver disease, defined as a transient
elastography score equivalent to METAVIR liver fibrosis stage 2
(portal fibrosis with few septa) or greater . The study presented
here follows up on this prior investigation with an in-depth analysis
of the herbs used by study participants and their relation to liver
This cross-sectional study enrolled 500 HIV-infected partici-
pants receiving care at five HIV care clinics within the Rakai
Health Sciences Program (RHSP) HIV Care Program. 500 HIV-
uninfected participants from the Rakai Community Cohort Study
(RCCS) were frequency- matched to these participants by age,
gender, and community. Begun in 1994 in one of Uganda’s
hardest-hit regions by the HIV epidemic, the RCCS conducts
annual surveys in a population of 10,000–15,000 people aged 15–
49 years, and is described in detail elsewhere . Participants
underwent a detailed liver-disease focused risk factor questionnaire
which included an assessment of herbal drug use, venous blood
collection, and transient elastography (FibroScanH, Echosense,
Paris, France) to quantify liver fibrosis.
Written informed consent was obtained from all participants.
Institutional Review Boards of theNational Institute of Allergy and
Infectious Diseases, the Johns Hopkins Medical Institutions, the
Scientific and Ethics Committee of the Uganda Virus Research
Institute, and the Uganda National Council for Science and
Technology approved this study. The study protocol conforms to
the ethical guidelines of the 1975 Declaration of Helsinki, and is
registered on clinicaltrials.gov (#NCT00782158).
Herb Use Assessment
Participants were asked about any current herb use and then to
name the two herbs they used most often. Scientific names were
assigned to local herb names in consultation with local traditional
medicine practitioners and a member of Makerere University
Botany Department (CKB). The Makerere University Herbarium
database was also used to validate herb identities. Some
participants reported non-plant substances such as clay and
spiritual charms as herb use. Participants reporting use of non-
plant based entities were reclassified as non-herb users in this
HIV-1 serology was determined by two HIV-1 enzyme
immuno-assays: Vironostika HIV-1 (OrganonTeknika, Charlotte,
North Carolina, USA) and Cambridge Biotech (Worcester,
Massachusetts, USA). Participants with discrepant HIV-1 enzyme
immune assay results were tested with western blot (HIV-1
Western Blot; Bio-Merieux-Vitek, St. Louis, Missouri, USA). For
HIV-infected participants, current CD4 count (within 12 months)
and CD4 count nadir were abstracted from the RHSP HIV Care
Program database. CD4 counts were measured by FACSCalibur
flow cytometer (software version 1.4, Becton Dickinson, San Jose,
California, USA). Hepatitis B virus surface antigen (HBsAg) was
determined using ELISA (ETI-MAK-2 Plus, Diasorin, Vercelli,
Italy). Alanine aminotransferase (ALT) was tested using standard
methods (COBAS CII; Roche, Basel, Switzerland), and hepato-
toxicity was defined by ALT elevations and classified according to
AIDS Clinical Trial Group criteria . The upper limit of
normal for ALT was defined as 19 IU/L in women and 39 IU/L
in men [12,13].
Transient elastography or FibroScanH is a novel, validated,
noninvasive technology for the evaluation of fibrosis in chronic
liver disease . A FibroScanH is approximately the size of an
ultrasound unit. A probe placed over a patient’s abdomen
produces vibration and the speed of the responding elastic wave
is detected by ultrasound. The propagation of these waves through
the liver is directly correlated to the degree of liver stiffness. The
results are instantaneously received as a single, quantitative
parameter of liver stiffness measurement (LSM, reported in kPa).
Each transient elastography scan takes ten liver stiffness measure-
ments in rapid succession over several seconds. The median of the
ten measurements is reported as the final liver stiffness measure-
ment. The procedure is non-invasive, painless, has no side effects,
and requires only a few minutes to perform. The device requires
minimal training and does not need to be performed by advanced
In this study a conservative liver stiffness measurement cutoff of
$9.3 kPa, from a validation study in persons of predominantly
African descent, was used to define significant fibrosis equivalent
to METAVIR fibrosis stage 2 (portal fibrosis with few septa) or
greater . Two study nurses at the Rakai Health Science
Program study site conducted all transient elastography scans after
receiving certification from the manufacturer. According to
manufacturer recommendations, scans with high variability—
defined as an interquartile range greater than 30% of the median
LSM value from an individual examination—were not considered
valid and were excluded from the analysis. Participants with
invalid scans on an initial attempt were repositioned and
rescanned up to 4 times to achieve a valid scan.
Baseline demographic, behavioral and clinical characteristics
were compared by HIV status. Differences in continuous variables
were assessed using t-tests and Wilcoxon-Mann-Whitney tests.
Categorical variables were compared using Pearson’s chi squared
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The primary outcome measure was liver fibrosis. Because odds
ratios may overestimate the magnitude of association between
variables if the outcome of interest is common, adjusted
prevalence risk ratios (adjPRR) with 95% confidence intervals
(95% CI) were estimated using modified Poisson regression .
The multivariable models adjusted for HIV, gender, occupation in
the fishing industry, chronic hepatitis B infection (positive hepatitis
B surface antigen), and drinking $1.25 liters per week of liquor, as
these risk factors were associated with liver disease in previous
analysis of this study population . Age was included in all
models and nadir CD4 cell count and ART status were included in
models restricted to HIV- infected participants for reasons of
biologic plausibility. STATA version 11.0 (STATA Corp, College
Station, TX) was used for statistical analysis.
The HIV-infected and uninfected groups each had 67% females
(see table 1). The median age of 38 years in the HIV-infected
group was close to the median age of 37 years in the HIV-
uninfected group (p=0.025). Only 2% of both HIV-infected and
uninfected participants were heavy liquor drinkers (p=0.65). The
prevalence of chronic HBV infection was similar in both groups,
5% in HIV-infected participants and 3% in HIV-uninfected
participants (p=0.010). 29% of HIV-infected participants and
17% of HIV-uninfected participants had any grade 1 or higher
hepatotoxicity by AIDS Clinical Trial Group (ACTG) criteria
(p,0.001). No participants demonstrated grade 4 hepatotoxicity.
At the time of enrolment HIV-infected participants had a
median CD4 count of 449 cells/mL (IQR 320–642) and 60% were
receiving ART with a median duration of 19 months (IQR 9–38).
Demographics of the HIV-infected group were also similar to
participants in the Rakai Health Sciences HIV Care Program, in
which 65% of participants are female, 64% are on ART, and the
median CD4 count is 480 cells/mL.
468/500 (94%) of HIV-infected participants and 494/500
(99%) of HIV-uninfected participants had valid elastography
scans. Those with valid scans were included in the assessment of
liver fibrosis and were included in the regression models.
Table 1. Baseline characteristics of study participants.
HIV-infected pts (n=500) HIV-uninfected pts (n=500)
n (% or IQR)n (% or IQR)p value
Median Age, years38 (IQR 31–44)37 (IQR 32–44)0.025
Female 312 (67%) 333 (67%)0.89
Heavy Liquor use (.1.25 L/week)11 (2%)9 (2%)0.65
Lifetime occupational fishing 5 (1%) 1 (0.2%)0.65
HBsAg positive23 (5%) 14 (3%)0.10
Valid TE scan468 (94%)494 (99%)
Current herb use8 (2%)33 (7%) 0.0001
Known herbs5 (0.9%)16 (3%)0.015
Unknown herbs4 (0.9%) 17 (3%)0.004
Asteraceae family2 (0.4%)6 (1%)0.16
Fabaceae family0 (0%) 6 (1%)0.014
Lamiaceae family1 (0.2%)4 (0.8%) 0.18
ACTG Heptatotoxicty Criteria
Median ALT (U/L) 22 (IQR 16–31) 19 (IQR 15–25)
Grade 0 (,1.256ULN) by ALT354 (71%) 414 (83%)
Grade 1 (1.25–2.56ULN) by ALT122 (24%) 77 (15%)
Grade 2 (2.6–56ULN) by ALT19 (4%)9 (2%)
Grade 3 (5.1–106ULN) by ALT5 (1%) 0 (0%)
Grade 4 (.106ULN) by ALT 0 (0%)0 (0%)
CD4 and ART Characteristics
Current CD4 count (cells/uL) 449 (IQR 320–642)
Nadir CD4 count (cells/uL)214 (IQR 130–350)
Nadir CD4 count ,100 cells/uL95 (19%)
On ART 302 (60%)
ART duration (months)19 (IQR 9–38)
HIV (Human Immunodeficiency Virus), IQR (Interquartile Range), HBsAg (Hepatitis B Surface Antigen), ACTG (AIDS Clinical Trials Group), CD4 (Cluster of Differentiation 4
positive Helper T cells), ART (Antiretroviral Therapy).
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Characteristics of Herb Users
42/1000 (4%) of all participants reported current use of
traditional herbal medicines, including 9/500 (2%) of HIV-
infected participants and 33/500 (7%) HIV-uninfected partici-
pants (table 1). 21/42 (50%) of participants could name at least
one herb they were taking. 4/46 (9%) of participants reporting
Table 2. Characteristics of participants reporting current herb use.
Using Herbs (n=42) Not Using Herbs (n=958)
Characteristic n (% or IQR)n (% or IQR)p value
Median Age, years39 (32–44 IQR)38 (31–44 IQR)0.61
Female 27 (64%)643 (67%)0.15
Heavy Liquor use (.1.25 L/week)3 (7%)17 (2%) 0.015
Lifetime occupational fishing1 (2%) 5 (0.5%)0.13
HBsAg positive2 (5%) 35 (4%)0.73
HIV infected 9 (20%)491 (50%) 0.0001
L (Liters), HBsAg (Hepatitis B Surface Antigen), HIV (Human Immunodeficiency Virus).
Table 3. Characteristics of known herbs in the Asteraceae, Fabaceae, and Lamiaceae families.
Local Names (n
Rakai for:Known Pharmacology Known Liver Toxicity and/or ART Interaction
Asteraceae (8) Vernonia
Mululuza (4) Bitter leaf Fever, fever
Hepatotoxic at high doses (750 mg/kg) . One herb from
the Veronia genus (V. lasiopus) was hepatotoxic in an in-
vitro rat precision cut liver slice model . Many herbs in
the Asteraceae family contain pyrrolizidine alkaloids, which
are associated with veno-occlusive liver disease 
Vernonia genus Kiluluuza (2)
A similar herb from the Microglossa family (M. pyrifolia) was
hepatotoxic in an in-vitro rat precision cut liver slice model
. Many herbs in the Asteraceae family contain
pyrrolizidine alkaloids, which are associated with veno-
occlusive liver disease 
Aspilia africana Makaayi (1) Wild
No hepatoxicity in rat in vivo model . Many herbs in the
Asteraceae family contain pyrrolizidine alkaloids, which are
associated with veno-occlusive liver disease 
May have estrogenic
Many herbs in the Fabaceae family contain pyrrolizidine
alkaloids, which are associated with veno-occlusive liver
Namasumi (2)Indigo Fever with
triterpenes, tannins, gallic
acid, caffeic acid, rutin and
Many herbs in the Fabaceae family contain pyrrolizidine
alkaloids, which are associated with veno-occlusive liver
Herb from Ocimum genus (O. lamiifolium) was hepatotoxic
in an in-vitro rat precision cut liver slice model , Ocimum
gratissimum caused hepatoxicity in-vivo rabbit liver model
Kamunye (3)To replace
*one patient took both Ocimum gratissimum and Hoslundia oopposita. mg (milligrams), kg (kilograms).
Traditional Herbal Medicine and Liver Disease
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herb use were reclassified as not taking herbs because they only
reported use of inert, non-plant substances including clay. Herb
users did not differ by age (p=0.61) or gender (p=0.15) from
those who did not report herb use (see table 2). Herb users were
not more likely to work in the fishing industry (p=0.13) or have
chronic hepatitis B infection (p=0.73). 7% of participants
reporting herb use drank liquor heavily ($1.25 L/week), com-
pared to 2% of participants who did not report herb use
(p=0.015). 19 unique herbs from 13 families were used, and are
characterized in tables 3 and 4. The most common families were
Asteraceae, Fabaceae, and Lamiaceae, which were used by eight,
six and five participants, respectively.
Herb Use and Liver Fibrosis
Among the 137/962 (14%) subjects with significant liver
fibrosis, 12/137 (9%) reported herb use. Of the 825/962 (86%)
subjects without significant liver fibrosis, 29/825 (4%) reported
current herb use (p=0.005). 56/494 (11%) of HIV-uninfected
participants had significant fibrosis, compared to 81/468 (17%) of
HIV-infected participants (p=0.008).
In multivariable analysis that adjusted for age, fishing occupa-
tion, HIV infection, positive HBsAg, gender, and heavy liquor use,
herb use was associated with two to five fold increases in significant
liver fibrosis (see table 5). Among all participants, use of any herb
(adjPRR=2.2, 95% CI 1.3–3.5, p=0.002), herbs from the
Asteraceae family (adjPRR=5.0, 95% CI 2.9–8.7, p,0.001),
and herbs from the Lamiaceae family (adjPRR=3.4, 95% CI 1.2–
Table 4. Characteristics of known herbs in remainder of plant families.
Family (n taking) Scientific Name Local Names (n taking) English Name Taken in Rakai for:
Toxicity and/or ART
Anacardiaceae (2) Rhus vulgaris or Rhus
Mangifera indicaMango Tree Bark (1)Mango tree barkLeaves contains
flavonoids , Peel
Primulaceae (2) Maesa lanceolata Oluwongwa, Oluwongo (2) Neonatal jaundice Contains Saponins ,
Euphorbiaceae (2) Sapium ellipticum Musasa, Omusiisa,
Contains phenols 
Amaryllidaceae (1)Allium sativumGarlic (1) Garlic— Contians diallyl
Induces CYP3A4 and
Pgp and should not be
taken with the
ATV, AZT, EFV, IDV,
LPV, NFV, NVP, SQV
Ekifabakazi (1)African tulip tree Dysmennorrhea,
oleanolic acid, others
Solanaceae (1) Solanum incanum Akatengotengo (1)Sodom appleCough, chest pain Contains alkaloids,
cause hemolysis of
are associated with
Kamombo (1) Peptic ulcers Contain carotenoids
C, Tocopherols, and
Myrtaceae (1) Callistemon citrinusBottlebrush (1) Bottlebrush tree Rhino-sinusitisContains 1,8-cineole,
APV (amprenavir), ATV (atazanavir), AZT (zidovudine), EFV (efavirenz), IDV indinavir), LPV (lopinavir), NFV (nelfinavir), NVP (nevirapine), SQV (saquinavir).
Traditional Herbal Medicine and Liver Disease
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9.2, p=0.017) were associated with increased significant fibrosis.
Use of herbs from the Fabaceae family was not associated with
significant liver fibrosis (adjPRR=1.6, 95% CI 0.26–10.3,
Of 81 HIV-infected subjects with significant liver fibrosis, 4
(5%) reported herb use (see table 6). Among 387 HIV-infected
subjects without significant liver fibrosis, 4 (1%) reported herb use
(p=0.014). In the multivariable analysis of HIV-infected partic-
ipants adjusted for age, occupational fishing, positive HBsAg,
gender, heavy liquor use, ART, and CD4 nadir, the associations
between herb use and significant liver fibrosis were similar to
findings among all participants. Among HIV-infected participants
the use of any herb (adjPRR=2.3, 95% CI 1.0–5.0, p=0.044)
and the use of herbs from the Asteraceae family (adjPRR=5.0,
95% CI 1.7–14.7, p=0.004) were associated with increased liver
Among all participants as well as HIV-infected participants,
herb use was not associated with increased hepatotoxicity. 8/41
(20%) of participants reporting herb use had ACTG grade 1–4
ALT elevations, compared to 216/961 (23%) who did not report
herb use (p=0.56). Among HIV-infected participants reporting
herb use, 6/33 (18%) had grade 1–4 ALT elevations, compared to
79/461 (17%) who did not report herb use (p=0.88).
Table 7 shows the proportion of participants who took
individual herbs in the Asteraceae, Lamiaceae, and Fabaceae
families who had significant liver fibrosis. 6/8 participants taking
herbs in the Asteraceae family had significant liver fibrosis. 4/6
subjects who used herbs in the Vernonia genus of the Asteraceae
family had significant liver fibrosis.
This study indicates that traditional herbal medicine use may
contribute to liver disease in Uganda. Use of traditional herbal
medicines was independently associated with two to five fold
increases in significant liver fibrosis. Herbs from the Asteraceae
family were the most often used and showed the strongest
association with significant liver fibrosis: a five-fold increase in all
participants (p,0.001) and HIV-infected participants (p=0.004).
Six of eight participants who took herbs in the Asteraceae family
had significant liver fibrosis (see table 5). Many plants in the
Asteraceae and Fabaceae families contain pyrrolizidine alkaloids, a
known risk factor for veno-occlusive liver disease [7,17]. Although
none of the alkaloid-containing herbs used by participants in this
study have been confirmed to contain pyrrolizidine alkaloids,
ingestion of plants containing pyrrolizidine alkaloids caused
outbreaks of veno-occlusive liver disease in Jamaica, India, Egypt,
and South Africa [17,18]. No outbreaks of veno-occlusive liver
disease associated with pyrrolizidine alkaloids have been reported
to our knowledge in East Africa. Pyrrolizidine alkaloids are inert
until dehydrogenation by cytochrome P450 3A4 (CYP3A4) in the
liver , where reactive toxic pyrrolic and N-oxide metabolites
directly damage liver sinusoidal endothelial cells and hepatocytes
(zone III of the liver acinus) . Pyrroles cause chromosomal
damage in a dose-dependent manner, resulting in an inflammatory
response that culminates in fibrin deposition [17,20,21].
Although plants in both the Asteraceae and Fabaceae families
ingested by study participants may contain pyrrolizidine alkaloids,
our data shows a strong association between significant liver
fibrosis and use of herbs in the Asteraceae family but not the
Fabaceae family. The literature about African traditional herbal
medicines is limited and does not explain why this difference might
exist. Traditional herbal medicine remedies used in Rakai and
throughout Uganda are often mixtures containing multiple herbs
[8,22]. It is possible that herbs in the Asteraceae family are taken
at high doses, or potentiate the toxicity of other herbs or
Table 5. Association of herbs with significant liver fibrosis in
Herb (n taking)PRR 95% CIP value adjPRR 95% CI P value
Any current herb use
2.2 1.3–3.6 0.0032.2 1.3–3.5 0.002
Asteraceae (8) 5.53.6–8.4
Fabaceae (6)1.2 0.19–7.10.861.6 0.26–10.3 0.60
Lamiaceae (5)188.8.131.52–8.4 0.0603.4 1.2–9.20.017
Unknown herb (21) 1.00.35–2.90.995 1.20.40–3.3 0.79
Multivariate model for all participants adjusts for: age, occupational fishing, HIV
infection, positive Hepatitis B surface antigen, gender, heavy liquor use
($1.25 L/week). Only participants with a valid TE scan (962/1000) were included
in the model. CI (Confidence Interval).
Table 6. Association of herbs with significant liver fibrosis in
Herb (n taking) PRR 95% CI P value adjPRR 95% CIP value
Any current herb use
3.0 1.4–6.20.0032.3 1.0–5.00.044
Asteraceae (2)6.0 4.9–7.3
Unknown herb (5)1.2 0.20–6.8 0.87 1.0 0.15–6.70.998
Multivariate model for HIV-infected participants adjusts for: age, occupational
fishing, positive Hepatitis B surface antigen, gender, heavy liquor use ($1.25 L/
week), ART, and CD4 nadir. Only participants with a valid TE scan (468/500)
were included in the model. CI (Confidence Interval).
Table 7. Use of specific herbs and significant liver fibrosis.
Proportion of participants taking
with significant liver fibrosis
Vernonia amygdalina 2/4
Vernonia, species unknown2/2
Pseudarthria hookeri 1/4
Indigofera congesta 1/2
Lamaceae Family 2/5 *
Ocimum gratissimum 1/3
Hoslundia opposita 1/3
*One participant took both Ocmum gratissimum and Hoslundia opposite.
Only participants with a valid TE scans are shown.
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Two participants with fibrosis reported use of Vernonia amygdalina
in the Asteraceae family. This particular herb is commonly used in
Africa is thought to have hepatoprotective properties .
However, animal studies show that at higher doses, this member
of the Asteracaae family may be hepatotoxic. In an in-vivo rat CCl4
liver injury model, low doses (250–500 mg/kg) of Vernonia
amygdalina were hepatoprotective, but a high dose (750 mg/kg)
caused increased hepatoxicity .
Herbs from the Lamiaceae family were associated with a 3.4
fold increase in significant liver fibrosis among all participants in
our study (p=0.017). Herbs in the Lamiaceae family have been
associated with hepatoxicity in an in-vivo rabbit model . In
addition, Aloe, taken by two participants in our study, has been
linked in case reports to severe hepatitis . However, data about
the potential hepatotoxicity of many herbs used by participants in
this study do not exist, or come from animal model studies only
that should be interpreted cautiously.
The risk of significant fibrosis associated with herb use was
similar in the overall and HIV- infected study populations. Data
on herb use was limited in the HIV-infected population, and plant
family specific analysis was only possible for the Asteraceae family.
Only two HIV- infected participants reported using herbs in the
Despite the small number of HIV-infected participants in this
study who reported herb use, it is important to note that ART may
alter the toxicity profile of co-administered herbs. CYP3A4 is a
major pathway for metabolism of a wide range of chemically
distinct foreign compounds including phytochemicals and antiret-
roviral drugs . Antiretroviral drugs of the non- nucleoside
reverse transcriptase inhibitor (NNRTI) and protease inhibitor (PI)
classes are also inducers or inhibitors of CYP3A4 activity [28,29].
Therefore, these drugs have potential to influence phytochemical
toxification or detoxification pathways in the liver. For example,
commonly used NNRTI in initial ART regimens in Uganda
(efavirenz and nevirapine) are inducers of CYP3A4 and therefore
have potential to increase generation of toxic metabolites of
pyrrolizidine alkaloids [27,28]. Inhibitors of CYP3A4 may lead to
accumulation of phytochemicals or their metabolites in the liver
which may also result in toxicity.
Conversely, herbs may potentiate ART toxicities by influencing
antiretroviral drug disposition in the liver, kidney, and gut. Herbs
may affect NNRTI and PI metabolism by CPY3A4 and alter
activity of cellular drug transporters and glucuronidation pathways
. Existing evidence from Africa about herb-ART interactions
is limited to two herb families commonly used in South Africa:
Hypoxis (African potato) and Sutherlandia, neither of which were
taken by participants in this study. Hypoxis causes a dose-
dependent inhibition of CYP3A4 up to 86% of the normal activity
of CYP3A4 and 50% reduction of the expression of P-
glycoprotein. Sutherlandia frutescens also causes a dose dependent
inhibition of CYP3A4 up to 96% of CYP3A4 activity . One
participant in this study reported garlic use, which is known to
significantly reduce concentrations of a PI (saquinavir), most likely
by induction of CYP3A4 . Since nevirapine and efavirenz are
also eliminated by CYP3A4, garlic may reduce plasma levels of
these drugs, but there are no clinical data on these interactions.
This study had limitations. The study was cross-sectional and
only information about current herb use was available for analysis.
Only 4% of participants in this study reported using herbs,
compared to other studies in Uganda in which 60% of HIV-
infected persons reported concurrent use of ART and herbs .
Some misclassification of herb exposure could have occurred due
to a social desirability or reporting bias, especially among HIV-
infected persons on ART who are counseled to avoid herbs in the
communities around Rakai. Only 2% of HIV- infected partici-
pants reported herb use. While this lower number of HIV-infected
participants reporting herb use could represent effective counsel-
ing, the difference in herb use among those on ART and those not
on ART was not significant (1% vs. 2%, p=0.42). The small
number of participants reporting herb use limited many compar-
isons (e.g., herb-ART interactions) and suggests that our findings
should be interpreted cautiously.
An important limitation of this study is the potential for reverse
causality. Although the most frequently used families of herbs in
this study contain known hepatotoxins (see table 3), it is possible
that the association of fibrosis with herb use could represent
reverse causality, or persons with symptomatic liver disease being
more likely to use herbal medicines. According to consultations
with local traditional practitioners, some of the herbs in Asteraceae
and other families are sometimes prescribed for ‘‘fever with
jaundice’’. However, none of the study participants had been
previously diagnosed with liver disease within the formal medical
system or by traditional healers. Most herbs used in this study to
treat fever are usually taken for general fever (‘‘fever’’ or
‘‘malaria’’), not fever with jaundice (‘‘yellow fever’’).
More studies are needed to assess the impact of traditional
herbal medicines in sub-Saharan Africa. Phytochemical, pharma-
cokinetic and prospective clinical studies are needed to investigate
herb contents, benefits, side effects, direct toxicity, and herb-ART
interactions. Plants in the Asteraceae family reported in this study
should be prioritized for these investigations.
The risk of liver disease associated with herb use was similar in
the overall study population and among HIV-infected partici-
pants. Given the potential of at least additive risk of hepatotoxicity
with long term use of some antiretroviral drugs, as well as the
potential for herbs to alter the pharmacology of antiretroviral
drugs, it may be prudent to counsel HIV-infected persons against
herb use in sub-Africa until there is data about the safety of specific
herbs. Counseling about herb use should be part of routine health
counseling and counseling of HIV- infected persons in sub-Africa.
Conceived and designed the experiments: LS SJR TCQ PO GDK.
Performed the experiments: LS SJR IB PO. Analyzed the data: BJA LS
GDK AN. Contributed reagents/materials/analysis tools: CKB. Wrote the
paper: BJA LS. Provided additional technical assistance and contributed to
interpretation of the data: BJA CKB ML CM AS PO VK IB FN AN MJW
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