PDF
(Download)
|
- Ashwagandha (Withania somnifera)
- Safety
- Tolerability
|
Date:
05-15-2013 | HC# 121264-472
|
Re: Ashwagandha in Healthy Humans: Physiological Effects and Safety
Raut
AA, Rege NN, Tadvi FM, et al. Exploratory study to evaluate tolerability,
safety, and activity of ashwagandha (Withania somnifera) in healthy
volunteers. J Ayurveda Integr Med. July 2012;3(3):111-114.
In
traditional Ayurvedic medicine, ashwagandha (Withania somnifera) root is
used to promote general strength and vitality. Several human studies have been
published in recent years, collectively showing that this plant's root,
ingested either in dried form or in extract form, decreased stress and improved
quality of life,1 improved sexual function in males,2
increased immunity,3 improved cardiorespiratory endurance and
neuromuscular coordination,4 and alleviated fatigue and weakness in
peri- and postmenopausal women.5 The ashwagandha root has also been
reported to be an adaptogen.6
The
present observational, dose-response study was designed to assess the safety
and tolerability of escalating doses of ashwagandha in healthy subjects, as
measured by vital signs and hematological and biochemical parameters. Secondary
endpoints were the percentage of body fat, lean body weight, muscle strength,
and exercise tolerance. It was a single-arm study with no placebo control
group.
Included
participants were males or females who were 18-30 years of age with a body mass
index (BMI) of 19-30 kg/m2 who did not take any medications,
supplements, or adhere to an exercise regimen within the prior month. Those
that had taken or donated blood within 3 months of the study were excluded.
Potential participants underwent a physical exam, an assessment of organ
function, a chest X-ray, and an electrocardiogram (ECG).
A
total of 18 subjects were enrolled in the study. At baseline, the mean age of
the subjects was 24.33 ± 2.14 years, the mean height was 165.94 ± 7.43 cm, the mean
weight was 66.65 ± 8.79 kg, and the mean BMI was 24.28 ± 2.70 kg/m2.
None of the subjects smoked or used tobacco or alcohol.
For
a 30-day period, doses of an ashwagandha aqueous extract were increased in 10-day
intervals, starting at 250 mg in the morning and 500 mg in the evening on days
1 to 10 (750 mg/day). From days 11 to 20, 500 mg was taken in the morning and
500 mg was taken in the evening (1,000 mg/day). The dosage on days 21 to 30 was
500 mg in the morning and 750 mg in the evening (1,250 mg/day).
The
test material was a gelatin capsule, containing 250 mg or 500 mg of 8:1
pulverized ashwagandha root aqueous extract. Neither the source, preparation
process/standardization, nor the manufacturer of the ashwagandha extract used
in this study is disclosed.
Vital
signs, body weight, BMI, ECG, exercise tolerance, muscle strength, and blood
panels were assessed at baseline and on days 11, 21, and 31. The blood panels
included hematological (erythrocyte sedimentation rate, platelet, hemoglobin,
differential, red, and white cell counts), organ and metabolic function (serum
bilirubin, protein, albumin, alanine transaminase, aspartate transaminase,
alkaline phosphatase, uric acid, and fasting blood glucose), and lipid (total
cholesterol, high-density lipoprotein [HDL], low-density lipoprotein [LDL], and
very-low-density lipoprotein [VLDL]) parameters. Exercise tolerance was
measured by cycle ergometer, and muscle strength was assessed by hand grip,
quadriceps, and back extensor force. Body fat percentage and lean body weight
were measured by skin fold thickness at the biceps, triceps, and subscapular
and suprailiac areas.
There
were no significant changes in vital signs (body temperature, pulse, blood
pressure, and respiration rate), body weight, or hematological parameters
during the study. Measures of organ function such as the serum bilirubin,
protein, albumin, alanine transaminase, aspartate transaminase, and alkaline
phosphatase remained within the normal range, as did uric acid and fasting
blood glucose levels. No significant changes in appetite, bladder or bowel
habits, or sleep duration were reported; although 6 (33%) of the subjects
voluntarily reported improved sleep quality. The authors note that
"Needrajaran" or sleep induction is an important clinical application
of ashwagandha in Ayurvedic medicine.
Muscle
force significantly increased in both the quadriceps (28.02 ± 8.23 kg vs. 34.05
± 8.10 kg, P<0.05) and the back extensor (26 ± 8.83 kg vs. 30.02 ± 8.10 kg,
P<0.05) as compared to baseline. Increasing trends were reported in handgrip
strength and exercise tolerance. The authors suggest that in accordance with
the traditional usage of ashwagandha, these results together with the observed
increase in serum creatinine (0.85 ± 0.14 mg/dl vs. 0.95 ± 0.13 mg/dl,
P<0.05) indicate muscle mass promotion activity, rather than adverse renal
function, since there was a significant concomitant drop in urea nitrogen
(10.93 ± 3.62 mg/dl vs. 9.78 ± 3.38 mg/dl, P<0.05).
These
findings were further supported by a trend towards decreasing body fat percentage
and increasing lean body weight, although body weight and BMI did not
significantly change. Total cholesterol significantly decreased (175.9 ± 24.62
mg/dl vs. 159.6 ± 17.22 mg/dl, P<0.05), and decreasing trends were also seen
in triglycerides, LDL cholesterol, fasting blood sugar, and BMI.
With
the exception of 1 subject, this study reports the good safety profile of daily
ashwagandha supplementation up to 1,250 mg. No changes were seen in vital
bodily functions or appetite, gastrointestinal habits, or sleep. It is
mentioned that the adverse side effects reported in the withdrawn subject may
be due to previously cited impacts of ashwagandha on the central nervous system
and libido. These potentially serious adverse side effects warrant further
study. However, the formulation was found to be safe in terms of hematological
and biochemical parameters; and it improved sleep quality, strengthened
muscles, and lowered lipids in healthy subjects. These positive results support
the use of ashwagandha to potentially aid in promoting strength and general
health. Future directions for ashwagandha clinical research include further
evidence of quality-of-life benefits for perimenopausal women, and
ashwagandha's potential efficacy in the treatment of sarcopenia.
—Amy
C. Keller, PhD
References
1Chandrasekhar K,
Kapoor J, Anishetty S. A prospective, randomized double-blind,
placebo-controlled study of safety and efficacy of a high-concentration
full-spectrum extract of ashwagandha root in reducing stress and anxiety in
adults. Indian J Psychol Med.
2012;34(3):255-262.
2Ahmad MK, Mahdi AA, Shukla KK, et al. Withania somnifera improves semen
quality by regulating reproductive hormone levels and oxidative stress in seminal
plasma of infertile males. Fertil Steril. 2010;94(3):989-996.
3Mikolai J, Erlandsen A,
Murison A, et al. In vivo effects of ashwagandha (Withania somnifera) extract on the activation of lymphocytes. J
Altern Complement Med. 2009;15(4):423-430.
4Sandhu JS, Shah B,
Shenoy S, Chauhan S, Lavekar GS, Padhi MM. Effects of Withania somnifera (ashwagandha) and Terminalia arjuna (arjuna) on physical performance and
cardiorespiratory endurance in healthy young adults. Int J Ayurveda Res.
2010;1(3):144-149.
5Pandey S. Changes in Body
Composition: Metabolic Syndrome and Sarcopenia in Menopause. Proceedings of
ICMR Symposium. Mumbai, India: Kasturba Health Society; 2008:112-132.
6Oliff HS. Ayurvedic
herbs tested for adaptogenic activity. HerbClip. June 30, 2000 (No. 011005-179).
Austin, TX: American Botanical Council. Review of Adaptogenic properties of six
Rasayana herbs used in Ayurvedic medicine by Rege NN, Thatte UM, Dahanukar SA. Phytother
Res. June 1999;13(4):275-291.
|