Clinical Studies

Clinical Studies

The anti-mutagenic effect of Cymbopogon Citratus: The consequences of technological progress and industrial revolution are the main causes of invasion by a large number of chemicals of different classes to the human body through air, food and water. It is widely accepted that most, if not all cancers, may be due to various environmental and dietary mutagens which can cause deleterious somatic and heritable changes without showing any immediate toxic effects. Mutagens are not only involved in genotoxicity and carcinogenesis but also involved in the inception and pathogenesis of several chronic degenerative diseases including hepatic disorders, neurodegenerative disorders, cardiovascular disorders, diabetes, arthritis, chronic inflammation and ageing. One of the best ways to minimize the detrimental effects of mutagens is by the use of natural antimutagens. Many a times these effects occur not only due to the presence of genotoxic agents but also due to lack of antimutagenic/ anticarcinogenic agents in our diet. The best way to minimize these effects is identifying the antimutagens and anticarcinogens in our diet and increasing their use.
Citral is a major constituent of Cymbopogon citratus. The anti-clastogenic effect of citral (20 mg/kg) was tested against the known mutagens cyclophoshamide, mitomycin-C and nickel metal (NiCl2) in Swiss Albino mice. Micronucleus (MN) frequency was evaluated in both bone marrow and peripheral blood erythrocytes. The sampling was done after 24 h, 48 h and 72 h of clastogen treatment. Results show that citral had significantly (p < 0.01) decreased the frequency of MN induced by the three clastogens in bone marrow and peripheral blood erythrocytes. A clastogen is a material that can cause breaks in chromosomes, leading to sections of the chromosome being deleted, added, or rearranged. This is a form of mutagenesis, and can lead to carcinogenesis, as cells that are not killed by the clastogenic effect may become cancerous. In the present investigation, citral had produced
anti-clastogenic effect evident from the decreased micronuclei frequency observed in polychromatic and normochromatic erythrocytes. Citral prevented the nuclear damage induced by cyclophosphamide, mitomycin-c and nickel chloride in both bone and peripheral blood micronucleus tests. So, Cymbopogon Citratus is found to possess natural anti-mutagenic quality.

Cymbopogon Citratus and its major constituent isointermedeol induce apoptosis by increased expression of mitochondrial cytochrome c and apical death receptors in human leukaemia HL-60 cells: Cymbopogon Citratus (CC) and its major chemical constituent sesquiterpene isointermedeol (ISO) were investigated for their ability to induce apoptosis in human leukaemia HL-60 cells because dysregulation of apoptosis is the hallmark of cancer cells. CC and ISO inhibited cell proliferation with 48h IC50 of approximately 30 and 20mug/ml, respectively. Both induced concentration dependent strong and early apoptosis as measured by various end-points, e.g. annexinV binding, DNA laddering, apoptotic bodies formation and an increase in hypo diploid sub-G0 DNA content during the early 6h period of study. This could be because of early surge in ROS formation with concurrent loss of mitochondrial membrane potential observed. Both CC and ISO activated apical death receptors TNFR1, DR4 and caspase-8 activity. Simultaneously, both increased the expression of mitochondrial cytochrome c protein with its concomitant release to cytosol leading to caspase-9 activation, suggesting thereby the involvement of both the intrinsic and extrinsic pathways of apoptosis. Further, Bax translocation, and decrease in nuclear NF-kappa B expression predict multi-target effects of the essential oil and ISO while both appeared to follow similar signalling apoptosis pathways. The easy and abundant availability of the oil combined with its suggested mechanism of cytotoxicity make CC highly useful in the development of anti-cancer therapeutics.

Hypoglycemic and hypolipidemic effects of Cymbopogon citratus Tea: The present study was designed to investigate the hypoglycemic and hypolipidemic effects of the single, daily oral dosing of 125-500 mg/kg of Cymbopogon citratus in normal, male Wistar rats for 42 days. The average weights of rats per group were taken at 2 weeks interval for 42 days. On day 43, blood samples from the rats were collected for fasting plasma glucose (FPG), total cholesterol, triglycerides, low-density lipoproteins (LDL-c), very low-density lipoprotein (VLDL-c) and high-density lipoprotein (HDL-c) assays through cardiac puncture under halothane anaesthesia. Acute oral dose toxicity study of CC was also conducted using limit dose test of the Up and Down Procedure statistical program (AOT425StatPgm, Version 1.0) at a dose of 5000 mg/kg body weight/oral route. Our results showed CC to lower FPG and lipid parameters dose dependently (p<0.05) while raising the plasma HDL-c level (p<0.05) in same dose-related fashion but with no effect on plasma triglycerides level (p>0.05). Results of acute oral toxicity showed CC to be of low toxicity and as such could be considered relatively safe on acute exposure. Thus, confirming its folkloric use and safety in suspected Type 2 diabetic patients.

Cymbopogon Citratus for hypertension: A 10% or 20% decoction of leaves was tested using arterial pressure in rats, urine production and carrageenan induced edema in rats. The decoction showed some dose-related hypotensive effects given intravenously and some weak diuretic and anti-inflammatory effect when given orally. This study suggests that CC could be good for hypertension.
Cymbopogon Citratus helps reduce cholesterol: This research investigated the toxicity and genotoxicity of Cymbopogon Citratus oil in male Swiss mice. The single LD50 based on a 24 h acute oral toxicity study was found to be around 3500 mg/kg. In a repeated-dose 21-day oral toxicity study, mice were randomly assigned to two control groups, saline- or Tween 80 0.01%-treated groups, or one of the three experimental groups receiving CC oil (1, 10 or 100 mg/kg). No significant changes in gross pathology, body weight, absolute or relative organ weights, histology (brain, heart, kidneys, liver, lungs, stomach, spleen and urinary bladder), urinalysis or clinical biochemistry were observed in CC oil - treated mice relative to the control groups. Additionally, blood cholesterol was reduced after CC oil - treatment at the highest dose tested. Similarly, data from the comet assay in peripheral blood cells showed no genotoxic effect from the CC oil. In conclusion, our findings verified the safety of Cymbopogon Citratus intake at the doses used in folk medicine and indicated the beneficial effect of reducing the blood cholesterol level.

Anti-inflammatory: Cymbopogon Citratus tea may offer potent anti-inflammatory benefits. Rich in polyphenol anti-oxidants, CC leaf extract inhibited nuclear factor kappa-B – a gene that promotes the body’s stress response – and also inhibited a pro-inflammatory enzyme, in the cell culture study thus concluded that CC tea may have promise for the treatment of inflammatory conditions.
Antibacterial activity and mechanical properties of partially hydrolyzed sago starch-alginate edible film containing Cymbopogon Citratus oil: Edible films were prepared from a mixture of partially hydrolyzed sago starch and alginate (SA). CC oil (0.1% to 0.4%, v/w) and glycerol (0% and 20%, w/w) were incorporated in the films to act as natural antimicrobial agent and plasticizer, respectively. The films were characterized for antimicrobial activity, water vapor permeability (WVP), tensile strength (TS), percent elongation at break (%E), and water solubility (WS). Fourier transform infrared (FTIR) spectroscopy was conducted to determine functional group interactions between the matrix and CC oil. The zone of inhibition was increased significantly
(P < 0.05) by addition of CC oil at all levels in the presence and the absence of glycerol. This indicates that the film containing CC oil was effective against Escherichia coli O157:H7 at all levels.

In vivo anti-malarial activity of Cymbopogon citratus: The essential oil obtained by hydro-distillation from fresh leaves of Cymbopogon Citratus was analyzed by GC and GC/MS. The main constituents of the oil of Cymbopogon citratus contained geranial (32.8 %), neral (29.0 %), myrcene (16.2 %) and beta-pinene (10.5 %). The effects of the oil on the growth of Plasmodium berghei were investigated. The oil showed significant anti-malarial activities in the four-day suppressive in vivo test in mice. At concentrations of 200, 300 and 500 mg/kg of mouse per day, the essential oil of CC produced the highest activity with the respective percentages of suppression of parasitaemia: 62.1 %, 81.7 % and 86.6.
Anti-proliferative effect of the essential oil of Cymbopogon citratus on intracellular amastigotes, bloodstream trypomastigotes and culture epimastigotes of Trypanosoma cruzi (Protozoa: Kinetoplastida): This study analyses the anti-proliferative effect of CC oil and its main constituent (citral) on all 3 evolutive forms of Trypanosoma cruzi. The IC50/24 h (concentration that reduced the parasite population by 50%) of the oil and of citral upon T. cruzi was determined by cell counting in a Neubauer chamber, while morphological alterations were visualized by scanning and transmission electron microscopy. Treatment with the essential oil resulted in epimastigote growth inhibition with IC50=126.5 microg/ml, while the IC50 for trypomastigote lysis was 15.5 microg/ml. The IC50/48 h for the Association Index (% macrophage infection x number of amastigotes per cell) was 5.1 microg/ml, with a strong inhibition of intracellular amastigote proliferation. Ultrastructural analysis demonstrated cytoplasmic and nuclear extraction, while the plasma membrane remained morphologically preserved. Our data show that CC oil is effective against T. cruzi trypomastigotes and amastigotes, and that its main component, citral, is responsible for the trypanocidal activity. These results indicate that CC oil can be a promising anti-parasitic agent, opening perspectives to the discovery of more effective drugs of vegetal origin for treatment of parasitic diseases.

Neurobehavioral effect: Tea obtained from leaves of Cymbopogon citratus is used for its anxiolytic, hypnotic and anticonvulsant properties in Brazilian folk medicine. CC oil from fresh leaves was obtained by hydro-distillation and orally administered to Swiss male mice 30min before experimental procedures. CC oil at 0.5 or 1.0g/kg was evaluated for sedative/hypnotic activity through pentobarbital sleeping time, anxiolytic activity by elevated plus maze and light/dark box procedures and anticonvulsant activity through seizures induced by pentylenetetrazole and maximal electroshock. CC oil was effective in increasing the sleeping time, the percentage of entries and time spent in the open arms of the elevated plus maze as well as the time spent in the light compartment of light/dark box. In addition, CC oil delayed clonic seizures induced by pentylenetetrazole and blocked tonic extensions induced by maximal electroshock, indicating the elevation of the seizure threshold and/or blockage of seizures spread. These effects were observed in the absence of motor impairment evaluated on the rotarod and open field test. Our results are in accord with the ethnopharmacological use of Cymbopogon Citratus, and after complementary toxicological studies it can support investigations assessing their use as anxiolytic, sedative or anticonvulsive agent.
Anti-Candida albicans activity of Cymbopogon Citratus oil and its component, citral: The effects of CC oil popularly used as antifungal treatments in aromatherapy, on growth of Candida albicans were investigated. Mycelial growth of C. albicans, which is known to give the fungus the capacity to invade mucosal tissues, was inhibited in the medium containing 100 micro g/ml of CC oil. Not only CC oil but also citral, a major component of CC oil (76%), in the range of 25 and 200 micro g/ml inhibited the mycelial growth but allowed yeast-form growth. More than 200 micro g/ml of citral clearly inhibited both mycelial and yeast-form growth of C. albicans. These results provide experimental evidence suggesting the potential value of CC oil for the treatment of oral or vaginal candidiasis.
Effects of Cymbopogon Citratus on human body: Cymbopogon Citratus can help significantly in detoxifying the organs in the digestive system like pancreas, kidney, bladder and liver by increasing the quantity and frequency of urination. This is made possible because Cymbopogon Citratus helps in cutting down cholesterol, uric acid and toxins in the system. At the same time, it helps in stimulating digestion and blood circulation. Consequently, gastroenteritis and indigestion can be avoided. It also strengthens and gives tone and vitality to the body, lowers body heat and prevents or cures spasms. Its use is recommended in cases of vomiting, diarrhoea, headache, dysmenorrhoea, chronic rheumatism, and sprains. It is also very useful for insomnia or sleeplessness.
Effects of daily two month administration in male and female rats and in offspring exposed "in utero": An infusion prepared from leaves of Cymbopogon citratus administered orally to adult rats for 2 months, in doses up to 20 times larger than the estimated corresponding human dosage, did not induce any effect which could be taken as evidence of toxicity. An absence of effects was also noted in male and female rats and in their offspring when the infusion was administered prior to mating or during pregnancy. These data strongly suggest that Cymbopogon Citratus has no toxic properties and is safe for human consumption.