Lemon grass induces childbirth

Can extracts of lemongrass (Cymbopogon citratus) and cocoa (Theobroma cacao) be effectively used to induce labour during childbirth?

A recent study published in Nigerian Journal of Basic and Applied Sciences concluded: “This study has shown that T. cacao and C. citratus stimulate uterine activity and may therefore be useful in the management of uterine contractility disorders.”

Induction of labour refers to techniques for stimulating uterine contractions to accomplish delivery prior to the spontaneous onset of such contractions.

Conventionally, oxytocin is used for induction of labour in women with an unscarred uterus. Oxytocin is a peptide hormone and neuropeptide. It is normally produced in the hypothalamus and released by the posterior pituitary. It plays a role in social bonding, sexual reproduction, childbirth, and the period after childbirth.

However, oxytocin like most other conventional medicines has its adverse side effects and limitations.

Consequently, there is a need to develop new drugs from natural products for the safe and effective management of female reproductive disorders and researchers have investigated two commonly consumed natural products on uterine function.

The study is titled “Ex-Vivo Uterine Activity of Theobroma Cacao (Malvaceae) Aqueous Seed Extract and Cymbopogon Citratus (Poaceae) Aqueous Leaf Extract – A Preliminary Investigation.”

Commonly called lemongrass, Cymbopogon citratus belongs to the plant family Graminae. To the French it is citronelle, citronella in Portuguese. In Nigeria, the Edos call it eti, Efik, ikon eti, Hausa, tsauri, Ibibio, myoyaka makara, Igbo (Owerri), achara ehi and Yoruba, kooko oba.

Until now, lemon grass is used in different parts of the world in the treatment of digestive disorders, fevers, menstrual disorder, rheumatism and other joint pains. The essential oil of the plant is used for the treatment of skin diseases.

Theobroma cacao, also called the cacao tree and the cocoa tree, is a small evergreen tree in the family Malvaceae, native to the deep tropical regions of Mesoamerica. Its seeds, cocoa beans, are used to make chocolate liquor, cocoa solids, cocoa butter and chocolate.

The ex-vivo uterine activity of Theobroma cacao (cocoa) aqueous seed extract and Cymbopogon citratus (lemon grass) aqueous leaf extract was investigated on non-pregnant mouse uteri. The effect of T. cacao (0.1 mg/mL) and C. citratus (0.1 mg/mL) on spontaneous uterine contractility and in the presence of oxytocin (11.54 nM) was examined.

This study showed that T. cacao elicited a significant increase in the amplitude of spontaneous uterine contractions with no significant change in the frequency, which was similarly observed with C. citratus leaf extract. An increase in amplitude and frequency of oxytocin-induced uterine contractions was observed in the presence of T. cacao while in the presence of C. citratus there was a significant reduction in amplitude and a non-significant reduction in the frequency of oxytocin-induced uterine contractions.

The researchers concluded: “The uterotonic effect of both extracts in the absence of agonists, as observed from this study maybe as a result of constituents with agonistic activity on intracellular calcium. This study has shown that T. cacao and C. citratus have stimulated uterine activity and may, therefore, be useful in the management of uterine contractility disorders.”

Also, a study published in the journal bioRxiv evaluates the potential of essential oil from Cymbopogon citratus (CEO) as an anti-inflammatory and antioxidant agent.

According to the study titled “In silico and In vitro evaluation of the anti-inflammatory and antioxidant potential of Cymbopogon citratus from North-western Himalayas”, CEO showed significant DPPH radical scavenging activity, as compared to Ascorbic acid (vitamin C). CEO also exhibited significant in-vitro anti-inflammatory activity as compared to diclofenac sodium.

Diclofenac sodium (Voltaren) is used to relieve pain, swelling (inflammation), and joint stiffness caused by arthritis.

Chemical constituents of the oil were determined using Gas Chromatography/Mass Spectroscopy, showed that 8-methyl-3,7-Nonadien-2-one (E), α-Pinene, limonene, citral, limonene oxide and Epoxy-α-terpenyl acetate were the major constituents.

According to the study, the in silico molecular docking study showed phytocompounds of CEO (Caryophyllene oxide and β-caryophyllene) have considerable binding potential with 1HD2 and 5IKQ receptors. PASS prediction of these phytocompounds also confirmed strong anti-inflammatory activity of C. citratus. The ADMET analysis also showed that these phyto-compounds are safer to replace the synthetic drugs with side effects. “This work establishes the anti-inflammatory potential of CEO as an alternative to existing therapeutic approach to the treatment of inflammation and also a natural source of antioxidant compounds,” it noted.

The researchers concluded: “C. citratus is one of the important herbs, which play an important role in human health due to the presence of phytochemicals which are responsible for its biological activity. However, the quantification of these phytochemicals in C. citratus is affected by geographical and climatic conditions. In the current investigation, CEO was examined for its chemical composition, in vitro antioxidant and anti-inflammatory activity, to provide a justification for its health benefits. CEO exhibit good DPPH radical scavenging activity, while FRAP and ABTS activity of CEO was very low which may be due to the combined effect of several phytocompounds.

“However, CEO showed significant anti-inflammatory activity. In silico prediction and molecular docking studies showed that Caryophyllene oxide and β-Caryophyllene contributed to antioxidant and anti-inflammatory activity of CEO.

However, except α-Pinene (hepatotoxic), all the phytocompounds were found to qualify ADME/T condition and are less toxic in nature.

“In a nutshell, the present study opens new avenues for the plant C. citratus to be used as safe and less toxic alternatives to synthetic drugs used in complications arising due to oxidative stress and inflammation.”

Researchers have also examined the cytotoxicity and antiviral activity evaluation of Cymbopogon spp hydroethanolic extracts.

The study was published in Brazilian Journal of Pharmaceutical Sciences.

Cymbopogon citratus and C. nardus are noteworthy among the several existing plant species displaying medicinal properties, due to the potential pharmacological activity of these species, including antiviral, antibacterial, antifungal and anti-trypanosomal activities.

The objective of this study was to carry out in vitro toxicity tests of plant extracts from both species and analyze potential antiviral activity against Human mastadenovirus serotype 5 (HAdV-5). Two cell lines (A549 and VERO) were used and mitochondrial and lysosomal viability was determined by the MTT and neutral red assay, respectively, after two exposure times (24 hours and six days).

The aim of these assays was to counteract the behavior of the extracts against the different cell lines and determine their non-toxic concentration range, in order to evaluate possible antiviral activity against HAdV-5. Plaque reduction and inhibition index of viral titer assays were performed using the maximum non-cytotoxic concentrations (MNCC) of each extract.

“The results indicate MNCC at 625 μg/mL for all extracts, except for Cymbopogon nardus obtained with 80% ethanol (CN80), which showed toxicity at concentrations higher than 312.5 μg/mL. CN80 was the only extract that displayed potential activity against HAdV-5, at a concentration of 75 μg/mL, becoming a candidate for extract fraction purification and/or the isolation of substances related to the observed antiviral activity.”

The Cymbopogon genus is widely distributed worldwide and applied in popular medicine for different therapeutic purposes. Biological activities are closely related to their constituents, such as phenolic acids, flavonoids and alkaloids, among other secondary metabolites. In different countries, the popular use of species belonging to this genus indicates applicability as a tranquilizer, antiseptic, antipyretic, anti-inflammatory and analgesic compound and insect repellent, among others.

Cymbopogon citratus (CC), a species are commonly known as “lemongrass”, has been used in the pharma­ceutical, food, perfumery and cosmetic industries for various purposes, while Cymbopogon nardus (CN), known as “citronella grass”, has been used as an insect repellent due to its intense aroma. Several reports in the scientific literature of antibacterial, antifungal and anti-trypanosomal activities are available.

Furthermore, these species have also been evaluated concerning possible antiviral activity. Some studies have demonstrated ethanolic extract CN activity against herpes simplex virus serotype 1 (HSV-1), as well as against measles using hexane-extracted fractions. In addition, the antiviral action of CC has been reported for its methanolic extract against dengue virus serotype 1, and for its essential oil against HSV-1, hepatitis A virus and murine norovirus.

Nigerian researchers have also demonstrated the efficacy of lemon grass and some other plant extracts as storage protectants.

The study published in the Journal of Biotechnology Biomaterials is titled “Efficacy of Some Plant Extracts as Storage Protectants against Callosobruchus maculatus.”

The researchers include Mojisola Esther Ojebode, Charles Openiyi Olaiya and Kayode Olayele Karigidi of the Nutritional and Industrial Biochemistry Research Laboratories, University of Ibadan, Oyo State; Adegoke Emmanuel Adegbite of the Department of Biological Sciences, Ondo State University of Science and Technology, Okitipupa, Ondo State; and Tosin Oluwaseun Ale of the Pharmaceutical Chemistry Research Laboratories, University of Ibadan.

The research was aimed at contributing to the collation and organisation of baseline data on natural insect repelling and insecticidal agents. It also aimed at discovering crop protection agents that would preferentially get rid of pests. The need to develop pest control measures, as an alternative to chemicals is a priority for scientists worldwide. Therefore, it is critical to find a cost effective and non-toxic method to prevent pest attack on the field or stored crops.

The researchers noted: “In this study, Cymbopogon citratus (lemon grass), Citrus sinensis (orange peel) and Azadirachta indica (neem) were used to investigate and evaluate the potency of the fixed and essential oils of these plants as pest control agent for the main storage insect pest of cowpea- Callosobruchus maculatus. All extracts were toxic to adult C. maculatus and prevented egg hatching.

“However, Citrus sinensis showed the highest weevil mortality on the first day of exposure, followed by Azadirachta indica and the least toxic was Cymbopogon citratus in the fixed oil category of extracts while in the essential oil category, Cymbopogon citratus showed 100 per cent adult weevil mortality within one hour of exposure and Citrus sinensis was able to achieve 100 per cent weevil mortality at the third hour of exposure. The Gas Chromatography/Mass Spectrometry (GC/MS) analysis of the essential oils of Cymbopogon citratus and Citrus sinensis was used to identify possible components of the oils comparing with existing data. This led to the development of technique adoptable for small holder farmers and cowpea traders.”

Also, another study published in the journal Clinical Phytoscience investigated the anti-diabetic action of lemongrass tea (LGT) in a type 2 diabetes (T2D) model of rats.

The fructose-streptozotocin (STZ) animal model for T2D was used and the LGT was prepared by boiling for 10 min in water, allowed to cool and administered at 0.25 or 0.5 per cent (ad libitum), for four weeks to the T2D rats.

The LGT showed higher phytochemical contents compared to the cold-water extract. The diabetic untreated animals exhibited significantly higher serum glucose and lipids, insulin resistance (HOMA-IR) index with significantly lower levels of serum insulin, β-cell function (HOMA-β) and liver glycogen compared to the normal animals. Oral supplemented of LGT for four weeks improved these changes comparable to the metformin treated group.

The researchers concluded: “The data suggests that LGT intake had an excellent anti-diabetic effect in a T2D model of rats attributed to the higher content of the ingredients.”

Another study has demonstrated the cellular antioxidant activity of lemon grass against liver cancer cells The results obtained from the study indicate that microemulsions are very good systems for applications of lemon grass in functional food and pharmaceutical industries.

The study is “Enhanced Antioxidant and Antiproliferative Activities of Cymbopogon citratus (DC.) Stapf Essential Oils in Microemulsion.”

The study was published in the journal ACS Sustainable Chemical Engineering.

Cymbopogon citratus essential oils (C.EO) have important applications in the food and pharmaceutical industries. However, the studies on microemulsions of C.EO (M-EO) are very limited though M-EO from other plants has been extensively studied. In this study, C.EO were first extracted by hydrodistillation and characterized by gas chromatography–mass spectrometry analysis with the identification of citronellal (35.7 per cent), citronellol (12.5 per cent), and geraniol (16.6 per cent) being the major oil compounds.

Furthermore, M-EO were prepared using Tween 80 as a surfactant and ethanol as a co-surfactant, and the pseudo-ternary phase diagrams were depicted at different surfactant/cosurfactant (Km) and surfactant + cosurfactant/essential oil (Smix) ratios. The M-EO structure changes were investigated and elaborated through the determination of electrical conductivity and viscosity of the system prepared at a Km of 2:1 and a Smix of 8:2. M-EO was relatively stable after 90 days at an ambient temperature of 25 °C. Extracellular antioxidant activities of M-EO were improved by approximately 47 per cent assessed by oxygen radical absorbance capacity assay and by 184 per cent by peroxyl radical scavenging capacity assay compared to the direct use of C.EO.

The cellular antioxidant activity of M-EO against liver cancer HepG2 cells was 151.1 ± 15.5 μmol quercetin equivalent/mg essential oils compared to negligible activity with C.EO. The EC50 of the antiproliferative activity of M-EO against HepG2 cells was 26.75 ± 2.91 μg essential oils/g, much lower than that (174.22 ± 8.20 μg essential oils/g) of C.EO. In addition, M-EO had little cytotoxicity against human normal cells, L02. The results obtained from this study indicate that microemulsions are very good systems for applications of C.EO in functional food and pharmaceutical industries.

Another study published in the journal Access Microbiology investigated the antiviral activity of leaf extract of lemon grass on viral diseases.

This study determined the in-ovo antiviral effect of crude Methanolic leaf extract of Cymbopogon citratus on Newcastle disease virus.

In ovo is Latin for in the egg. In medical usage, it refers to the growth of live virus in chicken egg embryos for vaccine development for human use, as well as an effective method for vaccination of poultry against various Avian influenza and coronaviruses.

Cold extraction was carried out using analytical grade methanol. Phytochemical screening of the crude extract was carried out using standard procedures. Antiviral assay was carried out in nine-day old specific pathogen free embryonated hens’ eggs in three designs made of five eggs per group (Virus with extract, the virus only and un-inoculated groups) with concentrations ranging from 12.5 to 100 mg ml−1. Egg toxicity of the extract was determined for concentrations of 12.5, 25, 50, 100, 200, 300 and 400 mg ml−1. Inoculated eggs were incubated at 37 °C and observed daily for 96 h for embryo survival and mortality. Spot haemagglutination was carried out on bacteria-free allantoic fluid from the embryonated eggs to detect the presence of the virus.

Phytochemical assay revealed the presence of saponins, flavonoids, steroids, terpenes, phlebotannins and terpenoids. Mild toxicity was observed at concentrations of 100 mg ml−1 and above. There was no haemagglutination of fluid from the eggs inoculated with a combination of Virus and extract at concentrations of 50 and 100 mg ml−1.

The current findings demonstrated that leaf extract of Cymbopogon citratus has potential medicinal value as well as antiviral activity against Newcastle disease virus in-vivo (inside a living organism). The specific mechanism of action remains to be studied to further elucidate on its potential as a therapeutic product for the treatment of Newcastle Disease.