Medicinal Studies on the Phytochemical Constituents of Justicia carnea by GC-MS Analysis
I. E. Otuokere1, *, A. J. Amaku1, K. K. Igwe2, G. C. Chinedum1
1Department of Chemistry, Michael Okpara University of Agriculture, Umudike, Abia, Nigeria
2Department of Vet. Biochem and Pharm, Michael Okpara University of Agriculture, Umudike, Abia, Nigeria
The phytochemical constituents of ethanol extracts of Justicia carnea leaf was analyzed using gas chromatography-mass spectrometry method. The ethanol leaf extracts of Justicia carnea was prepared by soxhlet extraction method and concentrated at 40°C using hot air oven. The concentrated ethanol extracts was subjected to phytochemical analysis using GC-MS. GC-MS analysis showed the presence of six phytocompounds. The phytocompounds are isonicotinic acid N-oxide (2.58%), phosphinodithioic acid, diphenyl- (1.93%), hexadecanoic acid(10.50%), 2,2,3,3,4,4,5,5,5-nonafluoro-pentanoic acid methyl ester (73.19%), 9,12,15-octadecatrien-1-ol (9.33%) and 7H-purine, 7-benzyl-2,6-dichloro- (2.48%). The result of the GC-MS analysis showed that the ethanol extract of Justicia carnea contains many pharmacologically important bioactive compounds. Traditionally, Justicia species are used in the treatment of inflammation, gastrointestinal diseases, respiratory tract infection, rheumatism and arthritis. There is need for isolation of these phytocompounds for the control of diseases.
Justicia carnea, Gas Chromatography, Mass Spectrometry, Extracts, Phytocompounds
Received: June 18, 2016
Accepted: June 30, 2016
Published online: July 16, 2016
@ 2016 The Authors. Published by American Institute of Science. This Open Access article is under the CC BY license. http://creativecommons.org/licenses/by/4.0/
Justicia carneais a floweing plant that belongs to Acanthaceae family . It is commonly called Brazilian plume flower, Brazilian-plume, flamingo flower and jacobinia. This flowering plant is a native of Atlantic Forest eco regions of eastern Brazil. It is also found in Nigeria. It is a decorative plant that is cultivated in warm temperate and subtropical climates. The genus Justicia was named after a Scottish gardener James Justice, in the 18th century . The plant can be wintered indoors and lifted into pots. The shades of the plant during summer ranges from white, pink, red, rose, magenta, orange, purple to coral/apricot . The flowers are tube like in shape and curves outward from the spike. The smaller varieties may grow about 2 feet high while others may grow to 6 feet tall by 6 feet wide . The pictorial view of Justicia carnea is shown in Figure 1.
Traditionally, Justicia species are used in the treatment of inflammation, gastrointestinal diseases, respiratory tract infection, rheumatism and arthritis . Because of their effect on the central nervous system, they are utilized as hallucinogens, sedatives and treatments for epilepsy, depressors, somniferous agents and mental disorders . Some species of Justicia are used in the treatment of diabetes, HIV and cancer . The root, flower, fruit and leaf of J. adhatoda have been used in the treatment of bronchitis, cold, whooping cough, asthma, helminthic, diarrhoea, dysentery, and glandular tumor, expectorant, tuberculosis, abortificient, microbial, tussive and cancer [4, 5]. In Benin, decoction of J. anselliana leaves and root are used in the treatment of heart diseases and testicles inflammation . The constituents of J. spicigera are potassium, calcium acetate, oxalate, sulfate, sodium chloride, simple carbohydrates, mucilages, pectins, glycosides, pigments, resin and essential oils. Flavonoids have been isolated from the leaves . Sepúlveda-Jiménez and co-workers reported the total phenols, flavonoids and antioxidant activity of J. Spicigera . Euler and Adam  characterization based on NMR, GC-MS and UV analysis of J. spicigera extracts suggested the presence of trirhamnosides of kaempferol and kaempferitrin. Domínguezet  identified the presence of β - sitosterol, 3-O - glucoside of β - sitosterol and cryptoxanthin in hexane-isopropyl ether–methanol extracts of J. spicigera.
Presently, the interest in studying and understanding the constituents of plants with healing properties have increased. The interest is focused in obtaining biologically active molecules and using them for curing various diseases. In continuation with the ongoing research on phytochemicals of Justicia species, we hereby present GC-MS analysis of ethanol extract of Justicia carnea.
2.1. Plant Materials
Fresh leaves of Justicia carnea was harvested at Ohafia town in Abia State, Nigeria. The plant leaves were identified at the Taxonomy section of College of Natural Resources and Environmental Management, Michael Okpara University of Agriculture, Umudike, Nigeria.
2.2. Preparation of Plant Extract
Justicia carnea was dried in a shady place for 10 days and pulverized to powder using electrical grinder. Extraction was performed using soxhlet method . Thirty five grams (35 g) of powdered sample was introduced into the extraction chamber of the soxhlet extractor using ethanol as solvent at a temperature of 70°C for 48 hrs. At the end of the extraction, the extract was concentrated in an oven at 35°C. Dried extract was sent for GCMS analysis.
2.3. GCMS Analysis of Justicia carnea
The characterization of the Phytochemicals in Justicia carnea was done using GC-MS QP2010 Plus (Shimadzu, Japan). The identification of the phytochemicals in the sample was carried out using aQP2010 gas chromatography with Thermal Desorption System, TD 20 coupled with Mass Spectroscopy(Shimadzu). The ionization voltage was 70eV. gas Chromatography was conducted in the temperature programming mode with a Restek column (0.25 mm, 60m, XTI-5). The initial column temperature was 80°C for 1min, and then increased linearly at 70°C min-1 to 220°C, held for 3 min followed by linear increased temperature10°C min-1 to 290°C for 10 min. The temperature of the injection port was 290°C and the GC-MS interface was maintained at 290°C. The sample was introduced via an all-glass injector working in the split mode, with helium carrier gas low rate of 1.2 ml min-1. The identification of compounds was accomplished by comparison of retention time and fragmentation pattern, as well as with mass spectra of the GC-MS.
2.4. Identification of Phytocompoments in Justicia carnea
The retention indices, peak area percentage and mass spectra fragmentation pattern of GC-MS chromatogram of ethanol extract of Justicia carnea was compared with the database of National Institute of Standards and Technology (NIST), NIST08.LIB , WILEY8.LIB  and with published literature. The name, molecular weight, formula, structure and bioactivities of the compounds were ascertained.
Gas chromatogram of the ethanol extract of Justicia carnea is presented in Figure 2.
The mass spectra data of Justicia carnea is show in Figure 3.
The GC shows six peaks. This implies that six compounds are present in the ethanol extract of Justicia carnea. The mass spectra (Figure 3) were used in the identification of the molecular or parent ions. The molecular ion peak appears as the highest mass number in the mass spectrum and corresponds to the molecular weight of the compound. This peak may sometimes be difficult to identify because it is usually of low intensity or may not appear at all. The names, retention time (RT), peak area percentage, molecular weight, molecular formula and bioactivities of the suggested compounds in the methanol extract of Justicia carnea are disscussed in Table 1. The structures are shown in Figures 4–9.
|S.No||Name of Compound||Retention time||Peak area %||Molecular weight||Molecular formula||Bioactivity|
|1||Isonicotinic acid N-oxide||14.96||2.58||139.10||C6H5NO3||Nitric-oxide-synthase-inhibitor, anaphylactic (antidote), arylamine-n-acetyltransferase-inhibitor, down regulation cytosol androgen .|
|2||Phosphinodithioic acid, diphenyl-||15.03||1.93||250.32||C12H11PS2||Acidifier, arachidonic-acid-inhibitor .|
|3||Hexadecanoic acid also known as Palmitic acid||16.55||10.50||256.42||C16H32O2||Acidifier, arachidonic-acid-inhibitor .|
|4||2,2,3,3,4,4,5,5,5-Nonafluoro-pentanoic acid methyl ester||18.67||73.19||278.07||C6H3F9O2||Acidifier, arachidonic acid-inhibitor .|
|5||9,12,15-Octadecatrien-1-ol||19.34||9.33||264.44||C18H32O||Oligosaccharide provider .|
|6||7H-Purine, 7-benzyl-2,6-dichloro-||20.50||2.48||279.12||C12H8Cl2N4||11β-HSD-inhibitor, 5-HT3-inhibitor, antidote (heavy metals) .|
Isonicotinic acid N-oxide (Figure 4) with retention time of 14.96 minutes and 2.58% peak area is anitric-oxide-synthase-inhibitor. It inhibition activity against nitric oxide is beneficial to man because nitric oxide is an air pollutant that causes cancer, inflammation and stroke. Researchers have shown that nitric oxide is a vascular relaxant [15-18] in the human body. Studies have shown that isonicotinic acid N-oxide is an anaphylactic antidote.
Anaphylaxis is a serious infection that might lead to death if not checked because its duration is within minutes to hours . It is an allergic reaction that is accompanied with low blood pressure, itching, swelling of the tongue, shortness of breath, vomiting, and light-headedness [21,23]. This allergic reaction is triggered by insect bites, medication, food or any foreign substance [20,22]. Justicia carnea ethanol extract might be a remedy to anaphylaxis because of presence of isonicotinic acid N-oxide (anaphylactic antidote).
ArylamineN-acetyltransferases are highly conserved enzymes  that are genetically polymorphic to certain types of cancers. Numerous publications have shown that some types of ArylamineN-acetyltransferases genotype have been associated with carcinogen exposure and cancer risk . Isonicotinic acid N-oxide helps down regulation of cytosol androgen . Prostate epithelial cells require androgen for growth . Androgen binds to androgen receptors, which further binds to androgen-responsive elements for the promotion of androgen-regulated genes such as prostate-specific antigen (PSA). The down regulation of cytosol androgen provides an important mechanism in prostatic cancer chemoprevention .
Phosphinodithioic aciddiphenyl- (Figure 5), Hexadecanoic acid (Figure 6) and 2,2,3,3,4,4,5,5,5-Nonafluoro-pentanoic acid methyl ester(Figure 7) have been reported to be acidifier and arachidonic acid inhibitor . Acidifiers are chemicals that reduce the pH of the body. They help in food digestion in patients suffering from achlorhydria. These patients are not able to secret HCl for food digestion. These compounds may be beneficial since they increase gastric acid when ingested. Arachidonic acid is present in the brain, muscles, and liver . Arachidonic acid is a fatty acid that is polyunsaturated in nature and responsible for the repair and growth of skeletal body tissue . Does not cause cancer but studies have proven that it might be a major cause of inflammation [30-33].
9,12,15-Octadecatrien-1-ol (Figure 8), one of the isolates of Justicia carnea with molecular weight 264.44 and peak area9.33% 9, is an oligosaccharide provider. It helps in cell division and cell binding. It also improves gastrointestinal health, energy levels and performance. Oligosaccharide provider simply means little sugar .
The primary activity of 11β-hydroxysteroiddehydrogenase (11β-HSD-Inhibitor) type 1 is to reduce cortisone to the active hormone cortisol. Too much of cortisol in the human body leads to obesity . 7H-Purine, 7-benzyl-2,6-dichloro- (Figure 9) has the tendency to reduce cortisone to cortisol. 5-HT3 receptor antagonists are widely used chemotherapy antiemetic drugs . They were first introduced in 1990 and have proven to be effective and safe against postoperative nausea and vomiting. Our report suggested that 7H-Purine, 7-benzyl-2,6-dichloro-, a constituent of Justicia carnea is an antagonists of5-hydroxyltryptamine (5-HT3) receptors. 7H-Purine, 7-benzyl-2,6-dichloro- also acts as an antidote for heavy metal. This compound can chelate heavy metals because it contains lone pairs of electrons that can act as electron donors. Heavy metals have empty d-orbitals onto which electrons may be promoted.
GC-MS is an effective method in the characterization of plant secondary metabolites. Several authors have used this method in the identification of bioactive compounds [38–43]. Hence, GC-MS analysis is a pioneer step in understanding the constituents of plants.
In this study, six compounds were identified in the ethanol extract of Justicia carnea. These identified phytocompounds may be helpful for drug development. This study may also enhance the traditional usage of Justicia carneadue to its bioactive compounds identified by GC-MS analysis. These phytocompounds needs further pharmacological investigation in order to develop new drugs for the treatment of specific diseases. Thus, GC-MS analysis is the pioneer step in understanding the nature of active components in Justicia carnea.