Research Journal of Pharmacognosy
Volume:8 Issue: 3, Summer 2021

Coronavirus disease 2019 (COVID-19) is a highly infectious disease caused by a new variant of coronavirus which has already spread in more than 150 countries and gained global attention. The absence of efficient and effective medicines towards this disease has indeed aggravated the situation [1]. Severe Acute Respiratory Syndrome-Coronavirus (SARS-CoV) was an extremely contagious virus that caused serious disease and death. This virus has been found to cause human respiratory, enteric, and neurological disorders. This is one of the seven known coronavirus strains, found to inflict human infection and the latest outbreak of coronavirus in 2019 was triggered by the strain called SARS-CoV-2. Other strains include HCoV-NL-63, HCoV-229E, HCoV-OC43, HCoV-HKu1, MERS-CoV, etc. [2,3]. Coronavirus 2019 has quickly spread to the international community originating from Wuhan city, Hubei in China [4]. The exponential growth of this new coronavirus strain has already imposed strict four-tier guidelines in UK. In September 2019, it was first observed in UK. In mid-December, this amounted to almost two-thirds of population in UK [5]. On 30th January 2020, it was first reported in India through a student from Wuhan [13]. The world health organization (WHO) declared corona virus outbreak as a global pandemic on 11th March 2020 [12]. Considering the structure, there are four key proteins included in the structural composition of coronaviruses. Those are Spike (S), Membrane (M), Envelope (E) and Nucleocapsid (N). Spike, a trimeric glycoprotein of CoV, establishes CoV variability and host tropism and also facilitates CoVs which bind to virus-cell membrane fusion and surface-specific receptor [6]. SARS-CoV-2 enters cells through this structural spike protein (S), which bind to the angiotensin converting enzyme-2 (ACE-2) receptor. Host cell receptors and endosomes are used by the spike proteins (S) to enter the cells after receptor binding. The transmembrane protease serine 2 (TMPRSS2), a host type 2 transmembrane serine protease, enables cell entry through the S-protein. The viral polyproteins which code for replicase transcriptase complex are synthesized once within the cell. SARS-CoV-2 synthesizes RNA through RNA dependent RNA polymerase enzyme. Structural proteins are generated, resulting in the formation and discharge of viral particles. The forthcoming drug treatments are included in these stages of the viral life cycle. Non-structural proteins like RNA dependent RNA polymerase, papain proteases, 3-chymotrypsin-like proteases which establish homologies with the other novel coronaviruses, are considered as promising medication targets. Additional drug targets include entry of virus and immune control [7]. At the time of sneezing and coughing, infection can transmit by enormous droplets through the symptomatic individuals. The infection may also occur in asymptomatic people before the symptoms start. In comparison to throat, studies indicate higher nasal cavity viral loads, with no viral load difference between asymptomatic and symptomatic individuals. The infection comes from the inhalation or contact with surfaces infected with such droplets, accompanied by the touch of the nose, eyes and mouth [4]. Natural products have been found to play significant role throughout the decades in prevention and treatment of several diseases. The essential oils and extracts derived from plants and animals are regarded as commendable source of biologically active molecules. A variety of natural products have already been reported as antiviral against enterovirus, hepatitis B, dengue, Influenza virus, coronavirus, and human immunodeficiency virus [8]. A research done by Wen et al. in 2007 examined that twenty-two terpenoids and lignoids could suppress SARS-CoV replication in African Green Monkey Kidney (Vero) E6 cells. The cytotoxicity of the metabolites against Vero E6 cells has been assessed and the inhibitory activity has been examined. The most active secondary metabolites have been reported as betulonic acid, savinin, ferruginol, 3ß,12-diacetoxyabieta-6, 8-11,13-tetraene and 7ß-hydroxydeoxycryptojaponol, respectively. These compounds were known as powerful effective inhibitors of viral replication at concentrations of 0.63, 1.13, 1.47, 1.39, 1.57 and 1.15 µM respectively [2]. Emodin, an anthraquinone from Rheum officinale Baill, and Reynoutria multiflora (Thunb.) Moldenkehas been used as anti-bacterial and anti-inflammatory agent. Ho et al. confirmed in 2007 that emodin inhibited the binding of S protein to ACE-2 and reduced infection of pseudo-typed S protein in cells of Vero E6. The dose-dependent interaction between S and ACE-2 was completely prevented by emodin with an IC50 of 200 μM, suggesting that it can be a therapeutic agent for SARS treatment [9]. Some of the popular natural immune boosters such as herbal medicines are useful in COVID-19 prevention. Herbal medicines include Glycyrrhiza glabra, Zingiber officinale, Echinacea spp., Nigella sativa, Hypericum perforatum, Allium sativum, Camellia sinensis. In addition, natural products play a significant role in the prevention of infection, especially in high-risk patients suffering from coronavirus infections [10]. Luo et al. stated that Atractylodis macrocephalae, Glycyrrhizae uralensis, Lonicerae japonica, Astragalus mongholicus, Saposhnikovia divaricata, Atractylodeslancea, Forsythia suspensa, Cyrtomium fortunei, Agastache rugosaetac were used in the prophylaxis of COVID-19 [11]. Inhibitory activity against SARS-CoV papain-like protease (PLpro) and SARS-CoV 3-chymotrypsin-like proteases (3CLpro) with IC50 values of 1.2 and 11.4 μM, respectively is reported from a chalcone named xanthoangelol E, which is isolated from the ethanolic leaf extract of Angelica keiskei [2]. The outbreak of this new strain of coronavirus has challenged medical, economic, and public health infrastructure of many countries. The outbreaks of these kinds of viruses and pathogens are very much probable to continue in future. Natural products have a pivotal role in the prophylaxis or prevention of COVID-19. But there is no such evidence in the literature that it can also prevent the mutant strain of coronavirus. Therefore, efforts should be implemented to devise measures and investigate the utilization of natural products more precisely which can prevent such outbreaks of viruses in the future.

Cirsium englerianum (Asteraceae) is an endemic medicinal plant to Ethiopia. It is used to treat skin infection, snake bite and cough. The aim of the present study was to evalute the bioactivity of root extracts of C. englerianum.

Phythochemical screening tests were employed by standard protocols to identifiy the phythochemicals. Column chromatographic separation was used to isolate the compounds and the spectroscopic techniques (IR, NMR  and ESMS) were used to elucidtae structures of  the  compounds. Disc diffusion technique was uesd to evalute antibacterial activity. In vitro antioxidant activity was assessed by 1, 1-diphenyl-2-picrylhydrazyl (DPPH), and phosphomolybdenun assays. The total flavonoids content was determined by aluminium chloride method.

Phytochemical screening tests revealed  presence of alkaloids, steroids, terpenoids, tannins, and flavonoids in the acetone root extract. Column chromatographic separation of chloroform/methanol (1:1) extract offered stigmasterol (1), and stigmasteryl stearate (2). The acetone extract was potentially effective against the tested bacterial strains (Bacillus cereus, Staphylococcus aureus, Escherichia coli and Salmonella typhi) at all concentrations (25, 50 and 100 mg/mL). In vitro antioxidant activity attributed that the acetone extract showed DPPH scavenging (IC50 =154.44±74 µg/mL)  and total antioxidant activity (8.24±0.9 mg of ascorbic acid equivalent per gram of dry extract). The total flavonoid content was observed in the range from 5.88 ±0.21 to 8.24±0.9  milligrams of catechin equivalents per gram of dry plant extract.

 Stigmasterol and stigmasteryl stearate were reported for the first time from this plant. The results proved  that  acetone extract exhibited potential antibacterial  and antioxidant activity which correlated with inhibition zone diameter, and free radical scavenging activity.

The mercury-induced liver pathogenesis is mainly mediated by oxidative stress. The aim of the current study was to evaluate the possible ameliorative effect of harmine, a natural compound, on liver toxicity induced by mercury chloride (HgCl2).

Forty-two male Balb/c mice were randomly divided into six groups (n = 7): Control, HgCl2 (0.5 mg/kg), harmine (20 mg/kg), and HgCl2 (0.5 mg/kg) + harmine (5, 10, or 20 mg/kg). The mice received treatments once per day for two weeks. After this period, the blood and tissue samples were collected for analyses.

HgCl2 caused a significant increase in levels of hepatic enzymes alanine aminotransferase, aspartate transaminase, and alkaline phosphatase; while harmine ameliorated these effects. Harmine in HgCl2-intoxicated mice, showed protective effects as evidenced by the increase in liver relative weight to body as well as the diameter of central vein in the co-treated group. Serum levels of malondialdehyde and nitric oxide increased in HgCl2, while they were declined in harmine co-treated groups compared to HgCl2 group. The serum level of superoxide dismutase and total antioxidant capacity improved following harmine treatment in the co-administrated group compared to HgCl2 group. Moreover, gene expression analysis demonstrated that harmine treatment improved the HgCl2-induced decreasing of Ho-1, Nrf2, Hqo1, and Trx1. The histopathological examination confirmed the protective effects of harmine.

Mercury can induce toxicity by elevation of oxidative stress in the liver and harmine attenuates hepatic injury induced by HgCl2, at least in part, through its antioxidant activities.

There are several documents about protective properties of saffron against stress conditions which refer to the effect of saffron on gene expression pattern of the treated samples.The aim of the present study was determination of the main regulated proteins by saffron extract.

Twenty differentially expressed proteins from a published research were investigated via network analysis and assessed to determine the crucial regulated individuals by Cetoscape software. The network was analyzed by network analyzer application of Cytoscape software, and the central nodes were identified.

Twenty queried proteins were included in a network with 9005 nodes and 11446 edges. Analysis of the network revealed that VCP, SOD1, GRP78 (HSPA5), GRP75 (HSPA9), PRDX1, PHB, COMT, and ATP5H are the central proteins which are regulated by saffron extract.

Based on the regulated proteins, regulation of mithoconderia and endoplasmic reticulum was identified as the main target of saffron in stress management.

Triterpene glycosides as the most bioactive components of sea cucumbers, have been considered for their various pharmacological properties especially anticancer and anti-metastasis activities. Due to the limited information on the biological properties of holothurin B as a marine triterpene glycoside, the present study aimed to examine its effect on angiogenesis and compare it with curcumin usinghuman umbilical vein endothelial cells (HUVECs). Holothurin B was isolated from Holothuria atra and identified by NMR and Mass spectroscopic data. Cell survival was estimated using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) technique and migration of cells was assessed by Transwell test. Angiogenesis was evaluatedin vitro by tube formation assay. Holothurin B reduced HUVECssurvival with IC50 value of 8.16 µg/mL. At the concentrations of 5 and 7.5 µg/mL, it significantly decreased the number of migrated cells, the average length and size of tubules, and mean number of junctions; it was more potent than curcumin. Holothurin B could be considered as a potent antiangiogenic constituent through suppressing endothelial cell proliferation, migration and tubulogenesis in vitro, suggesting its potential for further animal and clinical investigations.

Allergic asthma is a chronic inflammatory disease of the airways which has become prevalent globally. There are reports about the immunomodulatory and antioxidant effects of Pimpinella anisum L. seeds; so, in this study, we explored the suppressive effects of aqueous P. anisum L. seeds extract on ovalbumin-induced asthma in a mouse model.

The seeds were extracted with water and the extract was dried by freeze-drying method. Twenty-eight BALB/c male mice weighing 15–20 g were divided into four groups of seven animals. Ovalbumin was used to trigger allergic asthma in these animals. Negative and positive control mice received phosphate-buffered saline and ovalbumin, respectively. The remaining two groups were challenged with ovalbumin and then received budesonide and the seed extract, respectively. Thereafter, the eosinophils count and expression of IL-5, -13, and -33 were measured in bronchoalveolar lavage fluid of mice. Histopathological changes of the lung tissues were also analyzed.

Aqueous extract of P. anisum seeds hindered ovalbumin -stimulated asthmatic complications by declining eosinophils number and expression of IL-5, -13, and -33 in bronchoalveolar lavage fluid of mice. It also inhibited the hyperplasia of goblet cells, hypersecretion of mucus, and inflammation in peribronchial and perivascular spaces, which were consequences of ovalbumin exposure. The activity of the extract in suppressing inflammatory responses of asthma in our murine model was comparable to budesonide.

Our data underscored the effect of aqueous P. anisum seeds on the suppression of inflammatory responses of allergic asthma, proposing a promising suggestion for the treatment of the disease.

Thailand has abundant traditional medicinal plant species which are efficacious for many illnesses, but most of them still lack the supportive scientific information for their healing properties. The aim of this study was to evaluate and compare the constituents and antioxidant and antibacterial activities of some of these plants.

The medicinal plant extracts were assessed for their flavonoids and phenolics composition and tested for antibacterial activity using disk diffusion method. In vitroantioxidant capacity was evaluated by DPPH, ABTS, and FRAP assays.

Major flavonoids present in the medicinal plants were naringenin, (+)-catechin and quercetin. The highest contents of naringenin, quercetin and (+)-catechin were observed in Tinospora crispa (896.15 mg/100 g dw), Betula alnoides (521.57 mg/100 g dw) and Albizia procera (430.28 mg/100 g dw), respectively (P<0.05). Naringenin was first reported from T. crispa,quercetin and (-)-epicatechin were also found in this plant. The lowest EC50 value based on the DPPHassay was found in Capparis micracantha extracts (9.10 mg/mL). The strongest antioxidant capacities, examined by the DPPH, FRAP and ABTS assays, were found in Capparis micracantha (EC50 9.10 mg/mL), Zingiber cassumunar (334.00 mg Fe(II)/100 g dw) and Plumbago indica (61.56 mg TE/100 g dw), respectively (p<0.05). The extract of Plumbago indica root exhibited the highest antibacterial activity mainly against Bacillus subtilis (MIC = 1.56 mg/mL), Bacillus cereus (MIC = 0.39 mg/mL), Streptococcus faecalis (MIC = 0.19 mg/mL), Salmonella sp. (MIC = 0.39 mg/mL) and Salmonella  typhi (MIC = 0.19 mg/mL).

The results provided significant scientific data on phytochemical constituents and biological activities of Thai medicinal plants use in traditional medicine and the relation to their therapeutic properties.

Resveratrol is a natural phenol in food particularly the skin of fruits like red grapes. It has shown biological, and antidepressant effects. The objective of the present study was to evaluate the role of adrenergic system on antidepressant and anti-obsessive effect of resveratrol.

Male mice (weighing 27±2 g) were used. A tyrosine hydroxylase inhibitor, α-methyl-p-tyrosine (AMPT 100 mg/kg), α1 adrenergic receptors (AR) antagonist (prazosin, 1 mg/kg), α2-AR antagonist (yohimbine, 1 mg/kg), β-AR antagonist (propranolol, 2 mg/kg) and a tricyclic antidepressant (imipramine, 5 mg/kg), were injected before resveratrol (60 mg/kg). Locomotor activity, burring behavior during marble burring test, and immobility time during forced swimming test (FST) were evaluated.

No significant difference was observed in the locomotor activity between groups. The immobility time increased following pretreatment with AMPT (147.3±6.35s vs resveratrol alone 85.67±4.51s, p <0.001); marble burring behavior increased significantly, indicating the possible role of norepinephrine in resveratrol antidepressant and anti-obsessive-like effects. Propranolol (163.8±8.25 s, p <0.001) and yohimbine (151.0±6.47s, p=0.0030) pretreatment increased immobility in the FST compared to resveratrol. Pretreatment with prazosin did not cause important change in FST. Pretreatment with propranolol slightly increased marble burring behavior while no changes were observed following yohimbine or prazosin administration. Imipramine pretreatment did not have additive antidepressant effect with resveratrol and increased immobility time (136.1±16.88 s, p=0.014 vs resveratrol).

Resveratrol antidepressant-like effect is partly mediated by the noradrenergic system, and interaction with β-AR and α2-AR. Additionally, resveratrol anti-obsessive-like property involves noradrenergic system but not the β or α-AR.

Natural sources can be effective in treating diverse pathological conditions especially cancer. Molecular evaluations of pepper on renal cancer could provide further information about its anticancer property.

To achieve a clear understanding of pepper effect on cancer cells, protein-protein interaction network analysis of differentially expressed proteins (DEPs) in human renal adenocarcinoma cells treated with ghost pepper were evaluated. Cytoscape V. 3.8.2 and its applications were applied to analyze the DEPs.

Centrality study showed CYCS and CAT as DEPs were the hub-bottlenecks that were essential for the network stability. Among the 10 introduced central proteins, eight individuals belonged to the added first neighbors from STRING database. The finding indicated that the main central proteins belonged to the first neighbors of the queried proteins and were involved in the anticancer activity.

Analysis highlighted anticancer property of ghost pepper on the human renal adenocarcinoma cells and also antioxidant effect which was associated with catalase activity.

The genus Cymbopogon belongs to Poaceae family and contain about 54 species, commonly known as "lemongrass". Cymbopogon is a medicinal plant native to tropical and subtropical areas which is applied traditionally for its numerous properties including antirheumatic, antispasmodic, analgesic, antiseptic, hypotensive, antitussive and anticonvulsant ctivities, and as a treatment for gastrointestinal and nervous disorders and fever. The aims of this study were to discuss about current state of phytochemistry, pharmacology, and pharmacological effects of different species of Cymbopogon. Electronic databases including PubMed, Scopus, Cochrane library and Google Scholar were searched with the scientific name and the common name of the plant until November 2019. In spite of the small number of clinical investigations, Cymbopogon genus is widely evaluated for its phytochemistry, ethnopharmacology and biological activities. Monoterpenes specially geranial, citronellol and citral are the chief components of the essential oil. Biological activities including antioxidant, antibacterial, antiviral, insecticidal, anticancer, hepatoprotective activities as well as its effect on skin, urogenital, gastrointestinal, neuropsychological and cardiovascular systems are proved in cell lines and animal models. Extensive studies have been done on various biological activities of lemongrass; nevertheless, safety and efficacy of Cymbopogon species are not fully evaluated in human and further well-designed clinical trials are required to confirm preclinical findings.