Antimicrobial and immunological activity of ethanol extracts and fractions from Isopyrum thalictroides

Assembly and comparative analysis of the complete mitochondrial genome of Isopyrum anemonoides (Ranunculaceae)

Ranunculaceae is a large family of angiosperms comprising 2500 known species-a few with medicinal and ornamental values. Despite this, only two mitochondrial genomes (mitogenomes) of the family have been released in GenBank. Isopyrum anemonoides is a medicinal plant belonging to the family Ranunculaceae, and its chloroplast genome has recently been reported; however, its mitogenome remains unexplored. In this study, we assembled and analyzed the complete mitochondrial genome of I. anemonoides and performed a comparative analysis against different Ranunculaceae species, reconstructing the phylogenetic framework of Isopyrum. The circular mitogenome of I. anemonoides has a length of 206,722 bp, with a nucleotide composition of A (26.4%), T (26.4%), C (23.6%), and G (23.6%), and contains 62 genes, comprising 37 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, and three ribosomal RNA (rRNA) genes. Abundantly interspersed repetitive and simple sequence repeat (SSR) loci were detected in the I. anemonoides mitogenome, with tetranucleotide repeats accounting for the highest proportion of SSRs. By detecting gene migration, we observed gene exchange between the chloroplast and mitogenome in I. anemonoides, including six intact tRNA genes, six PCG fragments, and fragments from two rRNA genes. Comparative mitogenome analysis of three Ranunculaceae species indicated that the PCG contents were conserved and the GC contents were similar. Selective pressure analysis revealed that only two genes (nad1 and rpl5) were under positive selection during their evolution in Ranunculales, and two specific RNA editing sites (atp6 and mttB) were detected in the I. anemonoides mitogenome. Moreover, a phylogenetic analysis based on the mitogenomes of I. anemonoides and the other 15 taxa accurately reflected the evolutionary and taxonomic status of I. anemonoides. Overall, this study provides new insights into the genetics, systematics, and evolution of mitochondrial evolution in Ranunculaceae, particularly I. anemonoides.

Immunomodulatory potential of Nyctanthes abrortristis stem bark

Background

Phytotherapeutic modulation of the immune system to mitigate infectious ailments has been in vogue all over the world.

Objective

The present work has been designed to scientifically explore the immunomodulatory potential of Nyctanthes arbortristis stem bark using mice models.

Materials & method

Methanolic (MNA) and aqueous (ANA) extracts of N. arbortristis stem bark were evaluated for possible modulation in humoral immunity through serum immunoglobulin estimation. The variation in cellular immunity was assessed using neutrophil adhesion test, carbon clearance assay, and cyclophosphamide-induced neutropenia.

Results and discussion

Administration of MNA and ANA (both at 200 mg/kg, p.o.) significantly augmented the levels of serum immunoglobulins (humoral antibody), neutrophil adhesion, and phagocytic index (a measure of carbon clearance). Extracts also guarded the animals against cyclophosphamide-induced leukopenia, especially neutropenia.

Conclusion

Results indicate that cellular and humoral immune responses were aroused by pretreatment of the animal with methanol and aqueous extract of N. arbortristis. Thus, the methanol and aqueous extract of N. arbortristis stem bark possesses a significant immunostimulant activity and can be used to uplift the immune system in the infectious condition.

Phytochemical, toxicological and antimicrobial evaluation of Lawsonia inermis extracts against clinical isolates of pathogenic bacteria

Background

The emerging resistance of pathogen against the currently available antimicrobial agents demands the search of new antimicrobial agents. The use of medicinal plants as natural substitute is the paramount area of research to overwhelm the drug resistance of infectious agents. Scientists have not made enough effort on the evaluation of safety of medicinal plant yet.

Methods

In the present study antimicrobial activity of Lawsonia inermis is investigated against clinical isolates of seven bacteria including four Gram negative (Escherichia coli, Salmonella typhi, Klebsiella spp., Shigella sonnei) and three Gram positive (Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis) using disc diffusion method. Four types of Lawsonia inermis extracts were prepared using methanol, chloroform, acetone and water as extraction solvents, while DMSO (Dimethyl sulfoxide) and water as dissolution solvents. The rate and extent of bacterial killing was estimated by time-kill kinetic assay at 1× MIC of each bacterial isolate. The overall safety of Lawsonia inermis extracts was assessed in mice.

Results

Lawsonia inermis displayed noteworthy antimicrobial activity against both gram positive and gram negative bacterial strains used in the study. The minimum value of MIC for different bacterial strains ranged from 2.31 mg/ml to 9.27 mg/ml. At 1x MIC of each bacterial isolate, 3log₁₀ decrease in CFU was recorded after 6 hours of drug exposure and no growth was observed in almost all tested bacteria after 24 hours of exposure. No sign of toxidrome were observed during in vivo toxicity evaluation in mice at 300 mg/kg concentration.

Conclusion

In conclusion, the present study provides the scientific rational for medicinal use of Lawsonia inermis. The use of Lawsonia inermis extracts is of great significance as substitute antimicrobial agent in therapeutics.

Antiviral, immunomodulatory, and free radical scavenging activities of a protein-enriched fraction from the larvae of the housefly, Musca domestica

In our previous study, protein-enriched fraction (PEF) that was isolated from the larvae of the housefly, Musca domestica L. (Diptera: Muscidae), showed excellent hepatoprotective activity as well as the potential for clinical application in therapy for liver diseases. In this study, antiviral, immunomodulatory, and free radical scavenging activities of PEF were evaluated. The antiviral results demonstrated that PEF inhibited the infection of avian influenza virus H9N2 and had a virucidal effect against the multicapsid nucleopolyhedrovirus of the alfalfa looper, Autographa californica Speyer (Lepidoptera: Noctuidae) in vitro. The mortality of silkworm larve in a PEF treatment group decreased significantly compared with a negative control. PEF showed excellent scavenging activity for 1,1-diphenyl-2-picrylhydrazyl and superoxide anion radicals, which were similar to those of ascorbic acid. The imunomodulatory results suggested that PEF could effectively improve immune function in experimental mice. Our results indicated that PEF could possibly be used for the prophylaxis and treatment of diseases caused by avian influenza virus infection. In addition, PEF with virucidal activity against insect viruses might provide useful for the development of antimicrobial breeding technology for economically important insects. As a natural product from insects, PEF could be a potential source for the discovery of potent antioxidant and immunomodulatory agents.

Dysregulation of the Th1/Th2 cytokine profile is associated with immunosuppression induced by hypothalamic-pituitary-adrenal axis activation in mice

Hypothalamic-pituitary-adrenal (HPA) axis activation-induced immunosuppression is associated with increased concentration of circulating corticosterone and impaired cellular immune responses. The purpose of this study was to investigate the effect of chronic HPA axis activation on the cellular immune response, Th1/Th2 cytokine profile, and concentration of corticosterone. Mice were divided into two groups: a control group comprised of healthy, untreated mice that received no stress, and an HPA axis-activated group that received stress through electric shock (ES). The delayed-type hypersensitivity reaction to dinitrofluorobenzene, splenocyte proliferative response to mitogens Concanavalin A and lipopolysaccharide, Th1 and Th2 profile, and TGF-beta1 production were measured in plasma and in culture supernatants. The corticosterone concentration was also measured in plasma. In the ES group, elevated plasma corticosterone concentration was associated with immunosuppression and a significant decrease in plasma concentrations of IL-2, IL-4, and TGF-beta1. In vitro IL-2 production in response to Con A was significantly lower in the ES group than in the control group. TGF-beta1 production in nonstimulated and stimulated cultures in response to either mitogen was significantly lower in the ES group than in the control group. Plasma concentrations of IFN-gamma and IL-10 did not differ significantly between groups. The concentrations of IFN-gamma, IL-4, and IL-10 in the supernatants of splenocytes stimulated with either mitogen and IL-4 production by nonstimulated cells were significantly higher in the ES group than in the control group. These results suggest that corticosterone mediates the immunosuppression induced by HPA axis activation, and induces dysregulation of the Th1/Th2 cytokine profile.

Effect of Ginkgo biloba extract EGb 761 on the nonspecific and humoral immune responses in a hypothalamic-pituitary-adrenal axis activation model

We evaluated the immune response of healthy control and stressed Wistar rats submitted to hypothalamic-pituitary-adrenal (HPA) axis activation. Rats were treated with Ginkgo biloba extract (EGb 761) orally (100 mg/kg per day for 7 days). EGb 761 stimulated the digestion index of peritoneal and alveolar macrophages (PM and AM) of stressed rats. Likewise, the cellular immune response measured using the delayed-type hypersensitivity response to sheep red blood cells (SRBC) and the humoral immune response (measured through an anti-SRBC response), were also restored in stressed rats. Thus, this G. biloba extract possesses immunostimulatory activity in addition to its broad spectrum of pharmacological effects.

An experimental model of stress-induced immunosuppression produced by electrical stimulation of the brain in the rat

The present paper reports a model of stress induction, based on electrical stimulation of the brain in normal Wistar rats. Stress-related stimulation of the hypothalamic-pituitary-adrenal axis produced a rise in circulating corticosterone levels that correlated significantly with the impairment of some immunological parameters, such as delayed hypersensitivity reactions to dinitrofluorobenzene and to sheep red blood cells, together with changes in splenocyte proliferation and phagocytic activity of peritoneal macrophages. This experimentally elicited stress in the rat is proposed as a suitable model of immunosuppression that could be used for the evaluation of drugs with potential immunomodulatory properties.

Plant products as antimicrobial agents

The use of and search for drugs and dietary supplements derived from plants have accelerated in recent years. Ethnopharmacologists, botanists, microbiologists, and natural-products chemists are combing the Earth for phytochemicals and "leads" which could be developed for treatment of infectious diseases. While 25 to 50% of current pharmaceuticals are derived from plants, none are used as antimicrobials. Traditional healers have long used plants to prevent or cure infectious conditions; Western medicine is trying to duplicate their successes. Plants are rich in a wide variety of secondary metabolites, such as tannins, terpenoids, alkaloids, and flavonoids, which have been found in vitro to have antimicrobial properties. This review attempts to summarize the current status of botanical screening efforts, as well as in vivo studies of their effectiveness and toxicity. The structure and antimicrobial properties of phytochemicals are also addressed. Since many of these compounds are currently available as unregulated botanical preparations and their use by the public is increasing rapidly, clinicians need to consider the consequences of patients self-medicating with these preparations.

Complement modulatory activity of bisbenzylisoquinoline alkaloids isolated from Isopyrum thalictroides--I. Influence on classical pathway in human serum

Eleven bisbenzylisoquinoline alkaloids (BBI) were isolated from the plant Isopyrum thalictroides (L.). Treatment of normal human serum (NHS) with BBI resulted in a diminution of the haemolytic activity of the classical pathway (CP). The mode of action of the main alkaloids isopyruthaline (It1), fangchinoline (It2) and isotalictrine (It3) on CP activation was investigated in vitro. The inhibition was time- and temperature-related and for Itl and It3 depended on the concentration of Ca2+ and Mg2+ ions. It was established that the substances reduced C1 haemolytic activity. It2 and It3 enhanced the complement consumption caused by heat aggregated human IgG (HAGG). The BBI prevented the formation of C3 convertase of the classical pathway. The loss of haemolytic activity was partially restored by the addition of C142 reagent (zymosan-treated guinea pig serum) to alkaloids-treated NHS. The addition of the late components C3-9 (EDTA-treated rat sera) recovered to some extent the haemolytic activity of It1-treated NHS, but not of It2- and It3-treated NHS.