Bronco T (Shirisadi kasaya), a polyherbal formulation prevents LPS induced septicemia in rats

OBJECTIVE

Here, Bronco T (BT), a polyherbal formulation developed in 1984 for treating asthma, has been repurposed against septicemia-induced ALI.

MATERIALS AND METHODS

Lipopolysaccharides (3 mg/kg BW) were injected intraperitoneally before 24 hours of surgery to assess the cardiorespiratory parameters, blood PaO2/FiO2 and MPO, pulmonary water content and histological changes in the lungs. The pentoxifylline (PTX) (25 mg/kg BW) was used as the positive control and given one hour before LPS. BT was given 3 hours (orally at different doses of 3, 1.5 and 0.75 g/kg BW) before LPS.

RESULTS

The LPS treated group showed significant bradypnea, hypotension and bradycardia, through elongated peaks (RR) and (MAP) respectively and finally death after 95 minutes of LPS injection. The PTX and BT (3 g/kg BW) pretreatment significantly prevented these changes (dose-dependent in the BT group). The survival in these groups was maintained up to 190 min after LPS. The Pentoxifylline showed a better response (75%) than Bronco T (72%). In both the treatments, a significant decrease in pulmonary water content and minimal neutrophil infiltration and intact alveoli-capillary membrane was seen in the transverse section (T.S) of the lungs.

CONCLUSIONS

Significant improvement was noted in survival time with lesser tissue damage and improved pulmonary function was observed by pre-treating with Bronco T in LPS induced septicemia.

Impact of Nano Preparation of Phytoconstituents in Medulloblastoma

The conventional cancer treatment strategies from chemotherapy to surgery often lead to inadequate results which in some cases lead to relapsing of the tumor being treated. Medulloblastoma witness 30% relapse rate which is universally fatal among children. Although the treatment of primary medulloblastoma is well established including surgical excision, postsurgical irradiation, and, more recently, chemotherapy, there is no established treatment for its recurrence. Despite efforts to improve its therapy, frequent long-haul survivors have been recorded in the world's medical literature. In this book chapter, we have attempted to focus light on the nano preparation of phytoconstituents as an alternative approach as it has advantage of providing better bioavailability of the compound in terms of crossing the blood-brain barrier and an additional benefit in terms of limited adverse effects of the natural product over the traditional chemotherapeutic approaches. In recent times, biological methods or green approaches in the case of plants have received immense attention due to its safety and lack of contamination in the process. In this chapter, we will explore some plant products that have been incorporated into nanocarriers to improve their bioavailability in this tumor treatment.

Role of Ayurvedic Plants as Anticancer Agents

The use of natural products has been increasing at a rapid pace, worldwide, with the aim to maintain a healthy lifestyle and to modify one's dietary habits. Ayurveda is a domain that has numerous wealth of information concerning medicinal plants and its part in controlling numerous ailments, such as neoplastic, cardiovascular, neurological plus immunological ailments. The use of such medicinal plants is important for preventing such diseases, especially "cancer" which is the succeeding foremost cause of mortality collectively. Even though abundant developments have been made in the management and control of cancer progression, substantial deficits and scope for advancement still continue to be unchanged. Several lethal adjacent consequences occur throughout the course of chemotherapy. Natural treatments, such as the use of plant-derived products in the treatment of cancer, might reduce the hostile side effects. Presently, a few plant-based products and its phytoconstituents are being utilized for the management of cancer. Here we have focused on numerous plant-derived phytochemicals and promising compounds from these plants to act as anticancer agents, along with their mechanisms of action.

Scoping review on the role and interactions of hydroxytyrosol and alpha-cyclodextrin in lipid-raft-mediated endocytosis of SARS-CoV-2 and bioinformatic molecular docking studies

OBJECTIVE

The aim of the study was to show the effect that two naturally occurring compounds, a cyclodextrin and hydroxytyrosol, can have on the entry of SARS-CoV-2 into human cells.

MATERIALS AND METHODS

The PubMed database was searched to retrieve studies published from 2000 to 2020, satisfying the inclusion criteria. The search keywords were: SARS-CoV, SARS-CoV-2, coronavirus, lipid raft, endocytosis, hydroxytyrosol, cyclodextrin. Modeling of alpha-cyclodextrin and hydroxytyrosol were done using UCSF Chimera 1.14.

RESULTS

The search results indicated that cyclodextrins can reduce the efficiency of viral endocytosis and that hydroxytyrosol has antiviral properties. Bioinformatic docking studies showed that alpha-cyclodextrin and hydroxytyrosol, alone or in combination, interact with the viral spike protein and its host cell receptor ACE2, thereby potentially influencing the endocytosis process.

CONCLUSIONS

Hydroxytyrosol and alpha-cyclodextrin can be useful against the spread of SARS-CoV-2.

Microbiome and host crosstalk: A new paradigm to cancer therapy

The commensal microbiome of humans has co-evolved for thousands of years. The microbiome regulates human health and is also linked to several diseases, including cancer. The advances in next-generation sequencing have significantly contributed to our understanding of the microbiome and its association with cancer and cancer therapy. Recent studies have highlighted a close relationship of the microbiome to the pharmacological effect of chemotherapy and immunotherapy. The chemo-drugs usually interfere with the host immune system and reduces the microbiome diversity inside the body, which in turn leads to decreased efficacy of these drugs. The human microbiome, specifically the gut microbiome, increases the potency of chemo-drugs through metabolism, enzymatic degradation, ecological differences, and immunomodulation. Recent research exploits the involvement of microbiome to shape the efficacy and decrease the toxicity of these chemo-drugs. In this review, we have highlighted the recent development in understanding the relationship of the human microbiome with cancer and also emphasize on various roles of the microbiome in the modulation of cancer therapy. Additionally, we also summarize the ongoing research focussed on the improved efficacy of chemotherapy and immunotherapy using the host microbiome.

Phytochemical characterization, antimicrobial activity and reducing potential of seed oil, latex, machine oil and presscake of Jatropha curcas

OBJECTIVE

This study aims to evaluate the antimicrobial activity, phytochemical studies and thin layer chromatography analysis of machine oil, hexane extract of seed oil and methanol extract of presscake & latex of Jatropha curcas Linn (family Euphorbiaceae).

MATERIALS AND METHODS

J. curcas extracts were subjected to preliminary qualitative phytochemical screening to detect the major phytochemicals followed by its reducing power and content of phenol and flavonoids in different fractions. Thin layer chromatography was also performed using different solvent systems for the analysis of a number of constituents in the plant extracts. Antimicrobial activity was evaluated by the disc diffusion method, while the minimum inhibitory concentration, minimum bactericidal concentration and minimum fungicidal concentration were calculated by micro dilution method.

RESULTS

The methanolic fraction of latex and cake exhibited marked antifungal and antibacterial activities against Gram-positive and Gram-negative bacteria. Phytochemical analysis revealed the presence of alkaloids, saponins, tannins, terpenoids, steroids, glycosides, phenols and flavonoids. Reducing power showed dose dependent increase in concentration compared to standard Quercetin. Furthermore, this study recommended the isolation and separation of bioactive compounds responsible for the antibacterial activity which would be done by using different chromatographic methods such as high-performance liquid chromatography (HPLC), GC-MS etc.

CONCLUSION

The results of the above study suggest that all parts of the plants possess potent antibacterial activity. Hence, it is important to isolate the active principles for further testing of antimicrobial and other biological efficacy.

In-vitro α amylase and glycosidase inhibitory effect of ethanolic extract of antiasthmatic drug - Shirishadi

Asthma and diabetes have strong relationship; both are cause and effect of each other. Oxidative stress due to bronchial asthma may cause insulin resistance whereas lack of proper insulin can cause defective smooth muscle relaxant. There is no single medicine available that can manage both diseases, rather the mainstay treatment of bronchial asthma causes hyperglycemia. Keeping this problem in focus, in this study the hypoglycemic effect of an indigenous antiasthmatic Ayurvedic drug Shirishadi was evaluated. Pancreatic alpha amylase and glucosidase inhibitors offer an effective strategy to lower the level of post prandial hyperglycemia via control of starch breakdown. For evaluation of hypoglycemic activity of drug, in-vitro alpha amylase and alpha glucosidase enzyme inhibition was calculated. Ethanolic extract of compound showed 76.40% + 0.88% reduction in alpha amylase activity and 63.85% + 0.36% in alpha glucosidase activity with IC50 0.68 mg/ml and 2.89 mg/ml, respectively. This study suggests that the ethanolic extract of Shirishadi polyherbal compound effectively acts as alpha amylase and glucosidase inhibitor leading to a reduction in starch hydrolysis and hence acts as antiasthmatic as well as hypoglycemic drug.

Effect of hexane fraction of leaves of Cinnamomum tamala Linn on macrophage functions

The leaves of Cinnamomum tamala Linn (Lauraceae), component of Indian spices are associated with hypoglycemic property in Ayurveda; however, no report is available towards its immunomodulation property, which has been explored here. The dried powder of CT leaves was extracted with hexane and solvent free extract (CTH) was given orally to rats for 10 days, in various doses. Its effect was studied on peritoneal macrophage functions, and was compared with ascorbic acid (1,000 mg/kg, immune-stimulant) and cyclophosphamide (10 mg/kg, immune-suppressant). CTH significantly suppressed phagocytosis activity (EC(50) 2,355 +/- 52.45 mg/kg), reduced production of superoxide (EC(50) 275.91 +/- 10.21 microg/ml) and cellular NADPH (EC(50) 384.959 +/- 4.85 microg/ml) content in concentration dependent manner. It also inhibited LPS induced production of nitric oxide (EC(50) 143.75 +/- 3.40 microg/ml) and iNOS protein expression (EC(50) 183.132 microg/ml). Thus, it could be suggested that non-polar hexane fraction of leaves of C. tamala possesses immunosuppressive property, which is mediated through modulation of innate immunity.

Evaluation of Chenopodium ambrosioides oil as a potential source of antifungal, antiaflatoxigenic and antioxidant activity

Essential oil extracted from the leaves of Chenopodium ambrosioides Linn. (Chenopodiaceae) was tested against the aflatoxigenic strain of test fungus Aspergillus flavus Link. The oil completely inhibited the mycelial growth at 100 microg/ml. The oil exhibited broad fungitoxic spectrum against Aspergillus niger, Aspergillus fumigatus, Botryodiplodia theobromae, Fusarium oxysporum, Sclerotium rolfsii, Macrophomina phaseolina, Cladosporium cladosporioides, Helminthosporium oryzae and Pythium debaryanum at 100 microg/ml. The oil showed significant efficacy in inhibiting the aflatoxin B1 production by the aflatoxigenic strain of A. flavus. During in vivo investigation it protected stored wheat from different storage fungi for one year. Chenopodium oil also exhibited potent antioxidant activity when tested by ABTS method. All these observations suggest the possible exploitation of the Chenopodium oil as potential botanical fungitoxicant in ecofriendly control of post harvest biodeterioration of food commodities from storage fungi.

Effect of Momordica charantia on lipid profile and oral glucose tolerance in diabetic rats

In this study, the methanol extract of Momordica charantia fruit extract was administered to diabetic rats to assess the long term effect of the extract on the lipid profile and the oral glucose tolerance test. Treatment for 30 days showed a significant decrease in triglyceride, low density lipoprotein and a significant increase in high density lipoprotein level. A significant effect on oral glucose tolerance was also noted. Chronic administration showed an improvement in the oral glucose tolerance curve. The effect was more pronounced when the test was done in rats fed the extract on the day of the test compared with tests done in rats which were not fed the extract on the same day.

Effect ofAsparagus racemosus rhizome (Shatavari) on mammary gland and genital organs of pregnant rat

Asparagus racemosus (AR) Willd (family Liliaceae) is commonly known as Shatavari. The alcoholic extract of its rhizome was administered orally to adult pregnant female albino rats at a dose of 30 mg/100 g body weight, daily for 15 days (days 1-15 of gestation). The macroscopic findings revealed a prominence of the mammary glands, a dilated vaginal opening and a transversely situated uterine horn in the treated group of animals. The weight of the uterine horns of the treated group was found to be significantly higher (p < 0.001) but the length was shorter (p > 0.01). Microscopic examination of the treated group showed proliferation in the lumen of the duct of mammary gland. It was obliterated due to hypertrophy of ductal and glandular cells. Hyperplasia of the glandular and muscular tissue and hypertrophy of the glandular cells were observed in the genital organs. The parenchyma of the genital organs showed abundant glycogen granules with dilated blood vessels and thickening of the epithelial lining. The oviduct in the treated group showed hypertrophied muscular wall, whereas the ovary revealed no effect of the drug. The results suggest an oestrogenic effect of Shatavari on the female mammary gland and genital organs.

Semecarpus anacardium L, nuts inhibit lipopolysaccharide induced NO production in rat macrophages along with its hypolipidemic property

Traditionally S. anacardium is used for rejuvenation, rheumatoid arthritis, fever and neurological disorders. In the present study it was observed that a fraction of S. anacacrdium at dose of 1 mg/100 g body wt, significantly reduced serum cholesterol from 378.87 mg/dl in the rats fed with atherogenic diet (AD) to 197.99 mg/dl (45-52%) in the rats fed with AD diet and increased serum HDL-cholesterol (33-37%). The same fraction also inhibited LPS induced NO production in the culture activated rat peritoneal macrophages in the dose dependent manner with IC50 value at 50 ng/ml of the culture medium. The drug in the above doses was completely safe and non-toxic, (no change in the enzymes), to liver and kidney functions.

Antioxidant property of Smilex china Linn

Smilex china Linn. (Smilacaceae Syn Liliaceae) has special pharmacognostic feature as its root is multiseriate, with sclerenchymatic pericycle. The alcoholic extract of rhizome of S. china shows significant protection against FeSO4 induced lipid peroxidation in rat liver homogenate, but has no effect on the rate of oxidation of reduced glutathione. This fraction scavenges the superoxide and hydroxyl radicals, but the effect was more towards the removal of superoxide than that of hydroxyl radicals. Thus it could be concluded that rhizome of S. china has strong antioxidant property.

Effect of Semecarpus anacardium nuts on lipid peroxidation

Alcoholic extract of pericarp showed significant protection against FeSO4 induced lipid peroxidation, as compared with whole native nut and seeds. Mechanism of action may be through metal chelation or activation of endogenous antioxidant enzymes, because the extract did not show hydroxyl and super oxide anion scavenging property. Further in vitro experiments against FeSO4, it did not maintain the level of reduced glutathione.

Interaction of Strychnos nux-vomica-products and iron: with reference to lipid peroxidation

In this paper, it has been investigated that strychnine, the major active principle in the alcoholic extract of the seeds of Strychnos nux-vomica, is responsible for its antilipid peroxidative property. The mechanism of action of this drug is through the chelation of the free iron in the system. It has also been observed that strychnine does not have any pro-oxidant-property, because it does not convert Fe3+ to Fe2+ and vice versa in the reaction system, as has been observed with several other antioxidants.

Molecular approach to ayurveda

In ayurvedic system of medicine, it is considered that a living system is made of panch-mahabuta, in the form of Vata, pitta and kapha at the physical level and satwa, raja and tama at the mental level. This covers the psychosomatic constitution and commonly known as the Tridosh theory. The imbalance in these body humours is the basic cause of any type of disease manifestation. Till date, several objective parameters have been proposed to monitor the level of these basic humours but none of them is complete. In this exercise, now it is proposed to consider free radical theory of diseases as one of the objective parameters. To be more specific, vata can be monitored in terms of membrane bound signal transduction, pitta as the process of phosphorylation and de-phosphorylation of different proteins (signalling moieties and enzymes) and kapha can be viewed as the degree of gene expression as protein synthesis. This can be correlated with the ojas of the body or total body defence mechanism.

Role of alcoholic extract of shoot of Hypericum perforatum Linn on lipid peroxidation and various species of free radicals in rats

The alcoholic extract of the shoot of H. perforatum shows strong antioxidant property. It possesses the iron chelation property with more affinity to the ferrous form. It has scavenging property for both superoxide and for hydroxyl radicals but the response is more towards the superoxide radicals. Thus in addition to the anti-depressant property it has strong antioxidant property also.

The interaction of Rubia cordifolia with iron redox status: a mechanistic aspect in free radical reactions

The present publication investigates the antioxidant property and mechanistic aspect of alcoholic extract of R. cordifolia. The extract of R. cordifolia has shown significant inhibitory effect on FeSO4 induced lipid peroxidation. Study with iron redox status showed that R. cordifolia extract reduced or oxidixed; Fe3+ or Fe2+ respectively, in a dose dependent manner. Results with superoxide anion (O2-.) and hydroxyl radical (OH.), showed no radical scavenging activity. The alcoholic extract significantly maintains the reduced glutathione content both in time and dose dependent manner. It also reduced the rate of depletion of reduced glutathione (GSH) level in presence of ferrous sulphate (FeSO4) and cumene hydroperoxide (CHP). On the basis of these observations, it can be concluded that the antioxidant property of R. cordifolia is due to a direct interaction with iron.

Comparison of the antioxidant action of the alcoholic extract of Rubia cordifolia with rubiadin

The inhibition of FeSO4 induced lipid peroxidation in rat liver by alcoholic extract of Rubia cordifolia and by one of its constituent rubiadin (1, 3-dihydroxy-2-methyl anthraquinone) (pure form) has been compared. Both have been found to inhibit lipid peroxidation in a dose dependent manner. Whereas the former shows both oxidising and reducing properties with Fe2+ and Fe3+, the latter shows oxidising property only by converting Fe2+ to Fe3+. The former inhibits the oxidation of reduced glutathione while the latter does not.

Rubiadin, a new antioxidant from Rubia cordifolia

Rubiadin, a dihydroxy anthraquinone, isolated from alcoholic extract of Rubia cordifolia, possesses potent antioxidant property. It prevents lipid peroxidation induced by FeSO4 and t-butylhydroperoxide (t-BHP) in a dose dependent manner. The per cent inhibition was more in the case of Fe2+ induced lipid peroxidation. The antioxidant property of the preparation has been found to be better than that of EDTA, Tris, mannitol, Vitamin E and p-benzoquinone.

Antilipid peroxidative property of Nardostachys jatamanasi

Antiperoxidative property of N. jatamanasi was tested by using iron induced lipid peroxidation in 5% rat liver homogenate. The degree of peroxidation was quantitated by thiobarbituric acid reactive substance (TBARS) content. The extract provided protection against lipid peroxidation. The hexane fraction was more potent than the alcoholic extract. Results suggested antilipid peroxidative property of the plant.

Bacopa monniera Linn. as an antioxidant: mechanism of action

Bacopa monniera, Linn. (Brahmi: Scrophulariaceae) an Ayurvedic medicine is clinically used for memory enhancing, epilepsy, insomnia and as mild sedative. For the first time the effect of alcohol and hexane fraction of Brahmi has been studied on FeSO4 and cumene hydroperoxide induced lipid peroxidation. Alcohol fraction showed greater protection with both inducers. Results were compared with known antioxidants tris, EDTA and a natural-antioxidant vitamin E. The effect of Brahmi was also examined on hepatic glutathione content. The mechanism of action could be through metal chelation at the initiation level and also as chain breaker. The results suggested that Brahmi is a potent antioxidant. The response of Brahmi was dose dependent. Tris, an hydroxyl trapper did not show any protection in comparison to Brahmi where as EDTA and vitamin E did protect against FeSO4. In experimental conditions 100 micrograms Brahmi extract (alcoholic) was equivalent to 247 micrograms of EDTA (0.66 microM) and 58 micrograms of vitamin E. Interestingly Brahmi only slightly protected the autooxidation and FeSO4 induced oxidation of reduced glutathione on lower doses 100 micrograms/ml and below, but on higher concentrations it enhanced the rate of oxidation.

Role of Tamra bhasma, an Ayurvedic preparation, in the management of lipid peroxidation in liver of albino rats

Hepatoprotective effect of Tamra bhasma has been studied on cumene hydroperoxide (CHP) induced peroxidation, reduced glutathione content and superoxide dismutase (SOD)-in rat liver homogenate. The drug was orally given for 8 days which showed significant reduction in the level of malondialdehyde (MDA) production at different concentrations of cumene hydroperoxide in vitro. Glutathione content was maintained upto seventy minutes and SOD activity was enhanced to 166%. These animals did not show any rise in serum GOT and GPT. On similar doses no histological changes were observed in liver. The results suggested that Tamra bhasma is a strong antioxidant drug and could be used in the management of lipid peroxidation with no detectable adverse effect.

Assessment of endocrine response of Inula racemosa in relation to glucose homeostasis in rats

Alcoholic extract of the root of I. racemosa lowers blood glucose and enhances liver glycogen without increasing plasma insulin in rats. There is also no increase in degree of degranulation of the beta cells of pancreas. In similar conditions it does not show any effect on activity of adrenal gland. However, thyroid gland undergoes activation at the later stage (delayed response). It appears that hypoglycemic response of I. racemosa is not due to enhanced secretion/synthesis of insulin; the action may be at the peripheral level by potentiating the insulin sensitivity.

Antioxidant and anti-inflammatory property of Sandhika: a compound herbal drug

The present study was envisaged to assess the rationality for the use of "Sandhika", a popular Ayurvedic drug in rheumatoid arthritis. This drug, when tested against carrageenan induced paw oedema and cotton pellet granuloma, showed significant anti-inflammatory activity at the dose of 0.25 g/kg body weight. The antioxidant property was assessed by determining cumene hydroperoxide (CHP) induced lipid peroxidation and reduced glutathione content in rat liver homogenate (in vitro). Experiments show the significant protection against lipid peroxidation at the dose of 80 micrograms/ml, measured as reduction in the level of malondialdehyde (MDA) induced by 1.5 mM cumene hydroperoxide (CHP). This effect was accompanied by the maintained reduced glutathione (GSH) content in drug treated rats. Oral treatment of drug up to 2 g/kg body weight for 15 days did not show any rise in serum transaminases (SGOT and SGPT). The results suggest that "Sandhika" which is an indigenous drug for inflammation with no detectable adverse effect, might be acting through scavenging the free radicals.

Hepatoprotective and toxicological evaluation of hepatomed, an ayurvedic drug

Hepatoprotective effect of Hepatomed (an ayurvedic drug containing water extract of 6 medicinal plants) has been studied on cumene hydroperoxide (CHP) induced lipid peroxidation and reduced glutathione content in rat liver homogenate. In vitro experiments show significant reduction in the level of malondialdehyde (MDA) induced by 1.5 mM cumene hydroperoxide(CHP). Glutathione content was almost maintained to normal in drug treated rats. Oral treatment of drug up to 3 ml/100 g body weight for 15 days did not show any rise in serum GOT and GPT. On similar doses, significant choleratic effect was observed without any adverse histological changes after 4 days treatment. The results suggest that 'Hepatomed' is a strong hepatoprotective ayurvedic medicine with no detectable adverse effects.

Protective effect of Rubia cordifolia on lipid peroxide formation in isolated rat liver homogenate

Rubia cordifolia Linn. (Rubiaceae) is an important component of the ayurvedic system of medicine. It has a variety of uses such as blood purifier, immunomodulant, antiinflammatory and anti-PAF. In this report the anti-peroxidative property of the solvent free alcoholic extract of R. cordifolia has been studied in rat liver homogenate. It prevents the cumene hydroperoxide induced malondialdehyde formation in the dose and time dependent manner. This effect is accompanied by the maintained reduced glutathione level even in the presence of above toxin.

Anti-platelet activating factor property of Rubia cordifolia Linn

Rubia cordifolia is clinically used for the purification of blood by the physicians of the Indian System of Medicine. For the first time, the effect of the partially purified fraction of this whole plant has been studied on rabbit platelets. It inhibits the platelet aggregation induced by PAF (platelet activating factor) but not thrombin. It also inhibits the binding of 3H-PAF to the platelets in the dose-dependent manner. Thus it appears that R. cordifolia inhibits action of PAF at its receptor level either by it's blocking or by desensitization.

Involvement of tyrosine kinase and protein kinase C in platelet-activating-factor-induced c-fos gene expression in A-431 cells

In A-431 cells, platelet-activating factor (PAF) induces the expression of c-fos and TIS-1 genes in both the absence and the presence of cycloheximide in a structurally specific and receptor-coupled manner. We have now investigated the molecular mechanisms of this response, particularly in relation to the role of protein kinases. Pretreatment of cells with genistein or methyl-2,5-dihydroxycinnamate (tyrosine kinase inhibitors) or staurosporine (a protein kinase C inhibitor) for 20 min abolished the c-fos expression induced by PAF. Interestingly, when genistein was added 90 s after addition of PAF, no inhibition was observed. Similarly, staurosporine did not inhibit c-fos expression when added 8 min after PAF addition to the cells. These inhibitions were dose-dependent (IC50 for staurosporine was 180 nM, and for genistein 50 microM). Simultaneous addition of PAF and phorbol 12-myristate 13-acetate (PMA) did not give a synergistic effect on c-fos expression. Pretreatment of cells with PMA had no effect on [3H]PAF binding, but abolished the PAF-induced gene expression. PAF-stimulated gene expression was desensitized if cells were pretreated with PAF. Interestingly, epidermal growth factor was able to stimulate c-fos expression in PAF-desensitized cells, and thus indicated involvement of distinct mechanisms for the two stimuli. Forskolin, an activator of adenylate cyclase, did not induce c-fos expression and had no effect on the PAF response. Exposure of cells to PAF for as little as 1 min, followed by its removal, was sufficient to activate the gene expression and demonstrated the rapidity and the exquisite nature of the signalling involved in this process. It is concluded that activation of PAF receptor (a proposed G-protein-coupled receptor) causes rapid production of signals which induce the expression of c-fos gene and that this is mediated via tyrosine kinase and protein kinase C.

Platelet activating factor induces expression of early response genes c-fos and TIS-1 in human epidermoid carcinoma A-431 cells

The effect of platelet activating factor (PAF) on the induction of early response genes was investigated in A-431 cells (human epidermal carcinoma cells). PAF induced a transient expression of c-fos and TIS-1 mRNA in a time- and dose-dependent manner. As low as 10(-10) M PAF caused detectable expression of these genes with a maximum observed at 10(-7) M. In the presence of cycloheximide, increases in the gene expression were noticeable at 20 min and peaked between 30-60 min. A lack of induction with lyso-PAF, an inactive PAF metabolite, confirmed the specificity of PAF towards this expression. The cells pretreated with CV-6209, a PAF receptor antagonist, did not show any induction of these genes by PAF. It is concluded that PAF causes induction of the early response genes c-fos and TIS-1 in a structurally specific and receptor dependent manner. This finding offers a new role for PAF at the nuclear level and may have important implications in the long term effects of PAF in pathophysiological conditions.

Thyroid Stimulating Action of Z-Guggulsterone Obtained from Commiphora mukul

A ketosteroid has been isolated from the oleo-resin of COMMIPHORA MUKUL and its structure (4,17(20)trans pregnandiene 3,16-dione; Z-guggulsterone) established from its physico-chemical properties, specially UV, IR, NMR and mass-spectra. The isolated ketosteroid showed a strong thyroid stimulatory action when administered to albino rats. Its administration (1 mg/100 g body weight) brought about an increase in iodine-uptake by thyroid and enhanced activities of thyroid peroxidase and protease as well as oxygen consumption by isolated slices of liver and biceps muscle.