Physico-chemical study of Vaikranta bhasma.

BACKGROUND: Vaikranta has very important place in Rasa sastra and is placed under Maharasa and Upratna group. It has been mentioned that vaikranta can be used in the place of diamond, which is a very precious stone and whose use is beyond the limit of the common man. Vaikranta possesses pharmacological and therapeutic properties similar to diamond, but still very few researchers have worked on it. AIMS AND OBJECTIVES: The main aim of the present study is to analyze vaikranta bhasma by employing various organoleptic methods mentioned in Ayurvedic science along with analysis as per tools available today. SETTINGS AND DESIGN: In the present study, vaikranta bhasma was prepared according to method mentioned in Rasa Ratna Samuccaya. Final product is prepared according to classical parameters described in Ayurvedic science. MATERIALS AND METHODS: Ayurvedic scholars have described various parameters for the qualitative evaluation of vaikranta bhasma, but all those are subjective in nature and cannot be evaluated numerically for reproducibility of the result. With this in mind, in the present study, tests as per Ayurvedic science and analytical parameters such as scanning electron microscopy, energy dispersive X-ray analysis, Fourier transform infrared spectrometry and inductively coupled plasma spectrometry were adopted to analyze the final product. RESULTS AND CONCLUSIONS: Data suggests that vaikranta bhasma is a multi-mineral compound, which contains iron and silica as major constituents and others are present as trace elements. The data obtained in this study suggest that quality specifications for vaikranta bhasma can be developed using tests described in Ayurvedic science along with analytical tools available today.

Wound healing in guinea pigs after topical application of starfish Pentaceraster regulus extract.

OBJECTIVE: To investigate the healing efficacy of Pentaceraster regulus (starfish) aqueous-methanol extract on cutaneous wounds in guinea pigs. METHOD: Freshly collected starfish were washed with distilled water and soaked in methanol for transportation. After filtering, soaking and concentration, the extract was fractionated into chloroform soluble (5g), 50% aqueous-methanol soluble (20g) and insoluble fractions (25g). Primary screening demonstrated moderate wound-healing activity in male Swiss-strain guinea pigs, so further fractionation into chloroform, 50% aqueous-methanol and insoluble fractions was undertaken.Wound-healing activity was concentrated only in the aqueous-methanol fraction, so this was used for the study. Animals received either 1% aqueous-methanol extract, the vehicle alone or 5% providone-iodine. The following were measured: wound area,wound tensile strength, DNA, total protein and hydroxyproline levels in excised granulation tissue. Histological changes were observed under microscope. RESULTS: Extract-treated wounds healed faster, indicated by a significant contraction in wound area (42%). Cellular proliferation and collagen synthesis at the wound site increased, demonstrated by increase in DNA (33%), protein (29%) and hydroxyproline (37%) content when compared with the controls and povidone-iodine-treated animals (standard care). These findings were confirmed by histological examination. Proper folding of collagen was demonstrated by a significant increase in tensile strength (34%). CONCLUSION: The results suggest that the aqueous-methanol extract of starfish P. regulus promotes wound-healing activity.

Bioactivity of marine organisms: Part IX--screening of some marine flora from the Indian coasts.

Alcoholic extracts of 48 identified species of marine flora were screened for a wide range of biological activities. Of these, 3 extracts showed diuretic activity while 2 extracts showed hypotensive effect.

Immunomodulation by opioid peptidomimetic compound.

OBJECTIVE: As a follow-up to our earlier studies on immunomodulation with opioid peptides, we synthesized and evaluated immunomodulatory activity of four peptidomimetic compounds, i.e. Tyr-NH-C(Me)(2)-CH(2)-O-Phe-NH(2 )(1), Tyr-NH-C(6)H(5)-(o)-CH(2)-CH(2)-O-Phe-NH(2) (2), Tyr-NH-CH(2)-CH(2)-O-Phe-NH(2) (3) and Tyr-NH-CH(D-Et)-CH(2)-O-Phe-NH(2) (4). METHODS: These compounds were synthesized in solution phase and evaluated for their immunomodulatory properties in vitro by mixed lymphocyte reaction (MLR), proliferation of opioid receptor-expressing cells, production of tumor necrosis factor-alpha (TNF-alpha) and nitric oxide. RESULTS: This study shows the immunosuppressive potential of synthetic peptidomimetic compound 3. This compound inhibited two-way MLR and suppressed the proliferation of the mu-opioid receptor expressing human embryonic kidney cells HEK 293 in vitro. Inhibition of MLR by compound 3 was reversed by naloxone (opioid receptor antagonist) and beta-funaltrexamine hydrochloride (mu-opioid receptor antagonist). The immunosuppressive effect of compound 3 was further demonstrated by inhibition of TNF-alpha and nitric oxide production in lipopolysaccharide-stimulated human PBMCs and mouse macrophage cells RAW 264.7, respectively. CONCLUSION: These observations suggest that compound 3 inhibits MLR through mu-opioid receptor present on cells.

Synthesis, molecular modeling and QSAR studies in chiral 2,3-disubstituted-1,2,3,4-tetrahydro-9H-pyrido(3,4-b)indoles as potential modulators of opioid antinociception.

In view of coexistence of opioid and cholecystokinin (CCK) in the brain areas concerned with pain processing, some semirigid racemic and chiral analogues of a potent CCK receptor antagonist (benzotript) have been synthesized and tested for their modulatory role on opioid antinociception, which may be mediated by CCK-B receptor. Some of these compounds, 3e, 3g, 3h, 4a, 4b and 4h, exhibited antinociceptive potentiation comparable to benzotript and proglumide. In order to identify the essential chemical structural features important for this potentiation, molecular modeling and quantitative structure activity relationship (QSAR) studies have been carried out in the S and R enantiomers of some of these semi-rigid compounds. The 3D-biophore models, common to all molecules of the training set have been derived. These models with superimposition (match value >0.25) depicted three biophoric sites one each for, pi/hydrophobic interactions, hydrogen bonding and ionic interactions among the phenyl/pyrrole ring, indole nitrogen, amidic oxygen, pyridyl nitrogen and lone pair of amidic oxygen. The total hydrophobicity and S absolute stereochemistry are found to positively contribute to potentiation of antinociception induced by morphine and the resulting quantitative pharmacophoric model with good correlation is found to well describe the observed activity.

A time course study for the development of an immunocompromised wound model, using hydrocortisone.

Although wound healing is essentially a physiologic process, some chronic wounds exhibit considerable delay in healing. Often these do not heal perfectly in individuals with low immune profiles. Thus, the present study was undertaken to develop an excision wound model in the immunocompromised state induced by pretreatment with hydrocortisone (HC) 40 mg/kg intramuscularly in male rats. Wounds of 8-mm diameter were made on the preshaved dorsal surface of rats using an Acuderm biopsy punch, following pretreatment with HC. After 14 days HC-treated animals exhibited atrophy of spleen and adrenal glands and a significant reduction of circulating lymphocytes and increase in neutrophils; these changes are indicative of immunosuppressive state of animals. The cell proliferation was significantly affected as shown by decreases in DNA (23%) and protein (11%). Furthermore, there were also significant reductions in tensile strength (37%) and hydroxyproline (33%) contents. These results were further supported by lack of contraction of wound edges. It is concluded that animals primed with HC 1 week prior to wounding developed prolonged immunosuppression, which significantly impaired the wound healing as compared with other groups. Thus, this can be experimentally employed as an immunocompromised wound model for evaluating compounds as novel wound healers suitable for immunocompromised subjects.

Healing potential of Calotropis procera on dermal wounds in Guinea pigs.

Calotropis procera (Asclepiadaceae) is a well known plant in the Ayurvedic system of medicine. Based on its traditional use this plant was selected for evaluation of its wound healing potential. For this purpose four full thickness excisional wounds of 8.0 mm diameter were inflicted on the back of guinea pigs. Topical application of 20 microl of 1.0% sterile solution of the latex of C. procera twice daily was followed for 7 days. The latex significantly augmented the healing process by markedly increasing collagen, DNA and protein synthesis and epithelisation leading to reduction in wound area. Thus the present study provides a scientific rationale for the traditional use of this plant in the management of wound healing.

Synthesis and opioid activity of novel tetrapeptides analogous to sequence (1-4) of dermorphin.

Seven new tetrapeptides analogous to (1-4) sequence of dermorphin were synthesized and evaluated for their opioid activity. The peptides were synthesized by the solution phase method. Their opioid activity revealed that peptides II and V were the most potent in the analgesia test as well as in the peripheral assays. Peptide II was most active in the guinea pig ileum assay, whereas peptide VI was 2763 times more selective for mu-receptors.

Possible involvement of nitric oxide in red nucleus stimulation-induced analgesia in the rat.

There is considerable evidence that nitric oxide (NO) plays a role in synaptic transmission in both central and peripheral nervous systems. Recent studies have suggested the involvement of the L-arginine-NO pathway in nociceptive transmission/modulation. Electrical stimulation of the red nucleus in the rat evokes potent analgesia. Microinjection of different concentrations of L-arginine (1 nmol-1 mumol), but not of D-arginine, produced quick and long-lasting analgesia. Pretreatment with N-nitro-L-arginine methyl ester (1 mumol), a nitric oxide synthase inhibitor, significantly prevented L-arginine-induced analgesia. Further, pretreatment of animals with methylene blue, a known guanylate cyclase inhibitor, also attenuated the development of analgesia. Our results suggest that L-arginine caused production of NO, which in turn activated the red nucleus analgesic system.

Neurobehavioral, neurochemical and electrophysiological studies in 6-hydroxydopamine lesioned and neural transplanted rats.

Unilateral injection of 6-hydroxydopamine (6-OHDA) into the caudate nucleus of rat caused degeneration of dopaminergic terminals, evidenced by significant (P < 0.05) elevation of spontaneous and drug-induced motor behaviour, enhanced DA receptor binding and significant increase in the neuronal firing rate of caudate neurons, suggesting supersensitivity of dopaminergic receptors. Eight weeks following the transplantation of embryonic cell suspensions from caudate at the lesioned site, a significant restoration of the enhanced 3H spiperone binding and neuronal activity of caudate neurons was observed in comparison with lesioned rats. These results clearly demonstrate that transplanted embryonic neuronal tissue at the lesioned site is capable of restoring the neuronal deficits caused by 6-OHDA as evidenced by significant amelioration in neurochemical, behavioral and electrophysiological alterations.

Analgesic effect of morphine, clonidine and serotonin microinjected into the PTN of rats.

The study was aimed to delineate the neurotransmitter receptors involved in pretectal analgesic mechanisms by direct microinjection of neurotransmitter agonists and antagonists through chronically implanted cannulae in the pretectal nucleus of rats. Morphine, clonidine and serotonin, at doses of 2.5 and 5.0 micrograms microinjected into the pretectal nucleus, produced a significant and prolonged analgesia as measured by the tail-flick test. The analgesia produced by morphine, clonidine and serotonin is significantly attenuated by pretreatment of the animals with naloxone (1 micrograms), yohimbine (5 micrograms) and methysergide (5-10 micrograms) respectively. The results indicate the possible involvement of opioid, adrenergic and serotonergic mechanisms in pretectal analgesia.

Evidence for involvement of nitric oxide in pretectal analgesia in rat.

The study was undertaken to evaluate the role of nitric oxide (NO) in pretectal (PTN)-induced analgesia in rats. Microinjection of varying concentrations of L-arginine (1 nM to 1 microM) produced a quick, long-lasting and concentration-dependent analgesic response, whereas similar concentrations of D-arginine failed to produce analgesia. Moreover pretreatment with N-nitro-L-arginine methyl ester (L-NAME, 1 microM) significantly prevented L-arginine induced analgesia. Further, pretreatment of animals with methylene blue, a known guanylate cyclase inhibitor also prevented the development of analgesia. Our study suggests that L-arginine caused production of NO, which in turn activates pretectal analgesic system involving cyclic GMP.

Enkephalin antisense peptides: design, synthesis, and biological activity.

The antisense mRNA complementary to the sense strand of Metenkephalin encodes the antisense peptides, His-Glu-Ala-Pro-Ile (compound 88/62). The antisense peptide and its (Gln1)-analogue (compound 88/63) have synergestic effects on the opioid activity of Met-enkephalin in the GPI test system.

Atropine and naloxone sensitive stimulation produced analgesia from pretectal nucleus in rat.

Mild and brief electrical stimulation of sites in the pretectal nucleus (PTN) of rats evoked potent analgesia of long duration, without significant aversions and was unassociated with motor deficit. The present study has analysed effects of opioidergic and cholinergic neurotransmitter antagonists administered intracerebroventricularly (i.c.v.) on this analgesia. Pretreatment either with naloxone or atropine sulphate both in doses of 30 and 50 micrograms each, respectively i.c.v., 10 min prior to subsequent pretectal stimulation, significantly attenuated the increase in tailflick latency. The antagonism of pretectal stimulation produced analgesia (PSPA) by naloxone and atropine, raises the possibility of involvement of both endogenous opioids and cholinergic mechanisms in pretectal analgesia.

Involvement of adrenergic & cholinergic mechanisms in analgesia electrically induced from pretectal nucleus of rat.

Analgesia induced by pretectal stimulation in rat was analysed using suitable antagonists. Mild electrical stimulation of sites in the pretectal nucleus (PTN) caused analgesia of long duration, without signs of aversion and unassociated with motor deficit. Pretreatment of animals with ip atropine sulphate (1 mg/kg), phenoxybenzamine (5 mg/kg), sotalol (2 mg/kg) and haloperidol (1 mg/kg) but not with saline, markedly reduced the antinociceptive response to PTN stimulation. Mild PTN stimulation thus seems to induce potent and long lasting analgesia in rats probably involving multisynaptic antinociceptive pathway(s).

Effect of monoamine antagonists on pretectal evoked analgesia in rat.

Mild and brief electrical stimulation of sites in the pretectal nucleus of rat produced analgesia (SPA) of long duration without significant aversion. Intracerebroventricular (icv) administration of 5-HT receptor antagonists methysergide (50 micrograms) and ketanserin (50 micrograms) and the dopaminergic antagonist haloperidol (50 micrograms) had no significant effect on pretectal SPA, but alpha and beta adrenoceptor antagonists phenoxybenzamine (50 micrograms) and sotalol (50 micrograms) on icv injection significantly antagonised the pretectal SPA. The results suggest that pretectal SPA involves activation of central adrenoceptors.

Morphine-like activity of some N-substituted amides of met-enkephalin.

Opioid activity of a homologous series of met-enkephalin alkylamides was analysed. In guinea pig ileum test, the hexylamide derivative was most active, whereas the isopropylamide derivative was most potent in analgesia test. The results suggest that structural changes of this type at the C-terminus of the pentapeptide improve the opioid activity.

Morphine-like activity of substituted amides & imides of [D-Ala2, Met5]-enkephalin.

Six enkephalin analogues (N-substituted amides and imides of [D-Ala2, Met5]-enkephalin) were synthesized and tested for opioid activity. All the compounds, except one i.e., compound IV, showed analgesic activity which was much higher than Met-enkephalin and morphine in mice and inhibited electrically induced contractions of isolated guineapig ileum, [D-Ala2, Met5]-enkephalin-morpholide and [D-Ala2, Met5]-enkephalin-beta-Ala-amide were the most potent analgesics and nearly 6 and 500 times as active as morphine and Met-enkephalin respectively. Both the compounds were equipotent on the guineapig ileum preparation, whereas the beta-Ala-amide was about twice as active as the morpholide in the electrically stimulated mouse vas deferens preparation.