Dried Latex Research Articles

Spectral characterization, analgesic, and anti-inflammatory effects of ethanolic extract of Calotropis procera leaf and dry latex from Jazan, Kingdom of Saudi Arabia

Traditional healers have used the shrub Calotropis procera (CP) for many years for various therapies. The present study investigated the bioactive constituents of ethanolic extract of CP leaf and dried latex using gas chromatography-mass spectrometry and Fourier transforms infrared spectroscopy. The identification and characterization of the compounds were confirmed by examining the constituents' mass spectrum fragmentations and FT-IR spectra and comparing the results with those in the literature. The tail-flick method was used to investigate the analgesic properties of the extract and its anti-inflammatory activities using a rat model of formalin-induced oedema. Acute oral toxicity in rats was studied per OECD recommendations. Twenty male rats were divided into four groups and received an ethanolic extract of the leaves and dried milky sap of CP (200 mg/Kg) in groups 1, 2, and 3. Group 4 rats were administered aspirin 50 mg/kg as a positive control. The CP dried latex extract has the highest content of lupeol and its acetate derivative compared to its leaf extract. The CP dried latex extract inhibited inflammation more significantly than the ethanolic leaf extract and the drug indomethacin at a higher dosage (200 mg/kg). The ethanolic extracts showed analgesia comparable to aspirin. It suggests that fatty acids and their esters, particularly ethyl linoleate (8.96%), ethyl palmitate (7.99%), ethyl linoleate (6.98%), and palmitic acid (5.18%), may be valuable biomarkers for characterizing leaf and latex samples and describing the medicinal potential of CP.

In Vivo Efficacy of Latex from Calotropis procera in Ameliorating Fever-Biochemical Characteristics and Plausible Mechanism.

Calotropis procera latex fractions possessing anti-inflammatory property were characterized for their biochemical properties, compared for their efficacy in ameliorating fever in rats and their mechanism of action was elucidated. Aqueous fraction and methanol extract (AqDL and MeDL) were derived from the dried latex (DL) and proteins were separated from the fresh latex (LP). Polyacrylamide gel electrophoresis carried out under denaturing conditions showed the presence of proteins with some similarity in LP and AqDL and both of these fractions exhibited proteinase activity by gelatin zymography. A further analysis revealed that only the LP fraction possesses cysteine proteinase activity. Oral administration of both AqDL and MeDL produced a dose-dependent reduction in body temperature in rats where fever was induced by yeast and their effect was comparable to that of standard drug paracetamol while intravenous administration of LP was not so effective. Both AqDL and MeDL produced a significant reduction in the levels of TNF-α, PGE2, and immunoreactivity of COX-2 in the hypothalamus as compared to yeast control group. This study shows that both AqDL and MeDL, the orally effective anti-inflammatory fractions of latex, have therapeutic potential in treating various febrile conditions.

Protective effect of Calotropis procera latex extracts on experimentally induced gastric ulcers in rat

Aim of the study Calotropis procera is a wild growing plant with multifarious medicinal properties. The present study was carried out to evaluate the effect of dried latex (DL) of Calotropis procera and its methanol extract (MeDL) against gastric ulcers induced in rats. Materials and methods Aqueous suspension of DL (20 and 100 mg/kg) and MeDL (10 and 50 mg/kg) were given orally to 36 h fasted rats and ulcers were induced by ethanol, pyloric ligation and aspirin. Parameters like ulcer score and levels of oxidative stress markers were measured in all the models. The effect on gastric hemorrhage and tissue histology was studied in ethanol model and on acidity, pH and volume of gastric secretion was evaluated in pyloric ligation model. The protective effect of DL and MeDL was compared with that of standard anti-ulcer drug famotidine (20 mg/kg). Results DL and MeDL produced 85–95% inhibition of gastric mucosal damage in ethanol model and 70–80% inhibition in aspirin model. The protective effect of these extracts was associated with marked reduction in gastric hemorrhage, maintenance of tissue integrity and normalization of levels of oxidative stress markers like glutathione, thiobarbituric acid reactive substances and superoxide dismutase. Like famotidine, DL and MeDL decreased the gastric acidity from 376.17 ± 21.47 mequiv./l to 163.88 ± 6.86 and 201.48 ± 8.86 mequiv./l respectively in pyloric ligation model. These extracts increased the gastric pH without affording any protection to gastric mucosa in this model. Conclusion The latex of Calotropis procera has the therapeutic potential to relieve gastric hyperacidity and to prevent gastric ulceration induced by necrotizing agents.

Effect of aqueous suspension of dried latex of Calotropis procera on hepatorenal functions in rat

Aim of the study The present study was carried out to evaluate the effect of dry latex (DL) of Calotropis procera, a plant of the family Asclepiadaceae, on the functions of liver and kidney in normal rats. Materials and methods Aqueous suspension of DL was orally administered to rats at doses of 10, 100 and 400 mg/kg for a period of 45 days and the effect on various parameters reflecting liver and kidney functions was compared with that of normal controls. Results Treatment with DL did not alter the serum levels of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), creatinine, urea and urinary levels of glucose and protein as compared to the normal rats. It exhibited a modulatory role in maintaining the levels of blood glucose and serum insulin. The liver and kidney of DL treated and normal rats were also comparable with regard to the tissue levels of oxidative stress markers and histology. Further, no signs of toxicity were observed in the DL treated rats over the study period. Conclusion Our study reveals that aqueous suspension of Calotropis procera latex does not produce any toxicity and could be safely used for therapeutic purpose at the doses studied.

Calotropis procera latex affords protection against carbon tetrachloride induced hepatotoxicity in rats

In the present study, latex of Calotropis procera possessing potent antioxidant and anti-inflammatory properties was evaluated for its hepatoprotective effect against carbon tetrachloride (CCl 4) induced hepatotoxicity in rats. Subcutaneous injection of CCl 4, administered twice a week, produced a marked elevation in the serum levels of aspartate transaminase (AST), alanine transaminase (ALT) and tumor necrosis factor alpha (TNF-α). Histological analysis of the liver of these rats revealed marked necro-inflammatory changes that were associated with increase in the levels of TBARS, PGE 2 and catalase and decrease in the levels of glutathione (GSH), superoxide dismutase (SOD) and glutathione peroxidase (GPx). Daily oral administration of aqueous suspension of dried latex (DL) of Calotropis procera at 5, 50 and 100 mg/kg doses produced a dose-dependent reduction in the serum levels of liver enzymes and inflammatory mediators and attenuated the necro-inflammatory changes in the liver. The DL treatment also normalized various biochemical parameters of oxidative stress. Our study shows that the antioxidant and anti-inflammatory effects of DL and silymarin were comparable and suggests that DL could be used as a hepatoprotective agent.

Calotropis procera latex‐induced inflammatory hyperalgesia – effect of bradyzide and morphine

1 The milky white latex of the plant Calotropis procera induces inflammatory response upon accidental exposure and on local administration that could be effectively ameliorated by antihistaminic and standard anti-inflammatory drugs. 2 The aim of the present study was to evaluate the anti-oedematogenic and analgesic effect of the bradykinin antagonist, bradyzide (BDZ) and the opioidergic analgesic, morphine (Mor) against inflammatory hyperalgesia induced by the dried latex (DL) of C. procera in the rat paw oedema model. 3 An aqueous solution of DL (0.1 ml of 1% solution) was injected into the sub-plantar surface of the rat paw and the paw volume was measured at different time intervals. The inhibitory effect of bradyzide and morphine on oedema formation and hyperalgesic response was compared with that of cyproheptadine (CPH), a potent inhibitor of DL-induced oedema formation. 4 The hyperalgesic response was evaluated by the dorsal flexion pain test, compression test and by observing motility, stair-climbing ability, and the grooming behaviour of the rats. 5 The effect of these drugs was also evaluated against DL-induced writhings in the mouse model. 6 Both bradyzide and morphine inhibited DL-induced oedema formation by 30-40% and CPH was more effective in this regard (81% inhibition). The antihyperalgesic effect of both the drugs was more pronounced than that of CPH. Both bradyzide and morphine markedly inhibited the grooming behaviour and the effect of morphine could be reversed by pretreatment with naloxone. 7 Thus, our study shows that DL-induced oedema formation is effectively inhibited by antihistaminic/antiserotonergic drug and associated hyperalgesia by analgesic drugs.

A comparative study on the efficacy of rofecoxib in monoarticular arthritis induced by latex of Calotropis procera and Freund’s complete adjuvant

The role of prostaglandins in Calotropis procera latex induced inflammation and hyperalgesia has been well established. The acute inflammation induced by the dried latex (DL) of this plant could be effectively ameliorated by standard anti-inflammatory drugs. In present study we have evaluated the efficacy of rofecoxib, a COX-2 inhibitor in monoarthritis induced by intra-articular injection of DL and compared it with that against Freund's Complete Adjuvant (FCA). DL and FCA were injected into the right ankle joint of the rat and the joint diameter was measured by a micrometer screw gauge on day 0, 4, 8, 12, 20 and 28. Concomitantly the hyperalgesic response was also evaluated by motility test, stair climbing ability test, dorsal flexion pain test and compression test. The effect of rofecoxib was evaluated on these parameters in both the models. Both DL and FCA produced peak inflammation on day 4 that was associated with decreased pain threshold and functional impairment. Although rofecoxib was more effective in improving motility in the DL model, its effect on joint inflammation, hyperalgesia and stair climbing ability was comparable in both the models. Thus, our study indicates that DL induced monoarthritis could be used as a model for the screening and evaluation of anti-inflammatory and anti-arthritic drugs.

Anticancer and cytotoxic properties of the latex of Calotropis procera in a transgenic mouse model of hepatocellular carcinoma

To evaluate the anticancer property of the dried latex (DL) of Calotropis procera, a tropical medicinal plant, in the X15-myc transgenic mouse model of hepatocellular carcinoma and to elucidate its mechanism of action in cell culture. The young transgenic mice were orally fed with the aqueous suspension of DL (400 mg/kg for 5 d/wk) for 15 wk and their liver was examined for histopathological changes at 20 wk. Serum levels of vascular endothelial growth factor (VEGF) were also measured in these animals. To characterize the active fraction, DL was extracted with petroleum ether followed by methanol. The methanolic extract was sub-fractionated on a silica gel G column using a combination of non-polar and polar solvents and eleven fractions were obtained. Each fraction was analysed for cytotoxic effect on hepatoma (Huh7) and non-hepatoma (COS-1) cell lines and non-transformed hepatocytes (AML12) using tetrazolium (MTT) assay. Finally, the mechanism of cell death was investigated by measuring the levels of Bcl2, caspase 3 and DNA fragmentation. DL treatment of mice showed a complete protection against hepatocarcinogenesis. No adverse effect was observed in these animals. The serum VEGF level was significantly lowered in the treated mice as compared to control animals. Cell culture studies revealed that the methanolic extract of DL as well as its fraction 8 induced extensive cell death in both Huh-7 and COS-1 cells while AML12 cells were spared. This was accompanied by extensive fragmentation of DNA in Huh-7 and COS-1 cells. No change in the levels of canonical markers of apoptosis such as Bcl2 and caspase 3 was observed. DL of C. procera has the potential for anti-cancer therapy due to its differentiable targets and non-interference with regular pathway of apoptosis.

Calotropis procera Latex‐Induced Inflammatory Hyperalgesia—Effect of Antiinflammatory Drugs

The milky white latex of plant Calotropis procera produces inflammation of the skin and mucous membranes on accidental exposure. It produces edema on local administration due to the release of histamine and prostaglandins and is associated with hyperalgesia. In the present study we have evaluated the antiedematous and analgesic activity of antiinflammatory drugs against inflammatory response induced by dried latex (DL) of C procera in rat paw edema model. An aqueous extract of DL of C procera was injected into the subplantar surface of the rat paw and the paw volume was measured by a plethysmometer at 0, 1, 2, 6, 12, and 24 hours. Concomitantly the hyperalgesic response was also evaluated by motility test, stair climbing ability test, dorsal flexion pain test, compression test, and observing the grooming behavior. The inhibitory effect of diclofenac and rofecoxib on edema formation and hyperalgesic response was compared with cyproheptadine (CPH). DL-induced edema formation was maximum at 2 hours that was associated with decreased pain threshold, functional impairment, and grooming. Treatment with antiinflammatory drugs and CPH significantly attenuated the edematous response and grooming, increased the pain threshold, and improved functional parameters. Both antiinflammatory and antiserotonergic drugs significantly inhibited the hyperalgesia associated with DL-induced paw edema. Rofecoxib was found to be superior than diclofenac and was as effective as CPH in ameliorating the hyperalgesia. However, it was found to be less effective than CPH in attenuating edema formation.

Antiinflammatory Efficacy of Extracts of Latex of Calotropis procera Against Different Mediators of Inflammation

The latex of the plant Calotropis procera has been reported to exhibit potent antiinflammatory activity against carrageenin and formalin that are known to release various mediators. In the present study, we have evaluated the efficacy of extracts prepared from the latex of C procera against inflammation induced by histamine, serotonin, compound 48/80, bradykinin (BK), and prostaglandin E2(PGE2) in the rat paw oedema model. The paw oedema was induced by the subplantar injection of various inflammagens and oedema volume was recorded using a plethysmometer. The aqueous and methanol extracts of the dried latex (DL) and standard antiinflammatory drugs were administered orally 1 hour before inducing inflammation. The inhibitory effect of the extracts was also evaluated against cellular influx induced by carrageenin. The antiinflammatory effect of aqueous and methanolic extracts of DL was more pronounced than phenylbutazone (PBZ) against carrageenin while it was comparable to chlorpheniramine and PBZ against histamine and PGE2, respectively. Both extracts produced about 80%, 40%, and 30% inhibition of inflammation induced by BK, compound 48/80, and serotonin. The histological analysis revealed that the extracts were more potent than PBZ in inhibiting cellular infiltration and subcutaneous oedema induced by carrageenin. The extracts of DL exert their antiinflammatory effects mainly by inhibiting histamine and BK and partly by inhibiting PGE2.

Effect of anti-inflammatory drugs on pleurisy induced by latex of Calotropis procera in rats

In present study, we have characterized the inflammation induced by latex of Calotropis procera in the rat pleurisy model and evaluated the effect of various inhibitors of inflammatory mediators. Injection of dried latex (DL) into the pleural cavity elicited an acute inflammatory response characterized by protein rich fluid accumulation and leucocyte (polymorphonuclear cells, and mononuclear cells) infiltration in the pleural cavity. The peak inflammatory response was obtained at 6 h when the fluid volume, protein concentration and cell infiltration were maximum. All these parameters were attenuated by phenylbutazone (PBZ), celecoxib, dexamethasone, cyproheptadine and chlorpheniramine. All these drugs were also effective in inhibiting the production of prostaglandin E 2 (PGE 2). Of all the drugs tested, dexamethasone was most effective in inhibiting DL induced pleurisy. The results clearly indicate that prostaglandins (PGs) and biogenic amines play a key role in the development of pleurisy induced by DL and it serves as a model to evaluate drugs inhibiting cellular influx associated with inflammatory response.

Histamine mediates the pro-inflammatory effect of latex of Calotropis procera in rats.

Calotropis procera is known to produce contact dermatitis and the latex of this plant produces intense inflammation when injected locally. However, the precise mode of its pro-inflammatory effect is not known. In present study we have pharmacologically characterized the inflammation induced by latex of C. procera in a rat paw edema model and determined the role of histamine in latex-induced inflammation. Inflammation was induced in the hind paw of rats by injecting different doses of dried latex (DL) of C. procera. The inhibitory effect of phenylbutazone, dexamethasone, celecoxib, cyproheptadine, chlorpheniramine and compound 48/80 on edema volume was evaluated and compared with that against carrageenan. The histamine content of DL was measured fluorometrically. DL produced dose-dependent inflammation of the rat paw. Cyproheptadine and chlorpheniramine effectively inhibited DL-induced inflammation (90%; p < 0.01), while anti-inflammatory drugs phenylbutazone, dexamethasone and celecoxib were more effective against carrageenan-induced inflammation. Depletion of mast cell histamine by compound 48/80 produced a significant decrease in DL-induced inflammation as compared with carrageenan (500% versus 25%). DL was also found to contain about 6 microg/g of histamine. Thus, our study shows that the biogenic amines play a significant role in C. procera latex-induced inflammation and antihistaminic drugs could be effectively used to inhibit inflammatory response elicited by exposure to latex.

Anthelmintic Activity of Latex of Calotropis procera

The crude latex of Calotropis procera was evaluated for anthelmintic activity using adult earthworms. Both fresh as well as aqueous extracts of dried latex exhibited a dose-dependent inhibition of spontaneous motility (paralysis) and evoked responses to pin-prick. With higher doses (100mg/ml of aqueous extract of dry latex and 100% fresh latex) the effects were comparable with that of 3% piperazine. However, there was no final recovery in the case of worms treated with latex in contrast to piperazine with which the paralysis was reversible and the worms recovered completely within six hours. The results show that latex possesses wormicidal activity and thus, may be useful as an anthelmintic.

Inhibition of Calotropis procera Latex‐Induced Inflammatory Hyperalgesia by Oxytocin and Melatonin

The latex of the wild growing plant Calotropis procera produces inflammation of the skin and mucous membranes upon accidental exposure. On local administration it elicits an intense inflammatory response due to the release of histamine and prostaglandins that is associated with hyperalgesia. In the present study we have evaluated the anti-inflammatory and antinociceptive activity of oxytocin and melatonin against rat paw edema induced by dried latex (DL) of C procera and compared it with that against carrageenan-induced paw edema. Aqueous extract of DL of C procera or carrageenan (1%) was injected into the subplantar surface of the rat paw and the paw volume was measured at 0, 1, 2, 3, 4, 6, 10, and 24 hours. The associated hyperalgesic response and functional impairment were also evaluated concomitantly by dorsal flexion pain test, motility test, and stair climbing ability test. The inhibitory effect of oxytocin and melatonin on edema formation and hyperalgesic response was compared with dexamethasone. DL-induced edema formation was maximum at 2 hours and was associated with decreased pain threshold and functional impairment. Treatment with melatonin significantly attenuated the edematous response while both oxytocin and melatonin increased the pain threshold and improved functional parameters. Both oxytocin and melatonin significantly inhibited the hyperalgesia associated with DL-induced paw edema. Oxytocin was found to be as effective as melatonin in ameliorating the hyperalgesic response. However, it was found to be less effective than melatonin in attenuating edema formation.

Assessment of Spatial Order in Dried Latexes by Small-Angle X-ray Scattering

The spatial order present in a dried latex consisting of poly(styrene) (PS) particles (diameter: 106 nm) is investigated by small-angle X-ray scattering (SAXS). The process of drying is conducted below the glass transition temperature of PS to avoid deformation of the particles when going from the concentrated latex to a system of close-contact particles. The assessment of spatial order rests on the analysis of the structure factor S(q) (q = (4π/λ) sin(θ/2); θ = scattering angle; λ = wavelength) of the dry latex. S(q) has been obtained by SAXS measurements of the particles in the dilute latex and in the dried system. Special attention is paid to the different contrast between the particles and the surrounding medium when going from the waterborne latex particles to the dry film. It is demonstrated that the system under consideration here exhibits no true long-range order but a more liquidlike short range order. The data show furthermore that the deformation of the particles during the process of drying m...