In vitro immunomodulatory effect of Pouteria cambodiana (Pierre ex Dubard) Baehni extract

Inhibitory Effects of Saponin-Rich Extracts from Pouteria cambodiana against Digestive Enzymes α-Glucosidase and Pancreatic Lipase

Pouteria cambodiana is a perennial plant that has a wide distribution in tropical regions. It is commonly referred to as 'Nom-nang' in the northern region of Thailand. The bark of this plant has been used for the purpose of promoting lactation among breastfeeding mothers. Moreover, P. cambodiana bark has a high nutraceutical potential due to the presence of saponins, which are secondary metabolites. The purpose of this study was to determine the optimal conditions for ultrasound-assisted extraction (UAE) of saponins from the bark of P. cambodiana and to assess the in vitro inhibitory activities of saponin-rich extracts. The most effective extraction conditions involved a temperature of 50 °C and a 50% concentration level of ethanol as the solvent, which allowed the extraction of saponin at a concentration of 36.04 mg/g. Saponin-rich extracts and their hydrolysates from P. cambodiana bark were evaluated for their ability to inhibit α-glucosidase and pancreatic lipase. The IC50 values for saponin- and sapogenin-rich extracts inhibiting α-glucosidase were 0.10 and 2.98 mg/mL, respectively. Non-hydrolysed extracts also had a stronger inhibitory effect than acarbose. In the case of pancreatic lipase, only the hydrolysed extracts exhibited inhibitory effects on pancreatic lipase (IC50 of 7.60 mg/mL). Thus, P. cambodiana bark may be an applicable natural resource for preparing ingredients for functional products with inhibitory activity against α-glucosidase and pancreatic lipase. The phenolic contents, saponin contents, and antioxidant activities of the dried extract stored at a low temperature of 25 °C for 2 months showed the best stability, with more than 90% retention.

Stability and Antioxidant Activity of Pouteria macrophylla Fruit Extract, a Natural Source of Gallic Acid

Pouteria macrophylla (cutite) fruits are rich in phenolic acids, resulting in antioxidant and skin depigmenting activity. The aim of this study, then, is to evaluate the cutite extract stability under three variations of light, time, and temperature using a Box-Behnken experimental design to analyze through the surface response the variations of the total phenolic content (TPC), antioxidant activity (AA), and gallic acid content (GA). A colorimetric assay was also performed, and a decrease in the darkening index was noticed due to the high phenolic coloration in the presence of light, indicating less degradation to extract stability. The experimental planning showed variations in all responses, and second-order polynomial models were calculated and considered predictable, as well as the effects were significant. The TPC exhibited a variation in less concentrated samples (0.5% p/v) at higher temperatures (90 °C). In contrast, the temperature was the only influential variable for AA, where only higher temperatures (60-90 °C) were able to destabilize the fruit extract. Differently, GA showed only the concentration as the influential variable, exhibiting that neither temperature nor time of exposure could affect the gallic acid content stability of P. macrophylla extract. For this, P. macrophylla extract was shown to be highly stable, providing a great perspective on cosmetic application.

Platelet augmentation activity of mature leaf juice of Sri Lankan wild type cultivar of Carica papaya L: Insights into potential cellular mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Carica papaya L., a common fruit crop of the family Caricaceae and its leaf juice/extract is a traditionally commended preparation against dengue and other thrombocytopenic diseases by many Asian countries.

AIM OF THE STUDY

The present study posits the potential cellular mechanisms of platelet augmentation activity of mature leaf juice of Sri Lankan wild-type Carica papaya.

MATERIALS AND METHODS

C. papaya leaf juice prepared from different cultivar types, maturity of the leaf, agro-climatic region, and preparation methods were orally administered to hydroxyurea-induced thrombocytopenic rats at 0.72 ml/100 g BW dosage to investigate the most potent platelet increasing preparation. The papaya juice doses; low dose (LD-0.18 ml/100 g BW), human equivalent dose (HED-0.36 ml/100 g BW), and high dose (HD-0.72 ml/100 g BW), were administered to thrombocytopenic rats (N = 6/group) daily for three consecutive days and post-treatment plasma levels of interleukin 6 (IL-6), thrombopoietin (TPO), and platelet-activating factor (PAF) were quantified using specific rat ELISA kits. The mature leaf juice of C. papaya induced IL-6 secretion from bone marrow cell (BMC) cultures was quantified using ELISA. The ability of papaya juice to protect the platelet membrane, from the damage caused by the lytic agent was analyzed in vitro using the lactate dehydrogenase (LDH) assay. The effect of the mature leaf juice of C. papaya on secondary hemostasis was investigated using blood coagulation and clot hydrolyzing activity.

RESULTS

The comparative analysis revealed that the platelet increasing activity of C. papaya leaf did not significantly differ among different types of cultivar, maturity of the leaf, agro-climatic regions and preparation methods (p > 0.05). Both TPO and PAF levels in thrombocytopenic rats diminished when treated with all three doses of the mature leaf juice of C. papaya (p < 0.05), yet IL-6 plasma level was unaltered (p > 0.05). Nevertheless, ex vivo treatment of the mature leaf juice of C. papaya had significantly enhanced IL-6 levels of rat BMC cultures (p < 0.05). Pre-treatment of platelets with the mature leaf juice of C. papaya at different concentrations significantly inhibited LDH leakage from platelets and may have reduced the membrane damage caused by the lytic agent (p < 0.05). Treatment of mature leaf juice of C. papaya also significantly reduced blood clotting time through the extrinsic pathway of the blood coagulation cascade (p < 0.05). Further, prolonged incubation of the plasma clot with different concentrations of the papaya leaf juice revealed dose-dependent hydrolysis of the blood clot, indicating fibrinolysis activity.

CONCLUSIONS

The current study exceeded the traditional medicinal claims, and scientifically affirmed the platelet augmentation activity of mature leaf juice of C. papaya. The mechanistic rationale tested herein explicated that the platelet augmentation activity of the papaya leaf juice can be partially attributed to the stimulation of bone marrow megakaryocytes via modulating thrombopoietic cytokines TPO and IL-6, and by inhibiting the secretion of PAF, while reducing the peripheral platelet destruction by stabilizing the platelet membrane. Further, mature leaf juice of C. papaya imparted both pro-coagulation and fibrinolysis activity of secondary hemostasis endorsing its potential against thrombocytopenia.

Phytochemical and biological diversity of triterpenoid saponins from family Sapotaceae: A comprehensive review

Sapotaceae is a flowering plants family reported for its richness in triterpenoid saponins. Sapotaceae comprises a large number of fruit-producing plants of nutritional and medicinal value. Different species of family Sapotaceae received a considerable interest owing to their rich triterpenoid saponins content of a myriad pharmacological effects and health benefits. Several databases were searched for collecting papers for this review in the scope of phytochemistry, bioactivity and record of triterpenoid saponins from family Sapotacese such as PubMed, Google Scholar, Web of Science, Scopus and Reaxys from 1990 till now. Triterpenoid saponins reported from Sapotaceae plants are mostly of protobassic acid, 16-α-hydroxyprotobassic acid, bayogenin, and oleanolic acid derivatives with both monodesmosidic and/or bidesmosidic attached sugar side chains. Besides, the most frequently attached sugar units are glucose, glucoronic acid, apiose, xylose, rhamnose, and arabinose. The reported health effects of Sapotaceae plants in folk medicine in relation to their bioactive saponins were also reviewed with special attention to anti-inflammatory, antiulcer activity, antimicrobial activity, cytotoxic, anti-hypercholesterolemic, antioxidant, and immunomodulatory activities. This review aims to present a holistic compile on the phytochemical and biological diversity of triterpenoid saponins reported from family Sapotaceae with future perspectives.

N-acetylcysteine reduced the immunotoxicity effects induced in vitro by azoxystrobin and iprodione fungicides in mice

Azoxystrobin (AZO) and Iprodione (IPR) fungicides are extensively used worldwide, and therefore, contaminate all environmental compartments. The toxicity and the mechanisms by which they affected immune cells are complex and remain unknown. This study investigated the impact of AZO and IPR on the in vitro function of mice peritoneal macrophages including lysosomal enzyme activity and tumor necrosis factor (TNF)α and nitric oxide (NO) production in response to lipopolysaccharide (LPS) stimulation, the proliferation of mice splenocytes stimulated by concanavalin (Con)A and LPS, and the production of the Th1cytokine interferon-gamma (IFNγ) and the Th2 cytokine interleukin (IL)-4 and IL-10 by ConA-activated splenocytes. This is the first report indicating that AZO and IPR fungicides dose-dependently inhibited mice macrophage lysosomal enzyme activity and LPS-stimulated production of TNFα and NO. Mitogen-induced proliferation of mice splenocytes was also suppressed by AZO and IPR in a dose-dependent manner. More pronounced impact was observed on ConA-induced response. The production of IFNγ by ConA-stimulated splenocytes was dose-dependently inhibited; however, the production of IL-4 and IL-10 increased in the same conditions. These results suggested that AZO and IPR polarized Th1/Th2 cytokine balance towards Th2 response. Overall, marked immunosuppressive effects were observed for AZO. The immunomodulatory effects caused by AZO and IPR were partially reversed by the pharmacological antioxidant N-acetylcysteine (NAC), suggesting that both fungicides exerted their actions through, at least in part, oxidative stress-dependent mechanism. Collectively, our data showed that AZO and IPR fungicides exerted potent immunomodulatory effects in vitro with eventually strong consequences on immune response and immunologically based diseases.

Immunostimulatory and anti-allergic potential of novel heterotrimeric lectin from seeds of Zizyphus mauritiana Lam

Zizyphus mauritiana Lam. seeds (ZMS) have been used medicinally as sedative or hypnotic drugs in most of Asian countries. ZMS has significant benefits to the human health. Therefore, we have evaluated immunomodulatory effect of lectin extracted from these ZMSL in both in vitro and in vivo study. Anaphylaxis is a severe life-threatening allergic reaction and Arthus reaction is deposition of immune complex and complement system activation, so we hypothesized that if ZMSL can protect these severe allergic diseases. We have studied the effect of ZMSL on macrophages and Wistar albino rats and confirmed its protective effect against anaphylaxis and Arthus reaction. Results of this study suggest ZMSL have immunostimulatory and antiallergic activity.

Pharmacological Activity of Eriodictyol: The Major Natural Polyphenolic Flavanone

Eriodictyol is a flavonoid that belongs to a subclass of flavanones and is widespread in citrus fruits, vegetables, and medicinally important plants. Eriodictyol has been anticipated to explain the method of its activity via multiple cellular signaling cascades. Eriodictyol is an effective natural drug source to maintain higher health standards due to its excellent therapeutic roles in neuroprotection, cardioprotective activity, hepatoprotective activity, antidiabetes and obesity, and skin protection and having highly analgesic, antioxidant, and anti-inflammatory effects, antipyretic and antinociceptive actions, antitumor activity, and much more. This review aims to highlight the modes of action of eriodictyol against various diseases via multiple cellular signaling pathways.

Immunomodulatory Activity of the Marine Sponge, Haliclona (Soestella) sp. (Haplosclerida: Chalinidae), from Sri Lanka in Wistar Albino Rats: Immunosuppression and Th1-Skewed Cytokine Response

Natural secondary metabolites of sponges of the genus Haliclona are associated with an array of biological activity with therapeutic usage. We investigated the immunopharmacological properties of a presumably novel marine sponge species from Sri Lanka, Haliclona (Soestella) sp. Sponge material was collected from southern Sri Lanka by scuba diving. Sponge identification was based on spicule and skeleton morphology using light microscopy. Selected in vivo and ex vivo tests investigated nonfunctional and functional immunomodulatory activity of the Haliclona (Soestella) sp. crude extract (HSCE) in the Wistar rat model. Compared to the controls, rats orally gavaged daily for 14 consecutive days with 15 mg/kg dose of the HSCE manifested a significant reduction of immune cell counts of total WBCs (by 17%; p < 0.01), lymphocytes (38%), platelets (52%), splenocytes (20%), and bone marrow cells (BMC; 60%) (p < 0.001), with a concurrent increase in the neutrophil : lymphocyte ratio (p < 0.05); RBC counts abated by 53% (p < 0.001). A significant reduction of the splenosomatic index was evident with the 10 and 15 mg/kg doses (p < 0.001). Rat plasma TNF-α cytokine level was augmented by tenfold (p < 0.001), IL-6 level by twofold (p < 0.01) with the 15 mg/kg HSCE treatment, while IL-10 was detectable in rat plasma only with this treatment; the corresponding Th₁ : Th₂ cytokine ratio (TNF-α : IL-10) was indicative of an unequivocal Th1-skewed cytokine response (p < 0.01). Ex vivo bone marrow cell and splenocyte proliferation were significantly and dose dependently impaired by HSCE (IC₅₀ 0.719 and 0.931 μg/mL, respectively; p < 0.05). Subacute toxicity testing established that HSCE was devoid of general toxic, hepatotoxic, and nephrotoxic effects. In conclusion, HSCE was orally active, nontoxic, and effectively suppressed nonfunctional and functional immunological parameters of Wistar rats, suggestive of the potential use of the HSCE as an immunosuppressant drug lead.

The effect of cytoplasmic crude extracts of Trichophyton verrucosum on cell mediated immunity

OBJECTIVE

Trichophyton verrucosum is a slow growing dermatophyte responsible for a number of skin diseases such as ringworm, and is characterized by patches of hair loss and thick crusts on the host skin in domestic animals. In this study, we examined the immunomodulatory effects of crude extract of Trichophyton verrucosum (TV)cytoplasm in a mouse model.

METHODS

The TV variate was cultured on Sabouraud dextrose agar and the mycelium was grinded by mechanical force. The purified protein was obtained from crude extract of the fungus, and protein concentration was measured by BradFord assay. Six to eight week-female BALB/c mice were divided into three groups: test group, receiving cytoplasmic crude extract plus defibrinated sheep blood; control group, receiving defibrinated sheep blood; and normal group, receiving normal saline. Injections were performed on days 0, 3, 5, 7 and 9 and the mice were sacrificed four days after the last injection. T lymphocyte metabolic activity was examined by methyl thiazol tetrazolium (MTT) assay, and also interleukin-4 (IL-4) and interferon-γ (IFNγ) levels were evaluated by enzyme-linked immunosorbent assay (ELISA).

RESULTS

MTT assay showed that the TV extract stimulated lymphocyte metabolic activity. ELISA results showed that despite increase in the level of IFNγ, no changes were observed in IL-4 level.

CONCLUSIONS

Results indicated that crude extract of TV cytoplasm may probably act as an immune modulator, which affects Th₁ responses. The TV crude extract may be an appropriate agent to induce cellular immunity for combating dermatophytosis infection in animals; and therefore, TV extract may have some potential applications in vaccine/adjuvant technology.

Thermal treatment of luteolin-7-O-β-glucoside improves its immunomodulatory and antioxidant potencies

Phytochemicals extracted from flowers, roots and bark, leaves, and other plant sources have been used extensively throughout human history with varying levels of efficacy in prevention and treatment of disease. Recently, advanced methods for characterization and clinical use of these materials have allowed modern understanding of their properties to be used as immunomodulatory agents that act by enhancement of endogenous cytoprotective mechanisms, avoiding interference with normal physiologic signaling and highly effective medical treatment with minimal adverse side effects. Simple methods have been identified for improving their biological effects, such as thermal conditioning by heating or freezing-prominent example being heat treatment of lycopene and tetrahydrocannabinol. The present investigation shows improvement of the ability of heat to augment splenocyte proliferation, natural killer (NK) cell activities, and antioxidant capacity of the flavonoid luteolin-7-O-β-glucoside (L7G) in comparison with the native (non heat-treated) molecule, while further demonstrating that both the native and the heat-treated variants exhibit comparable antioxidant properties, as evidenced by their effects in macrophages by inhibition of nitric oxide production and lysosomal enzyme activity in experiments that strengthen lysosomal membrane integrity. Outcomes of these studies suggest that heat-treated L7G shows promise for use in immunotherapy, including anti-cancer regimens, as shown by its improvement of NK cell cytotoxicity.

Mature leaf concentrate of Sri Lankan wild type Carica papaya Linn. modulates nonfunctional and functional immune responses of rats

BACKGROUND

The leaf concentrate of Carica papaya is a traditionally acclaimed immunomodulatory remedy against numerous diseases; nonetheless comprehensive scientific validation of this claim is limited. The present study thus investigated the immunomodulatory potential of Carica papaya mature leaf concentrate (MLCC) of the Sri Lankan wild type cultivar using nonfunctional and functional immunological assays.

METHODS

Wistar rats (N = 6/ group) were orally gavaged with 3 doses (0.18, 0.36 and 0.72 ml/100g body weight) of the MLCC once daily for 3 consecutive days. Selected nonfunctional (enumeration of immune cells and cytokine levels) and functional (cell proliferation and phagocytic activity) immunological parameters, and acute toxic effects were determined using standard methods. Effect of the MLCC (31.25, 62.5, 125, 250, 500 and 1000 μg/ml) on ex vivo proliferation of bone marrow cells (BMC) and splenocytes (SC), and in vitro phagocytic activity of peritoneal macrophages (PMs), and their corresponding cytokine responses were evaluated. The phytochemical profile of the MLCC was established using liquid chromatography-mass spectrometry (LS-MS) and Gas chromatography-mass spectrometry (GC-MS).

RESULTS

Counts of rat platelets, total leukocytes, lymphocyte and monocyte sub populations, and BMCs were significantly augmented by oral gavage of the MLCC (p < 0.05). The highest MLCC dose tested herein significantly reduced pro inflammatory cytokines, Interleukin 6 (IL-6) and Tumor Necrosis Factor α (TNF α) levels of rats (p < 0.05). The in vivo phagocytic index of rat PMs significantly increased by oral gavage of all three doses of the MLCC (p < 0.05). In vitro phagocytic activity of rat PMs were enhanced by the MLCC and triggered a Th1 biased cytokine response. The MLCC at low concentrations elicited ex vivo proliferation of BMC (31.25 μg/ml) and SC (31.25 and 62.5 μg/ml) respectively. Conversely, high concentrations (500 and 1000 μg/ml) exhibited cytotoxicity of both BMC and SC with significant modulation of cytokines. Chemical profile of the MLCC revealed the presence of several immunomodulatory compounds. The oral gavage of the MLCC was found to be safe in terms of both hepatic and renal toxicities.

CONCLUSION

The present study established that the mature leaf concentrate (MLCC) of Carica papaya Sri Lankan wild type cultivar is orally active, safe and effectively modulates nonfunctional and functional immunological parameters of rats that unequivocally corroborate the traditional medical claims.

Immunomodulatory and cellular anti-oxidant activities of caffeic, ferulic, and p-coumaric phenolic acids: a structure-activity relationship study

Many studies have been performed to assess the potential utility of natural products as immunomodulatory agents to enhance host responses and to reduce damage to the human body. To determine whether phenolic compounds (caffeic, ferulic, and p-coumaric acids) have immunomodulatory effects and clarify which types of immune effector cells are stimulated in vitro, we evaluated their effect on splenocyte proliferation and lysosomal enzyme activity. We also investigated the activity of natural killer (NK) cells and cytotoxic T lymphocytes (CTL). In addition, induction of the cellular antioxidant activity in splenocytes, macrophages, and red blood cells was determined by measuring the fluorescence of the DCF product. The study first results indicated that caffeic, ferulic, and p-coumaric acids significantly promote LPS-stimulated splenocyte proliferation, suggesting a potential activation of B cells, and enhanced humoral immune response in hosts treated by the tested natural products. Phenolic acids significantly enhanced the killing activity of isolated NK and CTL cells but had negligible effects on mitogen-induced proliferation of splenic T cells. We showed that caffeic acid enhances lysosomal enzyme activity in murine peritoneal macrophages, suggesting a potential role in activating such cells. Immunomodulatory activity was concomitant with the cellular antioxidant effect in macrophages and splenocytes of caffeic and ferulic acids. We conclude from this study that caffeic, ferulic, and p-coumaric acids exhibited an immunomodulatory effect which could be ascribed, in part, to their cytoprotective effect via their antioxidant capacity. Furthermore, these results suggest that these natural products could be potentially used to modulate immune cell functions in physiological and pathological conditions.

Effect of heated naringenin on immunomodulatory properties and cellular antioxidant activity

Naringenin is one of the most popular flavonoids derived from citrus. It has been reported to be an effective anti-inflammatory compound. Citrus fruit may be used raw, cooked, stewed, or boiled. The present study was conducted to investigate the effect of thermal processes on naringenin in its immunomodulatory and cellular antioxidant activities. The effects of flavonoids on B and T cell proliferation were assessed on splenocytes stimulated or not with mitogens. However, their effects on cytotoxic T lymphocyte (CTL) and natural killer (NK) activities were assessed in splenocytes co-incubated with target cells. The amount of nitric oxide production and the lysosomal enzyme activity were evaluated in vitro on mouse peritoneal macrophages. Cellular antioxidant activity in splenocytes and macrophages was determined by measuring the fluorescence of the dichlorofluorescin (DCF). Our findings revealed that naringenin induces B cell proliferation and enhances NK activity. The highest concentration of native naringenin exhibits a significant proliferation of T cells, induces CTL activity, and inhibits cellular oxidation in macrophages. Conversely, it was observed that when heat-processed, naringenin improves the cellular antioxidant activity in splenocytes, increases the cytotoxic activity of NK cells, and suppresses the cytotoxicity of T cells. However, heat treatment maintains the anti-inflammatory potency of naringenin.

Investigation of immunomodulatory and anti-inflammatory effects of eriodictyol through its cellular anti-oxidant activity

Many studies have been performed to assess the potential utility of natural products as immunomodulatory agents to enhance host responses against infection or to ameliorate immune-based pathologies. To determine whether eriodictyol has immunomodulatory effects and clarify which types of immune effector cells are stimulated in vitro, we investigated the stimulatory effect of eriodictyol on spleen cells isolated from BALB/c mice. Eriodictyol significantly stimulated splenocyte proliferation. However, only B lymphocytes (not T lymphocytes) could be stimulated by eriodictyol in a dose-related manner. Studies assessing potential effect of eriodictyol on innate immunity reported that eriodictyol enhanced significantly the killing activity of natural killer (NK) cells, T lymphocytes, and macrophages. We also demonstrated that eriodictyol inhibited nitric oxide (NO) production and lysosomal enzyme activity in murine peritoneal macrophages cultured ex-vivo, suggesting a potential anti-inflammatory effect in situ. Eriodictyol revealed also a cellular anti-oxidant activity in splenocytes and macrophages. Furthermore, eriodictyol increased catalase activity in spleen cells. From this data, it can be concluded that eriodictyol exhibited an immunomodulatory effect that could be ascribed in part to a cytoprotective effect related to its anti-oxidant activity.

Modulation of macrophage functionality induced in vitro by chlorpyrifos and carbendazim pesticides

The immune response is the first defense against pathogens; however, it is very sensitive and can be impacted on by agrochemicals such as carbamate and organophosphate pesticides widely present in the environment. To understand how pesticides can affect immune cell function in vitro, this study investigated the effects of chlorpyrifos (CPF) and carbendazim (CBZ), the most commonly used pesticides worldwide, on murine immune cell (i.e. macrophage) functions, including lysosomal enzyme activity and pro-inflammatory cytokines (IL-1β and TNFα) and nitric oxide (NO) production by isolated mouse peritoneal macrophages. This study showed for the first time that CPF and CBZ dose-relatedly reduced macrophage lysosomal enzyme activity and LPS-induced production of IL-1β, TNFα and NO. In general, the effects caused by CPF appeared more pronounced than those by CBZ. Collectively, these results demonstrated that CPF and CBZ exhibited marked immunomodulatory effects and could act as potent immunosuppressive factors in vitro. This inhibition of macrophage pro-inflammatory function may be an integral part of the underlying mode of action related to pesticide-induced immunosuppression.

Oligoesculin fraction induces anti-tumor effects and promotes immune responses on B16-F10 mice melanoma

Laccase was used to enzymatically polymerize esculin. Oligoesculin fraction was obtained after ultrafiltration through a 5-kDa membrane. Several studies have been carried out to prove the effectiveness of natural substances such as immunomodulators to promote the anti-cancer activity in situ. The purpose of our report was to explore whether the anti-tumor potential of the oligoesculin fraction in vitro and in vivo is linked to its immunological mechanisms in melanoma-bearing mice. We revealed that oligoesculin fraction reduced B16-F10 proliferation and migration in vitro in a dose-related manner. Moreover, melanin synthesis and tyrosinase activity were inhibited in these melanoma cells in a concentration-dependent way. The anti-tumor potential of oligoesculin fraction was also assessed in vivo. Our results showed that intraperitoneal administration of oligoesculin fraction, at 50 mg/kg body weight (b.w.) for 21 days, reduced tumor size and weight with percentages of inhibition of 94 and 87 %, respectively. Oligoesculin fraction was effective in promoting lysosomal activity and nitric oxide (NO) production by peritoneal macrophages in tumor-implanted mice. In addition, the activities of natural killer (NK), cytotoxic T lymphocytes, and macrophages were significantly enhanced by oligoesculin fraction. These findings suggested that this polymer with its anti-tumor and immunomodulatory properties could be used for the treatment of melanoma.

Immunomodulatory potencies of isolated compounds from Crataegus azarolus through their antioxidant activities

The search of natural immunomodulatory agents has become an area of great interest in order to reduce damage to the human body. In this study, the immunomodulatory potential of Crataegus azarolus and its isolated hyperoside on mouse lymphocytes and macrophages in vitro was assessed. The effect of C. azarolus natural compounds on splenocytes proliferation, natural killer (NK) and cytotoxic T lymphocytes (CTL) activities, and on macrophage-mediated cytotoxicity were assessed by MTT test. Phagocytic activity and inhibition of nitric oxide (NO) release by macrophages were also evaluated. The antioxidant capacity of these products was evaluated by determining their cellular antioxidant activity (CAA) in splenocytes and macrophages. Depending on the concentrations, both ethyl acetate (EA) extract and hyperoside (Hyp) from C. azarolus affect macrophage functions by modulating their lysosomal enzyme activity and nitric oxide release. Whereas, the above-mentioned products significantly promote LPS and lectin-stimulated splenocyte proliferation, implying a potential activation of lymphocytes B and T enhancing humoral and cellular immune responses. Moreover, EA extract and Hyp could enhance the activity of NK and T lymphocytes cells, as well as the macrophages-mediated cytotoxicity against B16F10 cells. The anti-inflammatory activity was concomitant with the cellular antioxidant effect of the tested compounds against macrophages and splenocytes. Collectively, C. azarolus and its isolated hyperoside exhibited an immunomodulatory effect through their antioxidant activity. These findings suggest that C. azarolus should be explored as a novel potential immunomodulatory agent for the treatment of inflammatory diseases.

Immunomodulatory and cellular antioxidant activities of pure compounds from Teucrium ramosissimum Desf

Evaluation of the immunomodulatory activity of plant compounds is an interesting and growing area of research. Teucrium ramosissimum Desf. is a native and endemic medicinal plant from the South of Tunisia traditionally used for the treatment of many diseases. The anti-inflammatory activity of apigenin-7-glucoside, genkwanin, and naringenin isolated from T. ramosissimum were assayed. The phagocytic activities of macrophage and lymphocyte proliferation were investigated in the absence and presence of mitogens (lipopolysaccharide [LPS] or lectin). Depending on the concentrations, the compounds affect macrophage functions by modulating their lysosomal enzyme activity and nitric oxide (NO) release. The tested compounds enhance significantly splenocyte proliferation, either with or without mitogen stimulation. In studies to assess any potential effects of apigenin-7-glucoside, genkwanin, and naringenin on innate immunity, the results showed that these compounds significantly enhanced the killing activity of natural killer (NK) cells and cytotoxic activity of the T lymphocyte (CTL) isolated from splenocytes. These results suggest that T. ramosissimum compounds such as apigenin-7-glucoside, genkwanin, and naringenin may be potentially useful for modulating immune cell functions in physiological and pathological conditions.

Flavones induce immunomodulatory and anti-inflammatory effects by activating cellular anti-oxidant activity: a structure-activity relationship study

Flavonoids impart a variety of biological activities, including anti-oxidant, anti-inflammatory, and anti-genotoxic effects. This study investigated the effects of flavone luteolin and apigenin on immune cell functions, including proliferation, natural killer (NK) cell activity, and cytotoxic T lymphocyte (CTL) activity of isolated murine splenocytes. We report for the first time that flavones enhance lymphocyte proliferation at 10 μM. Luteolin and apigenin significantly promote lipopolysaccharide (LPS)-stimulated splenocyte proliferation and enhance humoral immune responses. Luteolin induces a weak cell proliferation of lectin-stimulated splenic T cells, when compared to apigenin. In addition, both flavones significantly enhance NK cell and CTL activities. Furthermore, our study demonstrated that both flavones could inhibit lysosomal enzyme activity, suggesting a potential anti-inflammatory effect. The anti-inflammatory activity was concomitant with the cellular anti-oxidant effect detected in macrophages, red blood cells, and splenocytes. We conclude from this study that flavones exhibited an immunomodulatory effect which could be ascribed, in part, to its cytoprotective capacity via its anti-oxidant activity.

Immunomodulatory Effect of Gymnema sylvestre (R.Br.) Leaf Extract: An In Vitro Study in Rat Model

Gymnema sylvestre Wild R.Br (family: Asclepidaceae) is a valuable medicinal plant used in folk medicine to treat diabetes, obesity, asthma etc. in India for antiquity. Diabetes mellitus is a syndrome characterized immunologically by lymphocyte apoptosis and reduced cell-mediated and humoral immunity. Modulation of immune responses to alleviate diseases has been of interest, and traditional herbal medicines may play an important role in this regard. In this study, we aim to evaluate the immunomodulatory potential of methanolic extract of G. sylvestre leaf using rat model. HPLC analysis of leaf extract was carried out for gymnemic acid. The method involves the initial hydrolysis of gymnemic acids, the active ingredients, to a common aglycone followed by the quantitative estimation of gymnemagenin, using gymnemagenin as reference standard. Gymnemic acid content was 2.40% (w/w) in G. sylvestre leaf extract. In vitro immunomodulatory activity of the methanolic extract of G. sylvestre leaf (1-200μg/ml) was evaluated by gauging its effects on nitroblue tetrazolium reduction and nitrite release in rat peritoneal macrophages and on mitogen (ConA, PHA and LPS) induced splenic lymphocyte proliferation. G. sylvestre leaf extract showed significant (<0.05) enhancement in NO and ROS generation in macrophages and in proliferation of lymphocytes in dose dependent manner. EC50 value was 3.10, 3.75 and 2.68 μg/ml for NBT reduction, nitrite release and lymphoproliferation, respectively. Potential effect was observed at 100 μg/ml in NO and ROS generation in macrophages and 20 μg/ml in lymphocyte proliferation. G. sylvestre leaf extract stimulates macrophage reactivity, increasing the level of activity even higher when combined with PMA or LPS. These findings suggest the presence of active compounds, gymnemic acid, in methanolic extract of G. sylvestre leaf that stimulates both myeloid and lymphoid components of immune system, and therefore can restore the innate immune function. Through this study, the traditional knowledge of anti-diabetic property of G. sylvestre is scientifically supplemented with its immunomodulatory properties.

Antitumoral potency of methanolic extract from Nitraria retusa leaves via its immunomodulatory effect

Background

The purpose of this study was to assess the antitumoral effect of the methanol extract (MeOH) from Nitraria retusa leaves and to investigate its immunomodulatory activity that mediated the prevention of tumor progression in tumor-bearing mice.

Methods

Balb/c mice weighing 18–20 g were subcutaneously implanted with B16-F10 cells then injected intra-peritoneally, 7 days later with (200 mg/kg bw) of MeOH extract, for 21 days. After euthanization on day 21, the tumors were weighed. Lymphocyte proliferation, cytotoxic T lymphocyte (CTL) and NK activity were evaluated using the MTT assay. Macrophage phagocytosis was studied by measuring their lysosomal activity and nitric oxide production.

Results

The methanol extract inhibited significantly the growth of the implanted tumor, and increased remarkably splenocyte proliferation as well as NK and CTL activities, in tumor-bearing mice. It also promoted lysosomal activity of treated animal macrophages.

Conclusion

Our findings suggest that antitumoral effect of MeOH extract is related with to immunomodulatory activity.

Immunomodulatory and anticancer effects of Pituranthos tortuosus essential oil

Many studies have been performed to assess potential utility of natural products as immunomodulants to enhance antitumor activity in situ. In this study, an essential oil (EO) from the aerial parts of Pituranthos tortuosus was prepared using hydrodistillation, its composition was characterized, and its immunomodulatory potential was assessed. The results indicated that the EO contained sabinene, α-pinene, limonene, and terpinen-4-ol as major constituents. EO was also found to be able to significantly promote lipopolysaccharide (LPS)-stimulated splenocyte proliferation, suggestive of a potential for activation of B cells and enhanced humoral immune responses in hosts given this product. Effects of EO on cell proliferation and apoptosis were also investigated in B16F10 melanoma cells. EO-induced tumor cell growth inhibition was associated with characteristic apoptotic changes in the cells, including nuclear condensation. In conclusion, these data suggested to us that an EO of P. tortuosus could evolve to be a potential medicinal resource for use in the treatment of cancers.

Flavonoid detection in hydroethanolic extract of Pouteria torta (Sapotaceae) leaves by HPLC-DAD and the determination of its mutagenic activity

It is well known that phytotherapy has grown in popularity in recent years. Because a drug cannot be administered without ensuring its effectiveness and safety, the standardization and regulation of phytotherapeutic drugs are required by the global market and governmental authorities. This article describes a simple and reliable high-performance liquid chromatography-diode array detection analysis method for the simultaneous detection of myricetin-3-O-β-D-galactopyranoside, myricetin-3-O-α-L-arabinopyranoside, and myricetin-3-O-α-L-rhaminopyranoside present in the hydroethanolic extract (ethanol/H2O, 7:3, v/v) of Pouteria torta. The mutagenic activity of the extract was evaluated on Salmonella typhimurium and by an in vivo micronucleus test on the peripheral blood cells of Swiss mice. The linearity, sensitivity, selectivity, repeatability, accuracy, and precision of the assay were evaluated. The analytical curves were linear and exhibited good repeatability (with a deviation of less than 5%) and demonstrated good recovery (within the 83-107% range). The results demonstrate that the hydroethanolic extract exhibited a mutagenic activity in both assays, suggesting caution in the use of this plant in folk medicine.

The in vitro immunomodulatory activity of a polysaccharide isolated from Kadsura marmorata

Kadsura marmorata has been used in traditional Chinese medicine as one of the major ingredients for the treatment of bronchial asthma, eczema, and acute and chronic infection due to either viruses or bacteria. The purpose of this study was to determine the immunomodulatory activities of the Kadsura polysaccharide (KPS) that was isolated and purified from the fruit of K. marmorata, designated as KPSIII and has a molecular weight of 130,406. The immunomodulatory effects of KPSIII were evaluated in vitro on chicken lymphocytes and macrophages. The results indicated that KPSIII could stimulate the cell proliferation of chicken T-lymphocytes, B-lymphocytes, and peritoneal macrophages and could significantly enhance cytokine secretion. Moreover, KPSIII regulated cytokine expression in T-lymphocytes and peritoneal macrophages. This study suggests that KPSIII has potential effects on regulating the immune system and might be an immunotherapeutic agent in treating various immunity-related diseases in chickens.

Immunomodulatory and cellular anti-oxidant activities of an aqueous extract of Limoniastrum guyonianum gall

ETHNOPHARMACOLOGICAL RELEVANCE

Many studies have been performed to assess the potential utility of natural products as immunomodulatory agents to enhance host responses to disease/infection/etc. or to ameliorate immune based pathologies (i.e., inflammation, autoimmune associated diseases, etc.). In this particular study, the immunomodulatory potential of gall aqueous extract from Limoniastrum guyonianum Boiss. (Zita) was assessed in vitro.

MATERIALS AND METHODS

The effect of G extract on splenocytes proliferation and NK activity were assessed by MTT test. The induction of NO production and the phagocytic activity of macrophages were evaluated in vitro. Activation of the cellular anti-oxidant activity in splenocytes was determined by measuring the fluorescence of the DCF product.

RESULTS

The studies first demonstrated that the extract could enhance lysosomal enzyme activity and nitrite oxide production in murine peritoneal macrophages, suggesting a potential role in activation of these cells. In studies to assess potential effects on humoral immunity, the results indicated that the extract could significantly promote LPS-stimulated splenocyte proliferation implying a potential activation of B-cells and enhanced humoral immune responses in hosts given this natural product. In studies to assess any effects of extract on cellular immunity, the results showed that the extract significantly enhanced the killing activity of isolated NK cells but had negligible effects on mitogen-induced proliferation of splenic T-cells. Considerable effects were also observed on the cellular anti-oxidant activity.

CONCLUSION

We conclude from these studies that aqueous extract from L. guyonianum gall exhibited an immunomodulator effect which could be ascribed, in part, to its cytoprotective effect via its anti-oxidant capacity. Furthermore, these results suggest that L. guyonianum gall extract contains potent components such as flavonoids which should be potentially used to modulate immune cell functions in physiological and pathological conditions.

Pharmacological, antioxidant, genotoxic studies and modulation of rat splenocyte functions by Cyperus rotundus extracts

BACKGROUND

Cyperus rotundus Linn. (Cyperaceae) is a Tunisian medicinal plant used in folkloric (traditional) medicine to treat stomach disorders and inflammatory diseases. The present study explored the analgesic, anti-inflammatory and genotoxic activities of extracts from the aerial parts of C. rotundus. The antioxidant capacity and the modulation of splenocyte functions by these extracts were also investigated in mice. The phytochemical analysis was carried out using standard methods.

METHODS

Aqueous, ethyl acetate, methanol and TOF-enriched extracts (300, 150, and 50 μg/ml) were evaluated for their analgesic and anti-inflammatory activities. 4, 2, and 1 mg/ml of each extract were tested to investigate their effect on lipid peroxidation. The genotoxic study was monitored by measuring the structural chromosome aberrations of mice treated with 300 mg/kg of extract. The proliferation of lymphocytes in the absence and presence of mitogens was assessed at a concentration range 1-1000 μg/ml.

RESULTS

The tested extracts were able to decrease the mouse ear oedema induced by xylene. Furthermore, it was shown that the same extracts reduced the number of abdominal contractions caused by acetic acid in mice, revealing the peripheral analgesic activity of these extracts. It is worth noting that mice treated with doses up to 300 mg/kg b.w. of Cyperus rotundus extracts did not exhibit any toxicity. The tested extracts significantly enhance lymphocyte proliferation at 1 mg/ml.

CONCLUSIONS

It appears that C. rotundus extracts contain potent components such as flavonoids that may potentially be useful for modulating the immune cell functions, provoking analgesic, anti-inflammatory and antioxidant effects.

In vitro immunomodulatory effects of an oleanolic acid-enriched extract of Ligustrum lucidum fruit (Ligustrum lucidum supercritical CO2 extract) on piglet immunocytes

This study was conducted to evaluate the in vitro immunomodulatory effects of supercritical CO(2)Ligustrum lucidum extract (LLE) on the immune cells of piglets. The results showed that the LLE enhanced the proliferative activity of piglet blood lymphocytes and up-regulated the CD4(+) CD8(+) and CD4(+) CD8(-) cell populations. The LLE also regulated the expression of Th1- and Th2-related cytokines; elevated the levels of IL-2, IFN-γ and TNF-α, which were produced by Th1 lymphocytes; and decreased the levels of IL-4 and IL-10, which were produced by Th2 lymphocytes. Furthermore, the LLE stimulated the NO secretion of lymphocytes. These results indicated that LLE might have potential immunomodulatory effects on the immune system of piglets and provided scientific and experimental foundations for the development of a new kind of LLE immune adjuvant in the pig production.

Anti-inflammatory and antiulcerogenic activities of leaf extracts and sesquiterpene from Teucrium ramosissimum (Lamiaceae)

Teucrium ramosissimum (Lamiaceae) is a native and endemic medicinal plant from South of Tunisia traditionally used for the treatment of many diseases. The anti-inflammatory and antiulcerogenic activities of sesquiterpene (β-eudesmol), chloroform, and ethyl acetate leaf extracts from T. ramosissimum were assayed. Macrophage phagocytic activity and lymphocyte proliferation in the absence and presence of mitogens (lipopolysaccharide [LPS] or lectin) were investigated. Depending on the concentrations, the extracts affect macrophage functions by modulating their lysosomal enzyme activity and nitric oxide (NO) release. For lymphocyte proliferation assay, tested extracts enhance significantly cell proliferation either with or without mitogen stimulation. These results suggest that leaf extracts from T. ramosissimum contain potent components such as flavonoids that may be potentially useful for modulating immune cell functions in physiological and pathological conditions. Antiulcerogenic activity was examined on rat ethanol-induced ulcerogenic model. Compared with control (cimetidine), leaf extracts from T. ramosissimum exert different protective effects against ethanol-induced ulcerogenesis.

Leaf extracts from Phlomis crinita Cav. subs. mauritanica Munby affect immune cell functions in vitro

Aqueous and methanolic leaf extracts from Phlomis crinita subs. mauritanica Munby were investigated for their potential immunomodulatory activity on mouse lymphocytes and macrophages in vitro. The phagocytic activity of macrophages and the proliferation of lymphocytes in the absence and presence of mitogens (lipopolysaccharide, LPS or lectin) were assayed. Depending on the concentrations, the extracts affect macrophage functions by modulating their lysosomal enzyme activity and nitric oxide release. For lymphocyte proliferation assay, both extracts enhance significantly cell proliferation either with or without mitogen stimulation. These results suggest that leaf extracts from P. crinita subs. mauritanica Munby contain potent components such as flavonoids that potentially may be useful for modulating immune cell functions in physiological and pathological conditions.

Induction of chronic inflammation in mice treated with titanium dioxide nanoparticles by intratracheal instillation

Titanium dioxide nanoparticles (TNP) are nanomaterials which have various applications including photocatalysts, cosmetics, and pharmaceuticals because of their high stability, anticorrosiveness, and photocatalytic properties. Induction of cytokines and potential chronic inflammation were investigated in mice treated with TNP (5 mg/kg, 20 mg/kg, and 50 mg/kg) by a single intratracheal instillation. Pro-inflammatory cytokines such as IL-1, TNF-a, and IL-6 were significantly induced in a dose-dependent manner at day 1 after instillation. The levels of Th1-type cytokines (IL-12 and IFN-gamma) and Th2-type cytokines (IL4, IL-5 and IL-10) were also elevated dose-dependently at day 1 and the inflammatory responses were sustained until the remainder of experimental period for 14 days. By the induction of Th2-type cytokines, the increased B cell distributions both in spleen and in blood, and increased IgE production in BAL fluid and serum were observed. In lung tissue, increase of inflammatory proteins (MIP and MCP) and granuloma formation were observed. Furthermore, the expressions of genes related with antigen presentation (H2-T23, H2-T17, H2-K1, and H2-Eb1) and genes related with the induction of chemotaxis of immune cells (Ccl7, Ccl3, Cxcl1, Ccl4, Ccl2) were markedly increased using microarray analysis. From these data, it could be suggested that TNP possibly cause chronic inflammatory diseases through Th2-mediated pathway in mice.

Early effects triggered by Larrea divaricata Cav. on murine macrophages at apoptotic concentrations

Decoction and infusion of Larrea divaricata were tested at apoptotic concentrations (1 and 4 mg/ml) on peritoneal murine macrophages. Consistent changes were observed after incubation with 4 mg/ml decoction. Phagocytosis of zymosan, lysosomal enzyme activity, nitric oxide production, TNF-alpha release, and expression of CD14, TLR4, and CR3 increased significantly. Decoction at 1 and 4 mg/ml increased the binding of LPS-FITC. Apoptosis triggered by L. divaricata decoction is consequence of cell activation. The effects are independent of nordihydroguaiaretic acid. This "activation and death" could be the mechanism of L. divaricata to exert the antituberculosis effect known in folk medicine.