Effect ofAerva lanataon cell-mediated immune responses and cytotoxic T-lymphocyte generation in normal and tumor-bearing mice

Pharmaceutical, Ethnopharmacological, Phytochemical and Synthetic Importance of Genus Aerva: A Review

Aerva plants are known widely for their exceptional medicinal uses. They have been employed conventionally for their medicinal properties by the common folk in several regions of the world. This indicates the efficacy of these remarkable herbs. They are also known for their multiple biological activities such as antioxidant, antibacterial, antilithiatic, hepatoprotective, antidiabetic, anticancer, antihyperlipidemic and nephroprotective potential. These pharmacological actions are associated with the presence of valuable nutrients and biochemical compounds such as sterols/terpenes, flavonoids, alkaloids, phenolics and sugars. The proper utilization of the substances obtained from these plants can enhance the finesse of the capabilities of these plants. These plants are not only medicinally important but are significantly serving several other scientific purposes. In the prospect of medicinal, scientific uses and the bioavailability of precious chemicals of Aerva species, a comprehensive review is compiled, which focuses on the detailed profile of biochemical compounds, pharmacological functions and biological activities of Aerva plants. The review also discusses the synthetic importance and the toxicity of these plants. The study aims to compile comprehensively what is already done and what more is needed to be done in the future investigations related to Aerva species.

Toxicological evaluation of the aqueous whole plant extract of Aerva lanata (l.) Juss. ex Schult (Amaranthaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Aerva lanata (L.) of the family Amaranthaceae is a Nigerian medicinal plant used traditionally for the management of lithiasis, headache, renal disorder, haematemesis, bronchitis, nasal bleeding, cough, scorpion stings, fractures and spermatorrhoea. Studies that show the pharmacological basis for some of such uses have been reported. There is, however, no scientific report on its toxicity profile to the best of our knowledge.

AIM OF THE STUDY

This study was therefore aimed at investigating the toxicity profile of the aqueous extract of Aerva lanata.

MATERIALS AND METHODS

Acute toxicity tests for the extract administered orally at 1-30g/kg and intraperitoneally at 0.1-2g/kg were carried out in albino mice; while a sub-chronic toxicity test was done by daily oral administration of the extract at 40-1000mg/kg to albino rats for 90 days. Anthropometric, biochemical and haematological parameters' assessments as well as vital organs histological examinations were performed in the sub-chronic toxicity study.

RESULTS

The LD₅₀ of the extract for oral and intraperitoneal acute toxicity tests were 22.62g/kg and 0.432g/kg respectively. The extract produced apparent changes in body weights of both male and female rats and significantly (p < 0.05) increased the weights of lungs, brain and pancreas of female rats while reducing the weight of testes in male rats. Haematological parameters were also altered with total leukocytes significantly (p < 0.05) increased and platelets significantly (p < 0.05) reduced in female rats; while neutrophils significantly (p < 0.05) increased in male rats. The extract (40-1000mg/kg) produced significant (p < 0.05) reduction of serum alanine transaminase concentration in both male and female rats. Aspartate transaminases and albumin were also significantly (p < 0.05) reduced in both male (at 1000mg/kg) and female (at 200mg/kg) rats. Alkaline phosphatase was also significantly (p < 0.05) reduced in female rats at 200mg/kg of the extract. Substantial alterations of creatinine, urea and uric acid were also observed. Triglyceride and cholesterol concentrations were significantly increased in male rats but decreased in female rats. At 1000mg/kg, the extract significantly elevated catalase and superoxide dismutase levels with no effect on malondialdehyde levels. It also reduced sperm count and motility of male rats. Mild to moderate cellular changes in the brain, kidney, liver, lungs, spleen and testes of treated rats were observed on histological examinations. Significant changes in biochemical and haematological parameters were also noted in treated animals when compared to control animals 30 days after cessation of treatment.

CONCLUSION

The overall findings of this study suggest that the aqueous extract of A. lanata is relatively safe on acute oral exposure, moderately toxic on acute intraperitoneal administration and is relatively safe with antioxidant actions on prolonged exposure. It however shows potentials for toxic effects such as cellular damage to organs, dyslipidaemia and reduction in male reproductive capacity. Caution must therefore be applied in its use on a long term basis.

Correlation of Circulating T Lymphocytes and Intracranial Hypertension in Intracerebral Hemorrhage

BACKGROUND

The close correlation between intracerebral pressure (ICP) and immunologic responses has been well described, but the role of T lymphocytes in this process remains unknown. This study targeted the relationship of circulating T lymphocytes and ICP in patients with intracerebral hemorrhage (ICH).

METHODS

Between October 2015 and October 2016, consecutive patients age 18-65 years with ICH were enrolled. ICP values were recorded hourly for 5 days, and the screened patients were divided into 2 groups based on ICP: the elevated ICP group (ICP >20 mmHg) and normal ICP group (ICP ≤20 mmHg). Peripheral blood was collected on admission and T lymphocyte subpopulations were analyzed by flow cytometry. Glasgow Coma Scale score on admission and Glasgow Outcome Scale (GOS) score at 30 days after ICH were analyzed.

RESULTS

A total of 44 patients were enrolled, including 18 patients in the elevated ICP group and 26 in the normal ICP group. Both CD3⁺ and CD4⁺ T lymphocyte counts were higher in the elevated ICP group (P = 0.004 and 0.000, respectively). The CD8⁺ T lymphocyte count was not significantly different between the 2 groups (P = 0.751). There were correlation trends between the maximum ICP value and CD3⁺ lymphocyte count (P = 0.003), CD4⁺ T lymphocyte count (P = 0.000), and the CD4⁺/CD8⁺ T lymphocyte ratio (P = 0.000). The area under the curve (AUC) of CD4⁺/CD8⁺ T lymphocyte ratio was the largest among them (P = 0.011 and 0.033), with a significant cutoff value and good specificity and sensitivity. There was a close correlation between the CD4⁺/CD8⁺ T lymphocyte ratio and the 30-day GOS score (P = 0.003, AUC = 0.812).

CONCLUSIONS

The CD4⁺/CD8⁺ T lymphocyte ratio may be a valuable indicator for predicting postoperative ICP and the short-term prognosis after ICH.

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.

Antidiabetic property of Aerva lanata (L.) Juss. ex Schult. is mediated by inhibition of alpha glucosidase, protein glycation and stimulation of adipogenesis

BACKGROUND

Diabetes is the leading cause of morbidity and mortality, with a number currently diagnosed as high as 371 million. Plant-based therapy could be an ideal choice because of fewer side-effects and wider acceptability. Hence, the antihyperglycemic potential of Aerva lanata, a herb prescribed for diabetes in Ayurveda was evaluated to elucidate its possible mechanism of action.

METHODS

High performance liquid chromatography analysis was used for the characterization of 70% ethanolic (aqueous leaf extract [ALE]) and ethyl acetate (AEA) extracts. Further, they were evaluated for their antioxidant, inhibition of alpha glucosidase, protein glycation dipeptidyl peptidase IV (DPP IV), protein tyrosine phosphatase 1B (PTP1B) and stimulation of glucose uptake and glitazone like property (adipogenic potential) using in vitro models. The promising alpha glucosidase inhibitory potential of ALE was further evaluated in normal and streptozotocin (STZ) diabetic rats.

RESULTS

ALE inhibited yeast (IC50 - 81.76 μg/mL) and rat intestinal alpha glucosidase (IC50 - 108.7 μg/mL), protein glycation, DPP IV enzyme (IC50 - 118.62 μg/mL) and PTP1B (IC50 - 94.66 μg/mL). ALE stimulated maximal adipogenesis at 50 μg/mL and enhanced insulin mediated glucose uptake (threefold of basal) at 100 μg/mL in L6 myotubes. ALE (500 mg/kg b.w.) showed a significant antihyperglycemic activity in sucrose loaded STZ normal (15.57%) and diabetic (18.44%) rats. HPLC analysis of ALE revealed the presence of bioactives like alpha amyrin, betulin and beta sitosterol.

CONCLUSIONS

Alpha glucosidase inhibition, antiglycation, and adipogenic potential significantly contribute to the antidiabetic property of Aerva lanata. In addition, insulin sensitization and antioxidant potential also enhance its therapeutic potential.

Effects of pituitary adenylate cyclase activating polypeptide on CD4(+)/CD8(+) T cell levels after traumatic brain injury in a rat model

BACKGROUND

The effect of pituitary adenylate cyclase activating polypeptide (PACAP) during traumatic brain injury (TBI) and whether it can modulate secondary injury has not been reported previously. The present study evaluated the potential protective effects of ventricular infusion of PACAP in a rat model of TBI.

METHODS

Male Sprague Dawley rats were randomly divided into 3 treatment groups (n=6, each): sham-operated, vehicle (normal saline)+TBI, and PACAP+TBI. Normal saline or PACAP (1 μg/5 μL) was administered intracerebroventricularly 20 minutes before TBI. Right parietal cortical contusion was produced via a weight-dropping method. Brains were extracted 24 hours after trauma. Histological changes in brains were examined by HE staining. The numbers of CD4(+) and CD8(+) T cells in blood and the spleen were detected via flow cytometry.

RESULTS

In injured brain regions, edema, hemorrhage, inflammatory cell infiltration, and swollen and degenerated neurons were observed under a light microscope, and the neurons were disorderly arrayed in the hippocampi. Compared to the sham group, average CD4(+) CD8(-) lymphocyte counts in blood and the spleen were significantly decreased in rats that received TBI+vehicle, and CD4(-) CD8(+) were increased. In rats administered PACAP prior to TBI, damage was attenuated as evidenced by significantly increased CD4(+), and decreased CD8(+), T lymphocytes in blood and the spleen.

CONCLUSION

Pretreatment with PACAP may protect against TBI by influencing periphery T cellular immune function.

Immunomodulatory effects of black cohosh (Actaea racemosa) extract in female B6C3F1/N mice

Black cohosh extracts (BCE; Actaea racemosa) are being used worldwide as an alternative to hormone replacement therapy for the management of menstrual and menopausal symptoms, yet the effects of BCE on the immune system are largely unknown. Female B6C3F1/N mice were treated daily with BCE (0, 62.5, 125, 250, 500, or 1000mg/kg) for 28 days by oral gavage. Liver weights were significantly increased (26-32%) at the 1000mg/kg dose. Dose-related increases in mean corpuscular volume and mean corpuscular hemoglobin were observed. Decreasing trends were observed in all thymic T cell populations, with the most notable dose-responsive effects on immature thymocytes. In the spleen, dose-related decreases were observed in all cell phenotypes evaluated, reaching the level of statistical significance at the 1000mg/kg BCE dose. Splenic natural killer (NK) cell numbers were significantly decreased at all BCE doses, with the exception of absolute NK numbers at the 125mg/kg dose. No effects were observed on T-dependent antibody responses of the humoral immune system, including the antibody-forming cell response to sheep erythrocytes (sRBC) and IgM antibody levels to both sRBC and keyhole limpet hemocyanin. Cytotoxic T cell (TCTL) activity was increased, as was the mixed leukocyte response in one of two studies. Anti-CD3 mediated proliferation and the delayed-type hypersensitivity response were unaffected. No effects were observed on innate immunity or on bone marrow cellularity and colony-forming units. Overall, BCE exposure in B6C3F1/N mice for 28 days at doses up to 1000mg/kg had minimal immune effects, with the exception of an increased TCTL response.