The influence of harvest time on total phenolic and flavonoid contents, antioxidant, antibacterial and cytotoxicity of Rheum khorasanicum root extract.

INTRODUCTION: For many centuries, medicinal herbs and their derivatives have been used to treat or prevent various diseases. However, environmental factors such as the season for collection of plant may change the therapeutic efficacy. The present work investigates seasonal variations of phenolic, flavonoid content, antioxidant, antibacterial, and cytotoxic potential of hydroalcoholic extract of Rheum khorasanicum (HER). METHODS: R. khorasanicum was collected in three different months: December, February, and April. The Folin-Ciocalteu assay was applied to measure the total phenolic content of HER. Antioxidant activities (DPPH and FRAP) were also determined. Next, the extracts were evaluated for antibacterial potential against some Gram-positive and Gram-negative strains. The minimal inhibitory concentration (MIC) was determined by the microdilution method. Finally, the effect of extracts on the viability of C6, A549, and HT-29 cells was evaluated via the MTT assay. RESULTS: All three extracts contained considerable phenolic and flavonoid contents and showed desirable antioxidant activity. The April sample exhibited the greatest phenolic and flavonoid content and significant antioxidant activity potential in the FRAP test. In addition, the April sample had the highest antibacterial activity and cytotoxic effect on the cancerous cell lines. CONCLUSION: The April extract showed more antioxidant, antibacterial and cytotoxic effect, probably because of its higher phenolic and flavonoid contents than other samples. These results demonstrate that the harvest timing of R. khorasanicum affects the plant's phenolic content and its antioxidant and cytotoxicity activities.

The effect of hydro alcoholic extract of Nigella sativa seeds on inflammatory mediators in C6 glioma cell line.

SUBJECT: Nigella sativa (N. sativa) is a highly valued nutritional plant, which has long been used in traditional medicine to treat a variety of human diseases. The multifaceted pharmacological impacts of N. sativa, such as attenuating oxidative stress and inflammation, make it a suitable therapeutic candidate against cardiovascular, hepatic, and neurological disorders as well as cancer. Therefore, the current study aimed to evaluate the effect of the hydroalcoholic extract of N. sativa seeds on several pro-inflammatory cytokines in the C6 glioma cell line and to compare it with the effect of the extract on the normal fibroblast cell line. METHODS: C6 and fibroblast cell lines were treated with the extract of N. sativa seeds, and 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay was performed to determine the half-maximal inhibitory concentration (IC50) after 72h of treatment. Real-time polymerase chain reaction (RT-PCR) was carried out to assess the expression levels of interleukin (IL)-6, IL-10, tumor necrosis factor-alpha (TNF-α), and transforming growth factor- ß1 (TGF-ß1) at the mRNA level in both cell lines after 72h of treatment with non-toxic and IC50 concentrations obtained from C6 cell line. RESULTS: The IC50 values for the hydroalcoholic extract of N. sativa seeds were 260±20µg/mL in the C6 cell line and 398±27µg/mL in fibroblast cells. The real-time PCR results indicated that the treatment of C6 and fibroblast cells with the extract at the IC50 value of N. sativa in C6 for 72h could increase the mRNA expression levels of IL-10 and reduce the mRNA expression levels of IL-6, TNF-α, and TGF-ß1 in C6 and fibroblast cells. The N. sativa extract showed a higher anti-inflammatory effect on C6 cells in comparison with fibroblast cells. CONCLUSIONS: Regarding the anti-inflammatory effect of Nigella sativa in C6 cell line, it may be considered a promising candidate to fortify antitumor actions in combination with other therapeutic options in the treatment of patients with GBM.

Evaluation of antioxidant potential of Heliotropium bacciferum Forssk extract and wound healing activity of its topical formulation in rat.

Wound healing is a dynamic process that occurs in the tissue under the skin. During this process, oxidative stress biomarkers are excessively produced, which finally lead to inflammation and cellular damage. In this study, efforts have been made to evaluate the antioxidant effect and wound healing activity topical formulation containing Heliotropium bacciferum Forssk extract. The in vitro antioxidant properties were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities and the ferric reducing antioxidant power (FRAP) assay. The herbal ointments (2.5% w/w and 5% w/w) were prepared from the hydroalcoholic extract of H. bacciferum Forssk and administrated on the induced wounds in Wistar rats. The chromatic assay, percentage of wound contraction, and histopathological studies were used for evaluating the wound healing activity. For the evaluation of reactive oxygen species (ROS), catalase (CAT) activity, superoxide dismutase (SOD), and glutathione (GSH) levels were examined. The DPPH method showed tremendous radical scavenging activities at the corresponding concentrations with EC50 value of 80µg/mL. Topical application of the ointment (5% w/w) showed the highest wound contraction in comparison to the positive control (treated with CICALFATE™) and the control group (treated with normal saline). Similarly, the histological study of the group treated with the extract ointment (5% w/w) showed full collagen tissue deposition with a complete epidermal regeneration. The results of the assessment of GSH levels as well as CAT and SOD activities in the treated group (5% w/w) confirmed the scavenging property of the extract ointment. Our findings indicated the proper wound healing impact of the topical formulation of H. bacciferum Forssk due to its notable antioxidant capacity.

In vitro antibacterial activity of some Iranian medicinal plant extracts against Helicobacter pylori.

Helicobacter pylori infection causes lifelong chronic gastritis, which can lead to peptic ulcer, mucosa-associated lymphoid tissue (MALT) lymphoma and gastric cancer. The growing problem of antibiotic resistance by the organism demands the search for novel candidates from plant-based sources. In the present study, we evaluated the in vitro anti-H. pylori activity of some selected medicinal plants on clinical isolates of H. pylori. Gastric biopsy samples were obtained from patients presenting with gastroduodenal complications. Helicobacter pylori was isolated from the specimens following standard microbiology procedures. The disc-diffusion method was used to determine the susceptibility of three H. pylori isolates to methanol extracts of 23 Iranian plants. All tests were performed in triplicate. Among them, the extracts of Punica granatum and Juglans regia had remarkable anti-H. pylori activity with mean of inhibition zone diameter of 39 and 16 mm at 100 µg disc⁻¹, respectively. In view of the results obtained with P. granatum (pomegranate), the peel extracts of nine cultivars of pomegranate (Shirin-e-Pust Sefid, Agha Mohammad Ali-e-Shirin, Sefid-e-Shomal, Sefid-e-Torsh, Shirin-e-Malase, Tabestani-e-Torsh, Shirin-e-Saveh Malase, Alak-e-Shirin, Pust Siyah) were further assayed against the clinical isolates of H. pylori. The results revealed that all Iranian pomegranate cultivars, except for Alak-e-Shirin, showed significant in vitro anti-H. pylori activity against the clinical isolates of H. pylori (mean of inhibition zone diameter ranging from 16 to 40 mm at 50 µg disc⁻¹).

Study of antiseizure effects of Matricaria recutita extract in mice.

Matricaria recutita L. is a well-known medicinal plant that is suggested as being carminative, analgesic, and anticonvulsant in traditional medicine. In the present investigation the effect of hydro-methanolic percolated extract of this plant on seizure induced by picrotoxin was studied in male mice. This study was performed on animals pretreated with doses of 100, 200, and 300 mg/kg of extract or 40 mg/kg phenobarbital as the reference drug via intraperitoneal injection. After 20 min each animal received 12 mg/kg picrotoxin for induction of seizure. Latency of onset time of seizure, duration of seizure, death latency, and death rate were determined in experimental and control groups. The results showed that latency of the beginning time of seizure was increased in groups that were pretreated with different doses of extract. The most effective dose was 200 mg/kg (P < 0.05). In addition, this dose delayed the time of death in mice (P < 0.01). The extract had no effect on the death rate. The results indicate that the extract of M. recutita possesses suitable effects on seizure induced by picrotoxin, and more experiments are needed in this field.

The analgesic effect of Tribulus terrestris extract and comparison of gastric ulcerogenicity of the extract with indomethacine in animal experiments.

Tribulus terrestris has been used in traditional medicine for relieving rheumatic pain and as an analgesic plant for a long time. In this investigation the analgesic effect of methanolic extract of this plant on male albino mice was evaluated by formalin and tail flick test. Extraction of the fruits of the plant was done by two different methods (suxheletion and percolation) with methanol 80%. The percolated extract was injected intraperitoneally in mice at 50, 100, 200, 400, and 800 mg/kg. The results showed that a dose of 100 mg/kg of percolated extract had the highest significant analgesic effect compared to the control group (P < 0.01) in formalin and tail flick test. There is no significant difference in the analgesic effect of suxheleted and percolated extract. The analgesic effect of the extract was lower than morphine, 2.5 mg/kg in both tests, and higher than ASA 300 mg/kg in chronic phase of pain in formalin test (P < 0.05). Pretreatment of animal with naloxone did not change the analgesia induced by the plant extract in both tests, therefore the involvement of opioid receptor in the analgesic effect of this plant was excluded. The results of ulcerogenic studies indicate that the gastric ulcerogenecity of plant extract is lower than the indomethacin in the rat's stomach. It can therefore be concluded that T. terrestris extract has a suitable analgesic effect and further studies are required to produce a more effective product of this plant to substitute for conventional analgesic drugs.