TOXICITY STUDIES OF THE WATER EXTRACT FROM THE CALYCES OF HIBISCUS SABDARIFFA L. IN RATS

Acute and chronic toxicities of the water extract from calyces of Hibiscus sabdariffa were studied in male and female rats. After 14 days of a single oral administration of test substance 5,000 mg/kg body weight, measurement of the body and organ weights, necropsy and health monitoring were performed. No signs and differences of the weights or behaviour compared to the control rats were observed. The results indicated that the single oral administration of H. sabdariffa extract in the amount of 5,000 mg/kg body weight does not produce acute toxicity. The chronic toxicity was determined by oral feeding both male and female rats daily with the extract at the doses of 50, 100, and 200 mg/kg body weight for 270 days. The examinations of signs, animal behaviour and health monitoring showed no defects in the test groups compared to the control groups. Both test and control groups (day 270th) and satellite group (day 298th) were analysed by measuring their final body and organ weights, taking necropsy, and examining haematology, blood clinical chemistry, and microanatomy. Results showed no differences from the control groups. Overall, our study demonstrated that an oral administration of H. sabdariffa extract at the doses of 50, 100 and 200 mg/kg body weight for 270 days does not cause chronic toxicity in rat

ANTI-INFLAMMATORY AND ANTI-ULCEROGENIC ACTIVITIES OF CHANTALEELA RECIPE

Chantaleela recipe is indicated for relieving fever in Thai traditional folk medicine. In the present study, Chantaleela recipe was investigated for anti-inflammatory, analgesic, antipyretic and anti-ulcerogenic activities. In preliminary investigation Chantaleela recipe was found to exert an inhibitory activity on the acute phase of inflammation as seen in ethyl phenylpropiolate-induced ear edema as well as in carrageenan-induced hind paw edema in rats. The results suggest that the anti-inflammatory activity of Chantaleela recipe may be due to an inhibition via cyclooxygenase pathway. In the analgesic test, Chantaleela recipe showed a significant analgesic activity in both the early and late phases of formalin test, but exerted the most pronounced effect in the late phase. The analgesic activity of Chantaleela recipe may act via mechanism at peripheral and partly central nervous system. In antipyretic test, Chantaleela recipe significantly decreased rectal temperature of brewer’s yeast-induced hyperthermia rats, probably by inhibiting synthesis and/or release of prostaglandin E2 in the hypothalamus. Therefore, the key mechanism of anti-inflammatory, analgesic, and antipyretic activity of the Chantaleela recipe likely involves the inhibition of the synthesis and/or release of inflammatory or pain mediators, especially prostaglandins. The oral administration of the Chantaleela recipe reduced ulcer formation in acute gastric ulcer models (EtOH/HCl-, indomethacin-, and stress-induced gastric lesions). In contrast, this recipe did not reduce the secretory rate, total acidity, and increase pH in rat stomach. These results indicated that Chantaleela seem to possess anti-ulcerogenic effect. This activity may be due to the increase of gastric mucosal resistance or potentiation of defensive factors and/or the decrease of aggressive factors but did not associate the anti-secretory activity. Moreover, the high oral doses treated did not cause acute toxicity in rats and the long term oral administration did not produce gastric and ileum lesions

ANTI-DIARRHEAL ACTIVITY AND TOXICITY OF LEARNG PID SAMUD RECIPE

Learng Pid Samud (LPS) recipe is a traditional remedy in Thai folk medicine to ease the common diarrhea. The anti-diarrheal potential of LPS recipe was herein examined in vitro using a guinea-pig ileum model. The LPS exerted an inhibitory effect on acetylcholine-induced smooth muscle contraction in the guinea pig ileum. Significantly, not only did the LPS reduce the total amount of feces in the induced diarrhea rats, but also the intestinal transit in the charcoal meal test. A single oral administration with the recipe at 5,000 mg/kg did not cause acute toxicity and the daily oral administration (1,000, 2,000 and 4,000 mg/kg) for 90 days in rats did not produce any toxic signs and symptoms. In conclusion, the Learng Pid Samud recipe remedy is evidently safe and effective for the anti-diarrheal treatment which supports its therapeutic uses in the alternative medicine

Effects of Wannachawee Recipe with Antipsoriatic Activity on Suppressing Inflammatory Cytokine Production in HaCaT Human Keratinocytes

Psoriasis is a chronic inflammatory and immune-mediated skin disease. The pathogenesis involves T cells activation via the IL-23/Th17 axis. Conventional treatments of psoriasis have adverse events influencing patients’ adherence. Wannachawee Recipe (WCR) has been effectively used as Thai folk remedy for psoriasis patients; however, preclinical evidence defining how WCR works is still lacking. This study defined mechanisms for its antiproliferation and anti-inflammatory effects in HaCaT cells. The cytotoxicity and antiproliferation results from SRB and CCK-8 assays showed that WCR inhibited the growth and viability of HaCaT cells in a concentration-dependent manner. The distribution of cell cycle phases determined by flow cytometry showed that WCR did not interrupt cell cycle progression. Interestingly, RT-qPCR revealed that WCR significantly decreased the mRNA expression of IL-1β, IL-6, IL-8, IL-17A, IL-22, IL-23, and TNF-α but induced IL-10 expression in TNF-α- and IFN-γ-induced HaCaT cells. At the protein level determined by ELISA, WCR significantly reduced the secretion of IL-17A, IL-22, and IL-23. The WCR at low concentrations was proved to possess anti-inflammatory effect without cytotoxicity and it did not interfere with cell cycle of keratinocytes. This is the first study to provide convincing evidence that WCR is a potential candidate for development of effective psoriasis therapies

Cytotoxic Effect of Coscinium fenestratum on Human Head and Neck Cancer Cell Line (HN31)

Coscinium fenestratum is widely used as a medicinal plant in many Asian countries. This study aimed to investigate the cytotoxic effect of a crude water extract of C. fenestratum (CF extract) compared to 5-fluorouracil (5-FU) on human HN31 cell line, a metastatic squamous cell carcinoma of the pharynx. The results revealed that cell morphology visualized under inverted light microscopy was changed from flat with a polygonal appearance to round appearance after CF extract application. The cell viability assay (MTT test) showed that the concentration producing 50% growth inhibition (IC50) at 48-hour incubation of CF extract on HN31 was 0.12 mg/mL, while the IC50 of 5-FU was 6.6 mg/mL, indicating that CF extract has a higher potency. However, combining various concentrations of 5-FU and CF extract at IC50 did not show synergistic effect. The CF extract dose dependently increased cell apoptosis determined by Annexin-V and propidium iodide staining. It decreased the phosphorylation of p38 MAPK and pAkt, while it increased the tumor suppressor protein p53. In conclusion, the cytotoxicity of CF extract was associated with the modulation of p38 MAPK, pAkt, and p53 signal molecules, leading to inhibiting cell survival and increasing apoptosis. No synergistic effects of CF extract and 5-FU were observed

Anti-Inflammatory Activity of Essential Oil from <i>Zingiber ottensii</i> Valeton in Animal Models

Zingiber ottensii (ZO) Valeton, a local plant in Northern Thailand, has been widely used in traditional medicine. Many studies using in vitro models reveal its pharmacological activities, including the anti-inflammatory activity of ZO essential oil, extracted from ZO rhizomes. However, the scientific report to confirm its anti-inflammatory activity using animal models is still lacking. The present study aimed to evaluate the anti-inflammatory activity and explore the possible mechanisms of action of ZO essential oil in rats. The results revealed that ZO essential oil significantly reduced the ear edema formation induced by ethyl phenylpropiolate. Pre-treatment with ZO essential oil significantly reduced the carrageenan-induced hind paw edema and the severity of inflammation in paw tissue. In addition, pre-treatment with ZO essential oil exhibited decreased COX-2 and pro-inflammatory cytokine TNF-α expression in paw tissue, as well as PGE2 levels in serum. On this basis, our study suggests that ZO essential oil possesses anti-inflammatory activity in animal models. Its possible mechanisms of action may involve the inhibition of TNF-α expression as well as the inhibition of COX-2 and PGE2 production. These findings provide more crucial data of ZO essential oil that may lead to new natural anti-inflammatory product development in the future

Gastroprotective Activities of Ethanol Extract of Black Rice Bran (Oryza sativa L.) in Rats

Black rice is a type of rice in the Oryza sativa L. species. There are numerous reports regarding the pharmacological actions of black rice bran, but scientific evidence on its gastroprotection is limited. This study aimed to evaluate the gastroprotective activities of black rice bran ethanol extract (BRB) from the Thai black rice variety Hom Nil (O. sativa L. indica) as well as its mechanisms of action, acute oral toxicity in rats, and phytochemical screening. Rat models of gastric ulcers induced by acidified ethanol, indomethacin, and restraint water immersion stress were used. After pretreatment with 200, 400, and 800 mg/kg of BRB in test groups, BRB at 800 mg/kg significantly inhibited the formation of gastric ulcers in all gastric ulcer models, and this inhibition seemed to be dose dependent in an indomethacin-induced gastric ulcer model. BRB could not normalize the amount of gastric wall mucus, reduce gastric volume and total acidity, or increase gastric pH. Although BRB could not increase NO levels in gastric tissue, the tissue MDA levels could be normalized with DPPH radical scavenging activity. These results confirm the gastroprotective activities of BRB with a possible mechanism of action via antioxidant activity. The major phytochemical components of BRB comprise carotenoid derivatives with the presence of phenolic compounds. These components may be responsible for the gastroprotective activities of BRB. The 2000 mg/kg dose of oral BRB showed no acute toxicity in rats and confirmed, in part, the safe uses of BRB

Antipsoriatic Effects of Wannachawee Recipe on Imiquimod-Induced Psoriasis-Like Dermatitis in BALB/c Mice

Psoriasis is a common immune-mediated chronic inflammatory skin disease characterized by thick and erythema raised plaques with adherent silvery scales. T-cells are activated via the IL-23/Th17 axis which is involved in psoriasis pathogenesis. Conventional treatments of psoriasis have adverse events that influence patients’ adherence. Wannachawee Recipe (WCR) is Thai traditional medicine that is known to be effective for psoriasis patients; however, preclinical evidence is still lacking. This study investigated the therapeutic potential of WCR on antiproliferant activity using imiquimod- (IMQ-) induced psoriasis-like dermatitis in a mouse model. Psoriasis-like dermatitis was induced on the shaved dorsal skin and right ear pinna of BALB/c mice by topical application of IMQ for 15 consecutive days after which WCR was administered to the mice by oral gavage for 10 days. Phenotypical observations, histopathological examinations, and ELISA of skin and blood samples were conducted. WCR significantly ameliorated development of IMQ-induced psoriasis-like dermatitis and reduced levels of Th17 cytokines (IL-17A, IL-22, and IL-23) in both serum and dorsal skin. Histopathological findings showed a decrease in epidermal thickness and inflammatory T-cell infiltration in the WCR-treated groups. The WCR has pharmacological actions which regulate Th17 related cytokines suggesting that it is a potential alternative therapeutic strategy for psoriasis