The ethanol and water extracts of Sansevieria trifasciata leaves showed dose-dependent and significant (P < 0.05) increase in pain threshold in tail-immersion test. Moreover, both the extracts (100 -200 mg/kg) exhibited a dose-dependent inhibition of writhing and also showed a significant (P < 0.001) inhibition of both phases of the formalin pain test. The ethanol extract (200 mg/kg) significantly (P < 0.01) reversed yeast-induced fever. Preliminary phytochemical screening of the extracts showed the presence of alkaloids, flavonoids, saponins, glycosides, terpenoids, tannins, proteins and carbohydrates.

The steroids 3,6,17-trihydroxy-stigmasta-4,7,24(28)-triene (A) and 14,15,18,20-diepoxyturbinarin (B) were isolated from the cyclohexane extract of brown alga, Turbinaria conoides (J. Agardh) Kutzing, and have been reported for their antimicrobial activity by us. In this study, the isolated compounds were evaluated for comprehensive antihistaminic, antiviral and cytotoxicity screening. The antihistaminic study was performed using in vitro standard animal models. Evaluation of the potency (EC(50)), affinity (pA(2)) and the maximal response (E(max)) of the histamine alone and in the presence of the compounds were determined. Antiviral activity and cytotoxicity were performed in Crandell-Rees feline kidney (CRFK) cells by a colorimetric formazan-based MTS assay. No significant antiviral activity or cytotoxicity were observed for the compounds in the CRFK cells. Compound A inhibited the histamine-induced concentration at 20 µg mL(-1)(p < 0.05). The most significant inhibition (97%) was observed for compound B (p < 0.01) at the same concentration, which was comparable to that of the positive control chlorpheniramine maleate (10 µg mL(-1)). This potentiality suggests that 14,15,18,20-diepoxyturbinarin (B) can be developed as a new lead antihistaminic agent.

The active principles of brown alga, Turbinaria conoides (J.Agardh) Kuetz. (Sargassaceae) was extracted with n-hexane, cyclohexane, methanol and ethanol-water (1:1) and investigated for acute toxicity and antipyretic activity. Phytochemical analysis of the extracts revealed the presence of steroids, flavonoids and reducing sugars. Acute toxicity study was performed in Wistar rats after administration of extracts orally. No mortality was observed up to the dose of 5g/kg for methanol and ethanol-water (1:1) extracts whereas n-hexane and cyclohexane extracts were found to be toxic at the dose levels of 1g/kg and 2 g/kg respectively. In biochemical analysis, n-hexane, cyclohexane and ethanol-water (1:1) extracts caused a significant (P<0.01) increase in serum cholesterol, protein and alkaline phosphatase levels. In haematological studies, a significant difference was observed for cyclohexane and ethanol-water (1:1) extracts in polymorphs, lymphocytes and eosinophils when compared to the control. Antipyretic activity of extracts (100-400 mg/kg doses) was carried out on yeast-induced pyrexia in rats. Cyclohexane extract exhibited more significant antipyretic activity (P<0.01) than the other extracts at a dose of 200mg/kg (54.43%), which was comparable to that of paracetamol at a dose of 33 mg/kg. The findings validated the use of this brown alga in traditional cure of children's fever.

Melastoma malabathricum Linn. (Melastomataceae), locally known as senduduk putih, is a wellknown plant in Malaysian traditional medicine. On the basis of its traditional use and literature reference, this plant was selected for evaluation of its wound healing and antibacterial activities. Methanol extract of M. malabathricum was examined for its wound healing activity in the form of an ointment in two types of wound model in rats: (i) the excision wound model and (ii) the incision wound model. The methanol extract ointment produced a significant response in both of the wound types tested. The results were also comparable with the standard drug, nitrofurazone, in terms of wound contracting ability, wound closure time, tensile strength and regeneration of tissues at the wound site. Regarding antibacterial activity, M. malabathricum extract inhibited the different clinical wound isolates of S. aureus and P. aeruginosa with MIC ranging from 3.0 mg/ml for 3 of the 4 clinical strains of S. aureus to 8.0 mg/ml for all the 3 clinical strains of P. aeruginosa tested.

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