To analyze the larvicidal activity of two plant leaf powder and leaf-extracts, Dregea volubilis and Bombax malabaricum against Culex quinquefasciatus. The larvicidal bioassay was done for powdered leaves of Dregea volubilis and Bombax malabaricum individually and their methanol extracts against first-, second-, third- and fourth-instar larval forms of Culex quinquefasciatus. Mortality rate was recorded after 24, 48 and 72 h of post-exposure. LC(50) and LC(90) values were calculated at different time intervals for third instar larvae. All the graded concentration (0.1%, 0.2%, 0.3%, 0.4%, 0.5%) of powdered leaves showed significant (P <0.05) larval mortality. The mortality rate was higher in 50 ppm doses of methanolic extracts of both the plants against Culex quinquefaciatus. The corresponding LC(50) values were 56.97 ppm and 48.85 ppm, respectively after 24 h of exposure. There is no mortality of non-target organism such as Chironomous circumdatus, Oreochromis niloticus niloticus and Diplonichus annulatum within 72 h of post exposure to 0.1%, 0.2%, 0.3% crude powdered leaves and methanolic extracts of both the two individual plants under the laboratory condition. The results of preliminary qualitative phytochemical analysis of both the plants revealed the presence of many bioactive principles such as steroids, tannins, flavonoids, triterpenoids, saponins, etc. that may be responsible for their bio-control potentiality. The results have shown potential and eco-friendly use of both plant extracts against larva of Culex quinquefasciatus for the first time.

Phytochemical Screening and In-vivo Antipyretic Activity of the Methanol Leaf-Extract of Bombax Malabaricum DC (Bombacaceae)

Context: In India, Dregea volubilis (L.f.) Benth. ex Hook.f. (Asclepediaceae), a large twining shrub with a woody vine, is used to treat tumors traditionally. Objective: This study evaluated the in vitro and in vivo antitumor activity of the methanol extract of Dregea volubilis leaves (MEDV) and elucidated its possible mechanism of action. Materials and methods: In vitro antitumor activity of MEDV was evaluated against Ehrlich ascites carcinoma (EAC) cell-line. In vivo antitumor and antioxidant activity of MEDV at three dose levels (50, 100, and 200 mg/kg) were determined against EAC tumor-bearing mice. After 24 h of EAC inoculation, the extract was administered for 9 consecutive days. After the administration of the last dose on the 9th day followed by 18 h fasting, mice from all groups were sacrificed to determine antitumor activity and hematological profiles along with liver related biochemical parameters like lipid peroxidation, antioxidant enzymatic activity, etc. Results: For in vitro antitumor activity, IC₅₀ value of MEDV for EAC tumor cells was 85.51 ± 4.07 µg/ml. The MEDV showed a decrease in tumor volume, packed cell volume and viable cell count and an increase in the non-viable cell count of the EAC tumor-bearing mice (p < 0.001). Hematological profile reverted near to normal level in extract treated mice. MEDV decreased the hepatic lipid peroxidation level and enhanced superoxide dismutase and catalase level in tumor-bearing mice (p < 0.001). Discussion and conclusion: MEDV exhibited in vitro and in vivo antitumor activity in EAC tumor-bearing mice mediated through augmenting antioxidant defense system.