Table 4 Clinical Studies involving African Potato and/ its Constituents

16 (12 males, 4 females) healthy HIV-seronegative adults, USA. The median age (range) was 28 yrs. (19–53 yrs). Median weight (range) was 78 kg (53–96 kg)

An open-label, two-period, fixed sequence, cross-over pharmacokinetic drug interaction study.

LPV/r 400/100 mg tablet orally twice a day for 14 days, then LPV/r with African potato (15 mg/ kg hypoxoside) orally once daily for 7 days.

Plasma samples collected on day 14 after LPV/r alone and day 21 after LPV/r plus African potato for AUC, C_max, C_trough, T_max, T_1/2, K_el, CL_F. Time of collection: within 1 h before dosing and at 1, 2, 4, 6, 8, and 12 h post-dose for both phases.

African potato combined with LPV/r was not associated with any change in LPV/r AUC, C_max, C_trough. No serious adverse events observed.

[18]

10, (9 black, 1 white) healthy HIV-negative males. The mean age (range) was 23 yrs. (19–27 yrs).

A single-dose, two-phase sequential study.

Efavirenz 600 mg tablet orally on day 1, then from day 16, a traditionally prepared African Potato decoction (15 mg/ kg of hypoxoside) given daily until day 30. On day 28, efavirenz 600 mg tablet was given orally.

Phase 1 started on day 1 and phase 2 on day 29, each phase lasting 3 days. Plasma samples were collected before dosing and at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 12, 18, 24, 36 and 48 h after dosing. Samples were assayed for AUC, C_max, T_max, T_1/2 and K_el.

The geometric mean ratios of C_max and AUC were within the limits of 80–125%. African potato did not alter the pharmacokinetics of efavirenz. No serious adverse effects were noted.

[17]

37 adult male patients with PTB in South Africa. 19 in the active group (mean age 43 yrs. and weight 49 ± 6 kg) and 18 in the placebo group (mean age 37 yrs. and weight 51 ± 9 kg).

A double-blinded, randomized, placebo-controlled trial to evaluate the effects of BSSG and BSS in the treatment of PTB.

Randomized to receive either the active capsule with sitosterols (0.2 mg BSSG, 20 mg BSS, 200 mg talcum) or placebo (200 mg talcum). One capsule three times daily together with their standard antituberculosis regimen (isoniazid, rifampicin, pyrazinamide) for 6 months.

Sputum culture positivity, chest radiography, weight gain, Mantoux test response, routine hematology and liver function. PTB was confirmed by sputum smear microscopy for acid-fast bacilli and culture for Mycobacterium tuberculosis.

Compared to placebo, there was significant weight gain, higher lymphocyte and eosinophil counts in PTB patients receiving sitosterols in addition to antituberculosis therapy.

[16]

24 patients with histologically proven squamous, large-cell, or adenocarcinoma, South Africa.

A randomized, open, single-dose study of the pharmacokinetic behavior of hypoxoside in patients with lung cancer.

Three groups with dosage levels of 1600, or 2400, or 3200 mg standardized hypoxis plant extract (200 mg capsules). The first 6 patients in the multiple-dose study took 4 capsules 3 times daily for 11 days.

Serum samples were collected at regular intervals up to 75 h after single doses for the detection of hypoxoside metabolites. In the multiple-dose study, blood was drawn before the first dose each day. Pharmacokinetic parameters of the major metabolites were analyzed using different models in the NONMEM program.

After oral ingestion, hypoxoside undergoes complete Phase II biotransformation to diglucuronide, disulphate, and mixed glucuronide-sulphate metabolites. Neither hypoxoside nor rooperol appears in the blood. The half-lives of the major metabolite were 50 h and 20 h for the minor metabolites.

[15]

200 male patients with symptomatic BPH not on any treatment, Germany.

A randomized, double-blind, placebo-controlled multicenter study.

Randomized to receive either 20 mg BSS capsule (including 01 mg BSSG) three times per day or placebo.

The endpoints were a difference of modified Boyarsky score (recorded monthly) for 6 months, changes in IPSS, urine flow, and prostate volume (every 3 months.)

There were improvements in the modified Boyarsky score, symptoms with the IPSS questionnaire, quality of life score and urinary flow in the BSS group compared to placebo. BSS was shown to be effective in the treatment of BPH.

[19]